Post detection integration in DFT modulated filter bank transceivers for cognitive radio

Abstract

A discrete Fourier transform (DFT) modulated filter bank (FB) transceiver architecture is considered which can be used for both spectrum sensing and spectrum access in cognitive radio systems operating in delay dispersive fading channels. A simple post-detection integration at the secondary user receiver using the FB output signals is employed for signal demodulation of differential phase-shift keying symbols transmitted on a set of subcarriers. A constrained optimization design for the FB prototype filter coefficients is proposed which combines timefrequency (TF) concentration properties for spectrum sensing with system specifications in terms of the maximum allowed bit-error rate (BER) for the fading channel characteristics and models the primary user signal as a Gaussian distributed process. The FB TF resolution properties as well as the BER performance are investigated for transmission with a raw bit rate of 30 Mbit/s in an indoor scenario.