Group demodulator employing multi-symbol chirp Fourier transform

This paper proposes a group demodulator that employs multi-symbol chirp Fourier transform to demodulate pulse shaped and time asynchronous signals without degradation; this is not possible with conventional group demodulators based on chirp Fourier transform. Computer simulation results show that the bit error rate degradation of the proposed group demodulator at BER = 10^-3 is less than 0.3 dB even when a root Nyquist (α = 0.5) filter is used as the transmission pulse shaping filter and the symbol timing offset between the desired channel and the chirp sweep is half the symbol period.