An ICI-Aware Approach for Physical-Layer Network Coding in Time-Frequency-Selective Vehicular Channels

Zhenhui Situ, Ivan Wang Hei Ho, Taotao Wang, Soung Chang Liew

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

1 Citation (Scopus)

Abstract

Applying physical-layer network coding (PNC) to vehicular ad-hoc networks (VANETs) can theoretically boost the network throughput by 100%, thus partially addressing the intermittent node connectivity and short contact time issues caused by high speed vehicle motions. However, the application of OFDM modulated PNC in VANETs faces detrimental effects caused by carrier frequency offsets (CFOs) and time-frequency-selective channels. CFOs may destroy the orthogonality of OFDM subcarriers, resulting in inter-carrier interference (ICI). The CFOs of two transmitters may also be different, and cannot be removed by CFO tracking and equalization at the receiver as in conventional single-user communication even if the CFOs are known. In addition, time-frequency- selective channels due to delay and Doppler spreads are difficult to estimate and non-accurate channel estimations will increase the detection bit error rate (BER). To address the two challenges, this paper proposes an ICI-aware approach that jointly exploits pilot and data for channel estimation and data detection. Specifically, our approach jointly uses the belief propagation (BP) algorithm to mitigate the CFO/ICI effect for data detection, and the expectation maximization (EM) algorithm to accurately estimate the channels. A linear interpolation method and an ICI compensation method are simulated as benchmarks. Simulation results indicate that our approach improves the BER performance compared to the two benchmarks (more than 2 dB SNR gain in most cases), especially in the high SNR regime.

Original languageEnglish
Title of host publication2018 IEEE 87th Vehicular Technology Conference, VTC Spring 2018 - Proceedings
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages1-6
Number of pages6
Volume2018-June
ISBN (Electronic)9781538663554
DOIs
Publication statusPublished - 20 Jul 2018
Event87th IEEE Vehicular Technology Conference, VTC Spring 2018 - Porto, Portugal
Duration: 3 Jun 20186 Jun 2018

Conference

Conference87th IEEE Vehicular Technology Conference, VTC Spring 2018
Country/TerritoryPortugal
CityPorto
Period3/06/186/06/18

ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics

Cite this