Adaptive receive diversity during discontinuous reception in mobile wireless device

• US 8,737,280 B2
• Filed: 09/13/2011
• Issued: 05/27/2014
• Est. Priority Date: 09/13/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Mujtaba, Syed A., Song, Kee-Bong, Wang, Xiaowen, Kim, Young Jae, Majjigi, Vinay R., Sebeni, Johnson O., Trilling, Romain, Shamim, Tahir, Anantharaman, Karthik
• Primary Examiner(s): Chung, Hoon J
• Assistant Examiner(s): Wang, Yaotang
• Application Number:
  US13/231,804
• Publication Number:
  US 20130064151A1
• Time in Patent Office: 987 Days
• Field of Search: 370/252, 370/331, 370/338, 455/522
• US Class Current: 370/311
• CPC Class Codes: H04B 7/0817 with multiple receivers and antenna path selection
• CPC Class Codes: H04B 7/082 selecting best antenna path
• CPC Class Codes: H04B 7/0871 using different reception schemes, at least one of them being a diversity reception scheme
• CPC Class Codes: H04L 43/0823 Errors, e.g. transmission errors

Abstract

A mobile wireless device adapts receive diversity during discontinuous reception based on downlink signal quality, page indicators and page messages. When the downlink signal quality exceeds a pre-determined threshold, the mobile wireless device decodes a page indicator channel through an initial antenna, and otherwise, decodes a paging channel through the initial antenna without decoding the page indicator channel. The mobile wireless device switches to decoding the paging channel through an alternate antenna when a page indicator decodes as an erasure. When a paging message received through a single antenna decodes with an incorrect error checking code, the mobile wireless devices enables receive diversity through multiple antennas for subsequent decoding. The mobile wireless device switches between single antenna reception and multiple antenna reception based on tracking multiple consecutive error checking code failures and successes.

Claims

1. A method of adapting antenna receive diversity in a mobile wireless device in communication with a wireless network, the method comprising:

during a discontinuous reception cycle in the mobile wireless device,

decoding at least one page indicator received on a page indicator channel through an initial antenna when a measured downlink signal quality exceeds a pre-determined threshold;

decoding one or more page messages received on a paging channel through the initial antenna without decoding the page indicator channel when the measured downlink signal quality does not exceed the pre-determined threshold;

where the paging channel and the page indicator channel are separate;

decoding one or more page messages received on the paging channel through an alternate antenna when a first page indicator received on the page indicator channel through the initial antenna decodes as an erasure value, where the erasure value indicates that an unequivocal value is not present; and

decoding one or more page messages received on the paging channel through the initial antenna and through the alternate antenna together and ignoring the page indicator channel when no paging message received on the paging channel through the initial antenna or through the alternate antenna alone decodes with a correct error checking code for a pre-determined period of time during the discontinuous reception cycle.

2. The method as recited in claim 1, further comprising:

decoding one or more page messages received on the paging channel through the initial antenna and through the alternate antenna together during a subsequent discontinuous reception cycle after decoding an incorrect error checking code in the current discontinuous reception cycle.

3. The method as recited in claim 2, further comprising:

ignoring the page indicator channel when decoding using the initial antenna and the alternate antenna together.

4. The method as recited in claim 1, further comprising:

switching from decoding the paging channel with one antenna to decoding with multiple antennas after measuring a first pre-determined number of incorrect consecutive error checking codes; and

switching from decoding the paging channel with multiple antennas to decoding the paging channel with one antenna after measuring a second pre-determined number of correct consecutive error checking codes.

5. The method as recited in claim 4, further comprising:

measuring the second pre-determined number of correct consecutive error checking codes by counting consecutive discontinuous reception cycles that contain at least one correct error checking code and no incorrect error checking codes.

6. The method as recited in claim 1, further comprising:

before decoding the at least one page indicators on the page indicator channel, selecting the initial antenna from a plurality of antennas based on a measurement of signal strength received through each of the plurality of antennas.

7. The method as recited in claim 1 wherein the wireless network operates using a CDMA2000 1×

communications protocol.

8. The method as recited in claim 7 wherein the error checking code is a layer 2 CRC segment of a layer 2 paging channel message.

