Research On MIMO Detection Algorithm For LTE System

MIMO and OFDM is the core technology of LTE technology, they are called "future4G" technology, it mainly devotes to develop the communications system that meeting the "higher transmission rate","more low latency","more small operation expenses" and "greater system capacity". MIMO (Multiple-Input Multiple-Out) technology exploit space resources fully, it can take advantage of the multipath fading without any increase in bandwidth fully. MIMO can increase the frequency utilization exponentially、improve the reliability and reduce the bit error rate effectively of system by receiving and sending signals with many antennas. The incorporation of detection algorithm and MIMO technology can improve the transmission performance and efficiency of the system better, so the research becomes a new hotpot on detection algorithm.This thesis mainly researches on MIMO detection algorithm bases on spatial multiplexing receiver of PDSCH in LTE system, firstly, introduces some basic concepts by introducing LTE agreement and MIMO system preliminary,so understands these basic concepts initially; secondly,realizes the general structure by analyzing the system model of the MIMO, and recommends some classical MIMO detection algorithms. The maximum likelihood detection is the optimal detection in the detection algorithm by researching, but it has high complexity because it presents index addition along with the addition of the antennas’ number, so it cannot be applied in practice. This thesis provides the simulation result by MATLAB software about that classic and simple detection algorithm relatively, and made the corresponding analysis.The current detection algorithm is researching on approaching ML detection algorithm,but can not realize the compromise between the complexity and performance. This thesis introduces two improved detection algorithms which are PreDe-ML detection algorithm and circle searching detection algorithm. The system performance of PreDe-ML detection algorithm is better than other algorithms, but its complexity don’t reduce well, so make the complexity further optimized later, then puts forward the circle search detection algorithm. The simulation results show that the detection algorithm brings about a compromise between performance and complexity and have a certain application value for the communication system in the receiver.