Research On Channel Estimation Algorithms For MIMO-SCFDE Systems

In broadband wireless access system, ISI caused by frequency selective fading transmission affect the performance of the communication system seriously. SC-FDE can combat ISI effectively without employing coding technology. MIMO technology can improve the system performance without increasing the transmission power and transmission bandwidth. So combining MIMO technology with SC-FDE technology to make the multiple antenna block transmission systems has been the research hotspot for higher transmission rate and quality. In these systems, the receiver need channel information to demodulation data. Therefore, channel estimation algorithm is the key technology for MIMO-SCFDE systems obtaining good performance.To begin with, the background and the value of research are presented in the thesis. Then, Summarize research statuses of MIMO-SCFDE systems, In addition, describe the basic principles of SC-FDE system and its various frequency domain equalization algorithm. Zero forcing equalization algorithm, minimum mean-squared error equalization algorithm and decision-feedback equalization algorithm are introduced in the thesis. The performances and the effects of those equalization algorithms in the SC-FDE system are analyzed and compared in theory and simulation.The results shown that SC-FDE and OFDM have the same complexity and similar performance. In addition, SC-FDE system overcomes the drawbacks of OFDM systemNext, the basic principles of SC-FDE system is described, the comparison of SC-FDE system and OFDM system in complexity, channel capacity, PAPR, ber performance are analyzed and compared in theory and simulation.At last, channel estimation algorithms for training sequences based on STBC-SCFDE systems is proposed in the thesis. One is m-sequences as training sequences, the other is the unique words as the training sequences. Simulation in STBC-SCFDE systems demonstrates that the frame structure employing unique words as the training sequences proposed method in the thesis is better than that employing of m-sequences approach.