Direction finding estimation for linear chirp signal

In this paper, we propose a fast maximum likelihood estimation (FMLE) to estimate the direction of arrival (DOA) /spl theta/ and the frequency sweeping rate (FSR) /spl alpha/ of a linear chirp signal impinging upon an M-elements linear sensor array from a far-field source. The estimators /spl theta/ and /spl alpha/ of a chirp signal can be estimated by globally maximizing the likelihood function on the /spl theta//spl sim//spl alpha/ plane. The global maximum is located on a ridge of the 2-D /spl theta//spl sim//spl alpha/ plane. To reduce the heavy 2-D ML computation, we propose an algorithm of 1-D FMLE to search for the global maximum only along the ridge.< >