Broadband reception method, design and medium based on los-mimo channel

Abstract

This application relates to a broadband reception method, design, and medium based on a LoS-MIMO channel, and pertains to the field of wireless communication. The aim of this application is to address the limitation of high-speed transmission in practical applications of LoS-MIMO systems. The receiving end of this application acquires the received signal and obtains multiple serial time-domain received signals after down-conversion; it performs timing synchronization on the time-domain received signals to determine the start position of OFDM symbols; it converts each received signal into multiple parallel low-speed data streams; it calculates and accumulates the local carrier frequency offset correlation value of the low-speed data using a cyclic prefix, and estimates the carrier frequency offset value based on the accumulation result; it uses the estimated value to perform phase compensation on each parallel low-speed data stream and removes the cyclic prefix, performing OFDM symbol demapping; it performs channel estimation and equalization based on the frequency-domain OFDM symbols, and performs inverse discrete Fourier transform and recovery processing on the equalized signal to obtain the original bitstream.

Description

Technical Field

[0001] This application belongs to the field of wireless communication, and in particular relates to a broadband reception method, design and medium based on a LoS-MIMO channel. Background Technology

[0002] MIMO (Multiple-Input Multiple-Output) technology is a crucial approach for achieving broadband high-speed data transmission. Traditional MIMO relies on a rich multipath environment to distinguish data streams, but LoS-MIMO (Line of Sigth MIMO) concentrates its energy primarily in the line-of-sight channel. It requires precise design of the spacing and geometric arrangement of the transmit and receive antenna arrays to artificially create path length differences between different transmit and receive antenna pairs, thereby generating orthogonal phase differences. This design mathematically decomposes the highly correlated LoS channel at the physical layer into multiple parallel, orthogonal sub-channels. Theoretically, multiple parallel, orthogonal sub-channels can be transmitted simultaneously, significantly increasing link capacity and meeting the extreme throughput demands of high-speed communication. However, practical applications of LoS-MIMO systems still face limitations in high-speed transmission. Summary of the Invention

[0003] This application aims to address the problem of limited high-speed transmission in LoS-MIMO systems during practical applications, and provides a broadband reception method, design, and medium based on LoS-MIMO channels.

[0004] The first aspect of this application provides a wideband reception method based on a LoS-MIMO channel, including:

[0005] The receiver of the LoS-MIMO system captures the received signal and obtains multiple serial time-domain received signals after down-conversion.

[0006] The multiple serial time-domain received signals are synchronized at a specific time to determine the starting position of the OFDM symbol;

[0007] The synchronized serial time-domain received signals are converted into multiple parallel low-speed data streams.

[0008] The local carrier frequency offset correlation value of each parallel low-speed data is calculated using the cyclic prefix, the local carrier frequency offset correlation value of all parallel branches is accumulated, and the carrier frequency offset value is estimated based on the accumulated result;

[0009] Phase compensation is performed on each parallel low-speed data stream using the estimated carrier frequency offset.

[0010] After removing the cyclic prefix of each parallel low-speed data after phase compensation, OFDM symbol demapping is performed to obtain frequency domain OFDM symbols;

[0011] Channel estimation and equalization are performed based on the frequency domain OFDM symbols. The equalized signal is then subjected to inverse discrete Fourier transform and recovery processing to obtain the original bit stream.

[0012] In one possible design, the timing synchronization of the multiple serial time-domain received signals to determine the start position of the OFDM symbol includes:

[0013] Different orthogonal CAZAC sequences added to different transmit antennas are used as frame synchronization header sequences;

[0014] At the receiver of the LoS-MIMO system, the received signal is correlated with the locally stored CAZAC sequence to find the maximum correlation peak.

[0015] When the maximum correlation peak reaches its peak value, the delay offset corresponding to the peak value is the starting position of the frame synchronization header, thereby determining the starting position of the OFDM symbol.

