Robbed bit signal detection and compensation

Abstract

Detection and compensation for periodic disturbances in sampled data such as the error introduced by robbed bit signaling (RBS) in a digital carrier system. A period of N samples, e.g., six or twelve frames, at which the periodic disturbance repeats is identified for collecting a subset of the sampled data, i.e., samples taken from a common frame. In a digital telephone network (DTN), the RBS disturbance repeats at an integer multiple of 6 frames; signaling bits A, B in a superframe (SF), or at a period of 12 frames. In an extended superframe (ESF), the RBS may repeat every 24 frames, using signaling bits A, B, C, D in one of every sixth frame. An embodiment detects the presence of the periodic robbed bit signaling disturbances in sampled data by integrating the least significant bits (lsbs) of the subset samples from a frame to determine whether in-band signaling is being performed in the frame. Thus, the octets of identified frames may be adjusted by plus or minus a half least significant bit magnitude to compensate for the error introduced by T-Carrier signaling and the like.

Dependencies are inferred from the claim text.