CN105827382A - Reference signal mapping method and device - Google Patents

Abstract

The invention discloses a reference signal mapping method and device. The method comprises that during coordinated multi-point transmission, each cell uses a cell ID of a main service cell to generate a reference signal sequence in the resource of coordinated transmission, and the reference signal sequence is a DMRS (Demodulation Reference Signal) sequence; and the generated reference signal sequence is mapped. According to the invention, the compatibility between reference signal mapping and coordinated transmission is improved, and further the performance of coordinated transmission is improved.

Description

Reference signal mapping method and device

The application is to the application number: 201010502535.0, filing date: the divisional application of the original application entitled "reference signal mapping method and apparatus" on 29/09.2010.

Technical Field

The invention relates to the field of communication, in particular to a reference signal mapping method and device.

Background

The high-order multi-antenna technology is one of key technologies of an LTE-a (long term evolution Advanced) system, and is used to improve a transmission rate of the system, and the LTE-a may also be referred to as LTE-Advanced. In order to realize channel quality measurement and data demodulation after introducing a high-order multi-antenna technology, an LTE-a system defines two types of reference signals respectively: demodulation reference signal (DMRS) and channel quality measurement reference signal (CSI-RS), wherein the DMRS is used for demodulation of a Physical Downlink Shared Channel (PDSCH). The CSI-RS is used for measuring Channel State Information (CSI), and is used for reporting information such as a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), and a Rank Indicator (RI). The two types of reference signals can be used for supporting new technical features of LTE-a, such as coordinated multi-Point (CoMP for short), spatial multiplexing, and the like.

In LTE, Common Reference Signals (CRS) are used for pilot measurement, i.e. all users use CRS for channel estimation. When the CRS is used, the transmitting end needs to additionally inform the receiving end of the specific preprocessing mode used by the transmitted data, and the overhead of the pilot frequency is high. In addition, in Multi-user Multi-input Multi-output (MU-MIMO), since a plurality of terminals use the same CRS, orthogonality of pilots cannot be achieved, and thus interference cannot be estimated.

In LTE-A, in order to reduce the overhead of pilot frequency, CSI-RS and DMRS are separately designed, and as the DMRS and data adopt the same preprocessing mode and are mapped according to the available rank information of a channel corresponding to a scheduling user, the overhead of the pilot frequency can be adaptively adjusted according to the rank information, so that the overhead of the pilot frequency can be greatly reduced under the condition of lower rank. The characteristics of DMRS signals include: (1) DMRS signals are terminal-specific, such as: the DMRS corresponding to the specific terminal and the data of the scheduling user adopt the same precoding processing; (2) DMRS signals exist only on the network side, e.g., resources and layers scheduled by an enhanced base station (eNB) for data transmission; (3) from the network side, DMRSs transmitted on different layers are orthogonal to each other.

At present, under the conditions of normal (normalcycprefix, abbreviated as normalccp) and extended cyclic prefix, patterns for DMRS mapping are already defined, fig. 1 is a schematic diagram of a DMRS mapping pattern under a normal cyclic prefix according to the related art, as shown in fig. 1, when a rank (rank) is 1-2, the DMRS mapping pattern in fig. 1 is adoptedThe resource elements shown perform the DMRS mapping, and two layersThe pilot frequency of the port corresponding to the (layer) is subjected to codebook multiplexing through an orthogonal code (OCC) code with the length of 2; when rank is 3-4, on the basis of rank being 1-2, adding Frequency Division Multiplexing (FDM) modeA set of resource units is shown, where the {0, 1} layers correspond toResource units shown, {2, 3} level correspondIn the resource unit, the pilot frequency of the port corresponding to each group of layers is subjected to code division multiplexing on a time domain by using an OCC with the length of 2; when rank is 5-8, mapping pilot frequency by using the same resource unit as that when rank is 3-4, wherein the layers {0, 1, 4, 6} correspond to each otherThe resource units shown, layers {2, 3, 5, 7} correspond toThe shown resource elements are code division multiplexed in the time domain by using OCCs with a length of 4, and Resource Elements (REs) in the same rectangular frame in fig. 1 indicate REs for code division multiplexing. Note that fig. 1 illustrates an example of one Physical Resource Block (PRB), and the mapping positions in different PRBs are the same. It should be noted that when rank>In case 2, the layer i corresponds to the port i +7 one by one, and will not be reiterated in the following description. Fig. 2 and 3 are DMRS mapping patterns at the time of a special subframe of DwPTS. Wherein in the figureRepresenting a common reference signal(ii) a FIGS. 2 to 3 are schematic illustrationsIndicating a guard interval. Wherein, the special subframe refers to: a subframe for uplink/downlink switching in a Time Division Duplex (TDD) system.

