The channel estimate for one subband after phase adjustment is: h_sub,adj (m)＝H_sub (m)*e^j*Δφ(m) Wherein H is_sub,adj (m) is a second channel estimation parameter, H_sub (m) is determined by an estimation index of an effective channel of one subband.

And step S104, determining frequency domain channel estimation parameters of the transmission channel according to the effective channel of each sub-band, the protective band of each sub-band and the second channel estimation parameters of each sub-band, wherein the frequency domain channel estimation parameters are used for calibrating the transmission channel.

In one embodiment, H is transformed by IFFT (inverse Fast Fourier transform)_sub,adj (m) converting from frequency domain to time domain to obtain time domain response h_sub (r)＝ifft(H_sub,adj (m)); wherein h is_sub (r) is a first time domain response parameter.

In one embodiment, time domain windowing comprises:

calculating power: p (r) = | h (r) & gtnon² ，r＝1:L；

And (3) fault judgment: if P (1) < P (r), r = 2L, reporting the sub-band fault;

windowing: reserving J paths with the strongest power, J<L, J values may be matched, e.g. 3<＝J<= L/2, and the rest weak paths are set to be 0, so as to obtain a new time domain response h_sub,new . Wherein h is_sub,new Is a second time domain response parameter.

In one embodiment, h is transformed by Fast Fourier Transform (FFT)_sub,new Converting from time domain to frequency domain to obtain frequency domain response H_sub,win (m)＝fft(h_sub,new (r)). Wherein H_sub,win (m) is a frequency domain response parameter.

In one embodiment, the phase adjustment is H_sub,win,adj (m)＝H_sub,win (m)*e^-j*Δφ(m) 。

In one embodiment, data splicing comprises: channel estimation for one subband H_sub,win,adj And (M), after removing M guard bands at two sides, selecting proper channel estimation, and splicing to form the frequency domain channel estimation value after noise suppression. As shown in table 3, channel estimation selection is performed.

Table 3 channel estimation selection

The channel estimation results selected by each sub-band are spliced in sequence to obtain the final channel estimation result H_ic (n) of (a). Wherein n = 1; h_ic (1)、H_ic (2)……H_ic (N) channel estimation parameters for subbands with guard bands removed, H_ic And (n) is a frequency domain channel estimation parameter of one transmission channel.

In the embodiment of the application, the calibration accuracy of the transmission channel under the medium-low signal-to-noise ratio is improved, and especially the phase accuracy of the bandwidth edge can be improved.

Another channel calibration method provided in the embodiment of the present application is executed by a network node, and a flowchart of the method is shown in fig. 4, where the method includes:

step S201, a calibration sequence is sent.

In one embodiment, the calibration sequence is generated locally and transmitted within a specified time.

Step S202, the calibration sequence is transmitted through the transmission network.

In one embodiment, the transmission network includes a differentiated plurality of transmission channels, such as a large-scale array antenna system, and a common calibration channel. When the calibration is sent, the calibration sequences in the transmission channels reach a public calibration channel through combination and reach a receiving end; when receiving and calibrating, the calibration sequence is sent through the public calibration channel and reaches each receiving channel in a shunt way;

step S203, calibrating signal reception.

In one embodiment, the received calibration signal is subjected to a corresponding transform operation, such as a cyclic prefix CP removal, time-frequency transform, and the like.

And step S204, channel estimation.

In one embodiment, the received calibration signal is frequency domain channel estimated using a locally pre-stored calibration sequence.

Step S205, detecting whether the transmission channel has a fault, and when detecting that the transmission channel has a fault, turning to the step S206 for processing; when it is not detected that the transmission path has a failure, the process goes to step S207.

In one embodiment, whether faults exist in each channel or not is detected according to the channel estimation result, and the faults include power faults, phase faults, timing faults, signal-to-noise ratios and the like.

And step S206, a fault alarm is given.

In one embodiment, a channel alarm is reported for a channel with a fault.

Step S207, smooth interpolation of the amplitude and/or phase of the transmission channel.

In one embodiment, the amplitude and/or phase of the transmission channel without failure is smoothed, interpolated, etc.

Step S208, when the SNR of the transmission channel is less than the threshold SNR of the preset SNR_TH Then go to step S209 for processing; SNR of transmission channelSNR or more_TH Then, the process proceeds to step S216.

Step S209, the sub-band segments of the transmission channel.

In one embodiment, an estimation index of an effective channel of each sub-band is determined according to a first channel estimation parameter of each sub-band in a transmission channel, and an upper guard band and a lower guard band included in a guard band of each sub-band.

Step S210, performing phase adjustment on the phase of each sub-band, and determining a second channel estimation parameter of each sub-band.

Step S211, the second channel estimation parameters of each sub-band are converted from frequency domain to time domain through IFFT, and the first time domain response parameters of each sub-band are obtained.

Step S212, the first time domain response parameter of each sub-band is subjected to time domain windowing to obtain a second time domain response parameter of each sub-band.

