Real-time modulation for GNSS pilot / data synthesis

Abstract

This application provides a method and receiver architecture for improving sensitivity and tracking performance in a Global Navigation Satellite System (GNSS) receiver by coherently combining pilot signals and data signals. [Solution] A pilot signal and a corresponding data signal are received from a common GNSS signal source, and the data bits in the data signal are demodulated using the pilot signal as a phase reference. The demodulated data bits are canceled or remodulated for alignment, enabling coherent synthesis of the pilot signal and data signal into a single synthesized signal. The system may use a phase rotator to remove a constant phase offset, perform secondary code cancellation, and dynamically adjust the synthesis gain based on an estimated bit error rate. Engagement control enables or disables synthesis based on the carrier-to-noise density ratio and a signal power threshold.

Claims

1. A method for coherently combining pilot signals and data signals in a Global Navigation Satellite System (GNSS) receiver, wherein the method is: The steps include receiving pilot signals and data signals from the same GNSS signal source, A step of demodulating the data bits in the data signal using the pilot signal as a phase reference, The steps include canceling the demodulated data bits from the data signal, The process includes the step of coherently combining the pilot signal and the data signal to generate a combined signal. method.

2. The further step includes, after integration and dumping operations, using a phase rotater to remove a constant phase offset between the pilot signal and the data signal. The method according to claim 1.

3. The further step includes performing a secondary code cancellation on both the pilot signal and the data signal after the integration and dumping operations, The method according to claim 2.

4. The process further includes generating an engagement decision to enable or disable data demodulation and pilot / data synthesis, wherein the engagement decision is: Mean carrier-to-noise density ratio (C / N) 0 ) exceeds the first threshold, and, The sum of the pilot signal power and the data signal power exceeds the second threshold. Based on, The method according to claim 1.

5. The step of demodulating the data bits includes the step of using differential demodulation between the pilot signal and the data signal. The method according to claim 1.

6. The synthesized signal is used as input to the frequency tracking loop, phase tracking loop, and code tracking loop of the GNSS receiver. The method according to claim 1.

7. The demodulation and coherent synthesis are performed over at least one integration period, and the coherent synthesis gain is dynamically adjusted based on a real-time estimate of the bit error rate. The method according to claim 1.

8. The aforementioned coherent synthesis is applied during acquisition to improve the sensitivity of the GNSS receiver by at least 1.5 dB compared to the pilot-only baseline. The method according to claim 1.

9. The step of demodulating the data bits in the data signal using the pilot signal as a phase reference is performed in real time. The method according to claim 1.

10. A Global Navigation Satellite System (GNSS) receiver, said GNSS receiver At least one processing unit, When executed by the aforementioned processing unit, the GNSS receiver: The operation of receiving pilot signals and data signals from the same GNSS signal source, The operation involves demodulating the data bits in the data signal using the pilot signal as a phase reference, An operation to cancel the demodulated data bits from the data signal, The operation involves coherently combining the pilot signal and the data signal to generate the combined signal, Includes memory that stores instructions to execute, GNSS receiver.

11. The processing unit is further configured to use a phase rotator to remove a constant phase offset between the pilot signal and the data signal after integration and dumping operations. The GNSS receiver according to claim 10.

12. The processing unit is further configured to perform secondary code cancellation on both the pilot signal and the data signal after the integration and dumping operations. The GNSS receiver according to claim 11.

13. The processing unit is further configured to generate an engagement decision to enable or disable data demodulation and pilot / data synthesis, and the engagement decision is Mean carrier-to-noise density ratio (C / N) 0 ) exceeds the first threshold, and, The sum of the pilot signal power and the data signal power exceeds the second threshold. Based on, The GNSS receiver according to claim 10.

14. The processing unit is configured to demodulate the data bits using differential demodulation between the pilot signal and the data signal. The GNSS receiver according to claim 10.

15. The synthesized signal is supplied as input to the frequency tracking loop, phase tracking loop, and code tracking loop of the GNSS receiver. The GNSS receiver according to claim 10.

16. The processing unit is configured to dynamically adjust the coherent synthesis gain based on a real-time estimate of the bit error rate. The GNSS receiver according to claim 10.

17. The processing unit is configured to perform the demodulation and coherent synthesis during the signal acquisition stage to improve the sensitivity of the GNSS receiver by at least 1.5 dB compared to the pilot-only baseline. The GNSS receiver according to claim 10.

18. The GNSS receiver is implemented by software such that the demodulation and coherent synthesis are performed without modifying the existing tracking loop architecture. The GNSS receiver according to claim 10.

19. The processing unit is configured to perform real-time demodulation of the data bits in the data signal using the pilot signal as a phase reference. The GNSS receiver according to claim 10.

20. A method for coherently combining pilot signals and data signals in a Global Navigation Satellite System (GNSS) receiver, wherein the method is: The steps include receiving pilot signals and data signals from the same GNSS signal source, A step of demodulating the data bits in the data signal using the pilot signal as a phase reference, The steps include modulating the pilot signal with the demodulated data bits, The process includes the step of coherently combining the pilot signal and the data signal to generate a combined signal. method.

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