Receiving device for receiving and demodulating spectral diffusion-modulated GPS wave.

摘要

A receiving device for receiving spread spectrum-modulated GPS signal transmitted from GPS (Global Positioning System) satellites to the earth. Received GPS signals are converted into IF signals which are despread-demodulated on the basis of C/A codes, resulting in demodulated PSK signals. Carriers are reproduced from the IF signals and a clock signal for C/A code generator is produced from the reproduced carrier and a local oscillation signal. The PSK signal is demodulated on the basis of a reference frequency of a PLL circuit to obtain a navigation message. With this construction, it is possible to stably receive GPS signals from a plurality of GPS satellites with suitable timing by using a simple circuit construction. <IMAGE>