Abstract: A method for detecting a skywave symbol, the method may include (i) receiving, by a skywave receiver, signals of different subcarriers that are within a skywave frequency range that comprises legal subcarriers and illegal subcarriers; (ii) performing sorting iterations to provide a sorted list of signals intensities; and (iii) providing a detection result indicative of a reception of the skywave symbol based on at least some members of the sorted list.

Abstract: A system and a method for counting the number of people passing a entry point in a predetermined direction. The system includes a foot-activated, pressure sensitive platform deployed at the entry point for providing a time-dependent pressure profile vector indicative of the manner in which a person arches one of his feet prior to at least partially stepping off the platform. The pressure profile vector is processed for determining whether the person completely passed through the entry point in the predetermined direction. In the affirmative case, a counter for recording the number of people completely passing through the entry point in the predetermined direction is incremented. The system can be adapted for providing a net count of the instantaneous number of people in a given area during the entering and leaving of people through an entry point into and from the given area.