CN102158436B - Channel Frequency Domain Correlation Calculation Method and Device, Channel Estimation Method and Device - Google Patents

Abstract

The invention discloses a channel frequency domain correlation calculation method and device and a channel estimation method and device. The channel frequency domain correlation calculation method comprises the following steps: analyzing the path delay distribution of the sample channel; analyzing a path energy distribution of the sample channel; constructing a channel model according to the path delay distribution and the path energy distribution of the sample channel; and calculating the channel frequency domain correlation according to the constructed channel model. The channel estimation method according to the present invention includes: calculating least square channel estimation of pilot frequency sub-carriers; reading the pre-stored channel frequency domain correlation; estimating the moving speed of the receiving end relative to the transmitting end; calculating the channel time domain correlation according to the moving speed of the receiving end relative to the transmitting end; calculating MMSE filter coefficients by using the calculated channel time domain correlation and the read channel frequency domain correlation; and acquiring channel estimation of the data subcarriers according to the calculated MMSE filter coefficient and the least square channel estimation of the pilot subcarriers, wherein the pre-stored channel frequency domain correlation is acquired by the channel frequency domain correlation calculation method.

Description

Channel frequency domain correlation calculation method and device, channel estimation methods and device

Technical field

Relate generally to radio communication of the present invention.Particularly, the present invention relates to a kind of channel frequency domain correlation calculation method and device thereof and channel estimation methods and device thereof.

Background technology

Be subject to the impact on Adjacent Buildings, object, pedestrian, vehicle and ground etc., wireless signal may reflect in transmitting procedure, refraction, diffraction and scattering etc.Therefore, the wireless signal that receiving terminal receives has all experienced serious decline and time delay expansion usually.For the data of recovering to send, receiver need to be estimated the wireless channel of signal experience, more suffered loss to received signal compensates.The module that channel is estimated is called channel estimation module, and the module compensated to received signal is called balance module.Channel estimation module is vital for wireless system, and the performance of channel estimating is better, and the error performance of system is better, and namely the correct data that receive of system are more.

OFDM (Orthogonal Frequency Division Multiplexing, OFDM) technology is in recent years emerging transmission technology.At first ofdm system carries out IFFT (Inverse Fast Fourier Transform, inverse fast Fourier transform) conversion at transmitting terminal to data to be sent it is become to time-domain signal, and this signal is propagated in time domain subsequently.At receiving terminal, receive signal and at first by FFT (Fast Fourier Transform, fast Fourier transform), be converted into frequency domain, then carry out the operations such as equilibrium, demodulation and decoding to recover to send data.Because signal transmission can equivalence be converted to falt fading channel after the multipath channel with a fixed response time expansion of time domain experience is being converted into frequency domain, therefore ofdm system has very strong anti-fading ability, and be widely used in recent years, as Wimax (Worldwide Interoperability for Microwave Access, the worldwide interoperability for microwave access) system and LTE (Long Term Evolution, Long Term Evolution) wireless communication system such as, and DMB-T (Digital Multimedia Broadcast-Terrestrial, DMB-ground), CMMB (China Mobile Multimedia Broadcasting, China Mobile multimedia broadcasting) and DVB (Digital Video Broadcasting, digital video broadcasting) digital television broadcasting system such as.

At this, the frequency domain data that makes k subcarrier in l OFDM symbol carry is X_{k, l}, corresponding frequency domain equivalent received signals Y with it_{k, l}can be expressed as

Y_k，l＝H_k，lX_k，l+N_k，l (1)

H wherein_{k, l}for X_{k, l}the equivalent frequency domain falt fading channel of experience, N_{k, l}for frequency domain equivalence additive white Gaussian noise, its average is zero, and variance is σ_n².

The channel estimating of ofdm system is to equivalent domain channel response H_{k, l}estimated.Least mean-square error (Minimum Mean Square Error, MMSE) criterion is a kind of criterion that makes evaluated error average minimum.Channel estimation method based on the MMSE criterion is one of preferred channels algorithm for estimating.According to the MMSE channel estimation method, the estimated value of the channel frequency domain response at k subcarrier place in l OFDM symbol

can calculate according to formula (2).

${\hat{H}}_{k,l}=w_{k,l}^H{\hat{H}}_{k,l}^P---\left(1\right)$

In above formula, variable

the estimated value of the channel frequency domain response of locating for subcarrier (k, l), vectorial w_{k, l}the filter coefficient of MMSE channel estimator, vectorarrange and form for the channel impulse response estimation value of the pilot tone point by the previously selected channel frequency domain response of locating for estimator carrier wave (k, l).Suppose that each data subcarrier utilizes M point of observation to carry out the MMSE channel estimating, and the sequence number of this M point of observation is respectively (k₁, l₁), (k₂, l₂) ..., (k_m, l_m), so vectorialcan be expressed as following formula (3).

According to MMSE criterion, w_{k, l}for making function J (w_{k, l}) minimum solution, wherein function J (w_{k, l}) by formula (4), provided.

$J\left(w_{k,l}\right)=E\left\{{\left|\right|{\hat{H}}_{k,l}-H_{k,l}\left|\right|}^2\right\}---\left(4\right)$

According to orthogonality principle, w_{k, l}can be calculated by following formula (5).

$w_{k,l}={\mathrm{\θ}}_{k,l}^T{\mathrm{\Φ}}_{k,l}^{-1}---\left(5\right)$

Wherein, θ_{k, l}locate the cross correlation vector of domain channel response and M point of observation reception value for subcarrier (k, l), it can be expressed as

${\mathrm{\&theta;}}_{k,l}={\left[\begin{array}{ccc}{\mathrm{\&theta;}}_{k-k_1,l-l_1}& {\mathrm{\&theta;}}_{k-{\mathrm{<figure-callout\; label="k"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">k</figure-callout>}}_2,l-{\mathrm{<figure-callout\; label="l"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">l</figure-callout>}}_2}...& {\mathrm{\&theta;}}_{k-k_M,l-l_M}\end{array}\right]}^T---\left(6\right)$

Cross correlation value in formula (6)

m=1,2 ..., M can be expressed as

${\mathrm{\&theta;}}_{k-k_m,l-l_m}=E\{H_{k,l}\&CenterDot;{\hat{H}}_{k_m,l_m}^{*}\}---\left(7\right)$

In formula (5), matrix Φ_{k, l}for the autocorrelation matrix of M point of observation reception value, it can be expressed as

autocorrelation value wherein

m=1,2 ..., the expression formula of M is

${\mathrm{\&Phi;}}_{k_m-k_{m^{\&prime;}},l_m-l_{m^{\&prime;}}}=E\{{\hat{H}}_{k_m,l_m}\&CenterDot;{\hat{H}}_{k_{m^{\&prime;},}{l}_{m^{\&prime;}}}^{*}\}---\left(9\right)$

The correlation provided in formula (7) and formula (9) has not only comprised relativity of time domain but also comprised frequency domain correlation.Generally, can think that relativity of time domain and frequency domain correlation in this correlation are independent of one another, therefore formula (7) and formula (9) can be expressed as the time domain correlation and the spectrum correlation value is amasss, as shown in following formula (10) and (11).

${\mathrm{\&theta;}}_{k-k_m,l-l_m}={\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)\&CenterDot;{\mathrm{\&theta;}}_{\mathrm{\&Delta;t}}(l-l_m)---\left(10\right)$

${\mathrm{\&Phi;}}_{k_m-k_{m^{\&prime;}},l_m-l_{m^{\&prime;}}}=\frac{{\mathrm{<figure-callout\; label="N"\; filenames="HSA00000017552800021.png,HSA00000017552800052.png"\; state="\{\{state\}\}">N</figure-callout>}}_0\mathrm{\&delta;}(k_m-k_{m^{\&prime;}},l_m-l_{m^{\&prime;}})}{E_s(k_m,l_m)}+{\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k_m-k_{m^{\&prime;}})\&CenterDot;{\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}({l_m}^{}-l_{m^{\&prime;}})---\left(11\right)$

N wherein₀for the single-side belt power spectral density of noise,

e_s(k_m, l_m) be subcarrier (k_m, l_m) carrying the transmitted signal energy, function δ (k_m-k_m', l_m-l_m') expression formula as follows.

$\mathrm{\&delta;}(k_m-k_{m^{\&prime;}},l_m-l_{m^{\&prime;}})=\left\{\begin{array}{cc}1& \mathrm{if}{k}_m=k_{m^{\&prime;}}\mathrm{and}{l}_m=l_{m^{\&prime;}}\\ 0& \mathrm{otherwise}\end{array},---\left(12\right)\right.$

Can find out known time domain correlation θ from top analysis_{Δ t}(l-l_m) and spectrum correlation value θ_{Δ f}(k-k_m) be the precondition that the MMSE channel estimation method can be implemented smoothly.

