Channel sounding for a spread-spectrum signal

• US 6,711,204 B2
• Filed: 07/19/2001
• Issued: 03/23/2004
• Est. Priority Date: 01/14/1999
• Status: Expired due to Term

• Current Assignee: Aperture Net LLC (IP Edge LLC)
• Original Assignee: Linex Technologies, Inc.
• Inventors: Schilling, Donald L.
• Primary Examiner(s): Ghayour, Mohammad H.
• Assistant Examiner(s): Nguyen, Dong X.
• Application Number:
  US09/908,639
• Publication Number:
  US 20010040878A1
• Time in Patent Office: 978 Days
• Field of Search: 375/140, 375/142, 375/143, 375/136, 375/147, 375/148, 370/335, 370/342, 370/329, 370/330, 455/69, 455/522
• US Class Current: 375/142
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence

Abstract

An improvement to a spread-spectrum code-division-multiple-access system, using a channel sounding signal from a base station (BS) to provide initial transmitter power levels for remote stations (RS). The base station transmits BS-spread-spectrum signals at a first frequency and receives RS-spread-spectrum signals, which are transmitted by the remote stations at the second frequency. The base station transmits a BS-channel-sounding signal at the same carrier frequency being used by the remote stations. The bandwidth of the BS-channel-sounding signal is much less than the bandwidth of the BS-channel-spread-spectrum signal. Each remote station tracks the BS-channel-sounding signal, for adjusting the initial RS-power level.

Claims

1. An improvement to a spread-spectrum system having a base station and a plurality of remote stations (RS), with said base station (BS) for transmitting a plurality of BS-spread-spectrum signals at a first frequency and for receiving, at a second frequency, a plurality of RS-spread-spectrum signals transmitted from said plurality of remote stations, respectively, the improvement comprising:

said base station for transmitting a BS-channel-sounding signal at the second frequency;

said plurality of remote stations for receiving the BS-channel-sounding signal at the second frequency, with said base station for transmitting the plurality of BS-spread-spectrum signals at the first frequency outside a correlation bandwidth of the plurality of RS-spread-spectrum signals transmitted by the plurality of remote stations at the second frequency; and

said plurality of remote stations, responsive to the BS-channel-sounding signal, for compensating to the second frequency the respective plurality of RS-spread-spectrum signals.

2. The improvement as set forth in claim 1, with said plurality of remote stations, responsive to the BS-channel-sounding signal, for adjusting an initial RS-power level of said plurality of remote stations.

4. The improvement as set forth in claim 1, 2, or 3, with said base station including an interference-reduction subsystem for reducing, at the second frequency, the BS-channel-sounding signal from the plurality of RS-spread-spectrum signals arriving at said base station.

5. The improvement as set forth in claim 1, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

6. The improvement as set forth in claim 2, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

7. The improvement as set forth in claim 1, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

8. The improvement as set forth in claim 2, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

10. The improvement as set forth in claim 1, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

11. The improvement as set forth in claim 2, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

12. The improvement as set forth in claim 1, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

13. The improvement as set forth in claim 2, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

15. The improvement as set forth in claim 1, with said base station including a filter for filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

16. The improvement as set forth in claim 2, with said base station including a filter for filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

17. The improvement as set forth in claim 1, with said base station including a filter for filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

18. The improvement as set forth in claim 2, with said base station including a filter for filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

19. The improvement as set forth in claim 2, with said base station including a filter for filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

20. The improvement as set forth in claim 2, with said base station including a filter for filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

3. An improvement to a spread-spectrum system having a base station and a plurality of remote stations (RS), with said base station (BS) for transmitting a plurality of BS-spread-spectrum signals at a first frequency and for receiving, at a second frequency, a plurality of RS-spread-spectrum signals transmitted from said plurality of remote stations, respectively, the improvement comprising:

said base station for transmitting a BS-channel-sounding signal at the second frequency;

said plurality of remote stations for receiving the BS-channel-sounding signal at the second frequency, with said base station for transmitting the plurality of BS-spread-spectrum signals at the first frequency outside a correlation bandwidth of the plurality of RS-spread-spectrum signals transmitted by the plurality of remote stations at the second frequency; and

said plurality of remote stations, responsive to the BS-channel-sounding signal, for adjusting an initial RS-power level of said plurality of remote stations.

