Extended spatial modulation scheme with low complexity detection algorithms

Extended spatial modulation (ESM) is proposed as a novel spatial modulation scheme in this paper. Extended spatial modulation is a spatial modulation design where the number of active antennas can be various. The data rate could be improved as more symbols are available for transmitting and thus more information bits can be modulated during each time slot. The minimum distance of the transmitted symbols can also be further maximized as more symbols are available for optimizing selection which further improves the symbol error performance. Moreover, a near-optimal detection scheme with low complexity is also proposed in this paper. An approximated analytical expression for the symbol error probability (SEP) of the proposed detection scheme is derived along with the complexity analysis. Numerical simulations are proposed to demonstrate the performance of the proposed detection scheme and to validate the theoretical analysis.