9. A mobile wireless device in communication with a wireless network and adapted for antenna receive diversity, comprising:

a processor configured to, during a discontinuous reception cycle in the mobile wireless device;

decode at least one page indicator received on a page indicator channel through an initial antenna when a measured downlink signal quality exceeds a pre-determined threshold;

decode one or more page messages received on a paging channel through the initial antenna without decoding the page indicator channel when the measured downlink signal quality does not exceed the pre-determined threshold;

where the paging channel and the page indicator channel are separate;

decode one or more page messages received on the paging channel through an alternate antenna when a first page indicator received on the page indicator channel through the initial antenna decodes as an erasure value, where the erasure value indicates that an unequivocal value is not present; and

decode one or more page messages received on the paging channel through the initial antenna and through the alternate antenna together and ignoring the page indicator channel when no paging message received on the paging channel through the initial antenna or through the alternate antenna alone decodes with a correct error checking code for a pre-determined period of time during the discontinuous reception cycle.

10. The mobile wireless device as recited in claim 9, wherein the processor is further configured to:

decode one or more page messages received on the paging channel through the initial antenna and through the alternate antenna together during a subsequent discontinuous reception cycle after decoding an incorrect error checking code in the current discontinuous reception cycle.

11. The mobile wireless device as recited in claim 10, wherein the processor is further configured to:

ignore the page indicator channel when decoding using the initial antenna and the alternate antenna together.

12. The mobile wireless device as recited in claim 9, wherein the processor is further configured to:

switch from decoding the paging channel with one antenna to decoding with multiple antennas after measuring a first pre-determined number of incorrect consecutive error checking codes; and

switch from decoding the paging channel with multiple antennas to decoding the paging channel with one antenna after measuring a second pre-determined number of correct consecutive error checking codes.

13. The mobile wireless device as recited in claim 12, wherein the processor is further configured to:

measure the second pre-determined number of correct consecutive error checking codes by counting consecutive discontinuous reception cycles that contain at least one correct error checking code and no incorrect error checking codes.

14. The mobile wireless device as recited in claim 9, wherein the processor is further configured to:

before decoding the at least one page indicators on the page indicator channel, select the initial antenna from a plurality of antennas based on a measurement of signal strength received through each of the plurality of antennas.

15. The mobile wireless device as recited in claim 9, wherein:

the wireless network operates using a CDMA2000 1×

communications protocol; and

the error checking code is a layer 2 CRC segment of a layer 2 paging channel message.

16. A non-transitory computer program product encoded in a non-transitory computer readable medium for adapting antenna receive diversity in a mobile wireless device in communication with a wireless network, the non-transitory computer program product comprising:

in the mobile wireless device, during a discontinuous reception cycle, non-transitory computer program code configured to;

decode at least one page indicator received on a page indicator channel through an initial antenna when a measured downlink signal quality exceeds a pre-determined threshold;

decode one or more page messages received on a paging channel through the initial antenna without decoding the page indicator channel when the measured downlink signal quality does not exceed the pre-determined threshold;

where the paging channel and the page indicator channel are separate;

decode one or more page messages received on the paging channel through an alternate antenna when a first page indicator received on the page indicator channel through the initial antenna decodes as an erasure value, where the erasure value indicates that an unequivocal value is not present; and

decode one or more page messages received on the paging channel through the initial antenna and through the alternate antenna together and ignoring the page indicator channel when no paging message received on the paging channel through the initial antenna or through the alternate antenna alone decodes with a correct error checking code for a pre-determined period of time during the discontinuous reception cycle.

17. The non-transitory computer program product as recited in claim 16, wherein the non-transitory computer program code is further configured to:

decode one or more page messages received on the paging channel through the initial antenna and through the alternate antenna together during a subsequent discontinuous reception cycle after decoding an incorrect error checking code in the current discontinuous reception cycle.

18. The non-transitory computer program product as recited in claim 17, wherein the non-transitory computer program code is further configured to:

ignore the page indicator channel when decoding using the initial antenna and the alternate antenna together.

19. The non-transitory computer program product as recited in claim 16, wherein the non-transitory computer program code is further configured to:

switch from decoding the paging channel with one antenna to decoding with multiple antennas after measuring a first pre-determined number of incorrect consecutive error checking codes; and

switch from decoding the paging channel with multiple antennas to decoding the paging channel with one antenna after measuring a second pre-determined number of correct consecutive error checking codes.

20. The non-transitory computer program product as recited in claim 19, wherein the non-transitory computer program code is further configured to:

measure the second pre-determined number of correct consecutive error checking codes by counting consecutive discontinuous reception cycles that contain at least one correct error checking code and no incorrect error checking codes.

21. The non-transitory computer program product as recited in claim 16, wherein the non-transitory computer program code is further configured to:

before decoding the at least one page indicators on the page indicator channel, select the initial antenna from a plurality of antennas based on a measurement of signal strength received through each of the plurality of antennas.

22. The non-transitory computer program product as recited in claim 16, wherein:

the wireless network operates using a CDMA2000 1×

communications protocol; and

the error checking code is a layer 2 CRC segment of a layer 2 paging channel message.