Abstract:

In order to meet the intensive needs of users, the developing cellular network has increased the energy consumption of the mobile system, but wider network coverage and lower power consumption of wireless communication system also bring more challenges to the wireless communication system. In view of these growing demands, this paper designs a multicell massive multiple input multiple output (MIMO) system downlink implementation method which can maximize energy efficiency.In this paper, an optimal closed-form expression of signal to interference plus noise ratio (SINR) is proposed in the case of imperfect channel state information (CSI), which includes the number of base station antennas, pilot multiplexing factor and the number of users. The downlink spectral efficiency of massive MIMO system is derived by the maximal ratio comlining (MRC) receiving technique, and then the overall energy efficiency of the system is obtained according to the power consumption model. The alternating iteration optimization algorithm is used to optimize the solution and obtain the relevant parameters when the energy effciency is the maximum. According to the simulation results, compared with the existing multicell methods, the proposed downlink implementation method of the multicell massive MIMO system can improve the energy efficiency by 12.2%, and it is more robust to the changes of the environment. Therefore, it has certain reference significance for the multicell massive MIMO system.

Key words: imperfect channel stare information (CSI), multicell, massive multiple input multiple output (MIMO), downlink