Method for frequency division duplex communications

• US 5,933,421 A
• Filed: 02/06/1997
• Issued: 08/03/1999
• Est. Priority Date: 02/06/1997
• Status: Expired due to Term

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Wireless Services Incorporated (AT&T, Inc.)
• Inventors: Zhang, Hongliang, Alamouti, Siavash, Hoole, Elliott, Jesse, Mary, Poon, Patrick, Veintimilla, Gregory J., Michelson, David G., Hirano, Michael, Casas, Eduardo F.
• Primary Examiner(s): Hofsass, Jeffery A.
• Assistant Examiner(s): TOWNSEND, CLEMENT G
• Application Number:
  US08/796,584
• Time in Patent Office: 908 Days
• Field of Search: 370/203, 370/206, 370/329, 370/330, 370/337, 370/336, 370/343, 370/344, 370/321, 370/280, 370/281, 375/267, 375/347, 375/299
• US Class Current: 370/330
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04J 3/0652 Synchronisation among time division multiple access [TDMA] nodes, e.g. time triggered protocol [TTP] bus network with centralized control in which slots are of a TDMA packet structure H04L12/4035
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04L 5/1484 operating bytewise
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource

Abstract

The high quality PCS communications are enabled in environments where adjacent PCS service bands operate with out-of-band harmonics that would otherwise interfere with the system'"'"'s operation. The highly bandwidth-efficient communications method combines a form of time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations. The method provides excellent fade resistance. The method enables changing a user'"'"'s available bandwidth on demand by assigning additional TDMA slots during the user'"'"'s session.

Claims

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

receiving at the base station a first incoming wireless signal comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station during a first time division multiple access (TDMA) interval;

receiving at the base station a second incoming wireless signal comprising a plurality of second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a second remote station during said first time division multiple access (TDMA) interval;

receiving at the base station a third incoming wireless signal comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a third remote station during a second time division multiple access (TDMA) interval;

receiving at the base station a fourth incoming wireless signal comprising a plurality of said second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a fourth remote station during said second time division multiple access (TDMA) interval;

transmitting at the base station said first outgoing wireless signal comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to said first remote station during a third time division multiple access (TDMA) interval;

transmitting at the base station said second outgoing wireless signal comprising a plurality of fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said second remote station during said third time division multiple access (TDMA) interval;

transmitting at the base station said third outgoing wireless signal comprising said plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said third remote station during a fourth time division multiple access (TDMA) interval; and

transmitting at the base station said fourth outgoing wireless signal comprising said plurality of said fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said fourth remote station during said fourth time division multiple access (TDMA) interval.

2. The highly bandwidth-efficient communications method of claim 1, wherein said first and second time division multiple access (TDMA) intervals are part of a TDMA frame interval, the method increasing communications capacity from said first remote station to said base station, further comprising the step of:

receiving at the base station a fifth incoming wireless signal comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said first remote station during an additional time division multiple access (TDMA) interval in said TDMA frame interval.

3. The highly bandwidth-efficient communications method of claim 1, wherein said third and fourth time division multiple access (TDMA) intervals are part of a TDMA frame interval, the method increasing communications capacity from said base to said first remote station, further comprising the step of:

transmitting at the base station a fifth outgoing wireless signal comprising a plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said first remote station during an additional time division multiple access (TDMA) interval.

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

receiving at the base station a first incoming wireless signal comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station at a first geographic location during a first time division multiple access (TDMA) interval;

receiving at the base station a second incoming wireless signal comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a second remote station at a second geographic location during said first time division multiple access (TDMA) interval;

spatially despreading the first and second incoming signals received at the base station by using spatial despreading weights;

receiving at the base station a third incoming wireless signal comprising a plurality of second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a third remote station during said first time division multiple access (TDMA) interval;

receiving at the base station a fourth incoming wireless signal comprising a plurality of said second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a fourth remote station during said second time division multiple access (TDMA) interval;

spatially spreading a first and second outgoing wireless signals at the base station by using spatial spreading weights;

transmitting at the base station said first outgoing wireless signal comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to said first remote station at said first geographic location during a third time division multiple access (TDMA) interval;

transmitting at the base station said second outgoing wireless signal comprising a plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said second remote station at said second geographic location during said third time division multiple access (TDMA) interval;

transmitting at the base station said third outgoing wireless signal comprising said plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said third remote station during a fourth time division multiple access (TDMA) interval; and

transmitting at the base station said fourth outgoing wireless signal comprising said plurality of said fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said fourth remote station location during said fourth time division multiple access (TDMA) interval.

