Patent ID: 6542551
Filing Date: 2003-04-01
Classification: H04B,H04J,H04L

Abstract:
In a PCM modem having a receiver for receiving PCM signals according to a frame containing a plurality of slots, an improvement comprising:a) means for receiving a training signal in said plurality of slots over a plurality of frames; b) means for finding average values (Ls) of portions of the training signal in each of said plurality of slots over said plurality of frames, and for finding average received levels (Lsf) for each of said plurality of slots in each of said plurality of frames; c) means for comparing each Lsf of each slot with the Ls of that slot to obtain a plurality of difference values (Dsf) for each slot; d) means for comparing said plurality of difference values of each slot to a threshold (Th), and for determining whether a given slot is subject to alternating robbed bit signaling based on magnitudes of said difference values for that slot and the magnitude of said threshold.