We consider an amplify-and-forward infrastructure non-concurrent two-way relaying (ncTWR) scenario where a base station serves a transmit-only user TUE and a receive-only user RUE. Unlike conventional two-way relaying, the RUE in ncTWR experiences back-propagating interference (BI). Uniform channel decomposition and Tomlinson-Harashima precoding improve the bit error rate (BER) of multiple-antenna-multiple-output (MIMO) systems. Inspired by these techniques, we design a transceiver to reduce BER of both users in MIMO ncTWR. This transceiver cancels BI of the RUE and uses spatial noise whitening filters, designed herein, to uniformly decompose MIMO channels of both TUE and RUE. This letter quantifies the improved BER of the proposed transceiver. © 2012 IEEE.

Bhaskar Ramamurthi

Department of Electrical Engineering

Bit error rate

Communication channels (information theory)

Transceivers

Amplify and Forward

BACK-PROPAGATING INTERFERENCE (BI)

BASE STATION SERVES

JOINT TRANSCEIVER DESIGN

Multiple antenna

TOMLINSON-HARASHIMA PRECODING

TWO-WAY RELAYING

UNIFORM CHANNEL DECOMPOSITION

Radio transceivers

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Joint Transceiver Design for Non-Concurrent MIMO Two-Way AF Relaying

IEEE Wireless Communications Letters

We investigate a joint design of linear precoders and receivers for multiple-input multiple-output non-simultaneous two-way relaying (NS-TWR). Unlike conventional two-way relaying, the base station in NS-TWR performs two-way relaying with two different users - a transmit-only user and a receive-only user (RUE). The RUE experiences back-propagating interference (BI). The proposed design cancels this BI and provides beamforming gain over existing designs. For NS-TWR, we maximize the weighted sum-rate (WSR) through joint power allocation, by solving a sequence of geometric programs. The precoder and the receiver designs as well as the power allocation program are then extended for a multi-user system with multiple transmit-only and receive-only users. With exhaustive simulations, we show that the proposed design provides significantly better WSR than the existing ones. The proposed design is also evaluated in a cellular framework using realistic path loss models, to assess the system-level performance gain achievable. © 2002-2012 IEEE.

IEEE Transactions on Wireless Communications

Joint precoder and receiver design for AF non-simultaneous two-way MIMO relaying

In conventional two-way relaying (TWR), it is assumed that a user has data to send and receive simultaneously from the base station (BS) via a relay. In cellular systems, data flow between the BS and a user is usually not simultaneous, e.g., a transmit-only user (say, TUE) may have uplink data to send in the multiple access (MAC) phase, but may not have downlink data to receive in the broadcast (BC) phase. Such one-way data flow will reduce TWR to spectrally inefficient one-way relaying. The multiple-input-multiple-output (MIMO) asymmetric TWR (ATWR) protocol considered here restores the two-way data flow via a relay. In ATWR, the BC phase following the MAC phase of a TUE is used to send downlink data to a receive-only user (say, RUE). However, the RUE will not be able to cancel the back-propagating interference. We design a structured precoder at the relay to cancel this interference. The proposed precoder also triangularizes the end-to-end MIMO channels. The channel triangularization reduces the weighted sum-rate maximization and relay power minimization problems to power allocation problems, which are then cast as geometric programs. Simulation results illustrate the effectiveness of the proposed precoder when compared with conventional solutions. © 2014 IEEE.

Fulltext

Linear precoders for nonregenerative asymmetric two-way relaying in cellular systems

IEEE Transactions on Vehicular Technology

Distributed Precoding for OFDM in Two-Way Relaying Communications

Performance Analysis of Adaptive Physical Layer Network Coding for Wireless Two-Way Relaying

IEEE Journal on Selected Areas in Communications

A Tutorial on the Optimization of Amplify-and-Forward MIMO Relay Systems

Journal	Data powered by TypesetIEEE Wireless Communications Letters
Publisher	Data powered by TypesetInstitute of Electrical and Electronics Engineers Inc.
ISSN	21622337
Open Access	No