[0016] In one possible design, at the receiver of the LoS-MIMO system, performing a correlation operation between the received signal and a locally stored CAZAC sequence to find the maximum correlation peak includes:

[0017] The maximum correlation peak can be found using the following formula:

[0018] ,

[0019] in, The highest correlation peak, The length of the CAZAC sequence. For CAZAC sequence index, For the known CAZAC sequence stored locally, the first A complex number symbol, for conjugate, No. The received signal of the root receiving antenna is at the sample index The value at that location, This is the time delay offset.

[0020] In one possible design, the calculation of the local carrier frequency offset correlation value of each parallel low-speed data stream using the cyclic prefix includes:

[0021] Extract the cyclic prefix and tail sequence of each parallel branch based on the starting position of the OFDM symbol;

[0022] The local carrier frequency offset correlation value of each parallel branch is calculated using the cyclic prefix and tail sequence of each parallel branch.

[0023] In one possible design, the extraction of the cyclic prefix and tail sequences of each parallel branch based on the start position of the OFDM symbol includes:

[0024] Extract the cyclic prefix and tail sequences of each parallel branch according to the following formula:

[0025] ,

[0026] ,

[0027] in, For the first The cyclic prefix sequence of parallel branches, For the first The tail sequence of parallel branches, For the first The received signal of the parallel branch, For the initial parallel index, For branch offset, This represents the total number of parallel branches. Let be the sample number of the parallel branch, and have , The length of the cyclic prefix. The number of subcarriers;

[0028] The calculation of the local carrier frequency offset correlation value of each parallel branch using the cyclic prefix and tail sequences of each parallel branch includes:

[0029] The local carrier frequency offset correlation value of each parallel branch is calculated according to the following formula:

[0030] ,

[0031] in, For the first Local correlation values ​​of parallel branches, for . conjugate.

[0032] In one possible design, estimating the carrier frequency offset based on the cumulative result includes:

[0033] Calculate the cumulative phase based on the cumulative results:

[0034] ,

[0035] in, For cumulative phase, This indicates a phase calculation. This is the cumulative result of the local carrier frequency offset correlation values ​​for all parallel branches. For carrier offset, The sampling period is Represents modulo operation;

[0036] Estimating carrier frequency offset using cumulative estimation:

[0037] ,

[0038] in, This is an estimate of the carrier frequency offset.

[0039] In one possible design, the phase compensation of each parallel low-speed data stream using the estimated carrier frequency offset includes:

[0040] The output phase of the numerically controlled oscillator is generated using the estimated carrier frequency offset:

[0041] ,

[0042] in, For the first The output phase of the parallel branch This is an estimate of the carrier frequency offset. The sampling period is This represents the total number of parallel branches. Let be the sample number of the parallel branch, and have , The length of the cyclic prefix;

[0043] The output phase is applied to the received signal of the corresponding parallel branch to achieve phase compensation:

[0044] ,

[0045] in, For the first The signal after compensation for the parallel branches For the first The first parallel branch One sample signal.

[0046] In one possible design, the recovery process includes:

[0047] The process involves sequentially performing symbol demapping, stream demapping, descrambling, rate matching demapping, and channel decoding.

[0048] A second aspect of this application provides a broadband receiving device based on a LoS-MIMO channel, the broadband receiving device based on a LoS-MIMO channel including a processor and a memory, the memory storing at least one instruction, the at least one instruction being loaded and executed by the processor to implement the broadband receiving method based on a LoS-MIMO channel as described above.

[0049] A third aspect of this application provides a computer storage medium storing at least one instruction, which is loaded and executed by a processor to implement the broadband reception method based on the LoS-MIMO channel described above.

[0050] The beneficial effects of this application are:

[0051] 1. This application constructs a broadband high-speed transceiver architecture adapted to LoS-MIMO. By applying DFT-s-OFDM in this scenario and introducing DFT extension at the transmitter, the problem of excessively high peak values ​​in traditional OFDM is solved, and the high requirements of the receiver on the dynamic range of the ADC and the linearity of the power amplifier are significantly reduced.

