Layers Ordered Multiple Feedback Successive Interference Cancellation in MU-MIMO

Abstract

Multi Input Multi Output (MIMO) is a promising technique to achieve higher data rates. In MIMO multiple data streams can be transmitted simultaneously using same frequency. Spectral efficiency can be increased by using Diversity and Multiplexing methods. Multiple antennas at both transmitting and at receiving sides can be used to minimize channel and noise effects. However, by using multiple antennas system complexity especially detection complexity increases and even system become more complex as modulation order increases. The throughput performance is generally limited by interference. A number of methods were proposed in literature to mitigate interference. In this thesis, we proposed a method named Layers Ordered Multiple Feedback Successive Interference Cancellation (LOMF-SIC) based on Spatial Multiplexed (SM), for uncoded, MU-MIMO systems. In this method layers are arranged according to the decreasing order of channel norm, SNR and SINR values. Arrangements of layers mitigate error propagation in feedback loop and enhance BER performance. Furthermore, we proposed Division of Constellation Diagram (DCD) method used to decide the reliability or unreliability of the detected symbols with low complexity. Simulation results show that layers ordering based on SINR outperform SNR and channel norm. Simulation results also show that LOMF-SIC based on SINR outperform MF-SIC and conventional SIC methods.