Burst DSP demodulator for low E/sub b//N/sub 0/ operation

The authors describe a receive filter modification that improves carrier and symbol timing recovery in a burst DSP (digital signal processing) QPSK (quadrature phase shift keying) demodulator for satellite communications. The experimental DSP demodulator has a low unique word miss probability (Pmiss) and cycle-skipping-rate at low E/sub b//N/sub 0/ (3 dB or less). The S/N (signal-to-noise ratio) of the carrier recovery is increased by about 1 dB and the S/N of the symbol timing recovery is increased by at least 3 dB. Pmiss is improved by a factor of 100 over that of a conventional DSP demodulator.<
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