In the related art, the method for generating DMRS sequences in LTER9 and R10 is proposed, and in the case of a normal prefix (normalCP) and an extended prefix (extendedCP), the DMRS is mapped in the following manner:

normal cp (cyclic prefix):

$r\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c(2m\left)\right)+j\frac{1}{\sqrt{2}}(1-2\·c(2m+1\left)\right),m=0,1,...,12\·N_{RB}^{\max ,DL}-1;$

whereinThe number of resource blocks corresponding to the maximum system bandwidth is shown, and c (i) is a pseudo-random sequence.

In sequence mapping, in the current 3GPP36.211 protocol, when the CP is normal, the relationship between the DMRSs of different ports and the mapping sequence is shown in the following formula

$a_{k,l}^{\left(p\right)}=s\·r(3\·l^{\′}\·N_{RB}^{\max ,DL}+3\·n_{PRB}+m^{\′})$

Wherein s represents spreading code values corresponding to ports on different REs, r is a reference signal sequence, l 'represents an OFDM symbol index of a DMRS in one subframe (the second OFDM symbol with the DMRS), and the values of the OFDM symbols corresponding to different DMRSs are respectively l' 0,1, 2, and 3 in normal cyclic prefix. m' corresponds to one of one resource blockDMRS resource element location index on DMRS ofdm symbol, when in normal cyclic prefix, m' is 0,1, 2. k denotes a frequency domain position where the DMRS needs to be mapped, and l denotes an OFDM symbol where the DMRS is placed with respect to an OFDM symbol index in one slot. And p represents a port number corresponding to the DMRS. n is_PRBRepresents the resource block index with the value range ofWhereinIndicating the number of resource blocks corresponding to the current system bandwidth.

Based on the mapping method of the DMRS sequence described in 36.211, under different bandwidths, the corresponding sequence position interception method is as shown in fig. 4, and in this way, the performance of joint transmission (j _ in transmission, abbreviated as JT) in cooperative diversity (coordinated multi-point transmission/reception, abbreviated as CoMP) is relatively poor.

Meanwhile, according to the existing DMRS sequence generation mode, the DMRS sequences of different cells are generated asThe DMRS sequences of different cells are different, resulting in degraded transmission performance of the commpjt.

Disclosure of Invention

The present invention mainly aims to provide a reference signal mapping method and apparatus, so as to solve the problem that the performance of cooperative transmission is poor due to the reference signal mapping method in the related art.

To achieve the above object, according to one aspect of the present invention, a reference signal mapping method is provided.

The reference signal mapping method according to the present invention includes: generating a reference signal sequence using a maximum system bandwidth; and selecting a mapped reference sequence from the generated reference signal sequences for mapping, wherein the mapped reference sequence is a reference signal sequence corresponding to the same resource position in the maximum system bandwidth.

In order to achieve the above object, according to another aspect of the present invention, there is also provided a reference signal mapping method.

The reference signal mapping method according to the present invention includes: when multi-point cooperative joint transmission is carried out, on joint transmission resources, each cell uses a cell identifier of a main service cell to generate a reference signal sequence, wherein the reference signal sequence is a demodulation reference signal (DMRS); and mapping the generated reference signal sequence.

