RESEARCH On MIMO Wireless Communication Technology Based On Space-Time Dimension Extension

Multiple Input Multiple Output (MIMO) wireless transmission technology is considered to be a major breakthrough in communication field. MIMO technology makes full use of spatial, within the effective bandwidth to improve the system spectral efficiency and high channel capacity. The transiver design for MIMO system affects the complexity and system performance of the whole system, then, we study the signal detection technology, and put forward a MIMO transmission system based on space-time dimension extension scheme, by making full use of spatial dimension and time dimension to improve the MIMO symbol dimension, finding the obvious advantages of MIMO technology.The content of this thesis mainly includes the following aspects:1. The thesis firstly describes the research background and significance, and then introduces MIMO wireless communication technology, we study and analyze the signal detection technology in MIMO communication technology, which effectively affects the system performance. We firstly introduce the traditional detection algorithm, and put forward a low complexity and high performance iteration interference cancellation (ⅡC) algorithm and partial-decision iteration interference cancellation algorithm. We carry out system simulations of all the algorithms, finding that the IIC algorithm is a high-performance and low-complexity algorithm, and it can achieve full receive diversity. Besides, the performance of IIC algorithm gradually closes to the curve of SISO AWGN with the antennas number increasing, that is large system effect, which means that IIC algorithm is applicable to large-scale MIMO system.2. Large MIMO systems show many major bottlenecks, including physical placement of such a large number of antennas, lack of practical low-complexity detectors and associated channel estimation issues and so on. Thus, we put forward a MIMO transmission system based on space-time dimension extension, adopting orthogonal transformation technology and interleaving technology, to makes full use of spatial dimension and time dimension, improving the MIMO symbol dimension with less number of antennas. Besides, the MIMO transmission system based on space-time dimension extension, when combined with some detection algorithms, can simplify the design of receiver, and significantly improve system performance.3. The thesis describes a MIMO transmission scheme that the transmitters adopt the MIMO transmission system based on space-time dimension extension, combining with the modified ⅡC algorithm and modified PD-ⅡC detection algorithm at the receiver. Then, we carry out system simulations using MATLAB, and the simulation results show that the modified PD-ⅡC algorithm and modified ⅡC algorithm obviously improve the system performance of ⅡC algorithm, which shows that the transmission scheme is feasible, especially for the moderate-scale MIMO system with the antennas number of the orders of tens. The transmission scheme makes full use of spatial dimension and time dimension of MIMO system, and is applicable to moderate-scale MIMO system, which effectively reduce the implementation complexity of MIMO system and exploits the advantages of MIMO technology.