Wherein, time domain correlation θ_{Δ t}(l-l_m) type of the Doppler decline experienced with relative moving speed and the channel of transmitting terminal and receiving terminal is relevant.For example, when the Doppler of channel power spectrum is modal Clarke model in the time of (being called again the Jakes model), time domain correlation θ_{Δ t}(l-l_m) can be expressed as

θ_Δt(l-l_m)＝J₀(2πf_dT_s(l-l_m)) (13)

Wherein, function J₀for first kind zero Bessel function, T_sfor system baseband sampling cycle, f_dfor the maximum Doppler frequency of single-side belt, it is relevant with the relative moving speed of transmitting terminal and receiving terminal, can be calculated by following formula (14).

$f_d=\frac{F_G\&CenterDot;v}{c}---\left(14\right)$

In formula (14), F_gfor carrier frequency, v is the translational speed of receiving terminal with respect to transmitting terminal, and c is the light velocity.In other words, under the prerequisite of known channel Doppler type, as long as estimate to obtain the translational speed of receiving terminal with respect to transmitting terminal, can obtain the time domain correlation properties of channel.

But, with the computational process of relativity of time domain, to compare, the calculating of the spectrum correlation characteristic of channel is more complicated.Because power and the time delay in the Shuo,Mei footpath, footpath of the time domain multipath channel that the spectrum correlation characteristic of channel experiences with signal are relevant.The algorithm that calculates frequency domain correlation generally is divided into two large classes, the first kind is that the time domain multipath channel that signal is experienced is estimated, Equations of The Second Kind is the definition from channel frequency-domain correlation, and a large amount of frequency domains reception pilot signals and frequency domain are received to the valuation that data-signal is added up to obtain channel frequency-domain correlation.No matter adopt any method, when carrying out channel estimating, channel frequency-domain correlation being carried out to synchronous estimation in real time all needs to carry out a large amount of calculating and statistics, and this is by the overhead that costs a lot of money and cause larger Time Delay of Systems.

Summary of the invention

In view of this, the present invention proposes a kind of method and device and corresponding channel estimation methods and device thereof that very simply calculates channel relevancy.This scheme greatly reduces the overhead while adopting the MMSE channel estimation method, the Time Delay of Systems while having reduced to adopt the MMSE channel estimation method.

To achieve these goals, according to an aspect of the present invention, provide a kind of channel frequency domain correlation calculation method, having comprised: distribute the path delay of time of analyzing samples channel; The path energy of analyzing samples channel distributes; According to distributing and path energy distribution structure channel model the path delay of time of sample channel; And calculate channel frequency-domain correlation according to the channel model built.

Channel frequency domain correlation calculation method in accordance with a preferred embodiment of the present invention also comprises: according to the selected a plurality of analystal sections of time delay expansion.In this case, for the distribution in the path delay of time of each analystal section analyzing samples channel, and distribute for the path energy of each analystal section analyzing samples channel.

Preferably, be evenly distributed a plurality of path delays of time in each analystal section or equal difference increases progressively and distributes or other distributions.The Energy distribution in each path is linear decrease and distributes, is exponential decrease and distribute, be that homenergic is uniformly distributed or other distributions in each analystal section.

In a specific embodiment, for different maximum delay expansions, calculate respectively channel frequency-domain correlation according to the channel model built according to the following formula:

${\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)=\mathrm{abs}\left(\underset{i}{\mathrm{\&Sigma;}}{\mathrm{\&sigma;}}_i^2{e}^{-\mathrm{<figure-callout\; label="j"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k-k_m){\mathrm{\&tau;}}_i}\right)$

Wherein, θ_{Δ f}(k-k_m) be the channel frequency-domain correlation function, abs () means absolute value calculating operation, (k-k_m) be the subcarrier spacing number between two frequencies that calculate channel spectrum correlation value, i is path sequence number, σ_i²be the path energy in i footpath, τ_iit is the path delay of time in i footpath.

Here, the sample channel comprises one or more in the channels such as PA channel, EPA channel, VA channel, EVA channel, PB channel, TU channel and ETU channel.

According to another aspect of the present invention, provide a kind of channel frequency-domain correlation calculation element, having comprised: the path delay of time analytic unit, distribute the path delay of time that is configured to the analyzing samples channel; The path energy analytic unit, the path energy that is configured to the analyzing samples channel distributes; The channel model construction unit, be configured to according to distributing and path energy distribution structure channel model the path delay of time of sample channel; And the frequency domain correlation computing unit, be configured to calculate channel frequency-domain correlation according to the channel model built.

Channel frequency-domain correlation calculation element in accordance with a preferred embodiment of the present invention also comprises: the analystal section selected cell is configured to according to the selected a plurality of analystal sections of time delay expansion.In this case, the path delay of time analytic unit for distributing in path delay of time of each analystal section analyzing samples channel, and the path energy analytic unit distributes for the path energy of each analystal section analyzing samples channel.

Preferably, the channel model construction unit according to the time delay in a plurality of paths in each analystal section be evenly distributed, equal difference increase progressively distribute or other distribute and each analystal section in the Energy distribution in each path be linear decrease and distribute, be exponential decrease and distribute, be that homenergic is uniformly distributed or the principle construction channel model of other distributions.

According to a further aspect of the invention, provide a kind of channel estimation methods, having comprised: the LS channel estimation that calculates pilot sub-carrier; Read the channel frequency-domain correlation prestored; Estimate the translational speed of receiving terminal with respect to transmitting terminal; Calculate the channel time domain correlation according to receiving terminal with respect to the translational speed of transmitting terminal; Utilize the channel time domain correlation of calculating and the channel frequency-domain correlation read to calculate the MMSE filter coefficient; And the channel estimating of obtaining data subcarrier according to the LS channel estimation of the MMSE filter coefficient calculated and pilot sub-carrier.Wherein, the described channel frequency-domain correlation prestored each channel frequency domain correlation calculation method according to the present invention obtains.

Channel estimation methods also comprises according to an embodiment of the invention: estimate the maximum delay expansion of channel; And read the channel frequency-domain correlation prestored correspondingly according to the maximum delay expansion of estimating.

Channel estimation methods according to an embodiment of the invention, in utilizing the channel time domain correlation of calculating and the channel frequency-domain correlation read calculating MMSE filter coefficient, utilize the channel time domain correlation of calculating and the channel frequency-domain correlation read to calculate the MMSE filter coefficient of pilot sub-carrier.In this case, the channel estimating of obtaining data subcarrier according to the LS channel estimation of the MMSE filter coefficient calculated and pilot sub-carrier comprises: the MMSE filter coefficient that utilizes the pilot sub-carrier calculated carries out MMSE filtering to the LS channel estimation of pilot sub-carrier; And the channel of data subcarrier is estimated to obtain the channel estimating of data subcarrier according to the filtered pilot sub-carrier of MMSE.

Preferably, by the filtered pilot sub-carrier of MMSE is carried out to the channel estimating that linear interpolation, second order interpolation, MMSE filtering, low-pass filtering or Spline interpolation are obtained data subcarrier.

Channel estimation methods in accordance with another embodiment of the present invention, in utilizing the channel time domain correlation of calculating and the channel frequency-domain correlation read calculating MMSE filter coefficient, utilize the MMSE filter coefficient of the channel time domain correlation of calculating and the channel frequency-domain correlation calculated data subcarrier read.In this case, in the LS channel estimation of the MMSE filter coefficient according to calculating and pilot sub-carrier obtains the channel estimating of data subcarrier, the MMSE filter coefficient of the data subcarrier that utilization is calculated carries out MMSE filtering to the LS channel estimation of pilot sub-carrier, obtains the channel estimating of data subcarrier.

According to a further aspect of the invention, provide a kind of channel estimating apparatus, having comprised: the pilot channel estimation unit is configured to calculate the LS channel estimation of pilot sub-carrier; The frequency domain correlation reading unit, be configured to read the channel frequency-domain correlation prestored; Motion speed estimation unit, be configured to estimate the translational speed of receiving terminal with respect to transmitting terminal; The relativity of time domain computing unit, be configured to calculate the channel time domain correlation according to receiving terminal with respect to the translational speed of transmitting terminal; MMSE filter coefficient computing unit, be configured to utilize the channel time domain correlation of calculating and the channel frequency-domain correlation read to calculate the MMSE filter coefficient; And the data channel estimation unit, be configured to obtain according to the LS channel estimation of the MMSE filter coefficient calculated and pilot sub-carrier the channel estimating of data subcarrier.Wherein, the described channel frequency-domain correlation prestored is obtained by each channel frequency-domain correlation calculation element according to the present invention.

Channel estimating apparatus also comprises according to an embodiment of the invention: the time delay spread estimation unit is configured to estimate the maximum delay expansion of channel; And the frequency domain correlation reading unit reads the channel frequency-domain correlation prestored correspondingly according to the maximum delay expansion of estimating.

