Impacts of Imperfect Channel State Information, Transceiver Hardware, and Self-Interference Cancellation on the Performance of Full-Duplex MIMO Relay System.

Ba Cao Nguyen,Le The Dung,Nguyen Nhu Thang,Xuan Nam Tran

doi:10.3390/s20061671

Abstract

Imperfect channel state information (I-CSI) and imperfect transceiver hardware often happen in wireless communication systems due to the time-varying and random characteristics of both wireless channels and hardware components. The impacts of I-CSI and hardware impairments (HI) reduce not only the system performance but also the self-interference cancellation (SIC) capability of full-duplex (FD) devices. To investigate the system performance in realistic scenarios, in this paper, we consider the performance of an FD multiple-input multiple-output (MIMO) relay system under the effects of I-CSI, imperfect SIC (I-SIC), and imperfect transceiver hardware. We mathematically derive the exact closed-form expressions of the outage probability (OP) and ergodic capacity of the considered HI-FD-MIMO relay system over Rayleigh fading channels with the existence of I-CSI, I-SIC, and HI. Numerical results indicate that the performance in terms of OP and capacity reaches saturation faster, especially when the channel estimation error, the residual self-interference (RSI), and HI levels are remarkable. Therefore, various solutions for effectively reducing the channel estimation error, RSI, and HI levels in the HI-FD-MIMO relay system should be carried out to improve the system performance. All derived mathematical expressions are verified through Monte-Carlo simulations.

Highlights

Full-duplex (FD) communication has greatly benefited future wireless networks due to its capability of doubling the spectral efficiency for wireless systems [1,2,3,4]
We evaluate the impacts of three imperfect factors—i.e., Imperfect channel state information (I-CSI), imperfect transceiver hardware, and I-self-interference cancellation (SIC)—on the outage probability (OP) and ergodic capacity of the considered hardware impairments (HI)-FD-multiple-input multiple-output (MIMO) relay system
The full-duplex MIMO relay system is a candidate for future wireless networks due to the increasing capacity compared with traditional wireless systems

Summary

Introduction

Full-duplex (FD) communication has greatly benefited future wireless networks due to its capability of doubling the spectral efficiency for wireless systems [1,2,3,4]. Some recent reports about FD-MIMO relay systems investigated the average error-probability performance in the case of imperfect self-interference cancellation (I-SIC) [24], the impact of HI on the spectral efficiency [25], and the achievable sum-rate [26]. From the mathematical expressions in our paper, we can obtain the OP and ergodic capacity of the FD-MIMO relay system with perfect CSI, perfect hardware, and perfect SIC, so that the performance of FD-MIMO relay systems in the case of three imperfect factors can be compared with that in the case of none, one, or two imperfect factors. HI-FD-MIMO relay system with MRT/MRC techniques over Rayleigh fading channels Based on these expressions, we can quickly obtain the expressions of the OP and ergodic capacity of the FD-MIMO relay system in the case of P-CSI, P-SIC, and ideal hardware.

System Model

Outage Probability Analysis

Ergodic Capacity Analysis

Numerical Results and Discussions

Conclusions