DSP type demodulator for both asymmetric and symmetric modulations.

The authors modify a digital signal processing (DSP) type digital phase-locked loop (DPLL) with high performance named tan-DPLL (for tangent-type DPLL) to an adaptive version which can extend a noise threshold about 8 dB. Using the adaptive tan-DPLL combined with a phase partition method, they propose a DSP-type demodulator for both asymmetric and symmetric modulations. It is shown by computer simulation that the performance of the proposed demodulator agrees well with the theory.