A signal generator and a method of generating a Composite Binary Offset Carrier signal, the Composite Binary Offset Carrier signal and a navigation signal thereof with a receiver to process the navigation signal

摘要

A signal generator and a method of generating a Composite Binary Offset Carrier signal (CBOC) or spreading modulation signal from first and second Binary Offset Carrier (BOC) signals are disclosed. The signal has a predetermined power spectral density comprising at least reduced cross spectral terms of the power spectral densities of the first and second BOC signal averaged over at least two predetermined time intervals. The signal generator comprises means to arrange for the states of the first and second BOC signals over a subsequent predetermined time interval of the at least two predetermined time intervals to be complementary to the states of the first and second BOC signals over a current predetermined time interval of the at least two predetermined time intervals. Further disclosed are the resulting Composite Binary Offset Carrier signal having a predetermined power spectral density and a navigation signal comprising a combination of a carrier, a ranging code and the CBOC signal. The CBOC comprises at least reduced cross spectral terms of the power spectral densities of first and second BOC signals averaged over at least two predetermined time intervals. The phase states of the first and second BOC signals over a subsequent predetermined time interval of the at least two predetermined time intervals are complementary to the phase states of the first and second BOC signals over a current predetermined time interval of the at least two predetermined time intervals. Further disclosed is a receiver comprising a means adapted to process the above described navigation signal. The receiver comprises an antenna for receiving the navigation signal; an RF processor for amplifying, filtering and frequency changing the received navigation signal, and producing digitised received signal samples therefrom.