BLOCK GENERALIZED SPATIAL MODULATION FOR MASSIVE MIMO SYSTEMS

Abstract

Spatial modulation techniques have the ability to convey information by both the positions of active antennas as well as the symbols they transmit. Such techniques include the generalized spatial modulation (GSM) that can provide high spectral efficiency. In general, however, the total number of available symbols in GSM is not a power of two. Therefore, selection of a symbol alphabet from the available symbols is needed. This is a numerically complex problem. In this paper, we propose to significantly reduce the complexity of the GSM symbol set selection problem by grouping antennas together to form blocks, thus producing block GSM (BGSM) symbols. A previously developed iterative combinatorial method is extended to BGSM symbol selection. The effects of the Rician K-factor, BGSM symbol block size, and antenna configuration on the performance and design complexity are studied. The algorithm is found to significantly reduce the complexity of the BGSM symbol set selection problem.