In channel estimating apparatus according to an embodiment of the invention, the channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency-domain correlation read calculate the MMSE filter coefficient of pilot sub-carrier.In this case, the data channel estimation unit comprises: pilot tone MMSE filter cell, and the MMSE filter coefficient that is configured to the pilot sub-carrier that utilize to calculate carries out MMSE filtering to the LS channel estimation of pilot sub-carrier; And the data channel estimator, be configured to the channel of data subcarrier be estimated to obtain the channel estimating of data subcarrier according to the filtered pilot sub-carrier of MMSE.

Preferably, the data channel estimator is by carrying out to the filtered pilot sub-carrier of MMSE the channel estimating that linear interpolation, second order interpolation, MMSE filtering, low-pass filtering or Spline interpolation are obtained data subcarrier.

Channel estimating apparatus in accordance with another embodiment of the present invention, the MMSE filter coefficient of the channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency-domain correlation calculated data subcarrier read; And the MMSE filter coefficient of the data subcarrier that calculates of data channel estimation unit utilization carries out MMSE filtering to the LS channel estimation of pilot sub-carrier, obtain the channel estimating of data subcarrier.

In addition, according to a further aspect in the invention, also provide a kind of storage medium.Described storage medium comprises machine-readable program code, and when on messaging device, carrying out described program code, described program code makes described messaging device carry out according to said method of the present invention.

In addition, in accordance with a further aspect of the present invention, also provide a kind of program product.Described program product comprises the executable instruction of machine, and when on messaging device, carrying out described instruction, described instruction makes described messaging device carry out according to said method of the present invention.

The accompanying drawing explanation

Below with reference to the accompanying drawings illustrate embodiments of the invention, can understand more easily above and other objects, features and advantages of the present invention.Parts in accompanying drawing are just in order to illustrate principle of the present invention.In the accompanying drawings, same or similar technical characterictic or parts will adopt same or similar Reference numeral to mean.In accompanying drawing:

Fig. 1 illustrates the process chart of channel frequency domain correlation calculation method according to an embodiment of the invention;

The schematic diagram that Fig. 2 is constructed according to one embodiment of present invention channel model;

Fig. 3 illustrates the block diagram of channel frequency-domain correlation calculation element according to an embodiment of the invention;

Fig. 4 illustrates the process chart of channel estimation methods according to an embodiment of the invention;

Fig. 5 illustrates the block diagram of channel estimating apparatus according to an embodiment of the invention;

Fig. 6 illustrates the process chart of channel estimation methods according to another embodiment of the invention;

Fig. 7 illustrates the block diagram of channel estimating apparatus according to another embodiment of the invention;

Fig. 8 illustrates the simulation result under the EPA channel according to channel estimation methods of the present invention and device thereof;

Fig. 9 illustrates the simulation result under the EVA channel according to channel estimation methods of the present invention and device thereof; And

Figure 10 illustrates and can be used for the schematic block diagram of enforcement according to the computer of the method and apparatus of the embodiment of the present invention.

Embodiment

In connection with accompanying drawing, example embodiment of the present invention is described in detail hereinafter.All features of actual execution mode are not described for clarity and conciseness, in specification.Yet, should understand, must make a lot of decisions specific to execution mode in the process of any this practical embodiments of exploitation, in order to realize developer's objectives, for example, meet those restrictive conditions with system and traffic aided, and these restrictive conditions may change to some extent along with the difference of execution mode.In addition, although will also be appreciated that development is likely very complicated and time-consuming, concerning the those skilled in the art that have benefited from present disclosure, this development is only routine task.

At this, what also need explanation is a bit, for fear of the details because of unnecessary fuzzy the present invention, only show in the accompanying drawings with according to the closely-related apparatus structure of the solution of the present invention and/or treatment step, and omitted other details little with relation of the present invention.In addition, also it is pointed out that element and the feature described can combine with element and feature shown in one or more other accompanying drawing or execution mode in an accompanying drawing of the present invention or a kind of execution mode.

Below will be at first referring to figs. 1 through Fig. 3, the basic functional principle of channel frequency domain correlation calculation method according to an embodiment of the invention and device thereof be described.

As shown in Figure 1, channel frequency domain correlation calculation method according to an embodiment of the invention comprises analyzing samples channel selection step S110, analystal section selection step S120, distributional analysis in path delay of time step S130, path energy distributional analysis step S140, channel model construction step S150 and channel frequency-domain correlation calculation procedure S160 etc.

At first, select in step S110 to be identified at the analyzing samples channel sample channel of analyzing.Consider in system applies the scene that likely occurs, select according to one embodiment of present invention to using lower channel as the sample channel for analyzing: PA (Pedestrian A) channel, EPA (ExtendedPedestrian A) channel, VA (Vehicular A) channel, EVA (Extended Vehicular A) channel, PB (Pedestrian B) channel, TU (Typical Urban) channel and ETU (ExtendedTypical Urb an) channel.

Then, at analystal section, select in step S120, using and 0 constantly start to the interval till the time delay expansion of channel, as whole observation interval, to determine as required analystal section.For example, according to one embodiment of present invention, can select 3 analystal sections [0, T/4], [0, T/2] and [0, T], the time delay expansion that wherein T is channel model yet to be built.Certainly, also can select the analystal section of other quantity, such as, 4 analystal sections [0, T/8], [0, T/4], [0, T/2] and [0, T], etc.

Then, in distributional analysis in path delay of time step S130, for each analystal section, the distribution in the path delay of time of all sample channels is added up.As specific embodiment, when table 1 shows for 3 analystal sections of top selection, distribute the path delay of time of each sample channel of statistics gained.

Table 1 sample distribution of multipath time delay statistics

The sample channel	The first analystal section [0, T/4] multipath number	The second analystal section [0, T/2] multipath number	The 3rd analystal section [0, T]multipath number
				EPA
	4	6	7
				PA	1	3	4
EVA	5	7	9
				VA	2	4	6
PB	3	4	6
				ETU	6	8	9
TU	3	5	6
				On average	3.428571	5.285714	6.714286
Select parameter	4	5	7

Next, in path energy distributional analysis step S140, for each analystal section, the path energy distribution of all sample channels is added up.Equally, as specific embodiment, the path energy that table 2 shows each sample channel of statistics gained distributes.

Table 2 sample multipath energy distribution statistics data

The sample channel	The first analystal section [0, T/4] multipath energy accounts for the gross energy ratio	The second analystal section [0, T/2] multipath energy accounts for the gross energy ratio	The 3rd analystal section [0, T] multipath energy accounts for the gross energy ratio
				EPA	94.02823％	99.73275％	100.00000％
PA	88.93453％	99.53326％	100.00000％
				EVA	90.20566％	97.98566％	100.00000％
VA	87.02543％	97.98128％	100.00000％
				PB	86.67225％	93.10198％	100.00000％
ETU	84.11011％	96.88237％	100.00000％
				TU	80.70734％	96.21473％	100.00000％
On average	87.38336％	97.34743％	100.00000％
				Select parameter
	87％	97％	100％

Afterwards, in channel model construction step S150, according to the distribution in the path delay of time of the sample channel obtained and the path energy obtained, distribute to build channel model in distributional analysis in path delay of time step S130 in path energy distributional analysis step S140.Here, distribution in the path delay of time and path energy with each sample channel shown in table 1 and table 2 are distributed as example, can find out that the first analystal section [0, T/4] multipath number mean value is 3.429, its average multipath energy accounts for 87.3834% of gross energy, the second analystal section [0, T/2] multipath number mean value is 5.286, its average multipath energy accounts for 97.347%, the three analystal section [0 of gross energy, T] multipath number mean value is 6.714, its average multipath energy accounts for 100.000% of gross energy.According to above average data, in the path delay of time of the channel model of this structure, distribute and the path energy distribution is chosen as, the first analystal section [0, T/4] multipath number is 4, and its multipath energy accounts for 87% of gross energy, the second analystal section [0, T/2] multipath number is 5, its multipath energy accounts for 97%, the three analystal section [0 of gross energy, T] multipath number is 7, its multipath energy accounts for 100% of gross energy.Fig. 2 has provided the schematic diagram of the channel model built.

As shown in Figure 2, according to the parameter of selecting, in interval [0, T/4], 4 footpaths are arranged, in interval [T/4, T/2], 1 footpath is arranged, in interval [T/2, T], 2 footpaths are arranged.According to one embodiment of present invention, can suppose [0, T/4] in the time delay in 4 footpaths be evenly distributed, interval [T/4, T/2] in 1 footpath be uniformly distributed, maximum delay expansion place that second footpath in interval [T/2, T] is placed in channel, and the first footpath in interval [T/2, T] is positioned at the center in this interval.In addition, also can make the time delay equal difference in every footpath increase progressively distribution etc.In addition, in each analystal section, the selection parameter that the gross energy obedience table 2 of multipath provides, the Energy distribution in every footpath is linear decrease.In addition, also can make the Energy distribution in every footpath be exponential decrease distributes, makes every footpath be homenergic being uniformly distributed or making every footpath energy to be other possible distributions etc.