[0052] 2. This application breaks through the clock frequency bottleneck by splitting high-speed serial data into P parallel low-speed branches, reducing the system processing clock frequency by a factor of P, enabling FPGA / ASIC chips to process broadband high-speed signals without improving the process technology, which has good engineering benefits.

[0053] 3. This application uses the correlation values ​​of P branches to perform coherent combining to obtain combining gain, which effectively suppresses the interference of independent noise on phase estimation and significantly improves the accuracy of frequency offset estimation. Attached Figure Description

[0054] Figure 1 This is a flowchart illustrating the broadband reception method based on the LoS-MIMO channel described in the embodiment.

[0055] Figure 2 This is a schematic diagram of the parallel processing flow at the receiving end in the embodiment.

[0056] Figure 3 This is a schematic diagram of the parallel carrier synchronization processing flow in the embodiment.

[0057] Figure 4 The example shows the LoS-MIMO-OFDM communication frame structure. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0059] Existing LoS-MIMO systems face the following limitations in high-speed transmission during practical applications:

[0060] First, multistream interference degrades the system's transmission performance and increases the receiver's demodulation complexity. Under Loss of Speed ​​(LoS) conditions, the channel matrix often exhibits ill-conditioned characteristics, with strong correlations between data streams. To correctly recover the signal, the receiver must perform complex serial interference cancellation or high-precision matrix inversion, resulting in high receiver complexity and significant processing delays.

[0061] Secondly, the high PAPR (Peak-to-Average Ratio) problem exacerbates the dynamic range pressure on the receiver. LoS-MIMO is often used in conjunction with OFDM (Orthogonal Frequency Division Multiplexing) to reduce the symbol rate and combat inter-symbol interference, but the high PAPR of OFDM signals makes it difficult for the receiver gain to respond quickly. To ensure linearity over a large dynamic range, the receiver requires a higher-precision ADC, which increases the complexity of baseband processing. Finally, there is an upper limit to the receiver's clock processing speed. When the air interface rate reaches the Gbps level, all modules at the receiver, including clock synchronization and carrier synchronization, face serious challenges, directly affecting the receiver's processing of broadband high-speed data.

[0062] In view of this, this application provides a frequency-domain parallel synchronization architecture for LosS-MIMO systems. Combining DFT-S-OFDM (Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing) with a lower receiver single-channel symbol processing rate, it reduces the stringent requirements of the algorithm on receiver processing complexity and latency, effectively improving carrier and timing synchronization accuracy, thereby enhancing the system's broadband high-speed data processing performance. The following will refer to the attached... Figures 1 to 4 The implementation scheme of this application will be described in detail.

[0063] Specific Implementation Method 1: The broadband reception method based on the LoS-MIMO channel described in this implementation method includes:

[0064] The receiver of the LoS-MIMO system captures the received signal and obtains multiple serial time-domain received signals after down-conversion.

[0065] The multiple serial time-domain received signals are synchronized at a specific time to determine the starting position of the OFDM symbol;

[0066] The synchronized serial time-domain received signals are converted into multiple parallel low-speed data streams.

[0067] The local carrier frequency offset correlation value of each parallel low-speed data is calculated using the cyclic prefix, the local carrier frequency offset correlation value of all parallel branches is accumulated, and the carrier frequency offset value is estimated based on the accumulated result;

[0068] Phase compensation is performed on each parallel low-speed data stream using the estimated carrier frequency offset.

[0069] After removing the cyclic prefix of each parallel low-speed data after phase compensation, OFDM symbol demapping is performed to obtain frequency domain OFDM symbols;

[0070] Channel estimation and equalization are performed based on the frequency domain OFDM symbols. The equalized signal is then subjected to inverse discrete Fourier transform and recovery processing to obtain the original bit stream.

[0071] In one implementation, the step of timing synchronization of the multiple serial time-domain received signals to determine the start position of the OFDM symbol includes:

[0072] Different orthogonal CAZAC sequences added to different transmit antennas are used as frame synchronization header sequences;

[0073] At the receiver of the LoS-MIMO system, the received signal is correlated with the locally stored CAZAC sequence to find the maximum correlation peak.

