On Transmit-Diversity for Spatial Modulation MIMO: Impact of Spatial-Constellation Diagram and Shaping Filters at the Transmitter
Abstract
In this paper, we contribute to the theoretical understanding, the analysis, and the design of Spatial Modulation (SM) MultipleInputMultipleOutput (MIMO) systems for transmit diversity without channel state information at the transmitter. The contribution is threefold: i) the achievable transmitdiversity of SMMIMO is analytically studied by analyzing the impact of various design parameters, notably spatialconstellation diagram and shaping filters at the transmitter; ii) the design of SM MIMO providing transmitdiversity and MaximumLikelihood (ML) optimum singlestream decoding is investigated; and iii) via Monte Carlo simulations, a comprehensive performance assessment of SMMIMO against stateoftheart MIMO (e.g., spatialmultiplexing, orthogonal spacetime block codes, Golden code, and double spacetime transmitdiversity) is conducted. It is shown that, for many system setups, properly designed SM MIMO outperforms, with lower decoding complexity, stateof theart MIMO. In particular, SMMIMO is especially useful in the downlink, where many antennaelements (with only few of them active) are available at the transmitter, and few antenna elements are available at the receiver.