Code tracking loop for M-ary/SS systems using outputs gating of correlators

Code tracking loop for M-ary/SS systems using outputs gating of correlators(GCL) method is proposed for the code tracking of a communication system based on M-ary/SS scheme in which one of several sequences prepared on the tranmitter side depending on several bits of data. In the correlator outputs gating method, a certain threshold level is assumed and all correlatorspsila outputs are blocked when all correlatorspsila outputs are smaller than the threshold level. In the code tracking system using the decision feedback loop(DFL) method that is the conventional method, a deterioration in the characteristic happens when decoding error occurs, that is noise level is high or low SNR. In the correlator outputs gating method, however, all correlatorspsila outputs arenpsilat fed into the synchronous system in a situation with low SNR and a high error rate. So that we can expect the improvement of code tracking characteristic that is often reprented by code tracking error. In this paper, numerical calculation is conducted by means of induced formula. In the numerical calculation, it was found that the code tracking characteristic is improved from conventional DFL system. As a result, we can get stable code tracking. The M-ary/SS scheme is expected mass data transfer for audio-visual(AV) systems. By using the GCL system, we can realize stable mass data transfer for AV systems.