A new group demodulator employing multi-symbol chirp Fourier transform

This paper proposes a group demodulator that employs a multisymbol chirp Fourier transform to demodulate pulse shaped and bit asynchronous signals: this is not possible with convectional group demodulators based on chirp Fourier transform. Moreover, a novel clock timing estimation scheme for the proposed group demodulator is proposed. This clock timing is estimated from the phase of two frequency components of the preamble signal with a simple calculation. Computer simulation results show that the total bit error rate degeneration of the proposed group demodulator employing a 7-symbol chirp Fourier transform is less than 0.3 dB at BER=10/sup 3/ even when root Nyquist (/spl alpha/=0.5) filtered asynchronous FDMA signals are received.