Transmission Optimized Generalized Spatial Modulation Over Correlated Fading Channels

Generalized spatial modulation (GSM) has shown its promising performance as an alternative to large-scale multiple-input multiple-output technology for future wireless communications. A novel transmission optimized GSM (TOGSM) is proposed based on minimizing the average bit error probability (ABEP) over spatial correlated fading environments. First, a union upper bound and a high signal-to-noise ratio (SNR) approximation of ABEP for traditional GSM with multi-stream transmission is derived when assuming maximum likelihood detection at the receiver side. In contrast, the new analytical result relaxes basic constraints on the channel model and the symbol modulation type in use when measuring the ABEP of SM. Then, TOGSM is presented through seeking the solution of an optimization problem for particular channel realizations, where the best combination of spatial modulation set and symbol modulation set can be obtained at a given spectral efficiency. Finally, the accuracy of the ABEP upper bound and its high SNR approximation is verified by Monte Carlo simulations. In addition, the performance advantages of TOGSM over the other schemes, such as fixed-GSM, V-BLAST and generalized space shift keying, are comparatively illustrated via some numerical examples.