Performance Comparison of Space Time Block Coding with Code Rate ½ and ¾ for Turbo Coded Multiple Input Multiple Output System

Abstract

This paper compares the performance of Space Time Block Coding with code rate ½ and ¾ for a Turbo Coded Multiple Input Multiple Output (MIMO) system and uncoded MIMO system. Turbo encoder encodes the input information bits and sends to a QPSK or 16 QAM or 64 QAM modulator. Modulated symbols are mapped by STBC. Outputs of STBC split into n streams which are simultaneously transmitted using n transmit antennas. The Rayleigh fading effected received signal at receiver is a linear superposition of the transmitted signals. It is observed that t here is around 7-11 db coding gain for using code rate ½ compared to code rate ¾ of a TC coded MIMO system and there is around 8-10 db coding gain for using code rate ½ compared to code rate ¾ of a uncoded MIMO system.