MULTI-CHANNEL DIGITAL RECEIVER FOR GLOBAL POSITIONING SYSTEM

摘要

A receiver for pseudorandom noise (PRN) encoded signals consisting of a sampling circuit and multiple channel circuits, with each channel circuit including a carrier and code synchronizing circuit and multiple digital correlators with dynamically adjustable code delay spacing. The sampling circuit provides high-rate digital samples of the incoming composite signal to each receiver channel. Within each channel, the synchronizing circuit detects cycle slips in a locally generated carrier reference signal as well as phase drift in a locally generated PRN code signal. The correlators compare the digital samples with a locally generated PRN code to produce early, late, and/or punctual correlation signals which are used to adjust the local PRN code. A non-linear sampling technique may be used to provide increased sensitivity in the presence of continuous wave interfering signals.