CN-122027427-A - Sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method and system

Abstract

The invention discloses a sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method and system. The invention firstly processes the frequency domain signals received by a base station according to sub-carriers to obtain dimension reduction vectors of each user group for group interference sparse detection, then utilizes the dimension reduction vectors of each user group and a preset score group interference sparse detector selected according to prior variance to implement group interference sparse signal detection, finally processes the signal detection result by combining all sub-carriers user by user, carries out IDFT, external information calculation, de-interleaving, soft input soft output decoding, interleaving, prior information updating and DFT on the frequency domain signal detection result of each user to obtain prior mean value and prior variance of the frequency domain signals of each user for next iteration detection decoding. The invention utilizes the interference sparse characteristic of the sky wave large-scale MIMO channel to carry out Turbo receiving processing under DFTS-OFDM modulation, and can effectively improve the power efficiency and the receiving performance while reducing the design and the realization complexity.

Inventors

• GAO XIQI
• SONG LINFENG
• SUN RUI
• SHI DING
• YOU LI
• ZHONG WEN

Assignees

• 东南大学

Dates

Publication Date

20260512

Application Date

20260227

Claims (10)

1. 1. The sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method is characterized by comprising the following steps: Processing the frequency domain signals received by the base station according to sub-carriers to obtain a dimension reduction vector of each user group for sparse detection of packet interference; The method comprises the steps of performing packet interference sparse signal detection by using a dimension reduction vector of each user group and a preset score group interference sparse detector selected according to prior variance, wherein the preset score group interference sparse detector is obtained by calculating a channel Gram matrix and a group of quantized variances, each quantized variance corresponds to a candidate detector, and a detector corresponding to the quantized variance closest to the prior variance is selected for packet interference sparse signal detection; And carrying out user-by-user joint all subcarrier processing on the signal detection result, carrying out IDFT, external information calculation, de-interleaving, soft input soft output decoding, interleaving, priori information updating and DFT on the frequency domain signal detection result of each user to obtain the priori mean value and the priori variance of the frequency domain signal of each user, respectively feeding back the signals for signal reconstruction and the selection of a preset score group interference sparse detector to carry out the next iteration detection decoding, and finally obtaining the information bit decoding output of each user through a soft input soft output decoder after a plurality of iterations.
2. 2. The method for sky-wave massive MIMO DFTS-OFDM uplink Turbo reception according to claim 1, wherein the processing the frequency domain signal received by the base station on a subcarrier-by-subcarrier basis to obtain the dimension-reducing vector for packet interference sparse detection for each user group includes: carrying out matched filtering on the space domain receiving signals of all subcarriers, and subtracting the matched and filtered receiving signals from signals obtained by using the prior mean value reconstruction of the frequency domain signals to obtain mean value removed matched filtering signals; And performing interference selection on the matched filtering signals with the mean value removed by using the interference groups of each user group, and extracting to obtain a dimension reduction vector of each user group of each subcarrier for packet interference sparse detection.
3. 3. The method for uplink Turbo reception of sky-wave massive MIMO DFTS-OFDM according to claim 1, wherein in the packet interference sparse detection, a user group and an interference group of each user group are constructed by using instantaneous channel state information or statistical channel state information, and the method comprises calculating a channel correlation degree or statistical channel correlation degree between each user by using the instantaneous channel state information or the statistical channel state information, constructing a user group by using the channel correlation degree or the statistical channel correlation degree by using a clustering method, and constructing a corresponding interference group by using the user group.
4. 4. The sky-wave massive MIMO DFTS-OFDM uplink Turbo receiving method according to claim 1, wherein the a priori variance for the selection of the pre-designed packet interference sparse detector is obtained by averaging a priori variances of the transmitted data symbols on each of the sub-carriers of each user.
5. 5. The sky wave massive MIMO DFTS-OFDM uplink Turbo receiving method according to claim 1, wherein the preset packet interference sparse detector is related only to channel and variance quantization modes, and can be multiplexed within channel coherence time and coherence bandwidth.
6. 6. The method for uplink Turbo reception of sky-wave massive MIMO DFTS-OFDM according to claim 1, wherein the packet interference sparse signal detection is implemented by multiplying each group of dimension-reducing vectors obtained by conjugate transpose of a preset score group interference sparse detector selected by each group according to a priori variance and interference selection, and then adding the result to the priori mean value of frequency domain symbols of each group.
7. 7. The sky wave massive MIMO DFTS-OFDM uplink Turbo receiving method according to claim 1, wherein the process of performing matched filtering on spatial domain received signals of each subcarrier is implemented by using IFFT of several base station antenna dimensions and sparsity of beam domain channels.
8. 8. The sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving system is used for realizing the sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method according to any one of claims 1-7 and is characterized by comprising a matched filtering and interference selecting module, a detector selecting module, a signal detecting module and an iterative updating module, wherein the matched filtering and interference selecting module is used for processing a base station received frequency domain signal according to subcarrier by subcarrier to obtain a dimensionality reduction vector of each user group for block interference sparse detection, the detector selecting module is used for selecting a preset score group interference sparse detector according to a priori variance, the signal detecting module is used for carrying out block interference sparse signal detection by utilizing the dimensionality reduction vector of each user group and the selected block interference sparse detector, the iterative updating module is used for carrying out user-by-user joint all subcarrier processing on signal detection results, carrying out IDFT, external information calculation, de-interleaving, soft input soft output decoding, interleaving and priori information updating and DFT on the frequency domain signal detection results of each user, obtaining the priori average value and the variance of each user frequency domain signal, feeding back the priori average value and the preset score group interference sparse detector for selection, carrying out next round detection, a plurality of round of iterative decoding and finally obtaining bit output information of each user through soft input soft output decoding.
9. 9. A computer system comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the computer program when executed by the processor performs the steps of the sky wave massive MIMO DFTS-OFDM uplink Turbo reception method according to any of claims 1-7.
10. 10. A computer program product comprising a computer program, characterized in that the computer program when executed by a processor implements the steps of the sky wave massive MIMO DFTS-OFDM uplink Turbo reception method according to any of claims 1-7.

