A space-frequency adaptive iterative anti-interference method for a 5G terminal, a storage medium and a terminal

Abstract

This invention discloses a space-frequency adaptive iterative anti-interference method for 5G terminals, comprising the following steps: In the 5G terminal, multiple antennas are used to receive downlink PBCH / PDCCH signals, and each time slot signal of each antenna is processed by FFT to obtain multiple signals in the frequency domain; the frequency domain is divided into multiple sub-bands, and beamforming processing for the first space-frequency anti-interference is performed; the beamformed signal is used to perform channel estimation and channel equalization using known pilot signals, and the equalized signal is demodulated; the demodulated signal is modulated, and the frequency domain is divided into multiple narrower sub-bands; the spatial domain anti-interference weighting coefficients are calculated using all signals in the sub-bands after the first anti-interference synthesis, demodulation, and modulation; the multiple signals of each sub-band are synthesized for anti-interference, and transformed to the time domain by IFFT to obtain the final anti-interference output signal. This invention also discloses a corresponding storage medium and device. Implementing this invention can reduce the computational load and bit error rate.

Description

Technical Field

[0001] This invention relates to the field of communication anti-interference technology, and in particular to a space-frequency adaptive iterative anti-interference method, storage medium and terminal for 5G terminals. Background Technology

[0002] In 5G communication systems, successful reception of signals from the Physical Broadcast Channel (PBCH) and Physical Downlink Control Channel (PDCCH) is crucial for the terminal to receive subsequent Physical Downlink Shared Channel (PDSCH) signals. However, due to its large bandwidth, 5G is highly susceptible to broadband electromagnetic interference, making strong anti-interference capabilities a prerequisite for the receiver to correctly process the received signal. Spatial anti-interference refers to receiving signals through multiple antennas, weighting and combining the data from these antennas according to certain criteria, and filtering the signal spatially to create nulls in the direction of interference, thereby achieving anti-interference.

[0003] However, traditional spatial domain anti-interference algorithms cannot combat strong broadband interference. In 5G communication systems, composite domain anti-interference algorithms are required to address strong broadband interference. However, traditional space-frequency adaptive anti-interference algorithms still rely on spatial filtering after narrowband frequency domain splitting. When the known pilot density is insufficient, the anti-interference performance limit remains low. In 5G, the pilot density of PBCH and PDCCH signals is 1 / 4, and they are QPSK modulated. Therefore, channel equalization and hard demodulation can be used to increase the known signal length, enabling adaptive iterative anti-interference and thus improving the anti-interference performance limit.

[0004] Space-time adaptive anti-interference and space-frequency anti-interference techniques have been applied to composite domain anti-interference algorithms, but existing solutions all have shortcomings to varying degrees, such as large computational load, weak anti-interference ability, and high bit error rate. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a space-frequency adaptive iterative anti-interference method, storage medium and terminal for 5G terminals, which adopts a space-frequency adaptive iterative anti-interference algorithm based on pilot and channel estimation to reduce the amount of computation and the bit error rate.

[0006] To address the aforementioned technical problems, as one aspect of the present invention, a space-frequency adaptive iterative anti-interference method for 5G terminals is provided, which includes at least the following steps:

[0007] Step S10: In the 5G terminal, multiple antennas are used to receive downlink PBCH / PDCCH signals, and FFT processing is performed on each time slot signal of each antenna to obtain frequency domain multiple signals.

[0008] Step S11: Divide the frequency domain into multiple sub-bands and perform the first spatial frequency anti-interference beamforming process.

[0009] Step S12: Perform channel estimation on the beam-synthesized signal using the known pilot signal, perform channel equalization, and demodulate the equalized signal.

[0010] Step S13: Modulate the demodulated signal and divide it into multiple narrower sub-bands in the frequency domain. Calculate the spatial anti-interference weighting coefficients using all signals in the sub-bands after the first anti-interference synthesis, demodulation, and modulation. Combine the multiple signals of each sub-band for anti-interference and transform them to the time domain using IFFT to obtain the final anti-interference output signal.

[0011] Preferably, step S10 further includes:

[0012] In a 5G receiving terminal, multiple antennas are used to receive downlink PBCH / PDCCH signals. Each time slot has a length of N. The received signal in the k-th time slot from M antennas is represented as: {x} i,k (0),x i,k (1),...,x i,k (N-1)|i=1,2,...,M};

[0013] Perform FFT processing on each time slot signal of each antenna to obtain the frequency domain multiplexed signal {X}. i,k (f1),X i,k (f2)...,X i,k (f N )|i=1,2,...,M}.

