Code Design of Space-Time Block Codes Coded Low-Density Parity-Check Code and System Performance Analysis

Abstract

In multiple input and multiple output system of wireless communications, space time coding using multiple transmit antennas is the attractive technique for high bit-rate and high capacity transmission. Methods for providing transmit diversity in communication over fading channels also been concerned.Although Space-Time Block Codes has full diversity gain but not coding gain.The concatenation scheme of STBC codes and LDPC (STBC-LDPC) was proposed and it has been shown that the STBC-LDPC can achieve the good error rate performance and coding gain. Low-density parity-check (LDPC) codes ,as it is the good error correcting codes achieving the near Shannon limit performance.In this paper, a concatenation scheme of LDPC codes and STBC which should apply full transmit rate with multiple transmit antennas is proposed. Refering to it as the ABBA-LDPC and OSTBC-LDPC.We evaluate the bit error rate (BER) of the two schemes in a quasi-static Rayleigh fading channel by the computer simulation. We show that the BER of the ABBA-LDPC is better than that of the STBC with same antennas in a quasi-static Rayleigh fading channel,and also it is better than OSTBC-LDPC which uses real constellation. When receive antennas increasing ,the diversity gain will be increasing too.