Throughput improvement of Adaptive Modulation System with optimal Turbo Coded V-BLAST technique using a STD Scheme

In this paper, we propose and analyze an adaptive modulation system with optimal turbo coded V-BLAST (vertical-Bell-Lab layered space-time) technique that adopts the extrinsic information from MAP (maximum a posteriori) decoder with iterative decoding as a priori probability in two decoding procedure of V-BLAST scheme; the ordering and the slicing. Also, comparing with the adaptive modulation system using conventional turbo coded V-BLAST technique that is simply combined V-BLAST scheme with turbo coding scheme, we observe how much throughput performance can be improved. In addition, we apply a STD (selection transmit diversity) scheme to the systems for more performance improvement. The results show that the proposed system applying a STD scheme gains about 1.77 Mbps at 11 dB SNR (signal to noise ratio) compared to the conventional system using 2 transmit and 2 receive antennas.