Performance Analysis of Joint Time Delay and Doppler-Stretch Estimation with Random Stepped-Frequency Signals

摘要

This paper investigates the performance of joint time delay andDoppler-stretch estimation with the random stepp ed-frequency (RSF) signal.Applying the ambiguity function (AF) to implement the estimation, we derive thecompact expressions of the theoretical mean square errors (MSEs) under highsignal-to-noise ratios (SNRs). The obtained MSEs are shown consistent with thecorresponding Cramer-Rao lower bounds (CRLBs), implying that the AF-basedestimation is approximately efficient. Waveform parameters including highercarrier frequencies, wider bandwidth covered by the carrier frequencies, andfrequency shifting codewords with larger variance are expected for a betterestimation performance. As a synthetic wideband signal, the RSF signal achievesthe same estimation performance as the OFDM signal within an identicalbandwidth. Due to its instantaneous narrowband character, requirement for thebandwidth of the receiver is much reduced.