To achieve the above object, according to still another aspect of the present invention, there is also provided a reference signal mapping apparatus.

The reference signal mapping apparatus according to the present invention includes: a first generating module for generating a reference signal sequence using a maximum system bandwidth; and the mapping module is used for selecting a mapped reference sequence from the generated reference signal sequences for mapping, wherein the mapped reference sequence is a reference signal sequence corresponding to the same resource position in the maximum system bandwidth.

To achieve the above object, according to still another aspect of the present invention, there is also provided a reference signal mapping apparatus.

According to the reference signal mapping apparatus of the present invention, the apparatus is located in each cell performing coordinated multipoint joint transmission, and includes: a second generating module, configured to generate a reference signal sequence on a resource of joint transmission by using a cell identifier of a main serving cell when performing coordinated multi-point joint transmission, where the reference signal sequence is a demodulation reference signal DMRS sequence; and the sequence mapping module is used for mapping the generated reference signal sequence.

By the invention, the reference signal sequence is generated by using the maximum system bandwidth. And selecting a mapped reference sequence from the generated reference signal sequence for mapping, wherein the mapped reference sequence is a reference signal sequence corresponding to the same resource position in the maximum system bandwidth, so that the problem of poor performance of cooperative transmission in the cooperative diversity caused by a reference signal mapping method in the related art is solved, and thus the compatibility of the reference signal mapping and the cooperative diversity is improved, and the effect of the joint transmission performance of the cooperative diversity is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a first diagram illustrating a mapping pattern of a DMRS under a normal cyclic prefix according to the related art;

fig. 2 is a diagram of a mapping pattern of a DMRS under a normal cyclic prefix according to the related art;

fig. 3 is a diagram of a mapping pattern of a DMRS under a normal cyclic prefix according to the related art;

fig. 4 is a schematic diagram of a mapping manner of DMRS sequences under different bandwidths in an LTE system according to the related art;

FIG. 5 is a first flowchart of a reference signal mapping method according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a mapping manner of DMRS sequences under different bandwidths according to an embodiment of the present invention;

FIG. 7 is a second flowchart of a reference signal mapping method according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a mapping manner of a DMRS sequence in CoMP joint transmission according to an embodiment of the present invention;

fig. 9 is a first structural block diagram of a reference signal mapping apparatus according to an embodiment of the present invention;

fig. 10 is a first preferred block diagram of a reference signal mapping apparatus according to an embodiment of the present invention; and

fig. 11 is a second structural block diagram of a reference signal mapping apparatus according to an embodiment of the present invention.

Detailed Description

The invention will be described in detail hereinafter with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

The present embodiment provides a reference signal mapping method, and fig. 5 is a first flowchart of the reference signal mapping method according to the embodiment of the present invention, as shown in fig. 5, the method includes:

step S502: the reference signal sequence is generated using the maximum system bandwidth.

Step S504: and selecting a mapped reference sequence from the generated reference signal sequences for mapping, wherein the mapped reference sequence is a reference signal sequence corresponding to the same resource position in the maximum system bandwidth.

Through the steps, the reference signal sequence is generated by using the maximum system bandwidth, and the corresponding reference signal sequence at the same resource position is selected to be mapped in the sequence when the maximum system bandwidth is selected, so that the same reference signal is provided at the same resource position, and the problem of poor performance caused by the inconsistency of the reference signal in cooperative joint transmission due to the adoption of a reference signal mapping method in the related technology is solved, so that the compatibility of reference signal mapping and cooperative transmission is improved, and the performance of the cooperative joint transmission is improved.

Preferably, the reference signal sequence comprises a DMRS sequence or a CSI-RS sequence.