[0014] Preferably, step S11 further includes:

[0015] Step S110: Divide the frequency domain signal of length N obtained in the k-th time slot into J sub-bands, each sub-band signal having a length of L, and combine the M signals within each sub-band as follows:

[0016]

[0017] Step S111: Calculate the weight coefficients within each sub-band using the MMSE criterion. Taking the j-th sub-band as an example, the specific steps are as follows:

[0018] Splice the frequency domain signals of K time slots within the sub-band in step S110: X j =[X j,k,X j,k+1 ,...,X j,k+K-1 ]; Calculate X j Autocorrelation: in,() H This represents the conjugate transpose operation of a matrix;

[0019] Calculate the cross-correlation between the received signal and the known pilot signal: in, For all known pilot signals in K time slots within a subband, The length of the pilot signal. For X j The column signal corresponding to the position of the pilot signal;

[0020] Calculate the anti-interference weighting coefficients within the sub-band: in,() -1 Represents finding the inversion of a matrix;

[0021] Step S112: Spatial beamforming is performed on the multiple signals within the sub-band using the following formula:

[0022]

[0023] Preferably, step S12 further includes:

[0024] Step S120: Channel estimation is performed using the LS algorithm, with frequency point f as an example. i The pilot frequency is D(f) i The signal received at this frequency is Y(f) i If the frequency point f is... i The channel estimation result is as follows:

[0025]

[0026] Linear interpolation is performed on frequency points without pilot signals, assuming the frequency point The channel estimation results are as follows: but The frequency channel estimation results are as follows:

[0027]

[0028] Step S121: Equalize the signal from step S120, assuming the signal Y(f) after anti-interference synthesis is equalized. j,l The channel estimation result for the corresponding frequency point is h(f) j,l If ), then the equalized output at that frequency point is:

[0029]

[0030] Step S122: Demodulate the equalized signal.

[0031] Preferably, step S13 further includes:

[0032] Step S130: Modulate the demodulated signal, and divide the frequency domain signal with a time slot length of N from step S10 into... Sub-bands, among which Greater than or equal to J in step S110, the length of each sub-band signal is The M-channel signals within each sub-band are combined according to step S110.

[0033] Step S131: The frequency domain signals of the K time slots within the sub-band are spliced ​​together according to the method in step S111.

[0034] Step S132, calculate Autocorrelation matrix:

[0035] Calculate the cross-correlation vector between the received signal and the modulated signal obtained in step S130: in, The modulation signal in all steps S130 within the K time slots of this sub-band;

[0036] Calculate the anti-interference weighting coefficients within the sub-band:

[0037] Step S133, follow the method of step S112 to Perform anti-interference synthesis;

[0038] Step S134: The synthesized signal is transformed into the time domain by IFFT to obtain the final anti-interference output signal, thus completing the space-frequency adaptive iterative anti-interference algorithm processing.

[0039] As another aspect of the present invention, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the method as described above.

[0040] As another aspect of the present invention, a 5G terminal is also provided, comprising at least a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described above.

[0041] Implementing the embodiments of the present invention has the following beneficial effects:

[0042] This invention provides a space-frequency adaptive iterative anti-interference method, storage medium, and terminal for 5G terminals. By employing a space-frequency adaptive iterative anti-interference algorithm based on pilot and channel estimation, anti-interference is achieved through an iterative method without significantly increasing the computational load, and the bit error rate can be significantly reduced at the same signal-to-noise ratio.

[0043] Implementing this invention, the calculated anti-interference weight coefficients have a fast convergence speed, do not increase the computational load compared to the conventional constant modulus algorithm, and can achieve a very low bit error rate in environments with no interference, weak interference, and strong interference. Compared with traditional space-frequency anti-interference algorithms, it can reduce the signal-to-noise ratio. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0045] Figure 1 This is a schematic diagram of the main flow of an embodiment of the space-frequency adaptive iterative anti-interference method for 5G terminals provided by the present invention;

[0046] Figure 2 This is a schematic diagram illustrating the processing principle of the present invention;

[0047] Figure 3 This is a schematic diagram illustrating the principles of each step in the present invention;

[0048] Figure 4 This is a schematic diagram of the final bit error rate curve obtained in a simulation experiment using the existing non-iterative traditional spatial interference suppression method.