Finally, in channel frequency-domain correlation calculation procedure S160, according to the channel model built, calculate the frequency domain correlation of channel in channel model construction step S150.In ofdm system, it is generally acknowledged that the maximum delay expansion of the time domain multipath channel that it experiences can not surpass the length of the Cyclic Prefix of system employing, so the length of Cyclic Prefix is a parameter with reference significance.In different applied environments, different proportion that can the selective system circulating prefix-length, such as 1/8,2/8,3/8,4/8,5/8,6/8,7/8,8/8 circulating prefix-length, as the maximum delay expansion of channel model, calculate the channel spectrum correlation value of different delay expansion according to following formula (15).

${\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)=\mathrm{abs}\left(\underset{i}{\mathrm{\&Sigma;}}{\mathrm{\&sigma;}}_i^2{e}^{-\mathrm{<figure-callout\; label="j"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k-k_m){\mathrm{\&tau;}}_i}\right)---\left(15\right)$

Wherein, θ_{Δ f}(k-k_m) be the channel frequency-domain correlation function, abs () means absolute value calculating operation, (k-k_m) be the subcarrier spacing number between two frequencies that calculate channel spectrum correlation value, i is path sequence number, σ_i²be the path energy in i footpath, τ_iit is the path delay of time in i footpath.

Consider LTE TDD (the Time Division Duplex with user's DRS (Dedicated Reference Signal) (UE-Specific Reference Signal) at this, time division duplex) concrete condition of system, and hypothesis treats that estimating resource is restricted to 1 Resource Block (Resource Block, so integer variable (k-k RB),_m) interval can be set to [0,10].Following table 3 has provided the maximum delay expansion of channel model and has elected 4/8 circulating prefix-length, (k-k as_m) the channel frequency-domain correlation concrete result of calculation of value while being [0,10].

Table 3 channel frequency-domain correlation result of calculation

(k-km)	θΔf(k-km)
		0	1
2	0.997809
		4	0.991323
6	0.980802
		8	0.96666
10	0.949455

Here, in the time of the result of calculation of channel frequency-domain correlation calculation procedure S160 can being stored as to form in order to channel estimating apparatus work, use.

Also it is to be noted in addition, it is not essential for the present invention that analyzing samples channel recited above selects step S110 and analystal section to select step S120, but can be as required for steps such as the direct execution route time delay distribution of given sample channel analytical procedure S130, path energy distributional analysis step S140, channel model construction step S150 and channel frequency-domain correlation calculation procedure S160.

The operation principle of channel frequency-domain correlation calculation element according to an embodiment of the invention is described below in conjunction with Fig. 3.As shown in Figure 3, according to the channel frequency-domain correlation calculation element of this embodiment, comprise: the path delay of time, analytic unit 320, and distribute the path delay of time that is configured to the analyzing samples channel; Path energy analytic unit 330, the path energy that is configured to the analyzing samples channel distributes; Channel model construction unit 340, be configured to according to distributing and path energy distribution structure channel model the path delay of time of sample channel; And frequency domain correlation computing unit 350, be configured to calculate channel frequency-domain correlation according to the channel model built.

In addition, channel frequency-domain correlation calculation element according to an embodiment of the invention can also comprise analystal section selected cell 310, is configured to according to the selected a plurality of analystal sections of time delay expansion.In this case, the path delay of time, analytic unit distributed for 320 path delays of time for each analystal section analyzing samples channel, and path energy analytic unit 330 is for the path energy distribution of each analystal section analyzing samples channel.

Here, the sample channel can comprise the one or more channels in PA channel, EPA channel, VA channel, EVA channel, PB channel, TU channel and ETU channel etc.

Due to the analystal section selected cell 310 included at channel frequency-domain correlation calculation element according to the present invention, the path delay of time, analytic unit 320, path energy analytic unit 330, channel model construction unit 340, and the processing in frequency domain correlation computing unit 350 is selected step S120 with the included analystal section of above-described channel frequency domain correlation calculation method respectively, distributional analysis in path delay of time step S130, path energy distributional analysis step S140, channel model construction step S150, and the processing in channel frequency-domain correlation calculation procedure S160 is similar, therefore for simplicity, omit the detailed description in these unit at this.

Below 1 to 3 describe the operation principle of channel frequency domain correlation calculation method and channel frequency-domain correlation calculation element according to an embodiment of the invention by reference to the accompanying drawings, below in conjunction with accompanying drawing 4 to 7 detailed descriptions, applied the channel estimation methods of above-mentioned channel frequency domain correlation calculation method and channel frequency-domain correlation calculation element and the operation principle of channel estimating apparatus.

Fig. 4 illustrates the process chart of channel estimation methods according to an embodiment of the invention.As shown in Figure 4, comprise pilot tone LS (Least Square, least square) channel estimation steps S410, maximum delay spread estimation step S420, channel frequency-domain correlation read step S430, moving speed estimation step S440, channel time domain correlation calculations step S450, MMSE filter coefficient calculation procedure S460, pilot tone MMSE filter step S470 and data subcarrier channel estimation steps S480 etc. according to the channel estimation methods of this embodiment.

At first, in pilot tone LS channel estimation steps S410, the domain channel response at system pilot subcarrier place is estimated.Suppose that pilot tone subcarrier of living in is for (k, l), its LS channel estimation results can be expressed as

$H_{k,l}^{\mathrm{LS}}=\frac{Y_{k,l}}{X_{k,l}}---\left(16\right)$

Wherein, Y_{k, l}for pilot tone X_{k, l}the reception value.

In maximum delay spread estimation step S420, the maximum delay expansion of time domain multipath channel is estimated.And, the maximum delay expansion of the multipath channel in channel frequency-domain correlation read step S430, estimation in maximum delay spread estimation step S420 obtained rounds up, choose one not only be greater than it but also with its immediate preset value, then according to this, round rear selected preset value the corresponding channel spectrum correlation value form that prestores read.

Here it is pointed out that due to regard to LTE TDD system, user's DRS (Dedicated Reference Signal) is had no idea for estimating the expansion of multipath channel maximum delay, so this maximum delay spread estimation step S420 is not essential for the present invention.In this case, the channel frequency-domain correlation form that can only prestore, therefore omit maximum delay spread estimation step S420, and the form that directly channel frequency-domain correlation prestored prestored in channel frequency-domain correlation read step S430 is read and got final product.

But, if other system, for example utilize public reference signal (Common ReferenceSignal) to do the LTE system of channel estimating, can frequency domain channel be converted into to time domain and carry out de-noising by the estimated result of public reference signal, finally according to the time domain channel estimated result, the maximum delay spread estimation of rough estimate channel.Generally, even the error of the maximum delay spread estimation value of channel is larger, still can obtain channel estimating effect preferably.Then choosing the corresponding channel frequency-domain correlation form that prestores according to the maximum delay spread estimation of estimating in channel frequency-domain correlation read step S430 reads.

In addition, in moving speed estimation step S440, receiving terminal is estimated with respect to the translational speed of transmitting terminal, and the receiving terminal that utilization is estimated in moving speed estimation step S440 in channel time domain correlation calculations step S450 is with respect to the estimated result of the translational speed of transmitting terminal, according to the relativity of time domain of top formula (13) and formula (14) calculating channel.Specifically, for the estimation of translational speed, with regard to LTE TDD system, can adopt public reference signal, by estimating the relativity of time domain of the channel that public reference signal experiences, estimate the translational speed of receiving terminal.

At this, should be noted that, also can first carry out moving speed estimation step S440 and channel time domain correlation calculations step S450, and then carry out maximum delay spread estimation step S420 and channel frequency-domain correlation read step S430, as long as can obtain frequency domain correlation and the relativity of time domain of channel.

Obtain respectively the frequency domain correlation and relativity of time domain of channel in channel frequency-domain correlation read step S430 and channel time domain correlation calculations step S450 after, in MMSE filter coefficient calculation procedure S460, according to formula recited above (10) and (11), calculate respectively cross correlation vector θ and autocorrelation matrix Φ and calculate the MMSE filter coefficient according to formula (5).In this specific embodiment, in order to save computing time, only utilize the channel time domain correlation of calculating in channel time domain correlation calculations step S450 and the channel frequency-domain correlation read in channel frequency-domain correlation read step S430 to calculate the MMSE filter coefficient of pilot sub-carrier.