Preferably, in the subframe of the normal prefix normal cp, the reference signal sequence is a DMRS sequence, and step S504 includes: selecting a mapped reference sequence from the generated reference signal sequences for mapping by using the following formula:

wherein,a reference signal indicating a correspondence of a p-th port on a k-th subcarrier of an l-th orthogonal frequency division multiplexing OFDM symbol, where l indicates an OFDM symbol index in one slot in which a DMRS is placed, k corresponds to a frequency domain position on the OFDM symbol where the DMRS exists, values of l and k are determined by a DMRS pattern, s indicates a spreading code value corresponding to the DMRS port, r is a reference signal sequence, l 'indicates a symbol index of OFDM of the DMRS in one subframe, and l' is 0,1, 2, 3,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth, n_PRBDenotes a resource block index, m 'is a DMRS resource element position index on one DMRS ofdm symbol corresponding to one resource block, and m' is 0,1, 2. Through the preferred embodiment, the reference signal sequence is mapped by the DMRS sequence in the subframe of the normal prefix normal CP, so that the compatibility of the reference signal mapping and the cooperative transmission is improved, and the performance of the cooperative transmission is improved.

Preferably, in a normal subframe of an extended prefix (extentCP), the reference signal sequence is a DMRS sequence, and step S504 includes: selecting a mapped reference sequence from the generated reference signal sequences for mapping by using the following formula:

wherein,a reference signal indicating a correspondence of a p-th port on a k-th subcarrier on an l-th orthogonal frequency division multiplexing OFDM symbol, wherein l indicates an OFDM symbol index in which the DMRS is placed with respect to an OFDM symbol in one slot, k corresponds to a frequency domain position to which the DMRS is mapped on the OFDM symbol in which the DMRS exists, l and k values are determined by the DMRS pattern, s indicates a spreading code value corresponding to the DMRS port, r is a pilot sequence, l 'indicates a symbol index of the OFDM of the DMRS in one subframe, and l' is 0,1, 2, 3,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth, n_PRBDenotes a resource block index, m 'is a DMRS resource element position index on one DMRS ofdm symbol corresponding to one resource block, and m' is 0,1, 2. Through the preferred embodiment, the reference signal sequence is mapped by the DMRS sequence in the normal subframe of the extended prefix extentCP, so that the compatibility of reference signal mapping and cooperative transmission is improved, and the performance of cooperative transmission is improved.

Preferably, in the special subframe of the extended prefix (extentCP), the reference signal sequence is a DMRS sequence, and step S504 includes: selecting a mapped reference sequence from the generated reference signal sequences for mapping by using the following formula:

wherein,denotes a reference sequence corresponding to a p-th port on a k-th subcarrier on an l-th orthogonal frequency division multiplexing OFDM symbol, where l denotes an OFDM symbol index in which a DMRS is placed with respect to an OFDM symbol in one slot, k corresponds to a frequency domain position to which the DMRS is mapped on the OFDM symbol in which the DMRS exists, values of l and k are determined by a DMRS pattern, s denotes a spreading code value corresponding to the DMRS port, r is a reference signal sequence, l 'denotes a symbol index of OFDM of the DMRS in one subframe, and l' is 0,1,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth, n_PRBDenotes a resource block index, m 'is a DMRS resource element position index on one DMRS ofdm symbol corresponding to one resource block, and m' is 0,1, 2. Through the preferred embodiment, the reference signal sequence is mapped by the DMRS sequence in the special subframe of the extended prefix extentCP, so that the compatibility of reference signal mapping and cooperative transmission is improved, and the performance of cooperative transmission is improved.