[0074] When the maximum correlation peak reaches its peak value, the delay offset corresponding to the peak value is the starting position of the frame synchronization header, thereby determining the starting position of the OFDM symbol.

[0075] In one implementation, the step of performing a correlation operation between the received signal and a locally stored CAZAC sequence at the receiver of the LoS-MIMO system to find the maximum correlation peak includes:

[0076] The maximum correlation peak can be found using the following formula:

[0077] ,

[0078] in, The highest correlation peak, The length of the CAZAC sequence. For CAZAC sequence index, For the known CAZAC sequence stored locally, the first A complex number symbol, for conjugate, No. The received signal of the root receiving antenna is at the sample index The value at that location, This is the time delay offset.

[0079] In one implementation, the step of calculating the local carrier frequency offset correlation value of each parallel low-speed data stream using a cyclic prefix includes:

[0080] Extract the cyclic prefix and tail sequence of each parallel branch based on the starting position of the OFDM symbol;

[0081] The local carrier frequency offset correlation value of each parallel branch is calculated using the cyclic prefix and tail sequence of each parallel branch.

[0082] In one implementation, the step of extracting the cyclic prefix and tail sequences of each parallel branch based on the start position of the OFDM symbol includes:

[0083] Extract the cyclic prefix and tail sequences of each parallel branch according to the following formula:

[0084] ,

[0085] ,

[0086] in, For the first The cyclic prefix sequence of parallel branches, For the first The tail sequence of parallel branches, For the first The received signal of the parallel branch, For the initial parallel index, For branch offset, This represents the total number of parallel branches. Let be the sample number of the parallel branch, and have , The length of the cyclic prefix. The number of subcarriers;

[0087] The calculation of the local carrier frequency offset correlation value of each parallel branch using the cyclic prefix and tail sequences of each parallel branch includes:

[0088] The local carrier frequency offset correlation value of each parallel branch is calculated according to the following formula:

[0089] ,

[0090] in, For the first Local correlation values ​​of parallel branches, for . conjugate.

[0091] In one implementation, estimating the carrier frequency offset based on the cumulative result includes:

[0092] Calculate the cumulative phase based on the cumulative results:

[0093] ,

[0094] in, For cumulative phase, This indicates a phase calculation. This is the cumulative result of the local carrier frequency offset correlation values ​​for all parallel branches. For carrier offset, The sampling period is Represents modulo operation;

[0095] Estimating carrier frequency offset using cumulative estimation:

[0096] ,

[0097] in, This is an estimate of the carrier frequency offset.

[0098] In one implementation, the step of performing phase compensation on each parallel low-speed data stream using an estimated carrier frequency offset includes:

[0099] The output phase of the numerically controlled oscillator is generated using the estimated carrier frequency offset:

[0100] ,

[0101] in, For the first The output phase of the parallel branch This is an estimate of the carrier frequency offset. The sampling period is This represents the total number of parallel branches. Let be the sample number of the parallel branch, and have , The length of the cyclic prefix;

[0102] The output phase is applied to the received signal of the corresponding parallel branch to achieve phase compensation:

[0103] ,

[0104] in, For the first The signal after compensation for the parallel branches For the first The first parallel branch One sample signal.

[0105] In one implementation, the recovery process includes:

[0106] The process involves sequentially performing symbol demapping, stream demapping, descrambling, rate matching demapping, and channel decoding.

[0107] To further illustrate the implementation scheme of this application, the following specific implementation schemes are provided, which will be described in detail below:

[0108] The transmission requirements of LoS-MIMO systems are There are a total of root transmitting antenna and Root receiving antenna, transmitting simultaneously If there is a data stream, then the single-stream transmission requirement is: In this embodiment, Dual-stream multiplexing combined with dual-polarized antennas achieves 4-stream spatial multiplexing capability, with a transmission bandwidth requirement of 50Gbps. The millimeter-wave LoS-MIMO baseband signal communication system adopts the LoS-MIMO-OFDM communication system. The OFDM system has a total of 8192 subcarriers, of which 6144 are effective data subcarriers. To reduce the average ratio, the DFT-S-OFDM communication system with a lower peak-to-average ratio is selected. The modulation method is 64QAM, and the encoding and decoding are 7 / 8 LDPC.

