Iterative Detection Algorithm For MIMO Wireless Communication Systems

With the rapid development of wireless communications, multimedia based service requests higher data rate and reliability. MIMO technology in LTE standard can increase data rate and reliability substantially. This dissertation focuses on iterative detection algorithm for MIMO wireless communication systems. The main contributions are as followed:1. Proposed a novel soft MIMO detection algorithm: PSFSD-SHC algorithm. (1) Proposed a new algorithm: PSFSD algorithm, which changes the method of constructing candidate list, making the detection require tree search only once. (2) Proposed a new enumeration method: SHC enumeration, taking prior information into consideration, which can approximate full extention well via low complexity. In the case of 16QAM modulation, the complexity of PSFSD-SHC with N=3 is only 27.1% of that of PSFSD with full extention.2. Optimized the whole system for better performance. (1) Adopted unbiased MMSE preprocessing. The performance of PSFSD-SHC with unbiased MMSE preprocessing added is enhanced by 0.5dB at 10-3 BER point. (2) Corrected systematic mismatches. Compensating the mismatches of computation of LLR information can improve the performance significantly. After 3 iterations, the performance is enhanced by 0.6dB at 10-3 BER point.3. Simplified PSFSD-SHC algorithm for realization. (1) Discussed the approximation of FSD ordering. The performance and complexity of FSD-SQRD algorithm and SOQRD algorithm were analyzed. (2) Improved the method of candidate adding. Expanding the partial best parent only needs node-expanding on each layer once, enhancing the efficiency of the algorithm.