[0049] Figure 5 This is a schematic diagram of the final bit error rate curve obtained by using the iterative anti-interference method proposed in this invention in a simulation experiment. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0051] like Figure 1 The diagram shows the main flow of an embodiment of a space-frequency adaptive iterative anti-interference method for 5G terminals provided by the present invention; combined with... Figure 2 and Figure 3 As shown. In this embodiment, the space-frequency adaptive iterative anti-interference method for 5G terminals includes at least the following steps:

[0052] Step S10: In the 5G terminal, multiple antennas are used to receive downlink PBCH / PDCCH signals, and FFT processing is performed on each time slot signal of each antenna to obtain frequency domain multiple signals.

[0053] Step S11: Divide the frequency domain into multiple sub-bands and perform the first spatial frequency anti-interference beamforming process.

[0054] Step S12: Perform channel estimation on the beam-synthesized signal using the known pilot signal, perform channel equalization, and demodulate the equalized signal.

[0055] Step S13: Modulate the demodulated signal and divide it into multiple narrower sub-bands in the frequency domain. Calculate the spatial anti-interference weighting coefficients using all signals in the sub-bands after the first anti-interference synthesis, demodulation, and modulation. Combine the multiple signals of each sub-band for anti-interference and transform them to the time domain using IFFT to obtain the final anti-interference output signal.

[0056] The following will be combined Figure 2 and Figure 3 Each step involved in the method of the present invention will be described in detail.

[0057] In a specific example, step S10 further includes:

[0058] In a 5G receiving terminal, multiple antennas are used to receive downlink PBCH / PDCCH signals. Each time slot has a length of N. The received signal in the k-th time slot from M antennas is represented as: {x} i,k (0),x i,k (1),...,x i,k (N-1)|i=1,2,...,M};

[0059] Perform FFT processing on each time slot signal of each antenna to obtain the frequency domain multiplexed signal {X}. i,k (f1),X i,k (f2)...,X i,k (f N )|i=1,2,...,M}.

[0060] In a specific example, step S11, which involves dividing the frequency domain into sub-bands and performing the first spatial-frequency anti-interference synthesis, further includes:

[0061] Step S110: Divide the frequency domain signal of length N obtained in the k-th time slot into J sub-bands, each sub-band signal having a length of L, and combine the M signals within each sub-band as follows:

[0062]

[0063] Step S111: Calculate the weight coefficients within each sub-band using the MMSE criterion. Taking the j-th sub-band as an example, the specific steps are as follows:

[0064] Splice the frequency domain signals of K time slots within the sub-band in step S110: X j =[X j,k ,X j,k+1 ,...,X j,k+K-1 ]; Calculate X j Autocorrelation: in,() H This represents the conjugate transpose operation of a matrix;

[0065] Calculate the cross-correlation between the received signal and the known pilot signal: in, For all known pilot signals in K time slots within a subband, The length of the pilot signal. For X j The column signal corresponding to the position of the pilot signal;

[0066] Calculate the anti-interference weighting coefficients within the sub-band: in,() -1 Represents finding the inversion of a matrix;

[0067] Step S112: Spatial beamforming is performed on the multiple signals within the sub-band using the following formula:

[0068]

[0069] In a specific example, in step S12, channel estimation is performed, the signal synthesized against interference is equalized, and then demodulated. Specifically, this further includes:

[0070] Step S120: Channel estimation is performed using the LS algorithm, with frequency point f as an example. i The pilot frequency is D(f) i The signal received at this frequency is Y(f) i If the frequency point f is... i The channel estimation result is as follows:

[0071]

[0072] Linear interpolation is performed on frequency points without pilot signals, assuming the frequency point The channel estimation results are as follows: but The frequency channel estimation results are as follows:

[0073]

[0074] Step S121: Equalize the signal from step S120, assuming the signal Y(f) after anti-interference synthesis is equalized. j,l The channel estimation result for the corresponding frequency point is h(f) j,l If ), then the equalized output at that frequency point is:

[0075]

[0076] Step S122: Demodulate the equalized signal.

[0077] In a specific example, in step S13, the demodulated signal from the previous steps is modulated, sub-bands are re-divided, the spatial anti-interference weighting coefficients of the sub-bands are calculated, and the original signal X is modulated. j,k Perform spatial domain synthesis. Specifically, this further includes:

[0078] Step S130: Modulate the demodulated signal, and divide the frequency domain signal with a time slot length of N from step S10 into... Sub-bands, among which Greater than or equal to J in step S110, the length of each sub-band signal is The M-channel signals within each sub-band are combined according to step S110.

[0079] Step S131: The frequency domain signals of the K time slots within the sub-band are spliced ​​together according to the method in step S111.

