Employing the fractional autocorrelation and cross-correlation operations in target detection and range estimation using polyphase pulse compression waveforms

Radars are mostly used for detection and ranging of a target. The transmitted signal is generally a sinusoidal waveform. However, it is known that linear frequency modulated (LFM) signals are commonly employed in radars to perform pulse compression. Beside the LFM signal, step LFM and polyphase coded signals such as, Frank, P1, P2, P3 and P4 codes are also used. Since the instantenous frequency of the LFM signal is changing in time linearly, it has a linear support region on the time ? frequency plane. Using this property of the LFM, we can detect it using the Radon ? ambiguity transform as suggested in some previous works. It was also proposed and shown that LFM signals can be detected using the fractional autocorrelation function. Using the similarity of ambiguity functions of polyphase coded signals with the LFM we suggested to detect these codes applying the fractional autocorrelation function. In this thesis,we show that the fractional autocorrelation also works for the detection and ranging applications of these codes via simulations using the MATLAB software. In radars, estimation of a target?s position can also be accomplished using cross ? correlation of the received and transmitted waveforms. We suggested using fractional cross ? correlation for estimating the delay of the received waveform when the transmitted signal is the LFM, step LFM or polyphase codes. We compare the performance of conventional and fractional cross ? correlations through simulations.