Abstract: Aiming at the high complexity of the maximum likelihood detection algorithm for spatial modulation systems, an improved maximum ratio combing algorithm was proposed. In this algorithm, a weighting factor was defined, whose subscript corresponded to the sequence number of transmitting antenna. Then the values of the weighting factor were sorted in descending order, and the antennas corresponding to the first L values were selected to form the antenna candidate set. Assuming that an antenna in the antenna candidate set was activated, the possible transmit signal was calculated by zero forcing algorithm. Maximum likelihood search was performed for all antennas and corresponding estimation symbols in the antenna candidate set. Simulation results show that the proposed algorithm can significantly reduce the complexity of the algorithm on the premise of ensuring the sub-optimal detection performance.

Key words: weight factor, spatial modulation, signal detection algorithm, candidate antenna