Low-complexity detection method for MIMO-OFDM system with subcarrier index modulation

Abstract

The invention belongs to the technical field of wireless communication, and relates to technologies of multi-input multi-output (MIMO), orthogonal frequency division multiplexing (OFDM), and subcarrier index modulation (SIM) and related signal detection technology. The method includes: firstly, ZF/MMSE equalization of a reception symbol vector corresponding to a sub-carrier block is performed to obtain an initial solution (current solution) vector, then neighborhood space search is performed based on the current solution vector, the neighborhood space is defined as a vector set of all solutions different from the current solution vector only via a modulation symbol or a sub-carrier index, and finally, ML costs of the current solution and a neighborhood solution thereof are compared, and the solution with the minimum ML cost is reserved as the current solution of the next cycle. The process is circulated and searched for many times until the ML cost of the current solution is smaller than the ML cost of all the neighborhood space solutions or the cycle is above the upper limit of the cycle frequency, the finally obtained current solution is outputted, and original information bits are recovered via demodulation. The method is advantageous in that the BER performance close to ML is obtained, and the calculation complexity is effectively reduced.

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), orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM), carrier index modulation (Subcarrier Index Modulation, SIM) technologies and related signal detection technologies. Background technique [0002] The proposal of the MIMO-OFDM system is a major breakthrough in the field of wireless communication. It has the advantages of high spectrum utilization, strong anti-fading performance, and large channel capacity. It is one of the core technologies of the physical layer of the next-generation broadband wireless communication system. [0003] Recently, a Subcarrier Index Modulation (Subcarrier Index Modulation, SIM) technology is proposed as a new MIMO-OFDM system transmission scheme (hereinafter referred to as MIMO-SIM-OFDM). The basic principle of this scheme i...

AI Technical Summary

Problems solved by technology

The ML detection algorithm has the best bit error rate (BitErrorRate, BER) performance, but the algorithm needs to jointly detect the position of the activated subcarrier and the constellation point symbol on the activated subcarrier, and this process involves an exhaustive search of all possible solutions , so the extremely high complexity limits the application of ML algorithms in practical communication systems

Images