Preferably, the reference signal sequence is a CSI-RS sequence, and selecting a mapped reference sequence from the generated reference signal sequences for mapping includes: selecting a mapped reference sequence from the generated reference signal sequences for mapping by using the following formula:

wherein,indicating that the p port is at the l OFDM (orthogonal frequency division multiplexing)) A corresponding reference signal on the kth subcarrier on the symbol, wherein l represents an OFDM symbol in which the CSI-RS is placed relative to an OFDM symbol index in a time slot, k corresponds to a frequency domain position of CSI-RS mapping on the OFDM symbol in which the CSI-RS exists, values of l and k are determined by a CSI-RS pattern, s represents a spreading code value of a corresponding CSI-RS port, r is a reference signal sequence,l' denotes a symbol index where the measurement reference signal exists,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth. By the preferred embodiment, the mapping that the reference signal sequence is the CSI-RS sequence is realized, so that the compatibility of the reference signal mapping and the cooperative transmission is improved, and the performance of the cooperative transmission is improved.

Fig. 6 is a schematic diagram of a mapping manner of DMRS sequences under different bandwidths according to an embodiment of the present invention, where as shown in fig. 6, a sequence of each RB under a current system bandwidth is the same as a sequence of a corresponding RB at the same frequency position under a maximum bandwidth. In FIG. 6, a practical system is illustrated asSystem bandwidth with a maximum system bandwidth ofThe relationship of the reference signal sequences in the two systems. In the context of this schematic drawing, the drawing,system andthe corresponding center frequency positions of the systems are the same, and at this timeThe reference signal corresponding to the system needs to beThe system refers to truncation of the signal sequence at the same frequency domain location.Corresponding sequences on respective RBs in the system andthe sequence of the corresponding frequency domain positions of the system is the same.

The same frequency domain position refers to the same frequency domain position of the baseband signal, and the reference signal in the above description may be a demodulation reference signal or a measurement reference signal.

Example one

In this embodiment, in combination with the above embodiment and the preferred implementation manner thereof, this embodiment provides a mapping method for a reference signal, and in this embodiment, a specific mapping method for a demodulation reference signal in a normal CP is implemented, where the method includes the following steps:

step 1: the DMRS sequence is generated according to formula (1) by using the method for generating the DMRS sequence in LTE, the length of the DMRS sequence is generated according to the maximum system bandwidth, and the maximum system bandwidth passes through the RB numberAnd (5) characterizing.

$r\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c(2m\left)\right)+j\frac{1}{\sqrt{2}}(1-2\·c(2m+1\left)\right),m=0,1,...,12N_{RB}^{\max ,DL}-1---\left(1\right)$

Wherein, c (i) is a pseudo random sequence, and it should be noted that the process of generating the pseudo random sequence is the same as the method for generating the pseudo random sequence of the system in the existing LTE.

Step 2: mapping of demodulation reference signals, resource block n_PRBThe above demodulation reference signal mapping manner is mapped. The mapping method can be expressed by formula (2):

wherein,a reference signal representing the correspondence of the p-th port on the k-th subcarrier on the l-th OFDM (orthogonal frequency division multiplexing) symbol, where l represents the OFDM symbol in which the DMRS is placed with respect to the OFDM symbol index in one slot, k corresponds to the frequency domain position of DMRS mapping on the OFDM symbol in which the DMRS exists, the values of l and k are determined by the DMRS pattern, s represents the spreading code value of the corresponding DMRS port, l ' represents the OFDM symbol index of the DMRS in one subframe, for a normal cyclic prefix, m ' is the DMRS resource element position index on one DMRS OFDM symbol corresponding to one resource block, and m ' is 0,1, 2;representing the number of resource blocks corresponding to the maximum system bandwidth;indicating the number of resource blocks corresponding to the current system bandwidth.

Example two

In this embodiment, a specific mapping method for demodulation reference signals in CP extension is implemented, where the method includes the following steps:

step 1: when the cyclic prefix is expanded, the method for generating the DMRS sequence generates the DMRS sequence according to the formula (3), the length of the sequence is generated according to the maximum system bandwidth, and the maximum system bandwidth passes the RB numberAnd (5) characterizing.

