Patent ID: 6377557
Filing Date: 2002-04-23
Classification: H04B,H04J,H04L,H04W,Y02D

Abstract:
A data signal, modulated by an orthogonal CDMA code, embodied in a carrier wave forming a satellite based telecommunications link between earth stations and terminals via satellites, said data signal comprising:a plurality of frames comprised of a sequence of quadrature phase shift keying (QPSK) code symbols, said QPSK code symbols within each of said frames being partitioned into a sync field and a multiuse field, each of said frames beginning with said sync field followed by said multiuse field; said sync field containing predetermined QPSK code symbols enabling acquisition and tracking of frequency and chip timing by a terminal and identifying a frame boundary; and said multiuse field comprising a broadcast signaling channel field providing a broadcast signal receivable by more than one user; wherein encoded information is transmitted over said traffic channel when said traffic channel field is active and encoded information is not transmitted over said traffic channel when said traffic channel field is inactive and the loop channel field is transmitted regardless of active or inactive state of the traffic channel.