Blind weak signal detection via dictionary learning in time-spreading distortion channels using vector sensors

This paper presents a blind passive signal detection method for underwater sparse time-spreading distortion (TSD) channels, employing a dictionary learning (DL) algorithm. This approach estimates and separates the unknown signal from the unknown channel impulse response. A log-likelihood ratio detector is derived and utilized for sparse TSD channels. Simulations and underwater experiments with a vector sensor are conducted to evaluate the performance of the proposed DL-based blind passive method and compare it with other approaches. The improved detection probabilities achieved by this blind method demonstrate its effectiveness in the detection of unknown signals within TSD channels.