Dengkui Zhu

Inter-cell spectrum efficiency improvement technology☆

Abstract Improvement in inter-cell spectrum efficiency is a valuable research topic in mobile communication system, which affects cell edge user experience especially. According to current research results, there are three methods to deal with inter-cell interference to improve inter-cell spectrum efficiency, including inter-cell interference randomization, inter-cell interference cancellation and inter-cell interference coordination. This paper analyzes three important inter-cell spectrum efficiency improvement technologies, soft frequency reuse (SFR), uplink power control, and downlink coordinated multi-point transmission/reception (CoMP), and relative research progress.

SINR prediction based on MU-MIMO in large scale antenna array system

Wireless data rates are prodicted to increase 1000 fold by 2020 and likely go up to 10,000 times by 2025. To meet the explosive growth in traffic during the next fifteen years, significant improvement in spectral efficiency is required. One of the promising innovative technologies to meet the above requirements is the massive MIMO technology adopting in large-scale antenna array system. The MIMO channel formed by the massive MIMO technology is likely to be very asymmetric and the number of possible independent data streams for transmission is limited by the number of antennas at the mobile station. Thus MU-MIMO (multi-user MIMO), which offer spatial multiplexing gain without the requirement of multiple antenna arrays at the mobile station, is very worthy of study in large scale antenna array system. In this paper, we give a formula of SINR prediction based on MU-MIMO in large scale antenna array system. Using the formula, a base station could easily predict the capacity loss because of non-deal Channel State Information (CSI), and then choose MIMO mode(e.g. adaptive switching between Single User-MIMO and MU-MIMO) or the best paired users properly in MU-MIMO system. Simulation results show the rationality of the formula.