Research On Key Technologies Of Multi-User MIMO

In the wireless communication systems, the technology of Multiple Input Multiple Output (MIMO) is to use multiple transmit and receive antennas to process the data transmission and reception. Without increasing the system bandwidth and transmit power of the antenna, MIMO technology can make the channel capacity increase linearly with the number of antennas increases. Therefore, MIMO technology has become one of the key techniques in the next generation mobile communications. Early MIMO technology applies only to the single-user MIMO (SU-MIMO) communication. In recent years, multi-user MIMO (MU-MIMO) has become a hot topic. With appropriate pre-coding techniques, Multi-user MIMO can occupy the same time and frequency resources for multi-user data to be transmitted, thus the system capacity can be further improved. Pre-coding MIMO technology is currently one of the hot technology researches. It can enhance the overall performance of MIMO systems.The main contents of this paper include pre-coding technology in multi-user MIMO systems. On the basis of MIMO system in the current hot3GPP LTE standard protocol and draft IEEE802.11ac agreement, an improved MIMO transmission scheme using joint coding and modulation diversity (JCMD) technique transmission scheme is proposed. In this improved scheme, the rotating modulation diversity technique is applied. The component interleavers is designed to fully take advantage of the diversity of spatial, time and frequency, and coding-gain of channel codes as well. Simulations show that for different transmission conditions, the improved scheme has a significant performance advantage over the current protocol transmission scheme. This paper first applies the JCMD technology to the SU-MIMO system, then to further promote the application in multi-user MIMO systems.