Research And Implementation On Detection Algorithms For MIMO Based On MCMC Method

With the development of cellular communications and wireless local area networks, especially the wireless access of Internet and multimedia applications on the information throughput growth in demand for data transmission rate requirements was further strengthened. It has become the focus on the developments of new wireless communications that make use of the limited resources more efficiently. Therotical work has shown that in sufficient rich scattering environments, multiple input multiple output (MIMO) systems hold the potential of enhancing spectral efficiency-hence capacity comparing with single-input single-output (SISO) systems. In the released standards of many mobile communication systems, MIMO technology has already been applied widely. With the increase in the number of antenna, higher requirements have been put forward to signal detection algorithm in the accuracy and complexity. Starting from basic MIMO detection methods the detection algorithm in wireless MIMO systems based on sphere decoding (SD) methods and the Markov chain Monte Carlo (MCMC) methods was studied and proved in simulations in this paper.The main contributions of this dissertation are recapitulated as follows:1. Much more attention has been paid in the domestic and oversea development process and trend, existing problems and research hotspot of MIMO detection methods. On the basis of thorough research on the academic model of channel, peculiarity of transmitted signal and the typical detection algorithm in MIMO systems the problem appeared in the technology of signal detection was analysed in this paper. The main content and the solutions of several kinds of detection algorithm were discussed. Performance of detection algorithm and complication of realization was analysed.2. The basic theories, characteristics and realizing methods of sphere decoding (SD) detection algorithm especially the detection mothod base on soft decision in MIMO systems have been studied detailedly. An iterative detection algorithm base on the posterior probability information was studied. The maximum likelihood ratio of the information bits was obtained. It is shown that the efficiency of detection algorithm has been improved in the results of the simulation.3. Iterative sampling idea in MCMC method base on conditional distribution and the possibility and effectiveness using in detection algorithm of MIMO system was analyzed, researched and applied in the detection algorithm of MIMO systems. On the Basis of studing basic iterative detection algorithm widely, the detection algorithm in MIMO systems based on Gibbs sampling was mainly studied. This algorithm was compared with sphere decoding detection algorithm. Finally, the simulation results show that this algorithm is effective and superior.