Simulation Reaserches On MIMO-SCMA Technology In 5G Mobile Communication System

The development of global mobile communications have gradually entered the fifth generation(5G)era.While the maximum transfer rate can reach 100Mbps in 4G,the fifth generation of mobile communications need to meet people’s requirements for higher rates.At the same time,the fifth generation mobile communications should also have the features of short delay,low power consumption and high reliability.Non-orthogonal multiple access technologies have become the key physical layer technique in current 5G research.The Sparse Code Multiple Access(SCMA)technology is recently proposed by Huawei to implement non-orthogonal multiple access in the frequency domain so as to improve the spectrum efficiency.On the other hand,multi-input and multi-output(MIMO)technology can improve the system capacity effectively without extra spectral resources.Aiming at 5G system,this thesis focuses on the simulation research of SCMA technique as well as its combination with MIMO technology.Based on the brief introduction to the system model and principles of SCMA,the thesis simulates and compares the performance of downlink SCMA and OFDMA,which shows that SCMA has obvious improvement in throughput performance compared with that of OFDMA.On the basis of this,different scheduling algorithms of the downlink SCMA system are simulated to analyze the tradeoff between throughput and fairness.Further,the thesis simulates the downlink MIMO-SCMA based on STBC to compare the performance between MIMO-SCMA and SISO-SCMA.The results show that MIMO-SCMA can enhance the downlink error performance obviously.In addition,the thesis studies the influences on error performance exerted by different MIMO receiver detection technologies and channel models.The results show that the combination of MIMO and SCMA technology can not only improve the spectrum efficiency but also provide higher reliability,and therefore would have good application prospects.