Linear precoder design for non-orthogonal AF MIMO relaying systems based on MMSE criterion

Yunida Yunida,Nasaruddin Nasaruddin,Rusdha Muharar,Yuwaldi Away

doi:10.1186/s13638-018-1295-y

Yunida Yunida, Nasaruddin Nasaruddin + Show 2 more

Open Access

https://doi.org/10.1186/s13638-018-1295-y

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Abstract

Multiple-input multiple-output (MIMO) relaying system has attracted the attention of cooperative network researchers, due to its advantage over the conventional single antenna system, in terms of system capacity and spatial diversity. Precoder design is a processing scheme implemented at a source and relay node to improve system performance. We propose a linear precoder design for non-orthogonal amplify-and-forward MIMO relaying systems based on the minimum mean square error (MMSE) criterion. We analyze an upper bound of MMSE using a convenient expression to determine the structure of precoding matrices using the singular-value decomposition technique. Simulation results demonstrate that the proposed precoded scheme outperforms both unprecoded and existing precoded schemes.

Highlights

Relaying techniques in cooperative wireless networks increase a network’s coverage area and data rate and reduce transmission power [1, 2]
Motivated by the above advantages of the minimum mean square error (MMSE) criterion in AF Multiple-input multiple-output (MIMO) networks, we propose a linear precoder design for half-duplex non-orthogonal AF (NAF) MIMO relaying networks based on the MMSE criterion
The superiority of the proposed scheme compared to the unprecoded system is due to the additional source and relay precoder design with the power allocation method, which improves the performance of the NAF MIMO relaying system

Summary

Introduction

Relaying techniques in cooperative wireless networks increase a network’s coverage area and data rate and reduce transmission power [1, 2]. The DF scheme is complex because the relay node must first decode the signal received from a source and transmit the re-encoded signal to the destination. Motivated by the above advantages of the MMSE criterion in AF MIMO networks, we propose a linear precoder design for half-duplex NAF MIMO relaying networks based on the MMSE criterion. To the best our knowledge, such a precoder design for non-orthogonal AF MIMO relay schemes has not been proposed. Compared to an MBER detector [15], the MMSE detector cannot achieve full diversity; the computational complexity of the MMSE detector is stable relative to the constellation size of the modulation schemes, while the MBER detector increases significantly [16] in terms of bit error rate (BER) performance.

Precoder for NAF MIMO relaying system

Proposed approach

Conclusions