Research On Signal Processing Schemes Of Interference Alignment And Cancellation Based On MIMO Network

With the rapid development of the communications industry, the reliability and capacity of wireless communication system needs to be improved. And that make the conventional communication system using a single antenna for both transmitter and receiver face serious challenges. Because of the limited band resources as well as the demand for data rate growth, how to increase bandwidth efficiency and improve system performance will undoubtedly become the focus of communication research in the field. MIMO uses diversity technology with the application of multi-antenna and space-time coding in the multipath environment. It can increase the spectrum efficiency under the premise of no additional transmit power and bandwidth, thereby increasing the channel capacity. However, there is a point that the increase of channel capacity is proportional to the number of antennas. In other words, it is limited by the number of antennas. In practical applications, the number of antennas can not be increased arbitrarily. So if it is possible to further increase spectrum efficiency by limited antenna, the performance of existing systems will be greatly improved.Interference alignment (IA) is a new approach proposed in recent years. It is based on MIMO networks and can overcome the restrictions of the number of antennas on the channel capacity so that further improve the spectrum efficiency of the system. In this paper, interference alignment and cancellation (IAC) is proposed which combines interference alignment and interference cancellation the two interference management technology.In this thesis, the research on IAC system is mainly about the following two aspects:1. Research and analyze the signal process and specific decoding algorithm in both two and three transmitter-receiver pairs environment of IAC system and then extend the scheme to general situation. Because of the complexity and flexibility of IAC system, the processing method is not fixed, so the paper also analyzes how the IAC system work when it encounter complex situations.2. In order to prove the reliability of the proposed scheme, we simulate its bit error rate performance and the results show that the IAC system can achieve a lower error rate, meaning it is practical. In the aspect of effectiveness, the paper first theoretically analyzes channel capacity and spatial degrees of freedom of both MIMO and IAC system. Then conduct a comparative simulation analysis, the results show that the IAC system can further increase the channel capacity, space freedom and improve the system performance above the MIMO system.