Next, the MMSE filter coefficient of the pilot sub-carrier that utilizes MMSE filter coefficient calculation procedure S460 to calculate in pilot tone MMSE filter step S470 carries out filtering to the domain channel response at the pilot sub-carrier place of pilot tone LS channel estimation steps S410 output, thereby improves the reliability of the domain channel response at these pilot sub-carrier places.

Then, in data subcarrier channel estimation steps S480, utilize the domain channel response estimated value at the pilot sub-carrier place through MMSE filtering of pilot tone MMSE filter step S470 output, treat the domain channel response at the data subcarrier place in estimating resource and estimated.In estimation procedure, concrete estimation way is unrestricted, generally adopt the simplest time domain and frequency domain respectively the channel estimation methods of linear interpolation can obtain ideal result.Certainly, also can adopt the methods such as second order interpolation, MMSE filtering, low-pass filtering and Spline interpolation.

For example, while in data subcarrier channel estimation steps S480, adopting the channel estimation methods of linear interpolation, can at first to the domain channel response estimated value at the pilot sub-carrier place through MMSE filtering, be analyzed, if channel changes and changes along frequency domain faster than channel along time domain, advanced line frequency territory linear interpolation, recycle frequency domain linear interpolation result and carry out the time domain linear interpolation.Otherwise, first carrying out the time domain linear interpolation, recycling time domain linear interpolation result carries out the frequency domain linear interpolation.

Finally by the channel estimation results of data subcarrier channel estimation steps S480 output, the operations such as the follow-up equilibrium for receiver, demodulation.

Here it is pointed out that the channel frequency-domain correlation prestored of reading is to calculate and obtain by the channel frequency domain correlation calculation method according to each embodiment of the present invention recited above or channel frequency-domain correlation calculation element in channel frequency-domain correlation read step S430.

Below in conjunction with Fig. 5, channel estimating apparatus according to an embodiment of the invention is described.As shown in Figure 5, according to the channel estimating apparatus of this embodiment, comprise: pilot channel estimation unit 501 is configured to calculate the LS channel estimation of pilot sub-carrier; Frequency domain correlation reading unit 507, be configured to read the channel frequency-domain correlation prestored; Motion speed estimation unit 504, be configured to estimate the translational speed of receiving terminal with respect to transmitting terminal; Relativity of time domain computing unit 505, be configured to calculate the channel time domain correlation according to receiving terminal with respect to the translational speed of transmitting terminal; MMSE filter coefficient computing unit 506, be configured to utilize the channel time domain correlation of calculating and the channel frequency-domain correlation read to calculate the MMSE filter coefficient; And data channel estimation unit 510, be configured to obtain according to the LS channel estimation of the MMSE filter coefficient calculated and pilot sub-carrier the channel estimating of data subcarrier.In the channel estimating apparatus according to this embodiment, the described channel frequency-domain correlation prestored that frequency domain correlation reading unit 507 reads is also to calculate and obtain by the channel frequency domain correlation calculation method according to each embodiment of the present invention recited above or channel frequency-domain correlation calculation element.

In addition, channel estimating apparatus according to this embodiment, in order to simplify computation complexity, the channel frequency-domain correlation that the channel time domain correlation that MMSE filter coefficient computing unit 506 only utilizes relativity of time domain computing unit 505 to calculate and frequency domain correlation reading unit 507 read calculates the MMSE filter coefficient of pilot sub-carrier.In this case, data channel estimation unit 510 comprises: pilot tone MMSE filter cell 502, and the MMSE filter coefficient of the pilot sub-carrier that is configured to utilize MMSE filter coefficient computing unit 506 to calculate carries out MMSE filtering to the LS channel estimation of the pilot sub-carrier of pilot channel estimation unit 501 outputs; And data channel estimator 503, be configured to the channel of data subcarrier be estimated to obtain the channel estimating of data subcarrier according to the filtered pilot sub-carrier of MMSE of pilot tone MMSE filter cell 502 outputs.

Data channel estimator 503, when being estimated, can adopt the simplest time domain and the frequency domain channel estimation methods of linear interpolation respectively, can obtain ideal result.Certainly, also can adopt the methods such as second order interpolation, MMSE filtering, low-pass filtering and Spline interpolation.Take that to adopt the channel estimation methods of linear interpolation be example, can at first to the domain channel response estimated value at the pilot sub-carrier place through MMSE filtering, be analyzed, if channel changes and changes along frequency domain faster than channel along time domain, advanced line frequency territory linear interpolation, recycle frequency domain linear interpolation result and carry out the time domain linear interpolation.Otherwise, first carrying out the time domain linear interpolation, recycling time domain linear interpolation result carries out the frequency domain linear interpolation.

In addition, for utilizing public reference signal to do the LTE system etc. of channel estimating, channel estimating apparatus can also comprise time delay spread estimation unit 508 according to an embodiment of the invention, is configured to estimate the maximum delay expansion of channel.In this case, the channel frequency-domain correlation prestored is correspondingly read in the maximum delay expansion that frequency domain correlation reading unit 507 is estimated according to time delay spread estimation unit 508.

The pilot channel estimation unit 501 comprised due to the channel estimating apparatus according to this embodiment, time delay spread estimation unit 508, frequency domain correlation reading unit 507, motion speed estimation unit 504, relativity of time domain computing unit 505, MMSE filter coefficient computing unit 506, pilot tone MMSE filter cell 502, and the pilot tone LS channel estimation steps S410 that comprises with the top channel estimation methods of describing with reference to accompanying drawing 4 respectively of the processing procedure in data channel estimator 503, maximum delay spread estimation step S420, channel frequency-domain correlation read step S430, moving speed estimation step S440, channel time domain correlation calculations step S450, MMSE filter coefficient calculation procedure S460, pilot tone MMSE filter step S470, and the processing in data subcarrier channel estimation steps S480 is similar, therefore for simplicity, omit its detailed description at this.

Next 6 and 7 the operation principle of channel estimation methods and channel estimating apparatus is according to another embodiment of the present invention described with reference to the accompanying drawings.

Fig. 6 illustrates the process chart of channel estimation methods according to another embodiment of the invention.As shown in Figure 6, comprise pilot tone LS channel estimation steps S610, maximum delay spread estimation step S620, channel frequency-domain correlation read step S630, moving speed estimation step S640, channel time domain correlation calculations step S650, MMSE filter coefficient calculation procedure S660 and MMSE filter step S670 etc. according to the channel estimation methods of this embodiment.

The pilot tone LS channel estimation steps S610 comprised according to the channel estimation methods of this embodiment, maximum delay spread estimation step S620, channel frequency-domain correlation read step S630, moving speed estimation step S640, and the pilot tone LS channel estimation steps S410 that comprises of the channel estimation methods described with reference accompanying drawing 4 respectively of the processing procedure of channel time domain correlation calculations step S650, maximum delay spread estimation step S420, channel frequency-domain correlation read step S430, moving speed estimation step S440, and the processing procedure of channel time domain correlation calculations step S450 is similar, therefore for simplicity, omit its detailed description at this.

The MMSE filter coefficient that only calculates pilot sub-carrier in the MMSE filter coefficient calculation procedure S460 described from reference Fig. 4 is different, in the MMSE filter coefficient calculation procedure S660 according to this embodiment, utilize the MMSE filter coefficient of the channel time domain correlation of calculating and the channel frequency-domain correlation calculated data subcarrier read in channel time domain correlation calculations step S650 in channel frequency-domain correlation read step S630.Then, in MMSE filter step S670, the MMSE filter coefficient of the data subcarrier that utilization is calculated in MMSE filter coefficient calculation procedure S660 carries out MMSE filtering to the LS channel estimation of the pilot sub-carrier of pilot tone LS channel estimation steps S610 output, in order to obtain the channel estimating of data subcarrier.Finally by the channel estimation results of MMSE filter step S670 output, the operations such as the follow-up equilibrium for receiver, demodulation.

Equally, it is pointed out that here due to regard to LTE TDD system, user's DRS (Dedicated Reference Signal) is had no idea for estimating the expansion of multipath channel maximum delay, so this maximum delay spread estimation step S620 is not essential for the present invention yet.In this case, the channel frequency-domain correlation form that can only prestore, therefore omit maximum delay spread estimation step S620, and the form that directly channel frequency-domain correlation prestored prestored in channel frequency-domain correlation read step S630 is read and got final product.

Similarly, if other system, for example utilize public reference signal to do the LTE system of channel estimating, can frequency domain channel be converted into to time domain and carry out de-noising by the estimated result of public reference signal, finally according to the time domain channel estimated result, the maximum delay spread estimation of rough estimate channel.Then choosing the corresponding channel frequency-domain correlation form that prestores according to the maximum delay spread estimation of estimating in channel frequency-domain correlation read step S630 reads.

Equally, in the channel estimation methods according to this embodiment, also can first carry out moving speed estimation step S640 and channel time domain correlation calculations step S650, and then carry out maximum delay spread estimation step S620 and channel frequency-domain correlation read step S630, as long as can obtain frequency domain correlation and the relativity of time domain of channel.

