Advanced SCAMP´s demodulator design for performing envelope recovery from hardlimited samples

A digital demodulator is described for use in envelope detection in Advanced SCAMP, a prototype portable EHF satellite communications terminal. A simple hardware implementation is made possible by processing one-bit hardlimited samples of the received signal and by carefully choosing the sample period and the frequency of the reference oscillator. A nonlinear transformation was performed on the I and Q accumulations to reduce the output variation due to input phase angle. Performance data for the Advanced SCAMP implementation showed that using the proposed transformation extended the linear operating region by approximately 8 dB, resulting in a well-behaved envelope discriminant up to 75 dB-Hz