An Improved Pilot Symbol Assisted Coherent Detection Scheme for Rician Fading Channels

Takashi ASAHARA  Toshiharu KOJIMA  Makoto MIYAKE  

IEICE TRANSACTIONS on Communications   Vol.E82-B   No.12   pp.2041-2048
Publication Date: 1999/12/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Multimedia Mobile Communication Systems)
mobile satellite communication,  pilot symbol,  coherent detection,  Rician fading,  

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This paper proposes a coherent detection scheme that can reduce the estimation errors of the carrier phase due to Gaussian noise in communication systems where pilot symbol assisted modulation is employed to compensate for Rician fading distortion. This paper introduces two functions in addition to conventional fading estimation methods using Wiener interpolation, etc. The first is the weighted average function for reducing the estimation errors of the fading distortion detected by pilot symbols. The second is the moving average function for estimating the phase errors that are residual after being compensated for by the estimated fading distortion. This paper evaluates the bit error rate (BER) performance for the proposed method in both Rician fading channel and additive white Gaussian noise (AWGN) channel by computer simulation. Simulation results verify that the BER performance of the proposed method is superior to that of a conventional method in both Rician fading channel and AWGN channel. Simulation results also confirm that the degradation of the BER performance of the proposed method is only 0.1 dB in AWGN channel and only 0.3 dB in Rician fading channel compared with the theoretical curves even if we reduce the number of computations by simplifying the calculation of interpolation coefficients optimized for Wiener interpolation.