Use of SCH bursts for co-channel interference measurements

• US 20070207740A1
• Filed: 03/02/2006
• Published: 09/06/2007
• Est. Priority Date: 03/02/2006
• Status: Active Grant

• Current Assignee: PCTEL, Inc.
• Original Assignee: PC-TEL Incorporated
• Inventors: Dickey, Sergey
• Granted Patent: US 7,639,985 B2
• Time in Patent Office: Days
• US Class Current: 455/67.110
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/3913 Predictive models, e.g. based on neural network models

Abstract

A method and apparatus for identifying signal sources in a multi-source signal. Levels of signal components transmitted by each of the co-channel base stations in the area under test in a wireless network are measured and associated with the appropriate (originating) base station in the presence of co-channel and adjacent-channel interference without interrupting service by sensing and responding to received, variable, patterns.

Claims

1. A method of analyzing a plurality of collected signal samples comprising:

evaluating and obtaining information from at least some of the samples, the information identifies a source of at least one respective sample;

selecting a sample from the plurality;

synthesizing a representation of a portion of an expected signal from a respective source according to some of the obtained information; and

correlating at least a portion of the selected sample with the representation.

2. A method as in claim 1 which includes carrying out the synthesizing and correlating with respect to each member of a second plurality of samples from the plurality.

3. A method as in claim 1 which includes:

decoding at least some of the samples; and

forming groups of decoded samples, the groups are each associated with a respective source.

4. A method as in claim 3 which includes:

obtaining information relative to the respective source from members of each of the groups.

5. A method as in claim 4 where synthesizing includes:

selecting a group and in accordance with group information as well as other information from the selected sample, then synthesizing the representation.

6. A method as in claim 5 which includes selecting each of the groups and synthesizing a respective representation of a signal from a respective source relative to the selected sample.

7. A method as in claim 6 which includes correlating each of the respective representations with the selected sample.

8. A method as in claim 1 where, responsive to results of correlating a respective signal strength indicator is formed.

9. A method as in claim 1 where synthesizing the representation includes synthesizing a representation of a variable data burst of a wireless communication system.

10. A method as in claim 1 where correlating is carried out relative to a time based interval of the selected sample.

11. A method as in claim 10 which includes associating the interval with a predetermined time of arrival of at least part of the representation.

12. A method comprising:

collecting plurality of wireless signal samples in a selected region;

identifying at least one source of signal samples using members of the plurality;

selecting one of the collected samples;

synthesizing a time based representation of a selected data pattern associated with the at least one source; and

correlating at least a portion of the one sample with the representation.

13. A method as in claim 12 where portions of the one sample present in a time based range are correlated with the representation.

14. A method as in claim 13 where the range includes an expected time of arrival of the representation.

15. A method as in claim 12 where the synthesized representation is based in part on information associated with the one source and in part on information associated with the one sample.

16. A method as in claim 15 which includes identifying a plurality of signal sources.

17. A method as in claim 16 which includes synthesizing a plurality of time based representations of data patterns associated with respective signal sources;

and

correlating the selected sample with each of the representations.

18. A method as in claim 12 which includes forming a plurality of groups of respective decodable samples with each group associated with a respective signal source.

19. A method as in claim 18 which includes repeating the selecting and the synthesizing steps, for a plurality of collected samples, for each of the members of the plurality of groups.

20. A method as in claim 18 where forming a group includes evaluating at least location, signal strength, and base station identification codes.

21. A method comprising:

conducting a drive test;

collecting and storing a plurality of wireless signal samples during the drive test;

identifying, responsive to source information associated with members of the plurality, at least one signal source;

relative to a signal sample from the plurality, synthesizing an expected signal portion corresponding to the identified signal source; and

correlating the signal sample with the synthesized portion to establish the presence of a signal from the identified source in the signal sample.

22. A method as in claim 21 where synthesizing is responsive to both information associated with the signal sample from the plurality and information associated with the identified source.

23. An apparatus comprising:

an antenna;

an RF receiver coupled to the antenna;

a data storage device;

control circuits including control software, coupled to the RF receiver, and the data storage device, the control software storing collected samples of a plurality of received wireless signals, along with time of arrival and location of receipt in the data storage device; and

analysis software recorded on a computer readable medium, the software, responsive to stored, collected samples selects at least one sample and, synthesizes an expected representation of a portion of a waveform from a source including additional software that correlates the one sample with the representation.

24. An apparatus as in claim 23 where the analysis software identifies sources of collected, at least partly decodable, signals in accordance with a predetermined criterion.

25. An apparatus as in claim 23, where responsive to selected results of correlation processing, a respective signal strength indicium is associated with the one sample.

26. An apparatus as in claim 23 where the software synthesizes a representation of a variable data pattern emitted by the source with respect to an expected time of arrival of the data pattern.

27. An apparatus as in claim 23 where the additional software attempts to establish correlations between a plurality of stored, collected samples, and respective representations.

28. An apparatus as in claim 23 where the additional software carries out a correlation process relative to a predetermined time of arrival of the expected representation.

29. An apparatus as in claim 28 where a correlation time interval is established relative to the time of arrival.

30. Software stored on a computer readable medium comprising:

first software that evaluates a plurality of samples of wireless signals, and which identifies a source associated with at least one sample, the software extracts respective source related information;

second software that synthesizes, for at least a selected sample from the plurality, a selected data pattern associated with the source in accordance with source related information and sample related information; and

third software that carries out correlation processing between at least a portion of the selected sample and the synthesized data pattern, and responsive to results of the correlation processing, establishes the presence of the data pattern in the selected sample in accordance with a predetermined criterion.

31. Software as in claim 30 which associates a source and signal strength with each member of the plurality where a correlation has been established between the selected sample and the synthesized data pattern.

32. Software as in claim 30 where the second software synthesizes synchronizing burst representations in accordance with at least one of, expected time of arrival, source identifier and reduced frame number.

33. Software as in claim 32 where the third software carries out correlation processing between respective synthesized synchronizing burst representations and the members of the plurality of samples relative to respective selected time windows.

34. Software as in claim 33 which associates signal strength indicia with correlated members of the plurality of samples.

35. A system comprising:

a data base that contains a first plurality of wireless signal samples collected from a selected region; and

an apparatus that analyzes the samples, the apparatus carries out a synthesis process, relative to each of at least some of the samples, the synthesis process establishes a representation of a portion of a signal, which might be present in a respective sample and subsequently correlates at least a portion of the sample with the representation.

36. A system as in claim 35 where the apparatus includes software which defines a group of decodable samples from the first plurality which have been emitted from a common source, and establishes time of arrival information usable in the synthesis process.

37. A system as in claim 36 where the software establishes the time of arrival information based at least in part on the characteristics of the group of decodable samples.

38. A system as in claim 35 where the apparatus includes software which identifies a plurality of different sample sources in accordance with selected decodable samples from the first plurality.

39. A system as in claim 38 where the apparatus includes software which carries out the synthesis process relative to each of the members of a second plurality of samples, from the first plurality, and with respect to each member of the plurality of sample sources.

40. A system as in claim 39 where the apparatus carries out correlation processing relative to each member of the second plurality and each respective representation associated with each member of the plurality of sources.

41. A system as in claim 35 where the data base comprises collected signal samples associated with a wireless communications system.

42. A system as in claim 35 where the representation corresponds to a variable data pattern emitted by a communications system.

43. A system as in claim 35 where the apparatus establishes at least one source for the signal in accordance with decodable signal samples from the first plurality.

44. A system as in claim 35 where prior to carrying out the synthesis process, the apparatus identifies a plurality of signal sources in response to information from the plurality of signal samples.