MIMO-OFDM wireless signal detection method and system with channel matrix preprocessing before detection

Abstract

A signal detection method for the MIMO-OFDM wireless communication system comprises the following steps: for each MIMO-OFDM data packet in a plurality of MIMO-OFDM data packets, obtaining a channel matrix of each subcarrier through channel estimation; receiving a receiving vector of each subcarrier; performing channel matrix preprocessing on the channel matrix of each subcarrier to generate a global dynamic K value table, the global dynamic K value table including a global dynamic K value corresponding to each search layer of each subcarrier; performing MIMO detection on each OFDM symbol in the MIMO-OFDM data packet, wherein the MIMO detection comprises the following steps executed on each subcarrier of the current OFDM symbol: reading a channel matrix preprocessing result and a receivingvector of the current subcarrier; converting the receiving vector of the current subcarrier into an LR search domain; and performing K-best search on the current subcarrier to obtain an LR domain candidate sending vector of the current subcarrier, in the K-best search, a K value applied to each search layer of the current subcarrier being a global dynamic K value corresponding to the search layerin a global dynamic K value table.

Description

technical field [0001] The invention mainly relates to a low-complexity detection technology of a multi-antenna wireless communication system, in particular to a MIMO-OFDM wireless signal detection method and system with channel matrix preprocessing before detection. Background technique [0002] With the rapid development of wireless communication technology, more and more wireless communication systems begin to adopt multi-antenna communication technology (MIMO) to expand the spectrum utilization and data rate of the system, and to obtain higher diversity gain and Improve the reliability of system data transmission. In particular, with the evolution of wireless communication theory, the number of antennas used in the new MIMO wireless communication technology is becoming or will become larger and larger. At the same time, user equipment is getting smaller and smaller, and its integration level is getting higher and higher. This makes the research on high-performance dete...

AI Technical Summary

Problems solved by technology

[0011] However, most of the current technical solutions in the prior art are devoted to solving single-carrier MIMO detection, while for the case of frequency-selective channels such as MIMO-OFDM, no practical method is given

Moreover, the soft value generation required for MIMO detection and channel decoding is not considered comprehensively, and the channel coding gain cannot be fully utilized.

[0012] The inventor noticed that the single-carrier MIMO detection method and system in the prior art at least have not been able to well solve the following problems in the MIMO-OFDM environment:

[0014] 2) The optimization of the LLR soft value applied to the channel decoder in MIMO-OFDM detection, that is, the reasonable allocation of search resources

[0015] For example, H. Yao and G. Wornell, "Lattice-Reduction-Aided Detectors for MIMO Communication Systems (Lattice-Reduction-Aided Detectors for MIMO Communication Systems)," in IEEEProc.Globecom, Taipei, Taiwan, November 17-21 2002. As the theoretical foundation of MIMO detection in the LR domain, a clear theoretical analysis and explanation of the physical meaning of the LR domain is given, but no specific implementation suggestions are given.

[0016] D.Wubben, R.Bohnke, V Kuhn, and K.-D.Kammeyer, "MMSE-Based LatticeReduction for Near-ML Detection of MIMO Systems (MMSE-Based Lattice Reduction for Near-ML Detection of MIMO Systems), "in ITG Proc.Workshop on Smart Antennas (WSA), Munich, Germany, Mar.2004. Proposed the optimal operation of LR domain transformation, but its MIMO detection is based on MMSE, so the detection performance is not satisfactory

[0017] M. Shabany and G. Gulak, "The application of lattice-reduction to the K-best algorithm for near-optimal MIMO detection (applying lattice-based reduction to the K-Best algorithm for near-optimal MIMO detection)," in Proc. IEEE Int.Symp.Circuits Syst., May 2008, pp.316–319. is the first document to give the LR domain K-best MIMO detection method, but it does not take the LR domain expansion boundary into consideration in the algorithm

At the same time, it is not designed for MIMO-OFDM, and there is no special consideration for soft value generation

[0018] S.Roger, A.Gonzalez, V.Almenar, and M.Vidal, "On decreasing the complexity of lattice-reduction-aided K-best MIMO detectors (reducing the complexity of lattice-reduction-aided K-best MIMO detectors), "in Proc.Eur.Signal Process.Conf., Glasgow, U.K., Aug.2009, pp.2411–2415. Although the K-best detection method with LR domain search boundary is given, the dynamic adjustment of K is also proposed. However, its preprocessing process is not optimal, and the process of dynamically adjusting the K value does not guarantee that the total amount of resources remains unchanged, but greatly increases the system search resources.

At the same time, it is not aimed at frequency-selective channels often encountered in MIMO-OFDM, nor is it optimized for soft value generation for channel codec gain

[0019] Chinese patent publication CN105814857A discloses a system and method for detecting symbols in a large-scale multiple-input multiple-output communication system. The non-MIMO-OFDM system it handles cannot cope with frequency selective fading caused by multipath channels

At the same time, the soft value generation is not optimized, and the gain of the channel codec is not maximized

Moreover, the LR domain search does not define boundaries, and the expansion efficiency is not maximized

[0020] Chinese patent CN103548310B discloses a detection method and receiver for a receiver based on a multiple-input multiple-output antenna communication system. Although the invention uses LR domain detection, there are two QR decompositions in the preprocessing, and the processing method is not the most simplified.

However, this patent is also designed for MIMO single-carrier systems, and does not provide any optimization for soft value generation in the case of frequency selective fading caused by multipath channels in MIMO-OFDM systems

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