Performance of Turbo Coded Vertical Bell Laboratories Layered Space Time Multiple Input Multiple Output system

Abstract

In this paper, performance of a Turbo Code (TC) and Vertical Bell Laboratories Layered Space Time (VBLAST) encoded wireless link is evaluated in the presence of Rayleigh fading for Multiple-Input Multiple-Output (MIMO) system. Turbo encoded bits are modulated using QPSK or 16 QAM or 64 QAM modulator and modulated data are further encoded using VBLAST and then split into n streams which are simultaneously transmitted through n transmit antennas. Simulation results obtained show that coded MIMO system provides 17 to 25 dB coding gain for different combination of transmit and receive antennas at a BER of 10-3 compared to uncoded MIMO system. And there is around 2 to 8 dB gain for increasing number of transmitting antennas from 2 to 3 or 3 to 4. On the other hand, capacities for (2 Tx, 2 Rx), (3 Tx, 3 Rx) and (4 Tx, 4 Rx) are almost same from 0 dB to 10 dB but change significantly with increasing SNR from 10 dB.