Step S213, the second time domain response parameter of each sub-band is converted from the time domain to the frequency domain through FFT, so as to obtain the frequency domain response parameter of each sub-band.

In step S214, a phase is adjusted for the frequency domain response parameter of each sub-band.

Step S215, determining the frequency domain channel estimation parameter of the transmission channel through data splicing.

In step S216, a calibration factor is determined.

In one embodiment, a calibration factor of a transmission channel is determined according to a frequency domain channel estimation parameter of the transmission channel, and the calibration factor is used for calibrating the transmission channel.

In one embodiment, the phase factor is obtained by a table lookup or CORDIC, etc. And obtaining the amplitude factor of the transmission channel according to the power of each transmission channel. And obtaining the calibration factor according to the product of the phase factor and the amplitude factor.

In the embodiment of the application, under a medium-low signal-to-noise ratio, for example, the signal-to-noise ratio is less than or equal to 20dB, partial gain of an edge RB (Resource Block) is achieved; with the improvement of the signal-to-noise ratio, the gain of the part is gradually reduced, and the residual phase difference of the edge RB (for example, 3 RBs at the upper edge and the lower edge) is correspondingly reduced, so that the calibration accuracy of the transmission channel under the medium-low signal-to-noise ratio is improved, and especially the phase accuracy of the bandwidth edge can be improved.

Based on the same inventive concept, the embodiment of the present application further provides a channel calibration apparatus applied to a network node, the structural schematic diagram of the apparatus is shown in fig. 5, and thetransceiver 1500 is configured to receive and transmit data under the control of theprocessor 1510.

Wherein in fig. 5, the bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented byprocessor 1510, and various circuits, represented bymemory 1520, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. Thetransceiver 1500 may be a number of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium including wireless channels, wired channels, fiber optic cables, and the like. Theprocessor 1510 is responsible for managing the bus architecture and general processing, and thememory 1520 may store data used by theprocessor 1510 in performing operations.

Theprocessor 1510 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or a Complex Programmable Logic Device (CPLD), and may also have a multi-core architecture.

Aprocessor 1510 for reading the computer program in the memory and performing the following operations:

In one embodiment, determining the frequency domain channel estimation parameters of the transmission channel according to the frequency domain response parameters of each sub-band, the effective channel of each sub-band and the guard band of each sub-band includes:

according to the effective channel of each sub-band, performing channel estimation on each sub-band from which the guard band is removed to obtain a channel estimation parameter of each sub-band from which the guard band is removed;

It should be noted that, the apparatus provided in the embodiment of the present invention can implement all the method steps implemented by the method embodiment and achieve the same technical effect, and detailed descriptions of the same parts and beneficial effects as the method embodiment in this embodiment are omitted here.

Based on the same inventive concept of the foregoing embodiments, an embodiment of the present application further provides a channel calibration apparatus, which is applied to a network node, and a schematic structural diagram of the apparatus is shown in fig. 6, and based on thechannel calibration apparatus 40, the apparatus includes afirst processing unit 401, asecond processing unit 402, athird processing unit 403, and afourth processing unit 404.

Afirst processing unit 401, configured to obtain first calibration information of a transmission channel, where the first calibration information includes a phase of each sub-band of the transmission channel and a first channel estimation parameter of each sub-band;

asecond processing unit 402, configured to determine an effective channel of each sub-band and a guard band of each sub-band according to the first channel estimation parameter of each sub-band;

athird processing unit 403, configured to perform phase adjustment on the phase of each sub-band, and determine a second channel estimation parameter of each sub-band;

afourth processing unit 404, configured to determine frequency domain channel estimation parameters of the transmission channel according to the effective channel of each sub-band, the guard band of each sub-band, and the second channel estimation parameters of each sub-band, where the frequency domain channel estimation parameters are used to calibrate the transmission channel.

In an embodiment, thefirst processing unit 401 is specifically configured to:

In an embodiment, thesecond processing unit 402 is specifically configured to:

In an embodiment, thethird processing unit 403 is specifically configured to:

In an embodiment, thefourth processing unit 404 is specifically configured to:

In an embodiment, thefourth processing unit 404 is further configured to:

It should be noted that the division of the unit in the embodiment of the present application is schematic, and is only a logic function division, and there may be another division manner in actual implementation. In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented as a software functional unit and sold or used as a stand-alone product, may be stored in a processor readable storage medium. Based on such understanding, the technical solutions of the present application, which are essential or contributing to the prior art, or all or part of the technical solutions may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, an optical disk, or other various media capable of storing program codes.

Based on the same inventive concept, the present application further provides a processor-readable storage medium storing a computer program, where the computer program is used to implement the steps of any one of the channel calibration methods provided in any one of the embodiments or any one of the alternative embodiments of the present application when the computer program is executed by a processor.

