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

TL;DR

This paper analyzes the performance of joint time delay and Doppler-stretch estimation using random stepped-frequency signals, deriving theoretical error bounds and demonstrating efficiency and advantages over traditional methods.

Contribution

It provides a theoretical analysis of the estimation performance with RSF signals, including MSE expressions and efficiency validation, and compares RSF with OFDM signals.

Findings

MSEs are consistent with CRLBs, indicating near efficiency.

Higher waveform parameters improve estimation accuracy.

RSF achieves similar performance to OFDM with reduced receiver bandwidth.

Abstract

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