[0109] 1. At the sending end

[0110] 1. Channel coding is performed on the data stream to improve error resilience. Typically, the system performs rate matching on the channel-coded bits based on actual channel conditions and coding rate requirements, ensuring their length matches the modulation and transmission rate needs. Subsequently, interleaving and scrambling steps are performed to further disperse the statistical characteristics of the data stream and reduce performance degradation caused by consecutive bit patterns.

[0111] 2. Map the channel-coded data stream to... parallel data stream, corresponding to road signal.

[0112] 3. The data stream sequence is symbol-mapped according to the system's modulation scheme (QAM / PSK mapping) to complex symbols, thereby improving the data transmission rate. Road data stream ( ) is denoted as .

[0113] 4. Time-domain symbols for each data stream conduct (In this embodiment) The pointwise DFT (Discrete Fourier Transform) is used to transform it to the frequency domain, yielding the frequency domain symbol. To achieve the low peak-to-average power ratio characteristic of the DFT-S-OFDM system:

[0114] , Indicates the time.

[0115] 5. Arrange frequency domain symbols according to the predetermined subcarrier positions. Known pilot symbols (known reference symbols that do not carry user information) are inserted to provide a reference for channel estimation at the receiver. After mapping the pilot symbols and data symbols (carrying valid user information) to designated subcarrier positions, OFDM subcarrier mapping is performed. The number of subcarriers in the system is... (In this embodiment, 8192 is used), and the subcarrier spacing is... ,make Indicates the first Road data stream The first OFDM symbol Transmitted symbols on each subcarrier, of which , The details are as follows:

[0116] Based on the OFDM modulation method, do Point IFFT OFDM subcarrier mapping yields a time-domain signal that can be represented as:

[0117] ,

[0118] in, The duration of an OFDM symbol, This represents the total number of OFDM symbols.

[0119] Take sampling period Then the first Road data stream The time-domain signal transmitted at each moment is:

[0120] .

[0121] 6. Add a length of [length missing] to the OFDM modulated time-domain signal. The cyclic prefix (CP) is used to resist inter-symbol interference (ISI) caused by channel multipath and timing offset.

[0122] 7. Complete the framing process and add the frame synchronization header and necessary control information. The frame synchronization header must have at least the following properties: good autocorrelation, with the original sequence and the shifted sequence being uncorrelated; and good cross-correlation, with the cross-correlation between different sequences approaching 0.

[0123] 8. Based on the LosS-MIMO channel state, for The roadbed band signal undergoes spatial precoding to initially eliminate interference between antennas and simplify the receiver's workload. The roadbed signal is transmitted by the antenna array through the LoS-MIMO channel.

[0124] II. The complex vector of the transmit symbol in a MIMO system is denoted as: The received symbolic complex vector is denoted as The channel matrix is ​​represented as , Indicates the first root transmitting antenna to the first The complex channel coefficients between the root receiving antennas. The received signal can be represented in the following matrix form:

[0125] ,

[0126] in, It is a complex noise vector.

[0127] The expansion of the above equation is:

[0128] .

[0129] III. At the receiving end

[0130] 1. The signal received by the receiving antenna array is down-converted, and the... The time-domain signal on the root receiving antenna can be expressed as:

[0131] ,

[0132] Among them, channel Includes a transmitting antenna to receiving antenna Path attenuation, delay, and carrier frequency offset between transmit and receive. Channel characteristics, etc.

