Cooperative Transmission Strategy over Users' Mobility for Downlink Distributed Antenna Systems

Abstract

Abstract-Previously, a scheme in [1] is proposed for the outdated channel state information (CSI) problem, for data transmission in time division duplex (TDD) systems. In user movement environment, the actual channel of data transmission at downlink time slot is different from the estimated channel due to channel variation. In this paper the effect of different user mobility on TDD downlink multiuser distributed antenna system is investigated. An efficient autocorrelation based feedback interval technique is proposed and updates CSI at less cost of the downlink time slots. In the proposed technique, the frequency of CSI feedback for different users is proportional to their speed. Cooperative clusters are formed to maximize sum rate where channel gain based antenna selection and user clustering based on SINR threshold is applied to reduce computational complexity. Numerical results show that sum rate superiority of the proposed scheme over the user mobility.

Downlink Spectral Efficiency Analysis in Distributed Massive MIMO with Phase Noise

“…Massive MIMO can be divided into two categories: one is co-located massive MIMO and the other is distributed massive MIMO [8]. The latter has promising advantages of increasing energy efficiency, system coverage and spectral efficiency, which results from the increase in macro-diversity gain and the reduction in access distance [9][10][11][12][13][14][15]. Considering these advantages, we analyze the spectral efficiency of distributed massive MIMO in this paper.…”