Resolution probability is the most important indicator for signal parameter estimator, including estimating time delay, and joint Doppler shift and time delay. In order to get high resolution probability, some procedures have been suggested such as compressed sensing. Based on the signal's sparsity, compressed sensing has been used to estimate signal parameter in recent research. After solving $\ell_0$ Norm Optimization problem, the methods would achieve high resolution. These methods all require high SNR. In order to improve the performance in low SNR, a novel implementation is proposed in this paper. We give a sparsity representation for the generalized matched filter output, or ambiguity function, while the former methods utilized the sparsity representation for channel response. By deconvolving the generalized matched filter output, 2D estimation for Doppler shift and time delay would be gotten by greedy method, optimization method based on relaxation, or Bayesian method.
Simulation demonstrates our method has better performance in low SNR than the method by the channel sparsity representation.