[0133] Receive signals for each data stream Timing synchronization is performed to determine the starting position of the symbols. Specifically, the frame format is specially designed to include a frame synchronization header. Different frame synchronization header sequences are added for different transmit antennas. At the receiver, correlation calculations are performed between the received signal and the local synchronization sequence to find the maximum correlation peak. Because the frame synchronization header sequence has good autocorrelation and cross-correlation, the correlation result shows the maximum peak when the frame synchronization header in the received signal exactly coincides with the position of the local synchronization sequence. Therefore, the timing positions of different transmit antennas can be accurately distinguished. After timing synchronization is completed at the receiver, the position of each OFDM symbol can be found based on the pre-designed CP length, pilot position, length, and OFDM symbol length. Details are as follows:

[0134] Different orthogonal CAZAC (constant envelope zero autocorrelation) sequences are added as frame synchronization header sequences for different transmit antennas in the frame format. The CAZAC sequence is defined as follows:

[0135] ,

[0136] in, For the known CAZAC sequence stored locally, the first A complex number symbol, The length of the CAZAC sequence. For CAZAC sequence index, For sequence parameters.

[0137] At the receiving end, correlation operations are performed between the received signal and the local synchronization sequence to find the maximum correlation peak. :

[0138] ,

[0139] in, To Take conjugate, No. The received signal on the root receiving antenna is at the sample index. The value at that location, This is the time delay offset.

[0140] Because the CAZAC frame synchronization header sequence has good autocorrelation and cross-correlation, when the frame synchronization header in the received signal exactly coincides with the position of the local synchronization sequence, i.e. When at the beginning of the frame synchronization header, the relevant results The maximum peak value appears. Therefore, the timing positions of different transmitting antennas can be accurately distinguished. After the receiving end completes timing synchronization, it can find the position of each OFDM symbol based on the pre-designed CP length, pilot position, length, and OFDM symbol length in the frame structure.

[0141] 2. Due to the different sources between the transmitter and receiver, the carrier frequency will deviate due to the inherent physical characteristics of the oscillators; in addition, the Doppler frequency shift between transmission and reception also introduces a certain carrier frequency offset. This carrier frequency offset will cause interference between subcarriers in the OFDM system, resulting in a degraded system performance. Therefore, it is necessary to detect and compensate for the carrier frequency offset of the received signal after timing synchronization to ensure the orthogonality of subsequent FFT / DFT operations. This embodiment uses CP to estimate CFO (carrier frequency offset). Specifically:

[0142] 2.1 The system sampling bandwidth is 3.48GHz. However, ordinary FPGA processing clocks cannot support such a high sampling rate. Therefore, to solve the problem of processing high-speed data, this embodiment converts the high-speed sampling data into... Parallel low-speed data processing reduces the processing clock speed by 16 times. At this point, the FPGA operates at 217.5MHz, making it ideal for engineering implementation.

[0143] Specifically, regarding the received signal , No. Parallel branch road in the first The data for each clock cycle is:

[0144] .

[0145] Phase detection and loop filtering are performed independently on each branch, but the numerically controlled oscillator (NCO) can be shared to save resources.

[0146] 2.2 Assume the current OFDM symbol starts at the serial index. Corresponding parallel index ,in This indicates rounding down and branch offset. , This represents modulo operations. Due to the earlier frame synchronization, this embodiment can start OFDM symbols at the serial index. Adjusted to 0, corresponding to parallel index Branch offset .

[0147] 2.3. Define the CP length. For the first Parallel branches:

[0148] No. CP sequence of parallel branches for:

[0149] ;

[0150] in, Indicates the sample number of the parallel branch. For the first The received signal of the parallel branch.

[0151] No. Tail sequence of parallel branches That is, the replication source corresponding to CP is delayed. The expression for a serial sample is:

[0152] .

[0153] when hour, All branches start from the same parallel cycle; when hour, This indicates that the branch needs to be extracted from the next parallel cycle, i.e., a cross-cycle situation has occurred.

[0154] 2.4 Calculate the local carrier frequency offset correlation value independently for each branch:

[0155] ,

[0156] in, For the first Local correlation values ​​of parallel branches, for . conjugate.

[0157] Substituting into a signal model containing CFO, the tail sequence Compared to There is a fixed phase rotation:

[0158] ,

[0159] in, For carrier offset, For noise terms, The sampling period.

[0160] Therefore, the first The local carrier frequency offset correlation value of the parallel branches can be expressed as:

[0161] .