5. The highly bandwidth-efficient communications method of claim 4, wherein said spatially spreading step further comprises the steps of:

delivering to the base station from a binary source a binary sequence of N bits of data in one TDMA interval;

converting the binary sequence into a sequence of M-bit symbols;

converting the symbol sequence into a vector having a plurality of P elements;

adding one symbol from a Link Control Channel (LCC) to form a resultant vector of a plurality of P+1 elements;

trellis encoding the resultant vector and outputting an encoded vector of a plurality of P+1 elements, where each element thereof is a signal within the set of (P+1)QAM constellation signals;

adding a known pilot symbol to form an output vector of a plurality of P+2 elements;

weighting the elements of the output vector with spreading weights according to one of a plurality of Q antennas through which the output vector is to be transmitted;

placing the elements of the output vector destined for each of said antennas in inverse DFT frequency bins where they are converted to time domain symbols;

mapping the time domain symbols into discrete frequency output tones; and

transmitting the discrete frequency output tones from the base station.

6. The highly bandwidth-efficient communications method of claim 5, which further comprises the steps of:

repeating said spatially spreading steps for a next binary sequence of N bits of data in a succeeding TDMA interval.

7. The highly bandwidth-efficient communications method of claim 4, wherein said spatially despreading step further comprises the steps of:

receiving signals at the base station on all of said plurality of antennas;

digitally sampling the signals and transforming them into a frequency domain;

despreading the transformed signals and spatially despreading them using despreading weights;

adding the despread signals from the antennas and forming a resulting P+2 element vector;

multiplying each element of the vector by a phase correction factor, and stripping a pilot symbol off the vector, forming a remaining vector; and

trellis decoding the remaining vector to form P symbols of traffic data, and 1 symbol of LCC data.

8. The highly bandwidth-efficient communications method of claim 7, which further comprises the steps of:

repeating said spatially despreading steps in a succeeding TDMA interval.

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

receiving at the base station a first incoming wireless signal polarized in a first polarization direction comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station during a first time division multiple access (TDMA) interval;

receiving at the base station a second incoming wireless signal polarized in a second polarization direction comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a second remote station during said first time division multiple access (TDMA) interval;

distinguishing the first and second incoming signals received at the base station by detecting said first and second polarization directions;

receiving at the base station a third incoming wireless signal comprising a plurality of second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a third remote station during said first time division multiple access (TDMA) interval;

receiving at the base station a fourth incoming wireless signal comprising a plurality of said second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a fourth remote station during said second time division multiple access (TDMA) interval;

forming a first and second outgoing wireless signals at the base station by polarizing them in said first and second polarization directions, respectively;

transmitting at the base station said first outgoing wireless signal polarized in said first polarization direction comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to said first remote station at said first geographic location during a third time division multiple access (TDMA) interval;

transmitting at the base station said second outgoing wireless signal polarized in said second polarization direction comprising a plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said second remote station at said second geographic location during said third time division multiple access (TDMA) interval;

transmitting at the base station a third outgoing wireless signal comprising said plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said third remote station during a fourth time division multiple access (TDMA) interval; and

transmitting at the base station a fourth outgoing wireless signal comprising said plurality of said fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said fourth remote station location during said fourth time division multiple access (TDMA) interval.