[0080] Step S132, calculate Autocorrelation matrix:

[0081] Calculate the cross-correlation vector between the received signal and the modulated signal obtained in step S130: in, The modulation signal in all steps S130 within the K time slots of this sub-band;

[0082] Calculate the anti-interference weighting coefficients within the sub-band:

[0083] Step S133, follow the method of step S112 to Perform anti-interference synthesis;

[0084] Step S134: The synthesized signal is transformed into the time domain by IFFT to obtain the final anti-interference output signal, thus completing the space-frequency adaptive iterative anti-interference algorithm processing.

[0085] As can be seen from the above, in the embodiments of the present invention, multiple antennas are used to receive signals at the receiving end, each time slot has a length of N, and the signal of the k-th time slot is {x}.i,k (n),x i,k (n+1),...,x i,k (n+N-1)|i=1,2,...,M}, the time-domain signal is transformed to the frequency domain using FFT; the frequency domain is divided into J sub-bands, and the spatial anti-interference weighting coefficients are calculated using the known pilot signals in each sub-band according to the MMSE criterion. Then, the multiplexed signals {X1(f)} of each sub-band are... j,1 ),...,X1(f j,L ),...,X M (f j,1 ),...,X M (f j,L The anti-interference synthesis is performed on {Y(f1), Y(f2), ..., Y(f)}|j=1,2,...,J}, and the output signal is {Y(f1),Y(f2),...,Y(f)}. N At this point, one space-frequency adaptive anti-interference cycle is completed; the iterative process is as follows: Figure 3 As shown, channel estimation is performed on the beam-synthesized signal using known pilot signals, and channel equalization is performed. The equalized signal is then demodulated. The demodulated signal is modulated and divided into multiple narrower sub-bands in the frequency domain. Spatial anti-interference weighting coefficients are calculated using all signals in the first anti-interference synthesis and demodulation of the modulated sub-bands. Finally, the multiple signals of each sub-band are synthesized for anti-interference, and the adaptive iterative space-frequency anti-interference process is completed by IFFT transformation to the time domain.

[0086] To further illustrate the beneficial effects of the present invention, a simulation experiment will be used as an example below.

[0087] During the simulation experiment, OFDM signals were used, and the pilot density was consistent with that of the 5G NR PBCH and PDCCH signals. The specific parameter configuration information is shown in Table 1.

[0088] Table 1 OFDM signal parameter configuration information

[0089]

[0090] The original signal is 164 bits, which becomes 512 bits after Polar encoding, 720 bits after rate matching, and 360 bits after QPSK modulation; the pilot signal is 120 bits long.

[0091] Four antennas are used to receive the signal. Both the interference and noise are Gaussian white noise. Both the signal and the interference pass through a multipath Ricean channel. The channel parameter configuration information is shown in Table 2.

[0092] Table 2 Channel Parameter Configuration Information

[0093]

[0094] Figure 4 The final bit error rate curves obtained using the existing non-iterative traditional spatial anti-interference method in this simulation experiment are shown. It can be seen that for no interference, 0dB interference, 10dB interference, 20dB interference, and 30dB interference, with signal-to-noise ratios of 8dB, 10dB, 10dB, 10dB, and 16dB respectively, the bit error rate can be reduced to below 1e-5.

[0095] Figure 5 The final bit error rate curve obtained by using the iterative anti-interference method proposed in this invention in the simulation experiment is shown, and compared with... Figure 4 As can be seen, under the same signal-to-noise ratio (SNR), the method of this invention significantly reduces the bit error rate compared to the traditional method. For interference-free, 0dB, 10dB, 20dB, and 30dB interference, with SNRs of 6dB, 8dB, 8dB, 8dB, and 14dB respectively, the bit error rate can be reduced to below 1e-5. Compared to the traditional method, the operating SNR can be reduced by about 2dB, and it has better anti-interference performance for interference-free, weak, and strong interference.

[0096] In summary, the method of the present invention has excellent anti-interference performance against 5G PBCH / PDCCH signals compared with traditional space-frequency anti-interference methods.

[0097] It is understood that, as another aspect of the present invention, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the aforementioned... Figures 1 to 3 The steps of the described method. For more details, please refer to the aforementioned section. Figures 1 to 3 The description of that will not be repeated here.

[0098] In another aspect, the present invention provides a 5G terminal, comprising at least a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the aforementioned... Figures 1 to 3 The steps of the described method. For more details, please refer to the aforementioned section. Figures 1 to 3 The description of that will not be repeated here.

