Performance of 4-State Asymmetric 8-PSK TCM-STBC in Fast Fading Channels

We use an asymmetric 8-PSK signal sets in the 4-state rate 2/3 trellis-coded modulation concatenated with space-time block coding (TCM-STBC) scheme for fast fading channels, and show performance gain over TCM-STBC scheme with symmetric 8-PSK constellations. The performance gain is due to an increase in the minimum product-sum distance and free distance of trellis code compared to that of the symmetric 8-PSK signal sets. Simulation for fast Rayleigh fading channels shows that the proposed asymmetric 8-PSK TCM-STBC scheme outperforms symmetric scheme by about 0.3 dB at frame error rate of 10^-3.