A Soft-Network-Coded Multilevel Forwarding Scheme for Multiple-Access Relay Systems

Dushantha N.K. Jayakody, Jun Li, Mark F. Flanagan

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

This paper proposes the novel technique of multilevel-Threshold-based soft quantization (MLT-SQ) for a multiple-Access relay system (MARS). The scheme is suitable for systems using binary phase-shift keying (BPSK) and network coding at the relay. In the proposed MLT-SQ protocol, the relay evaluates the reliabilities, which are expressed as log-likelihood ratios (LLRs), of the received signals from the two sources. It then computes the LLRs of the network-coded packet and quantizes these using a set of optimized multilevel thresholds, forwarding the resulting 'quantized soft symbols' to the destination. We provide the derivation for the bit error rate (BER) at the destination, and based on this, we optimize the multilevel thresholds to minimize the BER. Simulation results are provided for the proposed MLT-SQ system, both without coding and for the case where low-density parity-check (LDPC) coding is employed. The proposed system achieves full diversity order. Compared with competing schemes, the performance of our system is superior in terms of BER when the same amount of channel state information (CSI) is exploited.

Original languageEnglish
Article number7120177
Pages (from-to)3430-3439
Number of pages10
JournalIEEE Transactions on Vehicular Technology
Volume65
Issue number5
DOIs
Publication statusPublished - 1 May 2016
Externally publishedYes

Fingerprint

Multiple Access
Bit error rate
Relay
Error Rate
Quantization
Log-likelihood Ratio
Binary phase shift keying
Network coding
Packet networks
Channel state information
Coding
Binary System
Network Coding
Channel State Information
Phase Shift
Parity
Optimise
Minimise
Evaluate
Simulation

ASJC Scopus subject areas

  • Automotive Engineering
  • Aerospace Engineering
  • Computer Networks and Communications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

A Soft-Network-Coded Multilevel Forwarding Scheme for Multiple-Access Relay Systems. / Jayakody, Dushantha N.K.; Li, Jun; Flanagan, Mark F.

In: IEEE Transactions on Vehicular Technology, Vol. 65, No. 5, 7120177, 01.05.2016, p. 3430-3439.

Research output: Contribution to journalArticle

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