Here also it is pointed out that the channel frequency-domain correlation prestored of reading is also to calculate and obtain by the channel frequency domain correlation calculation method according to each embodiment of the present invention recited above or channel frequency-domain correlation calculation element in channel frequency-domain correlation read step S630.

Below in conjunction with Fig. 7, channel estimating apparatus is according to another embodiment of the invention described.As shown in Figure 7, according to the channel estimating apparatus of this embodiment, comprise: pilot channel estimation unit 701 is configured to calculate the LS channel estimation of pilot sub-carrier; Frequency domain correlation reading unit 707, be configured to read the channel frequency-domain correlation prestored; Motion speed estimation unit 704, be configured to estimate the translational speed of receiving terminal with respect to transmitting terminal; Relativity of time domain computing unit 705, be configured to calculate the channel time domain correlation according to receiving terminal with respect to the translational speed of transmitting terminal; MMSE filter coefficient computing unit 706, be configured to utilize the channel time domain correlation of calculating and the channel frequency-domain correlation read to calculate the MMSE filter coefficient; And data channel estimation unit 703, be configured to obtain according to the LS channel estimation of the MMSE filter coefficient calculated and pilot sub-carrier the channel estimating of data subcarrier.In the channel estimating apparatus according to this embodiment, the described channel frequency-domain correlation prestored that frequency domain correlation reading unit 707 reads is also to calculate and obtain by the channel frequency domain correlation calculation method according to each embodiment of the present invention recited above or channel frequency-domain correlation calculation element.

Similarly, 506 MMSE filter coefficients that calculate pilot sub-carrier of the MMSE filter coefficient computing unit of describing from reference Fig. 5 are different, in the MMSE filter coefficient computing unit 706 according to this embodiment, utilize the MMSE filter coefficient of the channel time domain correlation of calculating and the channel frequency-domain correlation calculated data subcarrier read at frequency domain correlation reading unit 707 in relativity of time domain computing unit 705.Then, in data channel estimation unit 703, the MMSE filter coefficient of the data subcarrier that utilizes MMSE filter coefficient computing unit 706 to calculate carries out MMSE filtering to the LS channel estimation of the pilot sub-carrier of pilot channel estimation unit 701 outputs, in order to obtain the channel estimating of data subcarrier.Finally by the channel estimation results of data channel estimation unit 703 output, the operations such as the follow-up equilibrium for receiver, demodulation.

Equally, for utilizing public reference signal to do the LTE system etc. of channel estimating, channel estimating apparatus can also comprise time delay spread estimation unit 708 according to an embodiment of the invention, is configured to estimate the maximum delay expansion of channel.In this case, the channel frequency-domain correlation prestored is correspondingly read in the maximum delay expansion that frequency domain correlation reading unit 707 is estimated according to time delay spread estimation unit 708.

Here it is pointed out that equally that the channel frequency-domain correlation prestored that frequency domain correlation reading unit 707 is read is also to calculate and obtain by the channel frequency domain correlation calculation method according to each embodiment of the present invention recited above or channel frequency-domain correlation calculation element.

In addition, the pilot channel estimation unit 701 comprised due to the channel estimating apparatus according to this embodiment, time delay spread estimation unit 708, frequency domain correlation reading unit 707, motion speed estimation unit 704, and the pilot channel estimation unit 501 that comprises of the channel estimating apparatus described with reference Fig. 5 respectively of the processing procedure of relativity of time domain computing unit 705, time delay spread estimation unit 508, frequency domain correlation reading unit 507, motion speed estimation unit 504, and the processing procedure of relativity of time domain computing unit 505 is similar, therefore for simplicity, omit its detailed description at this.

Fig. 8 and Fig. 9 have provided respectively the simulation result under EPA channel and EVA channel according to channel estimation methods of the present invention and channel estimating apparatus.This emulation is to carry out under the LTE TDD system that adopts user's DRS (Dedicated Reference Signal), and hypothesis treats that estimating resource is restricted to 1 Resource Block.This algorithm, when calculating channel spectrum correlation value, supposes that the maximum delay of channel expands to 4/8 circulating prefix-length.Wherein, the true maximum delay expansion of EPA channel is 410ns.4/8 circulating prefix-length is approximately 2343.7ns.Can find out, although the estimated value deviation of channel length is very large, the result of channel estimating is still ideal.This sufficient proof robustness and the validity of channel frequency domain correlation calculation method of the present invention and device and channel estimation methods and device thereof.

In addition, still need and be pointed out that here, in said apparatus, all modules, unit can be configured by the mode of software, firmware, hardware or its combination.Configure spendable concrete means or mode and be well known to those skilled in the art, do not repeat them here.In the situation that realize by software or firmware, from storage medium or network, the program that forms this software for example, is installed to the computer with specialized hardware structure (all-purpose computer shown in Figure 10 1100), this computer, when various program is installed, can be carried out various functions etc.

In Figure 10, CPU (CPU) 1101 is according to the program of storage in read-only memory (ROM) 1102 or carry out various processing from the program thatstorage area 1108 is loaded into random access memory (RAM)1103.In RAM 1103, also store as required data required whenCPU 1101 carries out variousprocessing etc.CPU 1101,ROM 1102 andRAM 1103 are connected to each other via bus 504.Input/output interface 1105 also is connected tobus 1104.

Following parts are connected to input/output interface 1105: importation 1106 (comprising keyboard, mouse etc.), output 1107 (comprise display, such as cathode ray tube (CRT), liquid crystal display (LCD) etc., with loud speaker etc.), storage area 1108 (comprising hard disk etc.), communications portion 1109 (comprising that network interface unit is such as LAN card, modulator-demodulator etc.).Communications portion 1109 is processed such as the internet executive communication via network.As required,driver 1110 also can be connected to input/output interface 1105.Detachable media 1111, such as disk, CD, magneto optical disk, semiconductor memory etc. can be installed ondriver 1110 as required, makes the computer program of therefrom reading be installed to as required instorage area 1108.

In the situation that realize above-mentioned series of processes by software, from network such as internet or storage medium such asdetachable media 1111 is installed the program that forms softwares.

It will be understood by those of skill in the art that this storage medium is not limited to wherein having program stored therein shown in Figure 10, with equipment, distributes separately to provide thedetachable media 1111 of program to the user.The example ofdetachable media 1111 comprises disk (comprising floppy disk (registered trade mark)), CD (comprising compact disc read-only memory (CD-ROM) and digital universal disc (DVD)), magneto optical disk (comprising mini-disk (MD) (registered trade mark)) and semiconductor memory.Perhaps, storage medium can be hard disk comprised inROM 1102,storage area 1108 etc., computer program stored wherein, and be distributed to the user together with the equipment that comprises them.

The present invention also proposes a kind of program product that stores the instruction code that machine readable gets.When described instruction code is read and carried out by machine, can carry out the above-mentioned method according to the embodiment of the present invention.

Correspondingly, for carrying the above-mentioned storage medium that stores the program product of the instruction code that machine readable gets, be also included within of the present invention open.Described storage medium includes but not limited to floppy disk, CD, magneto optical disk, storage card, memory stick etc.

In the above in the description to the specific embodiment of the invention, the feature of describing and/or illustrating for a kind of execution mode can be used in same or similar mode in one or more other execution mode, combined with the feature in other execution mode, or substitute the feature in other execution mode.

Should emphasize, term " comprises/comprises " existence that refers to feature, key element, step or assembly when this paper is used, but does not get rid of the existence of one or more further feature, key element, step or assembly or add.

In addition, the time sequencing of describing during method of the present invention is not limited to is to specifications carried out, also can according to other time sequencing ground, carry out concurrently or independently.The execution sequence of the method for therefore, describing in this specification is not construed as limiting technical scope of the present invention.

Although the above discloses the present invention by the description to specific embodiments of the invention,, should be appreciated that, above-mentioned all embodiment and example are all illustrative, and not restrictive.Those skilled in the art can design various modifications of the present invention, improvement or equivalent in the spirit and scope of claims.These modifications, improvement or equivalent also should be believed to comprise in protection scope of the present invention.

remarks

1. 1 kinds of channel frequency domain correlation calculation methods of remarks comprise:

Distribute the path delay of time of analyzing samples channel;

The path energy of analyzing samples channel distributes;

According to distributing and path energy distribution structure channel model the path delay of time of sample channel; And

Calculate channel frequency-domain correlation according to the channel model built.

Remarks 2., according to the described channel frequency domain correlation calculation method of remarks 1, also comprises:

According to the selected a plurality of analystal sections of time delay expansion; And

Wherein, for the distribution in the path delay of time of each analystal section analyzing samples channel, and distribute for the path energy of each analystal section analyzing samples channel.