10. The highly bandwidth-efficient communications method of claim 9, wherein said first remote station is at a first geographic location and said second remote station is at a second geographic location, the method further comprising the steps of:

spatially despreading the first and second incoming signals received at the base station by using spatial despreading weights; and

spatially spreading the first and second outgoing wireless signals at the base station by using spatial spreading weights.

11. A highly bandwidth-efficient communications method for improved fade resistance, comprising the steps of:

receiving at a base station a first incoming wireless signal bearing first data, the signal comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station during a first time division multiple access (TDMA) interval, said first signal having a first diversity receive path;

receiving at the base station a second incoming wireless signal bearing said first data, comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said first remote station during said first time division multiple access (TDMA) interval, said second signal having a second diversity receive path that is highly uncorrelated with said first diversity receive path;

selecting at the base station said first diversity receive path for said first incoming wireless signal or selecting said second diversity receive path for said second incoming wireless signal to receive said first data;

generating at the base station a first outgoing wireless signal for transmission over a first diversity transmit path and generating a second outgoing wireless signal for transmission over a second diversity transmit path, said first diversity transmit path being highly uncorrelated with said second diversity transmit path;

transmitting at the base station said first outgoing wireless signal comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to said first remote station over said first diversity transmit path during a third time division multiple access (TDMA) interval; and

transmitting at the base station said second outgoing wireless signal comprising a plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said first remote station over said second diversity signal path during said third time division multiple access (TDMA) interval.

12. The highly bandwidth-efficient communications method for improved fade resistance of claim 11, which further comprises:

said selecting step is maximal ratio combining.

13. The highly bandwidth-efficient communications method for improved fade resistance of claim 11, which further comprises:

said selecting step is equal gain combining.

14. The highly bandwidth-efficient communications method for improved fade resistance of claim 11, which further comprises:

said first diversity receive path having a first spatial characteristic and said second diversity receive path having a second spatial characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path; and

said first diversity transmit path having a third spatial characteristic and said second diversity transmit path having a fourth spatial characteristic such that the second diversity transmit path is highly uncorrelated with said first diversity transmit path.

15. The highly bandwidth-efficient communications method for improved fade resistance of claim 11, which further comprises:

said first diversity receive path having a first polarization characteristic and said second diversity receive path having a second polarization characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path; and

said first diversity transmit path having a third polarization characteristic and said second diversity transmit path having a fourth polarization characteristic such that the second diversity transmit path is highly uncorrelated with said first diversity transmit path.

16. The highly bandwidth-efficient communications method for improved fade resistance of claim 11, which further comprises:

said first diversity receive path having a first time characteristic and said second diversity receive path having a second time characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path; and

said first diversity transmit path having a third time characteristic and said second diversity transmit path having a fourth time characteristic such that the second diversity transmit path is highly uncorrelated with said first diversity transmit path.

17. The highly bandwidth-efficient communications method for improved fade resistance of claim 11, which further comprises:

said first diversity receive path having a first frequency characteristic and said second diversity receive path having a second frequency characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path; and

said first diversity transmit path having a third frequency characteristic and said second diversity transmit path having a fourth frequency characteristic such that the second diversity transmit path is highly uncorrelated with said first diversity transmit path.

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

said first diversity receive path having a first frequency hopping characteristic and said second diversity receive path having a second frequency hopping characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path; and

said first diversity transmit path having a third frequency hopping characteristic and said second diversity transmit path having a fourth frequency hopping characteristic such that the second diversity transmit path is highly uncorrelated with said first diversity transmit path.

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

receiving at the base station a third incoming wireless signal bearing second data, the signal comprising a plurality of second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a second remote station during said first time division multiple access (TDMA) interval, said third signal having a third diversity receive path;

receiving at the base station a fourth incoming wireless signal bearing said second data, comprising a plurality of said second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said second remote station during said first time division multiple access (TDMA) interval, said fourth signal having a fourth diversity receive path that is highly uncorrelated with said third diversity receive path; and

selecting at the base station said third diversity receive path for said third incoming wireless signal or selecting said fourth diversity receive path for said fourth incoming wireless signal to receive said second data.

