The Research Of MIMO Sphere Decoding Algorithm Based On LTE-A System

As mobile wireless communication technology developed, people’s requirements of high speed transmission, large capacity and low latency in communication system is also high. The LTE system performance facilitates the development of LTE-A system, OFDM and MIMO as two key technologies of LTE-A system in each aspect meet a great challenge. MIMO spatial multiplexing scheme can obtain higher data transmission rate and the anti-interference antenna fulfilling LTE-A higher data transmission rate and antenna configuration’s requirements, but also increasing the difficulties in the receiving end of LTE-A system in MIMO signal detection. This paper based on understanding the MIMO detection algorithm and LTE-A agreement, with deep research on LTE-A downlink MIMO fixed complexity sphere decoding algorithm and put forward the corresponding optimization and improvement, and relying on the LTE-A downlink physical Shared channel simulation platform to get the performance of the algorithm and mainly to complete the following several aspects:First of all, the further understanding of MIMO detection algorithm based on the background and the importance. Theory analysis and simulation of three MIMO classical detection algorithms based on the V-BLAST structure:the maximum likelihood algorithm, forced zero detection algorithm and minimum mean square error detection algorithm. The further theory research of classical sphere decoding algorithm, and the sphere decoding and maximum likelihood detection algorithms’ analysis and simulation of the complexity and performance.Then research on the LTE-A system’s fixed complexity sphere decoding algorithm, combined with LTE-A system antenna configuration and high order modulation and other characteristics, through reducing the signal’s exhaust search dimension to further reduce the FSD algorithm complexity, and then through the symbol SNR sorting optimization improving the detection performance. Research on LTE-A system downlink spatial multiplexing scheme, building the LTE-A downlink physical Shared channel simulation platform, relying on the simulation platform to get the ber performance and complexity of fixed complexity sphere decoding algorithm. The simulation shows that the improved FSD algorithm can decrease algorithm complexity at the expense of the cost of a small part of the performance, although performance in low channel signal-to-noise ratio is bad, but the improved FSD algorithm with optimization can get partial improvement, balancing the algorithm’s complexity and performance and achieve the expected targets.Finally review and summarize the full text of this article, and put forward a future work for the improved FSD algorithm.