For normal subframes:

$r\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c(2m\left)\right)+j\frac{1}{\sqrt{2}}(1-2\·c(2m+1\left)\right),m=0,1,...,16N_{RB}^{\max ,DL}-1---\left(3\right)$

for special subframes of a TDD system:

$r\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c(2m\left)\right)+j\frac{1}{\sqrt{2}}(1-2\·c(2m+1\left)\right),m=0,1,...,8N_{RB}^{\max ,DL}-1---\left(4\right)$

wherein, c (i) is a pseudo random sequence, and in LTE, the method is the same as the method for generating the pseudo random sequence of the existing system.

Step 2, mapping the demodulation reference signal, and carrying out resource block n_PRBThe above demodulation reference signal mapping manner is mapped. The formula is shown in formula (5).

Denotes a reference signal corresponding to the p-th port on the k-th subcarrier on the l-th OFDM (orthogonal frequency division multiplexing) symbol, where l denotes an OFDM symbol in which DMRS is placed with respect to an OFDM symbol index in one slot, and k pairsCorresponding to the frequency domain position mapped by the DMRS on the OFDM symbol with the DMRS, l and k values are determined by the DMRS pattern, s represents the spread spectrum code value corresponding to the DMRS port, r is a reference signal sequence, l 'represents the orthogonal frequency division multiplexing OFDM symbol index of the DMRS in a subframe, and l' is 0,1, 2 and 3 for a normal subframe and is 0,1, n for a special subframe_PRBRepresenting a resource block index, m 'is a DMRS resource element position index on one DMRS ofdm symbol corresponding to one resource block, and m' is 0,1, 2;representing the number of resource blocks corresponding to the maximum system bandwidth;the number of resource blocks corresponding to the current system bandwidth is represented, and m' is 0,1, 2, and 3 for the extended cyclic prefix.

EXAMPLE III

In this embodiment, in combination with the above embodiment and the preferred implementation manner thereof, the embodiment provides a mapping method for a reference signal, and in this embodiment, a specific mapping method for CSI-RS is implemented, where the method includes the following steps:

step 1: the measurement reference signal sequence is generated according to the formula (6), and the length of the sequence is also determined according to the maximum system bandwidth.

$r_{l,n_s}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c(2m\left)\right)+j\frac{1}{\sqrt{2}}(1-2\·c(2m+1\left)\right),m=0,1,...,2N_{RB}^{\max ,DL}-1---\left(6\right)$

And 2, mapping the measurement reference signal. When mapping is performed, the sequence of each RB in the current system bandwidth is the same as the sequence of the corresponding RB in the same frequency position in the maximum bandwidth, and the specific mapping is shown in formula 7: .

$a_{k,l}^{\left(p\right)}=s\·r(l^{\′}\·N_{RB}^{\max ,DL}+m^{\′})---\left(7\right)$

Wherein,representing a reference signal corresponding to a p-th port on a k-th subcarrier on an l-th OFDM (orthogonal frequency division multiplexing) symbol, wherein l represents an OFDM symbol index for placing a CSI-RS relative to an OFDM symbol in a time slot, k corresponds to a frequency domain position of CSI-RS mapping on the OFDM symbol with the CSI-RS, l and k values are determined by a CSI-RS pattern, s represents a spread spectrum code value corresponding to the CSI-RS port, r is a reference signal (CSI-RS) sequence,l 'denotes a symbol index where the sounding reference signal exists (the first OFDM symbol where the sounding reference signal exists), l' is 0,1,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth.

Example four

The present embodiment provides a method for mapping demodulation reference signals in cooperative transmission, and fig. 7 is a second flowchart of the method for mapping reference signals according to the embodiment of the present invention, as shown in fig. 7, the method includes:

step S702: when CoMP joint transmission is carried out, a reference signal sequence is generated by using the cell identification of the main service cell, wherein the reference signal sequence is a demodulation reference signal (DMRS) sequence.