20. The highly bandwidth-efficient communications method for improved fade resistance of claim 19, which further comprises:

receiving at the base station a fifth incoming wireless signal comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a third remote station during a second time division multiple access (TDMA) interval; and

receiving at the base station a sixth incoming wireless signal comprising a plurality of said second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a fourth remote station during said second time division multiple access (TDMA) interval.

21. The highly bandwidth-efficient communications method for improved fade resistance of claim 20, which further comprises:

generating at the base station a third outgoing wireless signal for transmission over a third diversity transmit path and generating a fourth outgoing wireless signal for transmission over a fourth diversity transmit path, said third diversity transmit path being highly uncorrelated with said fourth diversity transmit path;

transmitting at the base station said third outgoing wireless signal comprising a plurality of fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to said second remote station over said third diversity transmit path during said third time division multiple access (TDMA) interval; and

transmitting at the base station said fourth outgoing wireless signal comprising a plurality of said fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said second remote station over said fourth diversity signal path during said third time division multiple access (TDMA) interval.

22. The highly bandwidth-efficient communications method for improved fade resistance of claim 21, which further comprises:

transmitting at the base station a fifth outgoing wireless signal comprising said plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said third remote station during a fourth time division multiple access (TDMA) interval; and

transmitting at the base station a sixth outgoing wireless signal comprising said plurality of said fourth discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said fourth remote station location during said fourth time division multiple access (TDMA) interval.

23. A highly bandwidth-efficient communications method for improved fade resistance, comprising the steps of:

receiving at a base station a first incoming wireless signal bearing first data, the signal comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station during a first time division multiple access (TDMA) interval, said first signal having a first diversity receive path;

receiving at the base station a second incoming wireless signal bearing said first data, comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said first remote station during said first time division multiple access (TDMA) interval, said second signal having a second diversity receive path that is highly uncorrelated with said first diversity receive path;

selecting at the base station said first diversity receive path for said first incoming wireless signal or selecting said second diversity receive path for said second incoming wireless signal to receive said first data;

generating at the base station a first outgoing wireless signal and generating a second outgoing wireless signal;

transmitting at the base station said first outgoing wireless signal comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to said first remote station during a third time division multiple access (TDMA) interval; and

transmitting at the base station said second outgoing wireless signal comprising a plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said first remote station during said third time division multiple access (TDMA) interval.

24. The highly bandwidth-efficient communications method for improved fade resistance of claim 23, which further comprises:

said selecting step is maximal ratio combining.

25. The highly bandwidth-efficient communications method for improved fade resistance of claim 23, which further comprises:

said selecting step is equal gain combining.

26. The highly bandwidth-efficient communications method for improved fade resistance of claim 23, which further comprises:

said first diversity receive path having a first spatial characteristic and said second diversity receive path having a second spatial characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

27. The highly bandwidth-efficient communications method for improved fade resistance of claim 23, which further comprises:

said first diversity receive path having a first polarization characteristic and said second diversity receive path having a second polarization characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

28. The highly bandwidth-efficient communications method for improved fade resistance of claim 23, which further comprises:

said first diversity receive path having a first time characteristic and said second diversity receive path having a second time characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

29. The highly bandwidth-efficient communications method for improved fade resistance of claim 23, which further comprises:

said first diversity receive path having a first frequency characteristic and said second diversity receive path having a second frequency characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

30. The highly bandwidth-efficient communications method for improved fade resistance of claim 23, which further comprises:

said first diversity receive path having a first frequency hopping characteristic and said second diversity receive path having a second frequency hopping characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

31. The highly bandwidth-efficient communications method for improved fade resistance of claim 23, which further comprises:

receiving at the base station a third incoming wireless signal bearing second data, the signal comprising a plurality of second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from a second remote station during said first time division multiple access (TDMA) interval, said third signal having a third diversity receive path;

receiving at the base station a fourth incoming wireless signal bearing said second data, comprising a plurality of said second discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said second remote station during said first time division multiple access (TDMA) interval, said fourth signal having a fourth diversity receive path that is highly uncorrelated with said third diversity receive path; and

selecting at the base station said third diversity receive path for said third incoming wireless signal or selecting said fourth diversity receive path for said fourth incoming wireless signal to receive said second data.

