Modulation signals for a satellite navigation system
AssigneeThe Secretary of State of Defence
InventorsAnthony R. Pratt, John I. Owen
Life of this patent
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Abstract
The present invention relates to a modulation system in which an m-level, m>2, digital subcarrier is used to modulate a signal.
Claims43
-97. (canceled)
A receiver for processing a navigation signal, the navigation signal comprising a carrier signal, and at least one ranging code modulated by at least one subcarrier modulation signal, the at least one subcarrier modulation signal comprising a number, m, of amplitude levels, where m>2, the receiver comprising:
- means to receive the navigation signal;
- means to process the navigation signal to recover the modulated at least one ranging code;
- and
- means to process the recovered at least one modulated ranging code to recover at least one demodulated ranging code.
A method of processing a navigation signal, the navigation signal comprising a carrier signal, and at least one ranging code modulated by at least one sub-carrier modulation signal, the at least one subcarrier modulation signal comprising a number, m, of amplitude levels, where m>2, the method comprising the steps of:
- receiving the navigation signal;
- processing the navigation signal to recover the modulated at least one ranging code;
- and
- processing the recovered at least one modulated ranging code to recover at least one demodulated ranging code.
Dependencies are inferred from the claim text.