Method of polling second stations for functional quality and maintenance data in a discrete multitone spread spectrum communications system

• US 6,480,522 B1
• Filed: 11/28/2000
• Issued: 11/12/2002
• Est. Priority Date: 12/18/1997
• Status: Expired due to Fees

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Wireless Services Incorporated (AT&T, Inc.)
• Inventors: Stephenson, David, Hoole, Elliott, Jesse, Mary, Mechaley, Robert G. Jr., Ryan, David James
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Tran, Khai
• Application Number:
  US09/723,338
• Time in Patent Office: 714 Days
• Field of Search: 375/130, 375/136, 375/135, 375/140, 375/219, 375/146, 375/147, 375/232, 375/260, 370/342, 370/335, 370/320, 370/479, 455/135, 455/136, 455/132, 455/133
• US Class Current: 375/130
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/692 Hybrid techniques using combinations of two or more spread spectrum techniques
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7107 Subtractive interference cancellation
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/03019 adaptive, i.e. capable of adjustment during data reception
• CPC Class Codes: H04L 27/186 in which the information is carried by both the individual signal points and the subset to which the individual signal points belong, e.g. coset coding or related schemes
• CPC Class Codes: H04L 27/3416 in which the information is carried by both the individual signal points and the subset to which the individual points belong, e.g. using coset coding, lattice coding, or related schemes
• CPC Class Codes: H04L 5/0021 in which codes are applied as a frequency-domain sequences, e.g. MC-CDMA
• CPC Class Codes: H04L 5/0026 Division using four or more dimensions
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/026 using code division
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A discrete multitone stacked-carrier spread spectrum communication method is based on frequency domain spreading including multiplication of a baseband signal by a set of superimposed, or stacked, complex sinusoid carrier waves. In a preferred embodiment, the spreading involves energizing the bins of a large Fast Fourier transform (FFT). This provides a considerable savings in computational complexity for moderate output FFT sizes. Point-to-multipoint and multipoint-to-multipoint (nodeless) network topologies are possible. A code-nulling method is included for interference cancellation and enhanced signal separation by exploiting the spectral diversity of the various sources. The basic method may be extended to include multielement antenna array nulling methods for interference cancellation and enhanced signal separation using spatial separation. Such methods permit directive and retrodirective transmission systems that adapt or can be adapted to the radio environment. Such systems are compatible with bandwidth-on-demand and higher-order modulation formats and use advanced adaptation algorithms. In a specific embodiment the spectral and spatial components of the adaptive weights are calculated in a unified operation based on the mathematical analogy between the spectral and spatial descriptions of the airlink.

Claims

1. A highly bandwidth-efficient communications method, comprising the steps of:

receiving at a base station a spread signal comprising an incoming data traffic signal spread over a plurality of discrete traffic frequencies and an incoming functional quality and maintenance signal characterizing a remote station, spread over a plurality of common access channel frequencies;

adaptively despreading the signal received at the base station by using despreading weights;

storing said functional quality and maintenance signal at said base station;

analyzing functional quality data from said functional quality and maintenance signal and updating said despreading weights at the base station; and

analyzing maintenance data from said functional quality and maintenance signal and outputting a maintenance notice at the base station.

2. The highly bandwidth-efficient communications method of claim 1, wherein said base station and said remote station are part of a wireless discrete multitone spread spectrum communications system.

3. The highly bandwidth-efficient communications method of claim 1, wherein said step of analyzing functional quality data further comprises:

updating spreading weights at the base station.

4. The highly bandwidth-efficient communications method of claim 1, wherein said functional quality data includes SINR history data characterizing communications with said remote station.

5. The highly bandwidth-efficient communications method of claim 1, wherein said functional quality data includes path loss history data characterizing communications with said remote station.

6. The highly bandwidth-efficient communications method of claim 1, wherein said maintenance, data includes self-test results data characterizing said remote station.

7. The highly bandwidth-efficient communications method of claim 1, wherein said maintenance data includes battery status data characterizing said remote station.