In the case of the comp jt, the same DMRS sequence needs to be used to make the transmission of multiple transmission nodes transparent to the reception detection of the UE. As shown in fig. 8. The two cells are illustrated as joint cooperative transmission in the figure, whereinThe Physical Resource Block (PRB) is shown as a PRB used for joint transmission, and □ is shown as a PRB used for single-cell user transmission.

Step S704: and mapping the generated reference signal sequence.

Through the above steps, when performing coordinated multi-point transmission, on the resources of the joint transmission, each cell generates a DMRS sequence according to the cell ID of the primary serving cell, so that the same sequence is used on the resources of the joint transmission as the corresponding resources of the primary serving cell. The method avoids the generation of virtual cell ID in the related technology, which brings restriction to the dynamic switching of single-cell and multi-cell joint transmission, improves the compatibility of DMRS sequences and cooperative transmission, and improves the performance of cooperative transmission.

The following provides a reference signal mapping apparatus according to an embodiment of the present invention. Fig. 9 is a first structural block diagram of a reference signal mapping apparatus according to an embodiment of the present invention, as shown in fig. 9, the apparatus including: the first generation module 92 and the mapping module 94, the above structure is described in detail below:

a first generating module 92, configured to generate a reference signal sequence using a maximum system bandwidth;

a mapping module 94, connected to the first generating module 92, configured to select a mapped reference sequence from the reference signal sequences generated by the first generating module 82 for mapping, where the mapped reference sequence is a reference signal sequence corresponding to the same resource location at the maximum system bandwidth.

Fig. 10 is a first preferred block diagram of a reference signal mapping apparatus according to an embodiment of the present invention, and as shown in fig. 10, the mapping module 94 includes: the first mapping submodule 942, the second mapping submodule 944, the third mapping submodule 946, and the fourth mapping submodule 948 are described in detail below:

it should be noted that the reference signal sequence in this embodiment includes: DMRS sequences and CSI-RS sequences.

The mapping module 94 includes: a first mapping sub-module 942, connected to the first generating module 92, configured to select a mapped reference sequence from the reference signal sequences generated by the first generating module 92 to map when the reference signal sequence is a DMRS sequence in a normal prefix (normalCP) subframe, using the following formula:

wherein,a reference signal indicating a correspondence of a p-th port on a k-th subcarrier on an l-th orthogonal frequency division multiplexing OFDM symbol, wherein l indicates an OFDM symbol index in which the DMRS is placed with respect to the OFDM symbol in one slot, k corresponds to a frequency domain position to which the DMRS is mapped on the OFDM symbol in which the DMRS exists, l and k values are determined by the DMRS pattern, s indicates a spreading code value corresponding to the DMRS port, r is a reference signal sequence, l 'indicates a symbol index of the OFDM of the DMRS in one subframe, and l' is 0,1, 2, 3,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth, n_PRBDenotes a resource block index, m 'is a DMRS resource element position index on one DMRS ofdm symbol corresponding to one resource block, and m' is 0,1, 2.

The mapping module 94 includes: a second mapping sub-module 944, connected to the first generating module 92, configured to select a mapped reference sequence from the reference signal sequences generated by the first generating module 92 to map, when the reference signal sequence is a DMRS sequence in a normal subframe of an extended prefix (extentCP), using the following formula:

wherein,a reference signal indicating a correspondence of a p-th port on a k-th subcarrier on an l-th orthogonal frequency division multiplexing OFDM symbol, wherein l indicates an OFDM symbol index in which the DMRS is placed with respect to the OFDM symbol in one slot, k corresponds to a frequency domain position to which the DMRS is mapped on the OFDM symbol in which the DMRS exists, l and k values are determined by the DMRS pattern, s indicates a spreading code value corresponding to the DMRS port, r is a reference signal sequence, l 'indicates a symbol index of the OFDM of the DMRS in one subframe, and l' is 0,1, 2, 3,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth, n_PRBDenotes a resource block index, m 'is a DMRS resource element position index on one DMRS ofdm symbol corresponding to one resource block, and m' is 0,1, 2.