The processor-readable storage medium can be any available medium or data storage device that can be accessed by a processor, including but not limited to magnetic memory (e.g., floppy disks, hard disks, magnetic tape, magneto-optical disks (MOs), etc.), optical memory (e.g., CDs, DVDs, BDs, HVDs, etc.), and semiconductor memory (e.g., ROMs, EPROMs, EEPROMs, non-volatile memories (NAND FLASH), solid State Disks (SSDs)), etc.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer-executable instructions. These computer-executable instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the processor-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method of channel calibration, comprising:

and determining frequency domain channel estimation parameters of the transmission channel according to the effective channel of each sub-band, the guard band of each sub-band and the second channel estimation parameters of each sub-band, wherein the frequency domain channel estimation parameters are used for calibrating the transmission channel.

2. The method of claim 1, wherein the obtaining the first calibration information of the transmission channel comprises:

carrying out smooth interpolation processing on the amplitude and the phase of the transmission channel to determine the first calibration information;

the first calibration information further includes amplitudes of sub-bands of the transmission channel; the first channel estimation parameter for each sub-band is determined by the amplitude of each sub-band and the phase of each sub-band.

3. The method of claim 1, wherein the determining the effective channel of each sub-band and the guard band of each sub-band according to the first channel estimation parameter of each sub-band comprises:

4. The method of claim 1, wherein the phase adjusting the phase of each subband to determine the second channel estimation parameter of each subband comprises:

5. The method of claim 1, wherein determining the frequency-domain channel estimation parameters of the transmission channel according to the effective channel of each sub-band, the guard band of each sub-band, and the second channel estimation parameters of each sub-band comprises:

converting the second time domain response parameters of each sub-band from a time domain to a frequency domain to obtain frequency domain response parameters of each sub-band;

and determining the frequency domain channel estimation parameters of the transmission channel according to the frequency domain response parameters of the sub-bands, the effective channels of the sub-bands and the guard bands of the sub-bands.

6. The method of claim 5, wherein the determining the frequency-domain channel estimation parameters of the transmission channel according to the frequency-domain response parameters of the sub-bands, the effective channel of the sub-bands and the guard band of the sub-bands comprises:

removing the guard band of each sub-band according to the frequency domain response parameters of each sub-band to obtain the sub-band corresponding to each sub-band after the guard band is removed;

according to the effective channel of each sub-band, performing channel estimation on each sub-band with the guard band removed to obtain channel estimation parameters of each sub-band with the guard band removed;

7. The method of claim 1, wherein after determining the frequency-domain channel estimation parameters of the transmission channel according to the effective channel of each sub-band, the guard band of each sub-band, and the second channel estimation parameters of each sub-band, the method further comprises:

8. A channel calibration device, comprising a memory, a transceiver, a processor:

a memory for storing a computer program; a transceiver for transceiving data under control of the processor; a processor for reading the computer program in the memory and performing the following operations:

determining an effective channel of each sub-band and a guard band of each sub-band according to the first channel estimation parameter of each sub-band;

9. The apparatus of claim 8, wherein the obtaining the first calibration information of the transmission channel comprises:

10. The apparatus of claim 8, wherein the determining the effective channel of each sub-band and the guard band of each sub-band according to the first channel estimation parameter of each sub-band comprises:

11. The apparatus of claim 8, wherein the phase adjusting the phase of each subband to determine the second channel estimation parameter of each subband comprises:

12. The apparatus of claim 8, wherein the determining the frequency-domain channel estimation parameters of the transmission channel according to the effective channel of each sub-band, the guard band of each sub-band, and the second channel estimation parameters of each sub-band comprises:

13. The apparatus of claim 12, wherein the determining the frequency-domain channel estimation parameters of the transmission channel according to the frequency-domain response parameters of the sub-bands, the effective channel of the sub-bands, and the guard band of the sub-bands comprises:

14. The apparatus of claim 8, further comprising, after determining the frequency-domain channel estimation parameters of the transmission channel according to the effective channel of each sub-band, the guard band of each sub-band, and the second channel estimation parameters of each sub-band:

15. A channel calibration device, comprising:

a first processing unit, configured to obtain first calibration information of a transmission channel, where the first calibration information includes a phase of each sub-band of the transmission channel and a first channel estimation parameter of each sub-band;

a second processing unit, configured to determine, according to the first channel estimation parameter of each sub-band, an effective channel of each sub-band and a guard band of each sub-band;

a third processing unit, configured to perform phase adjustment on the phase of each sub-band, and determine a second channel estimation parameter of each sub-band;

a fourth processing unit, configured to determine a frequency domain channel estimation parameter of the transmission channel according to the effective channel of each sub-band, the guard band of each sub-band, and the second channel estimation parameter of each sub-band, where the frequency domain channel estimation parameter is used to calibrate the transmission channel.

16. A processor-readable storage medium, characterized in that the processor-readable storage medium stores a computer program for causing a processor to perform the method of any one of claims 1 to 7.