Study On Detection Algorithms For Layered Space-Time Codes

Space-time codes are a class of channel codes designed to use multiple transmit antennas to get diversity. They combine the advantages of space diversity and time diversity, and can achieve high data rate transmission without increase in the transmitting power and the system bandwidth in the future mobile systems. With the use of space-time codes, the quality of communication services and system capacity in the Rayleigh fading environment can be improved greatly.The organization of the thesis is as follows. First, we summarize the background and current studies of space-time codes, introduce some research results at present discussed in related fields. Secondly, the characteristic of space-time channel is introduced; space-time signal model and corresponding channel capacity are described. Thirdly, the performance of layered space-time is analyzed and the design criterions for layered space-time codes based on this analysis are presented. Finally, various encoding architectures and detection algorithms are given in detail. A detection algorithm which can achieve the tradeoff between computation complexity and system performance is proposed in this thesis. The basic principles and performance of the proposed algorithm are presented with simulation results. For the concatenated space-time coded systems with QPSK modulation, an effective estimation for the clipping values of soft reliability information between inner code and outer code is provided, and then followed by a feasibility analysis and simulation validation.