Remarks 3. is according to the described channel frequency domain correlation calculation method ofremarks 2, wherein

The time delay in a plurality of paths in each analystal section is evenly distributed or equal difference increases progressively distribution; And

The Energy distribution in each path is linear decrease and distributes or be exponential decrease and distribute or be homenergic and be uniformly distributed in each analystal section.

Remarks 4., according to the described channel frequency domain correlation calculation method of remarks 3, wherein, for different maximum delay expansions, calculates respectively channel frequency-domain correlation according to the channel model built according to the following formula:

${\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)=\mathrm{abs}\left(\underset{i}{\mathrm{\&Sigma;}}{\mathrm{\&sigma;}}_i^2{e}^{-\mathrm{<figure-callout\; label="j"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k-k_m){\mathrm{\&tau;}}_i}\right)$

Wherein, θ_{Δ f}(k-k_m) be the channel frequency-domain correlation function, abs () means absolute value calculating operation, (k-k_m) be the subcarrier spacing number between two frequencies that calculate channel spectrum correlation value, i is path sequence number, σ_i²be the path energy in i footpath, τ_iit is the path delay of time in i footpath.

Remarks 5. is according to the described channel frequency domain correlation calculation method ofremarks 4, and wherein the sample channel comprises one or more in PA channel, EPA channel, VA channel, EVA channel, PB channel, TU channel and ETU channel.

6. 1 kinds of channel frequency-domain correlation calculation elements of remarks comprise:

The path delay of time analytic unit, distribute the path delay of time that is configured to the analyzing samples channel;

The path energy analytic unit, the path energy that is configured to the analyzing samples channel distributes;

The channel model construction unit, be configured to according to distributing and path energy distribution structure channel model the path delay of time of sample channel; And

The frequency domain correlation computing unit, be configured to calculate channel frequency-domain correlation according to the channel model built.

Remarks 7., according to the described channel frequency-domain correlation calculation element of remarks 6, also comprises:

The analystal section selected cell, be configured to according to the selected a plurality of analystal sections of time delay expansion; And

Wherein, the path delay of time analytic unit for distributing in path delay of time of each analystal section analyzing samples channel, and the path energy analytic unit distributes for the path energy of each analystal section analyzing samples channel.

Remarks 8. is according to the described channel frequency-domain correlation calculation element of remarks 7, wherein the channel model construction unit according to the time delay in a plurality of paths in each analystal section, be evenly distributed or equal difference increase progressively distribute and each analystal section in the Energy distribution in each path be linear decrease and distribute or be exponential decrease and distribute or be the equally distributed principle construction channel model of homenergic.

Remarks 9. is according to the described channel frequency-domain correlation calculation element of remarks 8, and wherein the frequency domain correlation computing unit is for different maximum delay expansions, and the channel model built according to the channel model construction unit according to the following formula calculates respectively channel frequency-domain correlation:

${\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)=\mathrm{abs}\left(\underset{i}{\mathrm{\&Sigma;}}{\mathrm{\&sigma;}}_i^2{e}^{-\mathrm{<figure-callout\; label="j"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k-k_m){\mathrm{\&tau;}}_i}\right)$

Wherein, θ_{Δ f}(k-k_m) be the channel frequency-domain correlation function, abs () means absolute value calculating operation, (k-k_m) be the subcarrier spacing number between two frequencies that calculate channel spectrum correlation value, i is path sequence number, σ_i²be the path energy in i footpath, τ_iit is the path delay of time in i footpath.

Remarks 10. is according to the described channel frequency-domain correlation calculation element of remarks 9, and wherein the sample channel comprises one or more in PA channel, EPA channel, VA channel, EVA channel, PB channel, TU channel and ETU channel.

11. 1 kinds of channel estimation methods of remarks comprise:

Calculate the LS channel estimation of pilot sub-carrier;

Read the channel frequency-domain correlation prestored;

Estimate the translational speed of receiving terminal with respect to transmitting terminal;

Calculate the channel time domain correlation according to receiving terminal with respect to the translational speed of transmitting terminal;

Utilize the channel time domain correlation of calculating and the channel frequency-domain correlation read to calculate the MMSE filter coefficient; And

Obtain the channel estimating of data subcarrier according to the LS channel estimation of the MMSE filter coefficient calculated and pilot sub-carrier,

Wherein, the described channel frequency-domain correlation prestored obtains according to the arbitrary described channel frequency domain correlation calculation method in remarks 1 to 5.

Remarks 12., according to the described channel estimation methods of remarks 11, also comprises:

Estimate the maximum delay expansion of channel; And

Read the channel frequency-domain correlation prestored correspondingly according to the maximum delay expansion of estimating.

Remarks 13. is according to the described channel estimation methods of remarks 12, wherein

In utilizing the channel time domain correlation of calculating and the channel frequency-domain correlation read calculating MMSE filter coefficient, utilize the channel time domain correlation of calculating and the channel frequency-domain correlation read to calculate the MMSE filter coefficient of pilot sub-carrier; And

The channel estimating of obtaining data subcarrier according to the LS channel estimation of the MMSE filter coefficient calculated and pilot sub-carrier comprises:

The MMSE filter coefficient of the pilot sub-carrier that utilization is calculated carries out MMSE filtering to the LS channel estimation of pilot sub-carrier; And

The channel of data subcarrier is estimated to obtain the channel estimating of data subcarrier according to the filtered pilot sub-carrier of MMSE.

Remarks 14. is according to the described channel estimation methods of remarks 13, wherein by the filtered pilot sub-carrier of MMSE is carried out to the channel estimating that linear interpolation, second order interpolation, MMSE filtering, low-pass filtering or Spline interpolation are obtained data subcarrier.

Remarks 15. is according to the described channel estimation methods of remarks 12, wherein

In utilizing the channel time domain correlation of calculating and the channel frequency-domain correlation read calculating MMSE filter coefficient, utilize the MMSE filter coefficient of the channel time domain correlation of calculating and the channel frequency-domain correlation calculated data subcarrier read; And

In the LS channel estimation of the MMSE filter coefficient according to calculating and pilot sub-carrier obtains the channel estimating of data subcarrier, the MMSE filter coefficient of the data subcarrier that utilization is calculated carries out MMSE filtering to the LS channel estimation of pilot sub-carrier, obtains the channel estimating of data subcarrier.

16. 1 kinds of channel estimating apparatus of remarks comprise:

The pilot channel estimation unit, be configured to calculate the LS channel estimation of pilot sub-carrier;

The frequency domain correlation reading unit, be configured to read the channel frequency-domain correlation prestored;

Motion speed estimation unit, be configured to estimate the translational speed of receiving terminal with respect to transmitting terminal;

The relativity of time domain computing unit, be configured to calculate the channel time domain correlation according to receiving terminal with respect to the translational speed of transmitting terminal;

MMSE filter coefficient computing unit, be configured to utilize the channel time domain correlation of calculating and the channel frequency-domain correlation read to calculate the MMSE filter coefficient; And

The data channel estimation unit, be configured to obtain according to the LS channel estimation of the MMSE filter coefficient calculated and pilot sub-carrier the channel estimating of data subcarrier,

Wherein, the described channel frequency-domain correlation prestored is obtained by the arbitrary described channel frequency-domain correlation calculation element according in remarks 6 to 10.

Remarks 17., according to the described channel estimating apparatus of remarks 16, also comprises:

The time delay spread estimation unit, be configured to estimate the maximum delay expansion of channel; And

The frequency domain correlation reading unit reads the channel frequency-domain correlation prestored correspondingly according to the maximum delay expansion of estimating.

Remarks 18. is according to the described channel estimating apparatus of remarks 17, wherein

The channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency-domain correlation read calculate the MMSE filter coefficient of pilot sub-carrier; And

The data channel estimation unit comprises

Pilot tone MMSE filter cell, the MMSE filter coefficient that is configured to the pilot sub-carrier that utilize to calculate carries out MMSE filtering to the LS channel estimation of pilot sub-carrier; And

The data channel estimator, be configured to the channel of data subcarrier be estimated to obtain the channel estimating of data subcarrier according to the filtered pilot sub-carrier of MMSE.

Remarks 19. is according to the described channel estimating apparatus of remarks 18, wherein

The data channel estimator is by carrying out to the filtered pilot sub-carrier of MMSE the channel estimating that linear interpolation, second order interpolation, MMSE filtering, low-pass filtering or Spline interpolation are obtained data subcarrier.

Remarks 20. is according to the described channel estimating apparatus of remarks 17, wherein

The MMSE filter coefficient of the channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency-domain correlation calculated data subcarrier read; And

The MMSE filter coefficient of the data subcarrier that the utilization of data channel estimation unit is calculated carries out MMSE filtering to the LS channel estimation of pilot sub-carrier, obtains the channel estimating of data subcarrier.

