Modeling of intersymbol-interference in a Rayleigh fast fading channel with typical delay power profiles

By applying a propagation model which combines Rayleigh fast fading with typical, prescribed delay power profiles, the authors analyze intersymbol interference error performance of a single-bit differential detector. A quadrature modulation with +or- pi /2 phase rotation within one symbol period, which is the case for MSK, is assumed. An analytic expression is derived for the error probability as a function of the ratio of the average energies of the relevant symbol and the preceding interfering symbols. This interference is caused by the channel time dispersion. The error probability lies between an upper and a lower bound with a margin that never exceeds 3 dB. The upper bound error probability turns out to be almost identical to the cochannel interference as calculated by the model of K. Hirade et al. (1979). Using typical delay power profiles of European propagation environments, the authors calculate error probability versus symbol duration. For bad-urban and hilly-terrain cases, in which error bursts may last for a few milliseconds, several tens to several hundreds of successive symbols will be corrupted, unless proper signal recovery measures are taken.<
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