8. The highly bandwidth-efficient communications method of claim 1, which further comprises:

initiating an update in spreading and despreading weights at the base station in an effort to improve the ratio of signal to interference and noise of a traffic channel, in response to said functional quality data.

9. The highly bandwidth-efficient communications method of claim 1, which further comprises:

initiating an alarm at the base station to be used for realtime control, in response to said functional quality data.

10. The highly bandwidth-efficient communications method of claim 1, which further comprises:

logging the functional quality data for compilation of a longer term report of a traffic channel quality, in response to said functional quality signal.

11. A highly bandwidth-efficient communications method, comprising the steps of:

receiving at a base station a first spread signal comprising an incoming data traffic signal having a data portion spread over a plurality of discrete traffic frequencies, from a remote station;

receiving at said base station a second spread signal comprising an incoming functional quality and maintenance signal having a functional quality data portion and maintenance data portion spread over a plurality of common access channel frequencies, from said remote station;

adaptively despreading said second spread signal received at the base station by using despreading weights, recovering said functional quality data portion and said maintenance data portion;

storing said functional quality data and maintenance data at said base station;

analyzing said functional quality data and updating said despreading weights at the base station; and

analyzing said maintenance data and outputting a maintenance notice at the base station.

12. The highly bandwidth-efficient communications method of claim 11, wherein said base station and said remote station are part of a wireless discrete multitone spread spectrum communications system.

13. The highly bandwidth-efficient communications method of claim 11, wherein said step of analyzing functional quality data further comprises:

updating spreading weights at the base station.

14. The highly bandwidth-efficient communications method of claim 11, wherein said functional quality data includes SINR history data characterizing communications with said remote station.

15. The highly bandwidth-efficient communications method of claim 11, wherein said functional quality data includes path loss history data characterizing communications with said remote station.

16. The highly bandwidth-efficient communications method of claim 11, wherein said maintenance data includes self-test results data characterizing said remote station.

17. The highly bandwidth-efficient communications method of claim 11, wherein said maintenance data includes battery status data characterizing said remote station.

18. The highly bandwidth-efficient communications method of claim 11, which further comprises:

initiating an update in spreading and despreading weights at the base station in an effort to improve the signal and interference to noise ratio of a traffic channel, in response to said functional quality data.

19. The highly bandwidth-efficient communications method of claim 11, which further comprises:

initiating an alarm at the base station to be used for realtime control, in response to said functional quality data.

20. The highly bandwidth-efficient communications method of claim 11, which further comprises:

logging the functional quality data for compilation of a longer term report of a traffic channel quality, in response to said functional quality signal.

21. A highly bandwidth-efficient communications system, comprising:

means for receiving at a base station a spread signal comprising an incoming data traffic signal spread over a plurality of discrete traffic frequencies and an incoming functional quality and maintenance signal characterizing a remote station, spread over a plurality of common access channel frequencies;

means for adaptively despreading the signals received at the base station by using despreading weights;

means for storing said functional quality and maintenance signal at said base station;

means for analyzing functional quality data from said functional quality and maintenance signal and updating said despreading weights at the base station; and

means for analyzing maintenance data from said functional quality and maintenance signal and outputting a maintenance notice at the base station.

22. The highly bandwidth-efficient communications system of claim 21, wherein said base station and said remote station are part of a wireless discrete multitone spread spectrum communications system.

23. The highly bandwidth-efficient communications system of claim 21, which further comprises:

means for analyzing functional quality data by updating spreading weights at the base station.

24. The highly bandwidth-efficient communications system of claim 21, wherein said functional quality data includes SINR history data characterizing communications with said remote station.

25. The highly bandwidth-efficient communications system of claim 21, wherein said functional quality data includes path loss history data characterizing communications with said remote station.

26. The highly bandwidth-efficient communications system of claim 21, wherein said maintenance data includes self-test results data characterizing said remote station.

27. The highly bandwidth-efficient communications system of claim 21, wherein said maintenance data includes battery status data characterizing said remote station.

28. The highly bandwidth-efficient communications system of claim 21, which further comprises:

means for initiating an update in spreading and despreading weights at the base station in an effort to improve the signal and interference to noise ratio of a traffic channel, in response to said functional quality data.

