Research Of Coordinated Multi-points Transmission/reception Technology In Massive MIMO

Recently massive MIMO technology quickly became a hot topic in the communication field, because it can significantly improve the spectral efficiency and the energy efficiently. However, the performance issues of the cell-edge users, which has plagued the cellular communication system, will not be solved effectively by the large-scale antennas in the base station. CoMP(Coordinated Multiple Points Transmission/Reception)technology is an important method to elimination the inter-cell interference, so it can improve the communication performance of cell-edge users. In recent years IA(Interference Alignment) technology is considered to be an effective way to eliminate the inter-cell interference, as an implementation form of CoMP. At the same time, antenna selection technology has been widely studied because of the signal processing complexity which cause by the rising number of the antenna. The main research about the above technology on the paper was done as follow:This paper firstly introduces the basic principles of the massive MIMO system, IA and antenna selection technology, and then theoretically analyzes the spectral and energy efficiency of the massive MIMO system. After that this thesis introduces two basic criteria and serveral classical algorithms about the antenna selection, and the common linear IA algorithm and distributed iterative IA algorithm.Additionally, the thesis studies the role and the impact of the antenna selection in the IA system, and then alalyzes serveral antenna selection algorithm based on IA, such as maximizing the channel capacity, maximizing the chordal distance between the signal space, maximizing the SNR(Signal to Noise Ratio) and characteristic value and so on.And simulation and the performance evaluation is done for the above serveral algorithms.Thereafter, the IA and antenna selection technology are used for the downlink transmission of the massive MIMO system, sloving the inter-cell interference problem of the cell-edge users. And the thesis optimizes the computation of the antenna seleciton based on maxinum receiving SNR and then a low complexity menthod is proposed to search the target antenna subset. Additionally, a dymanic power allocation algorithm based on providing equal quality service for all users is proposed. The simulation results show that although the proposed algorithm makes a little improvement in the system sum-rate performance, it performs better than the original algorithm in the bit-error rate performance,about 2-3 dB at high SNR region.Finally, in order to eliminate inter-cell interference and simultaneously get the diversity gain to improve the transmission quality of cell-edge users, the alamouti coding is introduced. The thesis firstly analyzes the properties of Alamouti coding and the IA algorithm based on two antenna Alamouti coding, and then deduces the expression of the sum-rate and receive SNR performance of the algorithm. Then an improved algorithm based on the two antenna Alamouti coding IA algorithm is made and used for the uplink transmission of massive MIMO system, and the improved algorithm takes advantage of the large-scale number antennas in the base station to improve the receiving diversity gain, thereby it can improve the system sumrate and the transmission reliability at the same time.