[0162] Furthermore, to improve the CFO estimated signal-to-weight ratio, the carrier frequency offset correlation values ​​of all branches are accumulated. :

[0163] .

[0164] Find the phase after accumulation. :

[0165] ,

[0166] in, This indicates a phase calculation. The range is .

[0167] Solve for the estimated CFO value :

[0168] .

[0169] 3. Due to The range is CFO estimate Does a maximum value range exist? That is, half of the subcarrier spacing.

[0170] Obtain CFO estimate Then, the data is compensated. A rotation factor (output phase) for compensation is generated locally at the NCO. The output phase of each branch is expressed as :

[0171] ,

[0172] in, For the first The first parallel branch is later than the 0th parallel branch. The additional phase generated by each sampling point.

[0173] Output compensated parallel signal :

[0174] .

[0175] 4. Remove CP.

[0176] 5. OFDM symbol demapping, i.e., FFT (Fast Fourier Transform). Due to the excessively high data rate, this is used... Parallel FFT is used to demap OFDM symbols. The time-domain OFDM signal is restored to the frequency-domain subcarrier form. Parallel-to-serial conversion merges the data into a single high-speed serial data stream.

[0177] 6. After obtaining the frequency domain OFDM symbols, extract the symbols from the pilot positions, perform matrix-type channel estimation using the known pilots, and obtain the amplitude and phase responses of each transmit-receive antenna pair. Calculate the equalization matrix based on the channel estimation results, and perform matrix inversion to achieve spatial decoupling of multi-stream signals.

[0178] 7. Perform equalization on the signal. parallel roads The point IDFT (Inverse Discrete Fourier Transform) is the inverse process of the DFT (Discrete Fourier Transform) extension, restoring the frequency domain symbols to the time domain symbols.

[0179] 8. Perform symbol de-mapping, stream de-mapping, descrambling, rate matching de-matching, and channel decoding on the time-domain symbols after IDFT transformation to recover the original bit stream. This completes the parallel reception and demodulation of broadband high-speed signals.

[0180] Specific Implementation Method Two: The broadband receiving device based on the LoS-MIMO channel described in this implementation method includes a processor and a memory. The memory stores at least one instruction, which is loaded and executed by the processor to implement the broadband receiving method based on the LoS-MIMO channel as described in Specific Implementation Method One.

[0181] Specific Implementation Method 3: A computer storage medium as described in this embodiment stores at least one instruction, which is loaded and executed by a processor to implement the broadband reception method based on the LoS-MIMO channel as described in Specific Implementation Method 1.

[0182] While specific embodiments of this application have been described herein with reference to them, it should be understood that these embodiments are merely examples of the principles and applications of this application. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of this application as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A wideband reception method based on a LoS-MIMO channel, characterized in that, include: The receiver of the LoS-MIMO system captures the received signal and obtains multiple serial time-domain received signals after down-conversion. The multiple serial time-domain received signals are synchronized at a specific time to determine the starting position of the OFDM symbol; The synchronized serial time-domain received signals are converted into multiple parallel low-speed data streams. The local carrier frequency offset correlation value of each parallel low-speed data is calculated using the cyclic prefix, the local carrier frequency offset correlation value of all parallel branches is accumulated, and the carrier frequency offset value is estimated based on the accumulated result; Phase compensation is performed on each parallel low-speed data stream using the estimated carrier frequency offset. After removing the cyclic prefix of each parallel low-speed data after phase compensation, OFDM symbol demapping is performed to obtain frequency domain OFDM symbols; Channel estimation and equalization are performed based on the frequency domain OFDM symbols. The equalized signal is then subjected to inverse discrete Fourier transform and recovery processing to obtain the original bit stream.

2. The broadband reception method based on a LoS-MIMO channel according to claim 1, characterized in that, The step of timing synchronization of the multiple serial time-domain received signals to determine the start position of the OFDM symbol includes: Different orthogonal CAZAC sequences added to different transmit antennas are used as frame synchronization header sequences; At the receiver of the LoS-MIMO system, the received signal is correlated with the locally stored CAZAC sequence to find the maximum correlation peak. When the maximum correlation peak reaches its peak value, the delay offset corresponding to the peak value is the starting position of the frame synchronization header, thereby determining the starting position of the OFDM symbol.