9. The improvement as set forth in claim 3, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

14. The improvement as set forth in claim 3, with said base station for transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

21. An improvement to a spread-spectrum method having a base station and a plurality of remote stations (RS), comprising the steps of:

transmitting, from said base station, a plurality of BS-spread-spectrum signals at a first frequency;

transmitting, from said plurality of remote stations, a plurality of RS-spread-spectrum signals;

receiving, at said base station, at a second frequency, the plurality of RS-spread-spectrum signals transmitted from said plurality of remote stations, respectively;

transmitting, from said base station, a BS-channel-sounding signal at the second frequency;

receiving, at said plurality of remote stations, the BS-channel-sounding signal at the second frequency; and

compensating, at said plurality of remote stations, responsive to the BS-channel-sounding signal, to the second frequency, the respective plurality of RS-spread-spectrum signals.

22. The improvement as set forth in claim 21, further including the step of adjusting, at said plurality of remote stations, responsive to the BS-channel-sounding signal, an initial RS-power level of said plurality of remote stations.

23. The improvement as set forth in claim 21, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the plurality of BS-spread-spectrum signals at the first frequency outside a correlation bandwidth of the plurality of RS-spread-spectrum signals transmitted by the plurality of remote stations at the second frequency.

24. The improvement as set forth in claim 22, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the plurality of BS-spread-spectrum signals at the first frequency outside a correlation bandwidth of the plurality of RS-spread-spectrum signals transmitted by the plurality of remote stations at the second frequency.

27. The improvement as set forth in claim 21, 22, 23, 24, 25, or 26, further including the step of reducing, at the second frequency, the BS-channel-sounding signal from the plurality of RS-spread-spectrum signals arriving at said base station.

28. The improvement as set forth in claim 21, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

29. The improvement as set forth in claim 22, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

30. The improvement as set forth in claim 23, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

31. The improvement as set forth in claim 24, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

34. The improvement as set forth in claim 21, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

35. The improvement as set forth in claim 22, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

36. The improvement as set forth in claim 23, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

37. The improvement as set forth in claim 24, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

38. The improvement as set forth in claim 23, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

39. The improvement as set forth in claim 24, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than five percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

40. The improvement as set forth in claim 21, further including the step of filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

41. The improvement as set forth in claim 22, further including the step of filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

42. The improvement as set forth in claim 23, further including the step of filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

43. The improvement as set forth in claim 24, further including the step of filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

25. An improvement to a spread-spectrum method having a base station and a plurality of remote stations (RS), comprising the steps of:

transmitting, from said base station, a plurality of BS-spread-spectrum signals at a first frequency;

transmitting, from said plurality of remote stations, a plurality of RS-spread-spectrum signals;

receiving, at said base station, at a second frequency, the plurality of RS-spread-spectrum signals transmitted from said plurality of remote stations, respectively;

transmitting, from said base station, a BS-channel-sounding signal at the second frequency;

receiving, at said plurality of remote stations, the BS-channel-sounding signal at the second frequency; and

adjusting, at said plurality of remote stations, responsive to the BS-channel-sounding signal, an initial RS-power level of said plurality of remote stations.

26. The improvement as set forth in claim 25, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the plurality of BS-spread-spectrum signals at the first frequency outside a correlation bandwidth of the plurality of RS-spread-spectrum signals transmitted by the plurality of remote stations at the second frequency.

32. The improvement as set forth in claim 25, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

33. The improvement as set forth in claim 26, with the step of transmitting the plurality of BS-spread-spectrum signals including the step of transmitting the BS-channel-sounding signal with a bandwidth no more than twenty percent of the spread-spectrum bandwidth of the plurality of RS-spread-spectrum signals.

44. The improvement as set forth in claim 25, further including the step of filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.

45. The improvement as set forth in claim 26, further including the step of filtering the BS-channel-sounding signal from of the plurality of RS-spread-spectrum signals.