Viterbi algorithm detection of shaped BPSK in adjacent-channelinterference with bandlimiting

摘要

The effect of adjacent channel interference (ACI) in UHF satellitencommunications (SATCOM) narrowband channels utilizing shapednbiphase-shift keyed (SBPSK) modulation with Viterbi algorithm (VA)ndetection is examined. The SBPSK modulator, satellite channel, andndemodulator with VA detection are modeled by a Monte Carlo simulation.nThe degradation in energy-per-bit-to-noise-spectral-density ration(E_b/N₀) relative to BPSK performance in Gaussiannnoise is determined with channel separation as a parameter. This isncompared with earlier results using integrate-and-dump (I&D)ndetection. For VA metrics matched to the ideal non-bandlimited channel,nit is found that VA detection performs considerably better than I&Dndetection at low ACI ratios. For ACI ratios above 3 dB, the opposite isntrue. It is hypothesized that VA metrics more closely matched to thenchannel-induced distorted signal will give improved performance