Multiuser 3D massive MIMO transmission in full-duplex cellular system

Dongmei Zhang,Kui Xu,Wei Xie,Yijun Yang,Ximing Wang

doi:10.1186/s13638-018-1219-x

Abstract

In this paper, we provide an effective multiuser transmission scheme in three-dimensional (3D) massive multiple-input multiple-output (MIMO) cellular systems, where the full-duplex (FD) base station (BS) equips two separate large-scale uniform planar antenna array (UPA). In order to reduce the computational and implementation complexity, we investigate the characteristic of the beam-domain (BD) 3D massive MIMO channels and self-interference (SI) channel. We propose the 3D multiuser beamspace transmission (MUBT) scheme that requires the spatial angular information of the users and the SI channel. We show that, due to the reduced dimension property of the effective beamspace channel, the overhead for channel estimation is reduced. Furthermore, a user scheduling algorithm is proposed to enable the 3D MUBT scheme in the FD systems. Finally, both the theoretical analysis and simulation results show the the SI can be effectively reduced and demonstrate the effectiveness and superiority of the proposed 3D MUBT scheme on spectral efficiency compared with the conventional half-duplex (HD) and FD transmission schemes.

Highlights

With the booming development of smart terminals and the growing demand for new mobile services, the mobile Internet traffic will continue to grow exponentially, which will increase by roughly 1000 times beyond 2020
Utilizing the orthogonality of beamspaces between groups, we show that our the 3D multiuser beamspace transmission (MUBT) can eliminate the inter-group interference (IGI), and significantly reduce the overhead of channels estimation
Due to the fact that the antenna array at the base station (BS) are generally set at a relative high building where the scatters around are relatively sparse, most of the energy of the channels concentrate on several spatial directions [31], i.e., several beams of signals

Summary

Introduction

With the booming development of smart terminals and the growing demand for new mobile services, the mobile Internet traffic will continue to grow exponentially, which will increase by roughly 1000 times beyond 2020. Time-division duplex (TDD) seems to be more suitable for massive MIMO systems since the channel reciprocity can be exploited to obtain the instantaneous downlink (DL) CSI through uplink (UL) training [2]; the overhead for channel estimation is linear with the number of user antennas. For this reason, a great deal of research work has been done for TDD [3,4,5,6,7]. CN μ, σ 2 stands for the complex-Gaussian distribution with mean of μ and variance of σ 2. ei represents a vector whose ith entry is 1 and the other are 0. δ (·)is the Dirac delta function

Methods

Beam-domain characteristics of 3D massive MIMO channel

Beamspace of SI channel

Data transmission

Conclusions