A near-optimum detector with reduced out-of band response for narrowband signals

Reduced spectral response in adjacent spectral bins is very desirable for d etectors since it gives capability to detect narrow band signals in the pre sence of unknown interference and colored noise. Conventionally, this is ac hieved by applying a smoothing window on the signal at the cost of detectio n performance. In this correspondence, a new method of detecting narrowband signals that uses a close approximation to the matched filter and the extr apolated input signal is proposed. The Filter used has a frequency response that is very closely equal to that of the matched filter within a doppler bin anti nearly zero response outside it.