Performance comparison of V-BLAST receiver detection algorithms for double space time transmit diversity

Abstract

In recent years, wireless systems are rapidly having developed to serve high speed voice, text and multimedia internet services which were traditionally offered by wire line networks. To support these services, wireless transmission systems are required to enhance the performance and the capacities. Information theoretic investigations have shown that Multiple Input Multiple Output (MIMO) systems can achieve very high capacities. Space-Time Block Coding (STBC) and Bell Labs Layered Space-Time Architecture (BLAST) are widely used schemes which utilize the diversity offered by MIMO channels, and provide reliable high data rate wireless communication. Works to reduce the computation complexity in the receiver are also needed for realization. Recently, new scheme called Double Space Time Transmit Diversity (DSTTD) was proposed, which is a scheme that is a combination of STBC and BLAST to increase the diversity gain and data rates simultaneously, and various BLAST detection algorithms at the receiver. In this thesis, various BLAST detection schemes are considered to compare the performance of receiver signal detection in DSTTD system. The method used generally such as Zero forcing (ZF), Minimum Mean Square Error (MMSE) is introduced. ZF scheme has error propagation. So Ordered Successive Interference Cancellation (OSIC), the scheme to reduce error propagation with some detection order, is explained. This scheme has better performance than ZF. But computational complexity is high. The last, Sorted QR Decomposition (SQRD) is shown. SQRD method can reduce computational complexity with QR decomposition and sorting. In simulation results, we present the performance comparison of various BLAST detection methods for DSTTD system under Rayleigh flat fading channel. We can observe the improved performance and reduced complexity of receiver due to utilizing efficient receiver detection algorithms in DSTTD system.