[0099] Implementing the embodiments of the present invention has the following beneficial effects:

[0100] This invention provides a space-frequency adaptive iterative anti-interference method, storage medium, and terminal for 5G terminals. By employing a space-frequency adaptive iterative anti-interference algorithm based on pilot and channel estimation, anti-interference is achieved through an iterative method without significantly increasing the computational load, and the bit error rate can be significantly reduced at the same signal-to-noise ratio.

[0101] Implementing this invention, the calculated anti-interference weight coefficients have a fast convergence speed, do not increase the computational load compared to the conventional constant modulus algorithm, and can achieve a very low bit error rate in environments with no interference, weak interference, and strong interference. Compared with traditional space-frequency anti-interference algorithms, it can reduce the signal-to-noise ratio.

[0102] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) in which computer-usable program code is contained.

[0103] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can 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, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0104] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A space-frequency adaptive iterative anti-interference method for 5G terminals, characterized in that, It should include at least the following steps: Step S10: In the 5G terminal, multiple antennas are used to receive downlink PBCH or PDCCH signals, and FFT processing is performed on each time slot signal of each antenna to obtain frequency domain multiple signals. Step S11: Divide the frequency domain into multiple sub-bands and perform the first spatial frequency anti-interference beamforming process. Step S12: Channel estimation is performed on the beam-synthesized signal using the known pilot signal, and channel equalization is performed. The equalized signal is then demodulated. Step S13: Modulate the demodulated signal and divide it into multiple narrower sub-bands in the frequency domain. Calculate the spatial anti-interference weighting coefficients using all signals in the sub-bands after the first anti-interference synthesis, demodulation, and modulation. Combine the multiple signals of each sub-band for anti-interference and transform them to the time domain using IFFT to obtain the final anti-interference output signal. Step S11 further includes: Step S110, the first The length obtained from each time slot is The frequency domain signal is divided into There are 1 sub-bands, and the signal length of each sub-band is 1. Within each sub-band The road signal combination is as follows: Step S111: Calculate the weight coefficients within each sub-band using the MMSE criterion, with the first... Taking a sub-band as an example, specifically: In step S110, the sub-band splicing of frequency domain signals in one time slot: ;calculate Autocorrelation: ,in, This represents the conjugate transpose operation of a matrix; Calculate the cross-correlation between the received signal and the known pilot signal: , in, For sub-band All known pilot signals in each time slot, The length of the pilot signal. for The column signal corresponding to the position of the pilot signal; Calculate the anti-interference weighting coefficients within the sub-band: ,in, Represents finding the inversion of a matrix; Step S112: Spatial beamforming is performed on the multiple signals within the sub-band using the following formula: ； Step S12 further includes: Step S120: Channel estimation is performed using the LS algorithm, and the frequency point is set. Pilot frequency is The signal received at this frequency is then frequency point The channel estimation result is as follows: ； Linear interpolation is performed on frequency points without pilot signals, assuming the frequency point The channel estimation results are as follows: ,but The frequency channel estimation results are as follows: ； Step S121: Equalize the signal from step S120, assuming the signal after anti-interference synthesis... The channel estimation results for the corresponding frequency points are Then the equalized output at that frequency point is: ； Step S122: Demodulate the equalized signal.

2. The method of claim 1, wherein, Step S10 further includes: In 5G receiving terminals, multiple antennas are used to receive downlink PBCH or PDCCH signals, where each time slot has a length of [missing information]. ,but The antenna number The received signal for each time slot is represented as follows: ; The time slot signal of each antenna is FFT processed to obtain frequency domain multi-channel signals .

3. The method of claim 2, wherein, Step S13 further includes: Step S130: Modulate the demodulated signal, and then modulate the signal from step S10. The length of each time slot is The frequency domain signal is divided into Sub-bands, among which Greater than or equal to the value in step S110 The length of each sub-band signal is Within each sub-band The road signals are combined in accordance with step S110. ; Step S131, follow the method in step S111 to process the sub-band. The frequency domain signals of each time slot are spliced ​​together to form ; Step S132, calculating the autocorrelation matrix: ; Calculate the cross-correlation vector between the received signal and the modulated signal obtained in step S130: ,in, for The modulation signal in all steps S130 within the sub-band of each time slot; Calculate the anti-interference weighting coefficients within the sub-band: ; Step S133, follow the method of step S112 to Perform anti-interference synthesis; Step S134: The synthesized signal is transformed into the time domain by IFFT to obtain the final anti-interference output signal, thus completing the space-frequency adaptive iterative anti-interference algorithm processing.

4. A computer-readable storage medium having stored thereon a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 3.

5. A 5G terminal, comprising at least a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 3.

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