Many applications in signal processing require the search for a signal in a received waveform. A system for signal search usually processes the received samples through a non-linear receiver and makes a decision based on a decision rule. This is designed to achieve a performance goal in terms of detection rate or false-alarm rate. This search can be made through soft-decision or hard-decision approaches that typically yield suboptimal solutions for reducing complexity. The Inventors propose a new scheme for an adaptive system that performs signal search on compressed data which yields more optimal solutions. Their system is designed to solve an optimization problem whose objective function (i) is adaptive according to the variability of the operating environment and (ii) has low-complexity computation.