32. A highly bandwidth-efficient communications method for improved fade resistance, comprising the steps of:

receiving at a remote station a first incoming wireless signal bearing first data, the signal comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a base station during a first time division multiple access (TDMA) interval, said first signal having a first diversity receive path;

receiving at the remote station a second incoming wireless signal bearing said first data, comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said base station during said first time division multiple access (TDMA) interval, said second signal having a second diversity receive path that is highly uncorrelated with said first diversity receive path;

selecting at the remote station said first diversity receive path for said first incoming wireless signal or selecting said second diversity receive path for said second incoming wireless signal to receive said first data;

generating at the remote station a first outgoing wireless signal and generating a second outgoing wireless signal;

transmitting at the remote station said first outgoing wireless signal comprising a plurality of third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a second frequency band to said base station during a third time division multiple access (TDMA) interval; and

transmitting at the remote station said second outgoing wireless signal comprising a plurality of said third discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said second frequency band to said base station during said third time division multiple access (TDMA) interval.

33. The highly bandwidth-efficient communications method for improved fade resistance of claim 32, which further comprises:

said selecting step is maximal ratio combining.

34. The highly bandwidth-efficient communications method for improved fade resistance of claim 32, which further comprises:

said selecting step is equal gain combining.

35. The highly bandwidth-efficient communications method for improved fade resistance of claim 32, which further comprises:

said first diversity receive path having a first spatial characteristic and said second diversity receive path having a second spatial characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

36. The highly bandwidth-efficient communications method for improved fade resistance of claim 32, which further comprises:

said first diversity receive path having a first polarization characteristic and said second diversity receive path having a second polarization characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

37. The highly bandwidth-efficient communications method for improved fade resistance of claim 32, which further comprises:

said first diversity receive path having a first time characteristic and said second diversity receive path having a second time characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

38. The highly bandwidth-efficient communications method for improved fade resistance of claim 32, which further comprises:

said first diversity receive path having a first frequency characteristic and said second diversity receive path having a second frequency characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

39. The highly bandwidth-efficient communications method for improved fade resistance of claim 32, which further comprises:

said first diversity receive path having a first frequency hopping characteristic and said second diversity receive path having a second frequency hopping characteristic such that the second diversity receive path is highly uncorrelated with said first diversity receive path.

40. The highly bandwidth-efficient communications method for improved fade resistance of claim 32, wherein said first time division multiple access (TDMA) interval is part of a TDMA frame interval, the method increasing communications capacity from said base station to said remote station, further comprising the step of:

receiving at the remote station an additional incoming wireless signal comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said base station during an additional time division multiple access (TDMA) interval in said TDMA frame interval.

41. A highly bandwidth-efficient communications method for improved fade resistance, comprising the steps of:

receiving at a base station a first incoming wireless signal bearing first data, the signal comprising a plurality of first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in a first frequency band from a first remote station during a first time division multiple access (TDMA) interval, said first signal having a first diversity receive path, said first time division multiple access (TDMA) interval being part of a TDMA frame interval;

receiving at the base station a second incoming wireless signal bearing said first data, comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said first remote station during said first time division multiple access (TDMA) interval, said second signal having a second diversity receive path that is highly uncorrelated with said first diversity receive path;

selecting at the base station said first diversity receive path for said first incoming wireless signal or selecting said second diversity receive path for said second incoming wireless signal to receive said first data; and

increasing communications capacity from said first remote station to said base station by selectively, receiving at the base station an additional incoming wireless signal comprising a plurality of said first discrete frequency tones that are orthogonal frequency division multiplexed (OFDM) in said first frequency band from said first remote station during an additional time division multiple access (TDMA) interval in said TDMA frame interval.