Soft-decision algorithm and readable erasure correction for a BFSK demodulator

A soft decision algorithm is described for a tangent lock loop based BFSK (binary frequency shift keying) modem. The performance of DSP (digital signal processing)-based modems can be improved by making use of the "quality" of individual bits in a demodulated bitstream, where a confidence level can be assigned to bits by recording the parameter(s) used by a soft decision algorithm. Sample test results for demodulation and erasure correction using the CHU time signal are presented.<
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