3. The broadband reception method based on a LoS-MIMO channel according to claim 2, characterized in that, At the receiver of the LoS-MIMO system, the received signal is correlated with a locally stored CAZAC sequence to find the maximum correlation peak, including: The maximum correlation peak can be found using the following formula: ， in, The highest correlation peak, The length of the CAZAC sequence. For CAZAC sequence index, For the known CAZAC sequence stored locally, the first A complex number symbol, for conjugate, No. The received signal of the root receiving antenna is at the sample index The value at that location, This is the time delay offset.

4. The broadband reception method based on a LoS-MIMO channel according to claim 1, characterized in that, The calculation of the local carrier frequency offset correlation value of each parallel low-speed data using the cyclic prefix includes: Extract the cyclic prefix and tail sequence of each parallel branch based on the starting position of the OFDM symbol; The local carrier frequency offset correlation value of each parallel branch is calculated using the cyclic prefix and tail sequence of each parallel branch.

5. The broadband reception method based on a LoS-MIMO channel according to claim 4, characterized in that, The step of extracting the cyclic prefix and tail sequence of each parallel branch based on the start position of the OFDM symbol includes: Extract the cyclic prefix and tail sequences of each parallel branch according to the following formula: ， ， in, For the first The cyclic prefix sequence of parallel branches, For the first The tail sequence of parallel branches, For the first The received signal of the parallel branch, For the initial parallel index, For branch offset, This represents the total number of parallel branches. Let be the sample number of the parallel branch, and have , The length of the cyclic prefix. The number of subcarriers; The calculation of the local carrier frequency offset correlation value of each parallel branch using the cyclic prefix and tail sequences of each parallel branch includes: The local carrier frequency offset correlation value of each parallel branch is calculated according to the following formula: ， in, For the first Local correlation values ​​of parallel branches, for . conjugate.

6. The broadband reception method based on a LoS-MIMO channel according to claim 5, characterized in that, The estimation of carrier frequency offset based on the cumulative result includes: Calculate the cumulative phase based on the cumulative results: ， in, For cumulative phase, This indicates a phase calculation. This is the cumulative result of the local carrier frequency offset correlation values ​​for all parallel branches. For carrier offset, The sampling period is Represents modulo operation; Estimating carrier frequency offset using cumulative estimation: ， in, This is an estimate of the carrier frequency offset.

7. The broadband reception method based on a LoS-MIMO channel according to claim 1, characterized in that, The phase compensation for each parallel low-speed data stream using the estimated carrier frequency offset includes: The output phase of the numerically controlled oscillator is generated using the estimated carrier frequency offset: ， in, For the first The output phase of the parallel branch This is an estimate of the carrier frequency offset. The sampling period is This represents the total number of parallel branches. Let be the sample number of the parallel branch, and have , The length of the cyclic prefix; The output phase is applied to the received signal of the corresponding parallel branch to achieve phase compensation: ， in, For the first The signal after compensation for the parallel branches For the first The first parallel branch One sample signal.

8. The broadband reception method based on a LoS-MIMO channel according to claim 1, characterized in that, The recovery process includes: The process involves sequentially performing symbol demapping, stream demapping, descrambling, rate matching demapping, and channel decoding.

9. A broadband receiving device based on a LoS-MIMO channel, characterized in that, The broadband receiving device based on the LoS-MIMO channel includes a processor and a memory, wherein the memory stores at least one instruction, which is loaded and executed by the processor to implement the broadband receiving method based on the LoS-MIMO channel as described in any one of claims 1 to 8.

10. A computer storage medium, characterized in that, The computer storage medium stores at least one instruction, which is loaded and executed by a processor to implement the broadband reception method based on a LoS-MIMO channel as described in any one of claims 1 to 8.

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