Differentially coherent demodulation for differential BPSK inspread spectrum systems

摘要

A demodulator for differential phase-shift keying is proposed,nwhich outperforms significantly the noncoherent receiver. It is based onncoherent demodulation with decision-directed channel estimation followednby differential demodulation. The metric for maximum-likelihood decodingnis derived. The performance is estimated for spread spectrumncommunication on frequency-selective Rayleigh fading channels. It isndemonstrated that the proposed demodulator is attractive in particularnfor systems with low maximum Doppler frequency