Radio Frequency (RF) Signal Multiplexing

• US 20090274079A1
• Filed: 04/28/2009
• Published: 11/05/2009
• Est. Priority Date: 05/01/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Row, Chang Shik, Rahmat, Arie, Grover, Doulgas, Rowitch, Douglas Neal, Bhatia, Ashok, Farmer, Dominic Gerard
• Granted Patent: US 8,634,785 B2
• Time in Patent Office: Days
• US Class Current: 370/310
• CPC Class Codes: H04B 1/3805 with built-in auxiliary receivers
• CPC Class Codes: H04B 1/403 using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency

Abstract

In a radio frequency (RF) receiver, a receiver RF chain is tuned to a first (e.g., global positioning system (GPS)) channel to permit receipt of a first (e.g., GPS) signal over the first (e.g., GPS) channel on the receiver RF chain during a first time duration. The receiver RF chain is tuned to a second (e.g., cellular page) channel to permit receipt of a second (e.g., cellular page) signal over the second (e.g., cellular page) channel on the receiver RF chain during a second time duration, following the first time duration. The first (e.g., GPS) signal is processed during the first time duration and the second time duration, without any apparent interruption of the first (e.g., GPS) signal during the second time duration. The processing, for example, treats the actual interruption as a temporary, short term fade of the first (e.g., GPS) signal during the second time duration, or provides a bridge signal (e.g., an estimated GPS signal on the receiver RF chain or an actual GPS signal received on another receiver RF chain) during the second time duration.

Claims

1. A method comprising:

tuning to a first channel on a first receiver radio frequency (RF) chain to permit receipt of a first signal during a first time duration;

tuning to a second channel on the first receiver RF chain to permit receipt of a second signal during a second time duration, following the first time duration; and

processing the first signal during the first time duration and during the second time duration, without any apparent interruption of the first signal during the second time duration.

2. The method of claim 1, further comprising:

providing a bridge signal, representative of the first signal that was expected to be received over the first channel on the first receiver RF chain during the second time duration to permit processing of the first signal during the first time duration, and

processing of the bridge signal during the second time duration.

3. The method of claim 2, wherein the bridge signal comprises:

an estimate of the first signal that was not received over the first channel on the first receiver RF chain during the second time duration.

4. The method of claim 2, further comprising:

tuning to the first channel on a second receiver RF chain, different from the first receiver RF chain, to permit receipt of the first signal over the first channel on the second receiver RF chain during a third time duration;

wherein the bridge signal comprises the first signal actually received over the first channel on the second receiver RF chain during the second time duration.

5. The method of claim 4, wherein the third time duration corresponds to the second time duration and is aligned in time with a beginning of and an end of the second time duration.

6. The method of claim 4, wherein the third time duration corresponds to the second time duration and overlaps in time with at least one of a beginning of and an end of the second time duration.

7. The method of claim 1, further comprising:

interrupting the receipt of the first signal over the first channel on the first receiver RF chain;

wherein the tuning to the second channel is in response to the interrupting.

8. The method of claim 1, further comprising:

determining first channel tuning information for the first channel on the first receiver RF chain before an end of the first time duration; and

storing the first channel tuning information for the first channel in response to determining the first channel tuning information.

9. The method of claim 1, further comprising:

determining second channel tuning information for the second channel on the first receiver RF chain before an end of the second time duration; and

storing the second channel tuning information for the second channel in response to determining the second channel tuning information.

10. The method of claim 1, in which the first signal comprises a satellite positioning system (SPS) signal, and the method further comprises adjusting a phase of the SPS signal, once received, based upon a continuously-on digital counter.

11. The method of claim 10, in which the adjusting further comprises shifting the phase in a plurality of shared filters.

12. A method comprising:

tuning to a satellite positioning system (SPS) channel on a first receiver radio frequency (RF) chain to permit receipt of at least one SPS signal during a first time duration;

tuning to a cellular page channel on the first receiver RF chain to permit receipt of a cellular page signal during a second time duration, following the first time duration; and

processing the SPS signal during the first time duration and during the second time duration, without any apparent interruption of the SPS signal during the second time duration.

13. The method of claim 12, further comprising:

providing a bridge signal, representative of the SPS signal that was expected to be received over the SPS channel on the first receiver RF chain during the second time duration to permit the processing of the SPS signal during the first time duration and processing of the bridge signal during the second time duration.

14. The method of claim 13, wherein the bridge signal comprises:

an estimate of the SPS signal that was not received over the SPS channel during the second time duration.

15. The method of claim 13, further comprising:

tuning to the SPS channel on a second receiver RF chain, different from the first receiver RF chain, to permit receipt of the SPS signal over the SPS channel on the second receiver RF chain during a third time duration;

wherein the bridge signal comprises the SPS signal actually received over the SPS channel on the second receiver RF chain during the second time duration.