The mapping module 94 includes: the third mapping submodule 946, connected to the first generating module 92, is configured to select, in the special subframe of the extended prefix (extentCP), a mapped reference sequence from the reference signal sequences generated by the first generating module 92 to map, using the following formula:

wherein,indicating a reference sequence corresponding to a pth port on a kth subcarrier on a lth Orthogonal Frequency Division Multiplexing (OFDM) symbol, wherein l indicates an OFDM symbol index in one slot in which the DMRS is placed, k corresponds to a frequency domain position on the OFDM symbol in which the DMRS is present, values of l and k are determined by the DMRS pattern, s indicates a spreading code value corresponding to the DMRS port, r is the reference signal sequence, l 'indicates a symbol index of the OFDM of the DMRS in one subframe, and l' is 0,1,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth, n_PRBDenotes a resource block index, m 'is a DMRS resource element position index on one DMRS ofdm symbol corresponding to one resource block, and m' is 0,1, 2.

The mapping module 94 includes: a fourth mapping sub-module 948, connected to the first generating module 92, for selecting a mapped reference sequence from the reference signal sequences generated by the first generating module 92 to map when the reference signal sequence is a CSI-RS sequence, using the following formula:wherein,representing a reference signal corresponding to a p-th port on a k-th subcarrier on an l-th OFDM (orthogonal frequency division multiplexing) symbol, wherein l represents an OFDM symbol index for placing a CSI-RS relative to an OFDM symbol in a time slot, k corresponds to a frequency domain position mapped by the CSI-RS on the OFDM symbol with the CSI-RS, l and k values are determined by a CSI-RS pattern, s represents a spread spectrum code value corresponding to the CSI-RS port, r is a reference signal (CSI-RS) sequence,the number of resource blocks corresponding to the maximum system bandwidth,indicating the number of resource blocks corresponding to the current system bandwidth.

It should be noted that, in an actual system application, one or more of the four sub-modules, i.e., the first mapping sub-module 942, the second mapping sub-module 944, the third mapping sub-module 946, and the fourth mapping sub-module 948 in the mapping module 94 may be selected to be applied in combination.

This embodiment provides a reference signal mapping apparatus, and fig. 11 is a second structural block diagram of the reference signal mapping apparatus according to the embodiment of the present invention, as shown in fig. 11, the apparatus includes: the second generating module 112 and the sequence mapping module 114, the following describes the above structure in detail:

a second generating module 112, configured to generate a reference signal sequence using the cell identifier of the primary serving cell, where the reference signal sequence is a DMRS sequence; and a sequence mapping module 114, connected to the second generating module 112, for mapping the reference signal sequence generated by the second generating module 112.

In summary, through the above embodiments, the mapping manner of the DMRS sequences under different bandwidths described in the above embodiments is used, so that the coordinated cell and the UE perform sequence mapping without knowing system bandwidths of other cells, and meanwhile, the sequence mapping manner under different bandwidths is more consistent with the sequence interception manner of different users under a uniform bandwidth, and in addition, other cells generate sequences based on the cell ID of the primary serving cell, so that CoMP transmission is transparent to UE reception detection.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (2)

1. A method for reference signal mapping, comprising:

when multi-point cooperative joint transmission is carried out, on joint transmission resources, each cell uses a cell identifier of a main service cell to generate a reference signal sequence, wherein the reference signal sequence is a demodulation reference signal (DMRS) sequence;

and mapping the generated reference signal sequence.

2. An apparatus for mapping reference signals, the apparatus being located in each cell performing coordinated multi-point joint transmission, comprising:

a second generating module, configured to generate a reference signal sequence on a resource of joint transmission by using a cell identifier of a main serving cell when performing coordinated multi-point joint transmission, where the reference signal sequence is a demodulation reference signal DMRS sequence;

and the sequence mapping module is used for mapping the generated reference signal sequence.