Capacity gain and design trade-offs for partial-duplex OFDM wireless communications

Hamid R Barzegar,Luca Reggiani,Laura Dossi

doi:10.1186/s13638-018-1301-4

Abstract

A hybrid transmission method between classical half-duplex and full-duplex is here considered for point-to-point orthogonal frequency division multiplexing (OFDM) links experiencing frequency selective fading. This partial-duplex solution uses only a portion of the available bandwidth for full-duplex transmission. It aims to increase the overall bidirectional system rate w.r.t. an equivalent half-duplex system, relaxing at the same time the high self-interference cancelation requirements that practical full-duplex systems have to provide. In this paper, we analyze the regions of self-interference cancelation values where partial-duplex systems outperform half-duplex ones in terms of achievable spectral efficiency. We investigate the potential of the proposed hybrid method by deriving the analytical distributions of the spectral efficiency gain regions in the presence of frequency selective Rayleigh fading. For different strategies in the selection of the sub-carriers that operate in full-duplex, we highlight the role of the different parameters involved and the peculiarity of this system in terms of design flexibility.

Highlights

The interest for wireless full-duplex (FD) communication in the future 5G and beyond networks is increasing due to its potential of contributing to some of the ambitious goals in the evolution of the generation of wireless communication: increased distance and capacity of the wireless links, spectrum virtualization, and enhanced interference coordination [1, 2]
The effect of the leakage that the FD sub-carriers generate into the HD ones is modeled as an error vector magnitude (EVM) noise with average power proportional to the residual self-interference generated by the FD sub-carriers PD parameter (PDP) · PT /self-interference cancelation (SIC), as PDP · (PT /SIC)/γE
We expect a loss in the accuracy of the analytical results depending on the error introduced in the above approximations. We remark that both expressions of SIC0,Selective partial-duplex (SPD) and SIC99,SPD in (29) and (33) are composed of two factors: SIC0,Additive white Gaussian noise (AWGN), which depends on the radio link parameters

Summary

Introduction

The interest for wireless full-duplex (FD) communication in the future 5G and beyond networks is increasing due to its potential of contributing to some of the ambitious goals in the evolution of the generation of wireless communication: increased distance and capacity of the wireless links, spectrum virtualization, and enhanced interference coordination [1, 2]. The SPD strategy exploits the maximum available selectivity of multi-carrier transmission, allowing the selection of the FD sub-carriers as those ones with the higher signal-to-interference-plusnoise ratio γFD,i,j providing potentially the best spectral efficiency gain. The effect of the leakage that the FD sub-carriers generate into the HD ones is modeled as an EVM noise with average power proportional to the residual self-interference generated by the FD sub-carriers PDP · PT /SIC, as PDP · (PT /SIC)/γE According to these assumptions, the power of the received signal of interest PR,i on the ith sub-carrier at frequency fi, assuming all the sub-carriers at the same transmit power PT transmit and receive antenna gains GT ·GR = Gant and channel power gain gi = |Hi|2, is given by: PR,i. This derivation constitutes, as it will be shown in the numerical results, a reference for the system potential gain

Selective partial-duplex

Block partial-duplex

ITU-VehA channel

Conclusions