Channel-aided, decision-directed delay-locked loop

摘要

The present invention is a channel-aided, decision-directed delay-locked loop (CADD-DLL) implemented, in one embodiment of the present invention, for pilot-symbol-aided (PSA) code-division multiple-access (CDMA) communication. In one embodiment of the present invention initial pseudo-noise (PN) code acquisition is accomplished with the aid of a conventional non-coherent PN code acquisition system, and, upon acquiring the initial PN code epoch, PN code tracking is performed using a channel-aided, decision-directed PN code tracking mechanism. The tracking loop in accordance with the present invention includes delay and advance PN correlators. The correlators are followed by data and phase correction as well as amplitude matching devices, the outputs of which are subtracted to form an error signal for code tracking purposes.