초록 ▼

A digital receiver for GPS C/A-code signals is described. The GPS receiver of the present invention provides reception and tracking a plurality of satellites simultaneously, using four separate receiver channels. The GPS receiver of the present invention includes an analog front-end for selecting an

A digital receiver for GPS C/A-code signals is described. The GPS receiver of the present invention provides reception and tracking a plurality of satellites simultaneously, using four separate receiver channels. The GPS receiver of the present invention includes an analog front-end for selecting and frequency translating the received GPS signal. The GPS receiver further includes a highspeed digital signal processor for recovering the despread data of the GPS signal. The baseband signal is further processed by a general purpose digital signal processor for signal search, tracking, and data recovery operations, and a microprocessor provides overall receiver control, and interface with the operator of the GPS receiver.

대표청구항 ▼

An improved substantially digital receiver apparatus for the reception of one or more direct-sequence-coded spread spectrum signals, which exhibit substantially equal carrier frequencies, except for Doppler shifting, said apparatus comprising: (a) first means for coupling a wideband radio frequency

An improved substantially digital receiver apparatus for the reception of one or more direct-sequence-coded spread spectrum signals, which exhibit substantially equal carrier frequencies, except for Doppler shifting, said apparatus comprising: (a) first means for coupling a wideband radio frequency (RF) signal containing said spread spectrum signals to said receiving apparatus; (b) second means, including preselector and down-converting means, coupled to said first means, for selecting a composite signal containing said spread spectrum signals from said wide-band RF signal and for frequency-translating said composite signal to an intermediate frequency; (c) digitizing means, coupled to said second means, for converting said translated composite signal to a digital composite signal, at a predetermined sampling rate, wherein the predetermined sampling rate is determined according to the relationship: m fs=4fi wherein fi is said intermediate frequency and fs is the predetermined sampling rate; (d) first processing means, coupled to said digitizing means, for separating and despreading each of said spread spectrum signals from said digital composite signal, and for deriving a prompt and auxiliary late-early signal corresponding to each spread-spectrum signal; and (e) second processing means, coupled to said first processing means, providing for each desired signal, code delay search and tracking and carrier search and tracking processing for each of said doppler shifted signals, and data recovery processing.