An Efficient Track-Before-Detect Algorithm Based on Complex Likelihood Ratio in Radar Systems

In this paper, we presented a track-before-detect (TBD) method which can cope with range-Doppler ambiguity for medium pulse repetition frequency (MPRF) radars. The target state evolutions in the ambiguous range-Doppler domain are considered as a hybrid system with the range-Doppler ambiguous number deemed as mode variable. Phase information of measurement is used to provide a detection sensitivity improvement, and the reduction of computation is acquired by using complex likelihood instead of the envelope likelihood. Finally, a dynamic programming algorithm is used to estimate target state and ambiguous number of every PRF, and the true trajectory of target is backtracked after resolving the ambiguity. Simulation results show that the proposed method achieves 1.2 dB performance improvement at 50 % detection rate compared with the present method. Copyright © 2014 IFSA Publishing, S. L.