摘要 : This paper presents a novel phase precoding (pre-equalization)technique to equalize frequency-selective Rayleigh and Rician slowlyfading channels for personal communication systems using phasemodulation. In order to achieve inters... 展开 This paper presents a novel phase precoding (pre-equalization)technique to equalize frequency-selective Rayleigh and Rician slowlyfading channels for personal communication systems using phasemodulation. In order to achieve intersymbol interference (ISI)-freetransmission, the precoding technique pre-distorts the signaltransmitted from a base station to a portable unit. The novelty of thetechnique lies in using a spiral curve design: (1) to ensure thestability of the precoder even in equalizing a non-minimum-phasechannel; (2) to obtain an ISI-free received signal; and (3) to keep aconstant transmitted signal amplitude. Using the precoder can improvethe bit-error-rate (BER) transmission performance without increasing thecomplexity of the portable unit receiver. The BER performance ofcoherent quadrature phase-shift-keying (QPSK) with the channelpre-equalization is analyzed theoretically for both Rayleigh and Ricianfading channels. Analytical and simulation results demonstrate thatcoherent QPSK using the proposed channel precoder has a significantlylower BER than that using a conventional decision-feedback equalizer(DFE) because the precoder does not suffer from error propagation 收起