16. The method of claim 15, wherein the third time duration corresponds to the second time duration and overlaps in time with at least one of a beginning of and an end of the second time duration.

17. A method comprising:

tuning to a satellite positing system (SPS) channel on a first receiver radio frequency (RF) chain;

receiving a SPS signal on the SPS channel on the first receiver RF chain during a first time duration in response to tuning to the SPS channel;

interrupting the receiving of the SPS signal over the SPS channel on the first receiver RF chain;

tuning to a cellular page channel on the first receiver RF chain in response to interrupting the receiving of the SPS signal;

receiving a cellular page signal, when present, on the cellular page channel on the first receiver RF chain during a second time duration, following the first time duration in response to tuning to the cellular page channel;

providing a bridge signal, representative of the SPS signal that was expected to be received over the SPS channel on the first receiver RF chain during the second time duration; and

processing the SPS signal during the first time duration and the bridge signal during the second time duration, without any apparent interruption of the SPS signal during the second time duration.

18. The method of claim 17, wherein the bridge signal comprises:

an estimate of the SPS signal that was not received over the SPS channel on the first receiver RF chain during the second time duration.

19. The method of claim 17, further comprising:

tuning to the SPS channel on a second receiver RF chain, different from the first receiver RF chain, to permit receipt of the SPS signal over the SPS channel on the second receiver RF chain during a third time duration;

wherein the bridge signal comprises the SPS signal actually received over the SPS channel on the first receiver RF chain during the second time duration.

20. The method of claim 19, wherein the third time duration corresponds to the second time duration and overlaps in time with at least one of a beginning of and an end of the second time duration.

21. A radio frequency (RF) receiver comprising:

a first receiver radio frequency (RF) chain;

a first tuning signal processor that;

tunes to a first channel on the first receiver RF chain to permit receipt of a first signal over the first channel during a first time duration; and

tunes to a second channel on the first receiver RF chain to permit receipt of a second signal over the second channel during a second time duration, following the first time duration; and

a first signal processor that processes the first signal during the first time duration and during the second time duration, without any apparent interruption of the first signal during the second time duration.

22. The RF receiver of claim 21, further comprising:

a second receiver RF chain, different from the first receiver RF chain; and

a second tuning signal processor that tunes to the first channel on the second receiver RF chain to permit receipt of the first signal over the first channel on the second receiver RF chain during the second time duration;

wherein the first signal processor processes the first signal from the first receiver RF chain during the first time duration and processes the first signal from the second receiver RF chain during second time duration to provide a reconstituted first signal, without any apparent interruption of the first signal on the first receiver RF chain during the second time duration.

23. The RF receiver of claim 21, wherein the first signal processor processes the first signal during the first time duration and processes an estimate of the first signal during the second time duration to provide a restored first signal, without any apparent interruption of the first signal during the second time duration.

24. The RF receiver of claim 21, comprising:

a real time clock, coupled to the first tuning signal processor, for providing a clock signal on which to time the tuning to the first channel during the first time duration and to time the tuning to the second channel during the second time duration.

25. A radio frequency (RF) receiver comprising:

means for tuning to a first channel on a receiver radio frequency (RF) chain to permit receipt of a first signal over the first channel during a first time duration;

means for tuning to a second channel on the receiver RF chain to permit receipt of a second signal over the second channel during a second time duration, following the first time duration; and

means for processing the first signal during the first time duration and during the second time duration, without any apparent interruption of the first signal during the second time duration.

26. A computer readable medium tangibly storing program code, comprising:

program code to tune to a first channel on a receiver radio frequency (RF) chain to permit receipt of a first signal over the first channel during a first time duration;

program code to tune to a second channel on the receiver RF chain to permit receipt of a second signal over the second channel during a second time duration, following the first time duration; and

program code to process the first signal during the first time duration and during the second time duration, without any apparent interruption of the first signal during the second time duration.

27. A method comprising:

tuning to a first channel on a second receiver radio frequency (RF) chain to permit receipt of a first signal over the first channel on the second receiver RF chain during a first time duration;

tuning to the first channel on a first receiver RF chain, different from the second receiver RF chain, to permit receipt of the first signal over the first channel on the first receiver RF chain during a third time duration; and

processing the first signal from the second receiver RF chain during the first time duration and the first signal from the first receiver RF chain during the third time duration to provide a reconstituted first signal during the first and third time durations.

28. The method of claim 27, comprising:

tuning to a second channel on the second receiver RF chain to permit receipt of a second signal over the second channel on the second receiver RF chain during a second time duration, following the first time duration.

29. The method of claim 27, wherein the third time duration corresponds to the second time duration and overlaps in time with at least one of a beginning and an end of the second time duration.

30. The method of claim 29, further comprising estimating a fractional carrier phase difference between the first signal from the first receiver RF chain and the first signal from the second receiver RF chain during the overlap;

wherein the processing accounts for the estimated fractional carrier phase difference.