Low-complexity detection method for MIMO-SCMA system

Abstract

The invention belongs to the technical field of wireless communication, and relates to a low-complexity detection method for an MIMO-SCMA system. The method mainly comprises the following steps: (1) carrying out ZF or MMSE detection on a received signal, and carrying out MPA detection on data of multiple users on antennas to get an initial solution; (2) converting a mathematical model of an MIMO-SCMA system into a mathematical model of an MIMO system through linear equivalent transformation; (3) if the ML value of the initial solution is less than a threshold value, directly outputting the initial solution; and (4) if the initial solution does not satisfy the threshold value, searching for neighboring solutions of the initial solution, and taking the first m optimal neighboring solutions as m initial solutions; and searching for neighboring solutions of the m solutions at the same time, retaining n optimal neighboring solutions for each current solution, retaining the first m different optimal solutions in m*n neighboring solutions as current solutions of next iteration, and carrying out cyclic iterative search until the termination condition is satisfied. The beneficial effect is that the method has obvious advantage in bit error rate performance, and has the advantage of low complexity.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and relates to multiple-input multiple-output (Multiple-Input Multiple-Output, MIMO), sparse code multiple access (Sparse Code Multiple Access, SCMA) technology and related signal detection technology, in particular to a A low-complexity detection method for MIMO-SCMA systems. Background technique [0002] With the continuous development of the mobile Internet and the Internet of Things, various emerging services continue to emerge, and the existing fourth-generation mobile communication system (4G) network will not be able to meet future needs. At present, non-orthogonal multiple access technology has received extensive attention in the industry and is regarded as the most potential key air interface technology in 5G networks. SCMA technology is a candidate technical solution in non-orthogonal multiple access technology. SCMA technology is a new type of multiple access technology...

AI Technical Summary

Problems solved by technology

For the MIMO-SCMA system, the current typical algorithms can be divided into two categories: one is the maximum likelihood (Maximum Likelihood, ML) detection algorithm, which belongs to the joint detection algorithm, which needs to jointly search for all possible codewords sent by multiple users. The advantage is that it has the best bit error rate performance, but its complexity increases exponentially with the number of users, the number of transmitting antennas and the number of codewords, so the extremely high complexity limits the application of ML algorithms in actual communication systems; One is the ZF-MPA / MMSE-MPA algorithm, which combines ZF / MMSE detection with Message Passing Algorithm (MPA) detection, which has the advantage of low complexity but poor detection performance

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