Description

Sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method and system Technical Field The invention belongs to the technical field of communication, and particularly relates to a sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method and system. Background The sky wave communication is used as a key mode for realizing long-distance transmission, and mainly utilizes a short wave frequency band of 3 to 30 MHz to realize beyond-the-horizon signal propagation through alternate reflection of electromagnetic waves on an ionosphere and the ground. However, the transmission rate of conventional sky-wave communications faces significant bottlenecks, limited by the limited spectrum resources and the complexity of the ionospheric environment. The large-scale MIMO technology can effectively support multi-user data parallel transmission by virtue of a large number of antenna array elements configured on the base station side, thereby greatly improving the space division multiplexing capability and the frequency spectrum efficiency. Therefore, it is of great importance to study sky-wave massive MIMO communication. Sky-wave massive MIMO uplink reception is a key issue for sky-wave massive MIMO communications. However, existing sky-wave massive MIMO uplink receivers all operate under an OFDM modulation framework. As the system bandwidth increases, the peak-to-average ratio of the transmitted signal under the OFDM waveform will be high. In addition, since the transmission distance of the sky-wave communication is usually thousands of kilometers, the power amplifier of the user terminal is required for the sky-wave massive MIMO-OFDM uplink transmission. The DFTS-OFDM waveform is widely applied to ground cellular communication and underwater acoustic communication due to the low peak-to-average ratio characteristic, and is expected to be used as a sky-wave large-scale MIMO uplink transmission waveform to improve the power efficiency of a user terminal. The Turbo receiver can effectively improve uplink reception performance by iteratively transferring soft information about information bits between the soft-in soft-out detector and the soft-in soft-out decoder. However, for a massive MIMO scenario in which the number of base station antennas and the number of service users are both greatly increased, the signal detection process in a conventional MMSE Turbo receiver would face unacceptable computational complexity. Furthermore, unlike linear reception, the fact that the detector in the Turbo receiver needs to be recalculated in each iteration based on the updated a priori variance, and cannot be multiplexed within the channel coherence time and coherence bandwidth, places a limit on the practical application of the Turbo receiver. Therefore, in order to improve the power efficiency of the user terminal and reduce the uplink receiving complexity, the research on the efficient sky-wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method by combining the sky-wave large-scale MIMO channel characteristics has important value. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method and system, which utilizes the interference sparsity of channels, combines and improves a Turbo receiving frame, and effectively improves the power efficiency and the detection decoding performance of a user terminal while reducing the design and the realization complexity. The technical scheme is that in order to solve the technical problems, the invention provides the following technical scheme: A sky wave large-scale MIMO DFTS-OFDM uplink Turbo receiving method comprises the following steps: Processing the frequency domain signals received by the base station according to sub-carriers to obtain a dimension reduction vector of each user group for sparse detection of packet interference; The method comprises the steps of performing packet interference sparse signal detection by using a dimension reduction vector of each user group and a preset score group interference sparse detector selected according to prior variance, wherein the preset score group interference sparse detector is obtained by calculating a channel Gram matrix and a group of quantized variances, each quantized variance corresponds to a candidate detector, and a detector corresponding to the quantized variance closest to the prior variance is selected for packet interference sparse signal detection; And carrying out user-by-user joint all subcarrier processing on the signal detection result, carrying out IDFT, external information calculation, de-interleaving, soft input soft output decoding, interleaving, priori information updating and DFT on the frequency domain signal detection result of each user to obtain the priori mean value and the priori variance of the frequency domain signal of each user, respectively feeding back the signals for signal reconstruction and