29. The highly bandwidth-efficient communications system of claim 21, which further comprises:

means for initiating an alarm at the base station to be used for realtime control, in response to said functional quality data.

30. The highly bandwidth-efficient communications system of claim 21, which further comprises:

means for logging the functional quality data for compilation of a longer term report of a traffic channel quality, in response to said functional quality signal.

31. A highly bandwidth-efficient communications system, comprising:

means for receiving at a base station a first spread signal comprising an incoming data traffic signal having a data portion spread over a plurality of discrete traffic frequencies, from a remote station;

means for receiving at said base station a second spread signal comprising an incoming functional quality and maintenance signal having a functional quality data portion and maintenance data portion spread over a plurality of common access channel frequencies, from said remote station;

means for adaptively despreading said second spread signal received at the base station by using despreading weights, recovering said functional quality data portion and said maintenance data portion;

means for storing said functional quality data and maintenance data at said base station;

means for analyzing said functional quality data and updating said despreading weights at the base station; and

means for analyzing said maintenance data and outputting a maintenance notice at the base station.

32. The highly bandwidth-efficient communications system of claim 31, wherein said base station and said remote station are part of a wireless discrete multitone spread spectrum communications system.

33. The highly bandwidth-efficient communications system of claim 31, which further comprises:

means for analyzing functional quality data by updating spreading weights at the base station.

34. The highly bandwidth-efficient communications system of claim 31, wherein said functional quality data includes SINR history data characterizing communications with said remote station.

35. The highly bandwidth-efficient communications system of claim 31, wherein said functional quality data includes path loss history data characterizing communications with said remote station.

36. The highly bandwidth-efficient communications system of claim 31, wherein said maintenance data includes self-test results data characterizing said remote station.

37. The highly bandwidth-efficient communications system of claim 31, wherein said maintenance data includes battery status data characterizing said remote station.

38. The highly bandwidth-efficient communications system of claim 31, which further comprises:

means for initiating an update in spreading and despreading weights at the base station in an effort to improve the signal and interference to noise ratio of a traffic channel, in response to said functional quality data.

39. The highly bandwidth-efficient communications system of claim 31, which further comprises:

means for initiating an alarm at the base station to be used for realtime control, in response to said functional quality data.

40. The highly bandwidth-efficient communications system of claim 31, which further comprises:

means for logging the functional quality data for compilation of a longer term report of a traffic channel quality, in response to said functional quality signal.

41. A highly bandwidth-efficient communications method, comprising the steps of:

receiving at a first station a spread signal comprising an incoming functional quality signal characterizing a second station, spread over a plurality of frequencies;

adaptively despreading the signals received at the first station by using despreading weights;

storing said functional quality signal at said first station;

analyzing functional quality data from said functional quality signal and updating said despreading weights at the first station.

42. A highly bandwidth-efficient communications method, comprising the steps of:

receiving at a first station a spread signal comprising an incoming functional quality signal having a functional quality data portion spread over a plurality of frequencies, from a second station;

adaptively despreading said spread signal received at the first station by using despreading weights, recovering said functional quality data portion;

storing said functional quality data at said first station;

analyzing said functional quality data and updating said despreading weights at the first station.

43. A highly bandwidth-efficient communications system, comprising:

means for receiving at a first station a spread signal comprising an incoming functional quality signal characterizing a second station, spread over a plurality of frequencies;

means for adaptively despreading the signals received at the first station by using despreading weights;

means for storing said functional quality signal at said first station;

means for analyzing functional quality data from said functional quality signal and updating said despreading weights at the first station.

44. A highly bandwidth-efficient communications system, comprising:

means for receiving at a first station a spread signal comprising an incoming functional quality signal having a functional quality data portion spread over a plurality of frequencies, from a second station;

means for adaptively despreading said spread signal received at the first station by using despreading weights, recovering said functional quality data portion;

means for storing said functional quality data at said first station;

means for analyzing said functional quality data and updating said despreading weights at the first station.