Claims (8)

Translated fromChinese

1.一种信道估计方法，包括：1. A channel estimation method, comprising:计算导频子载波的最小二乘信道估计；calculating a least squares channel estimate for the pilot subcarriers;读取预存的信道频域相关性；Read the pre-stored channel frequency domain correlation;估计接收端相对于发送端的移动速度；Estimate the moving speed of the receiving end relative to the sending end;根据接收端相对于发送端的移动速度计算信道时域相关性；Calculate the time-domain correlation of the channel according to the moving speed of the receiving end relative to the sending end;利用计算的信道时域相关性和读取的信道频域相关性计算MMSE滤波器系数；以及calculating MMSE filter coefficients using the calculated channel time-domain correlation and the read channel frequency-domain correlation; and根据计算的MMSE滤波器系数和导频子载波的最小二乘信道估计获取数据子载波的信道估计，Obtain channel estimates for the data subcarriers based on the computed MMSE filter coefficients and the least squares channel estimates for the pilot subcarriers,其中，所述预存的信道频域相关性根据如下信道频域相关性计算方法来获取，该信道频域相关性计算方法包括：Wherein, the pre-stored channel frequency domain correlation is obtained according to the following channel frequency domain correlation calculation method, the channel frequency domain correlation calculation method includes:分析样本信道的路径时延分布；Analyze the path delay distribution of the sample channel;分析样本信道的路径能量分布；Analyzing the path energy distribution of the sample channel;根据样本信道的路径时延分布和路径能量分布构建信道模型；以及Constructing a channel model based on the path delay distribution and path energy distribution of the sampled channel; and根据构建的信道模型计算信道频域相关性。Calculate the channel frequency domain correlation according to the constructed channel model.2.根据权利要求1所述的信道估计方法，其中2. The channel estimation method according to claim 1, wherein在利用计算的信道时域相关性和读取的信道频域相关性计算MMSE滤波器系数中，利用计算的信道时域相关性和读取的信道频域相关性计算导频子载波的MMSE滤波器系数；以及In Calculating MMSE Filter Coefficients Using Calculated Channel Time-Domain Correlation and Read Channel Frequency-Domain Correlation, Calculate MMSE Filtering of Pilot Subcarriers Using Calculated Channel Time-Domain Correlation and Read Channel Frequency-Domain Correlation device coefficient; and根据计算的MMSE滤波器系数和导频子载波的最小二乘信道估计获取数据子载波的信道估计包括：Obtaining channel estimates for data subcarriers based on calculated MMSE filter coefficients and least squares channel estimates for pilot subcarriers includes:利用计算的导频子载波的MMSE滤波器系数对导频子载波的最小二乘信道估计进行MMSE滤波；以及MMSE filtering the least squares channel estimate for the pilot subcarriers using the computed MMSE filter coefficients for the pilot subcarriers; and根据MMSE滤波后的导频子载波对数据子载波的信道进行估计以获取数据子载波的信道估计。The channels of the data subcarriers are estimated according to the MMSE-filtered pilot subcarriers to obtain channel estimates of the data subcarriers.3.根据权利要求1所述的信道估计方法，其中所述信道频域相关性计算方法还包括：3. The channel estimation method according to claim 1, wherein the channel frequency domain correlation calculation method further comprises:根据时延扩展选定多个分析区间；以及Select multiple analysis intervals based on delay spread; and其中，针对每一个分析区间分析样本信道的路径时延分布，并且针对每一个分析区间分析样本信道的路径能量分布。Wherein, the path delay distribution of the sample channel is analyzed for each analysis interval, and the path energy distribution of the sample channel is analyzed for each analysis interval.4.根据权利要求3所述的信道估计方法，其中在所述信道频域相关性计算方法中，4. The channel estimation method according to claim 3, wherein in the channel frequency domain correlation calculation method,各个分析区间内的多个路径的时延呈均匀分布或者等差递增分布；以及The time delays of multiple paths in each analysis interval are distributed uniformly or with increasing arithmetic difference; and各个分析区间内每个路径的能量分布呈线性递减分布或者呈指数递减分布或者呈等能量均匀分布。The energy distribution of each path in each analysis interval is a linear decreasing distribution or an exponential decreasing distribution or an equal energy uniform distribution.5.一种信道估计装置，包括：5. A channel estimation device, comprising:导频信道估计单元，配置为计算导频子载波的最小二乘信道估计；a pilot channel estimation unit configured to calculate a least squares channel estimate of the pilot subcarriers;频域相关性读取单元，配置为读取预存的信道频域相关性；A frequency domain correlation reading unit configured to read prestored channel frequency domain correlations;移动速度估计单元，配置为估计接收端相对于发送端的移动速度；a moving speed estimation unit configured to estimate the moving speed of the receiving end relative to the sending end;时域相关性计算单元，配置为根据接收端相对于发送端的移动速度计算信道时域相关性；A time-domain correlation calculation unit configured to calculate channel time-domain correlation according to the moving speed of the receiving end relative to the sending end;MMSE滤波器系数计算单元，配置为利用计算的信道时域相关性和读取的信道频域相关性计算MMSE滤波器系数；以及An MMSE filter coefficient calculation unit configured to calculate MMSE filter coefficients using the calculated channel time-domain correlation and the read channel frequency-domain correlation; and数据信道估计单元，配置为根据计算的MMSE滤波器系数和导频子载波的最小二乘信道估计获取数据子载波的信道估计，A data channel estimation unit configured to obtain a channel estimate of the data subcarrier according to the calculated MMSE filter coefficients and the least squares channel estimation of the pilot subcarrier,其中，所述预存的信道频域相关性由如下信道频域相关性计算装置来获取，该信道频域相关性计算装置包括：Wherein, the pre-stored channel frequency domain correlation is obtained by the following channel frequency domain correlation calculation device, the channel frequency domain correlation calculation device includes:路径时延分析单元，配置为分析样本信道的路径时延分布；a path delay analysis unit configured to analyze the path delay distribution of the sample channel;路径能量分析单元，配置为分析样本信道的路径能量分布；a path energy analysis unit configured to analyze the path energy distribution of the sample channel;信道模型构建单元，配置为根据样本信道的路径时延分布和路径能量分布构建信道模型；以及a channel model construction unit configured to construct a channel model according to the path delay distribution and path energy distribution of the sample channel; and频域相关性计算单元，配置为根据构建的信道模型计算信道频域相关性。The frequency domain correlation calculation unit is configured to calculate channel frequency domain correlation according to the constructed channel model.6.根据权利要求5所述的信道估计装置，其中6. The channel estimation device according to claim 5, whereinMMSE滤波器系数计算单元利用计算的信道时域相关性和读取的信道频域相关性计算导频子载波的MMSE滤波器系数；以及The MMSE filter coefficient calculation unit calculates the MMSE filter coefficient of the pilot subcarrier using the calculated channel time domain correlation and the read channel frequency domain correlation; and数据信道估计单元包括：The data channel estimation unit includes:导频MMSE滤波器单元，配置为利用计算的导频子载波的MMSE滤波器系数对导频子载波的最小二乘信道估计进行MMSE滤波；以及a pilot MMSE filter unit configured to perform MMSE filtering on the least squares channel estimate of the pilot subcarriers using the calculated MMSE filter coefficients of the pilot subcarriers; and数据信道估计器，配置为根据MMSE滤波后的导频子载波对数据子载波的信道进行估计以获取数据子载波的信道估计。The data channel estimator is configured to estimate the channels of the data subcarriers according to the MMSE filtered pilot subcarriers to obtain the channel estimates of the data subcarriers.7.根据权利要求5所述的信道估计装置，其中所述信道频域相关性计算装置还包括：7. The channel estimation device according to claim 5, wherein said channel frequency domain correlation calculation device further comprises:分析区间选择单元，配置为根据时延扩展选定多个分析区间；以及An analysis interval selection unit configured to select a plurality of analysis intervals according to the delay extension; and其中，路径时延分析单元针对每一个分析区间分析样本信道的路径时延分布，并且路径能量分析单元针对每一个分析区间分析样本信道的路径能量分布。Wherein, the path delay analysis unit analyzes the path delay distribution of the sample channel for each analysis interval, and the path energy analysis unit analyzes the path energy distribution of the sample channel for each analysis interval.8.根据权利要求7所述的信道估计装置，其中信道模型构建单元按照各个分析区间内的多个路径的时延呈均匀分布或者等差递增分布、以及各个分析区间内每个路径的能量分布呈线性递减分布或者呈指数递减分布或者呈等能量均匀分布的原则构建信道模型。8. The channel estimation device according to claim 7, wherein the channel model construction unit is uniformly distributed or incrementally distributed according to the time delay of multiple paths in each analysis interval, and the energy distribution of each path in each analysis interval The channel model is constructed according to the principle of linear decreasing distribution, exponential decreasing distribution or equal energy uniform distribution.

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