SELF-CORRELATION DETECTION AND IN-BAND AND OUT-OF-BAND SIGNAL DETECTION FOR AUTOMATIC GAIN CALIBRATION SYSTEMS

摘要

An embodiment of the present invention provides an automatic gain control system for a wireless receiver that quickly differentiates desired in-band signals from high power out-of-band signals that overlap into the target band. The system measures power before and after passing a received signal through a pair of finite impulse response filteres (205-IP), (210-IP), (205-Q), (210-Q) and (220) that largely restrict the signal's power to that which is in-band. By comprising the in-band energy of the received signal after filtering to the total signal energy prior to filtering (215), it is possible to determine whether a new in-band signal has arrived. The presence of this new in-band signal is then verified by a multi-threshold comparison of the normalized self-correlation (225) to verify the presence of a new, desired in-band signal.