EAS system employing pseudorandom coding system and method

摘要

According to the invention, a system and method of reducing noise interference in a way that employs pseudorandom coding. A transmitter and receiver are provided to send and receive a string of non-periodic pulses. The string of non-periodic pulses can be a sequence of pseudorandom codes. The random transmission of pulses in a non-periodic manner promotes a significant immunity to periodic interferences of constant noise operating in a surveillance area. The string of non-periodic pulses can be mutually spaced and binary, in the form of 0 or 1, and can include several bits per cycle to measure the mean and standard deviation of the string of non-periodic pulses received. A circuit is coupled to the transmitter and receiver for comparing the portion of the string of non-periodic pulses received with the string of non-periodic pulses transmitted; and whereby an alarm in triggered if the portion of the string of non-periodic pulses is above a threshold value.