9 Citations (Scopus)

Abstract

In mobile-to-mobile channels, the Doppler shift is affected by mobile terminal velocities of the transmitter and the receiver end. Hence, the Doppler frequency becomes very high if both terminals move very fast. In this condition, the channel will change rapidly and cause large inter-carrier-interference (ICI) in OFDM system. A channel estimation technique using piece-wise linear approximation has previously been developed for ICI mitigation technique employing frequency-domain-equalizer (FEQ). Unfortunately, this channel estimation technique is limited by normalized maximum Doppler shift of 0.2, below which a negligible error results. In this paper, the carrier-frequency offset (CFO) compensation technique is proposed to improve this ICI mitigation technique, so that linear channel estimation still works well although normalized maximum Doppler shift is larger than 0.2. The CFO compensation frequency f 0 that should be added depends on transmitter Doppler shift f d and has an optimal value, i.e. f 0 = 0.55f d for mobile-to-fixed channels and f 0 = 0.6f d1 for mobile-to-mobile channels. The channel estimation using linear approximation technique can be applied with negligible error up to normalized Doppler spread f d = 0.4 (100 % higher than systems without CFO compensation) and the sum f dT = f d1 + f d2 higher than 0.4 for mobile-to-mobile channels that is inversely proportional to the ratio a = f d2 / f d1. Furthermore, assuming f d1 ≥ f d2 for mobile-to-mobile channel, the BER performance increases significantly if CFO compensation is applied.

Original languageEnglish
Title of host publication2011 International Conference on ICT Convergence, ICTC 2011
Pages430-435
Number of pages6
DOIs
Publication statusPublished - 2011
Event2011 International Conference on ICT Convergence, ICTC 2011 - Seoul, Korea, Republic of
Duration: 28 Sept 201130 Sept 2011

Publication series

Name2011 International Conference on ICT Convergence, ICTC 2011

Conference

Conference2011 International Conference on ICT Convergence, ICTC 2011
Country/TerritoryKorea, Republic of
CitySeoul
Period28/09/1130/09/11

Keywords

  • CFO compensation
  • Doppler
  • ICI
  • OFDM
  • channel estimation
  • high-speed
  • linear piece-wise

Fingerprint

Dive into the research topics of 'ICI mitigation with CFO compensation for OFDM in mobile-to-mobile channel'. Together they form a unique fingerprint.

Cite this