Method and apparatus for high data rate wireless communications over wavefield spaces

• US 6,603,806 B2
• Filed: 08/31/2001
• Issued: 08/05/2003
• Est. Priority Date: 05/28/1999
• Status: Expired due to Fees

• Current Assignee: WJ Communications, Inc. (Qorvo, Inc.)
• Original Assignee: WJ Communications, Inc. (Qorvo, Inc.)
• Inventors: Martone, Massimiliano Max
• Primary Examiner(s): Ghebretinsae, Temesghen
• Application Number:
  US09/945,134
• Publication Number:
  US 20020003843A1
• Time in Patent Office: 704 Days
• Field of Search: 375/219, 375/265, 375/324, 375/340, 375/316, 372/267, 372/347, 455/132
• US Class Current: 375/219
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04L 25/03178 Arrangements involving sequence estimation techniques
• CPC Class Codes: H04L 27/0004 using wavelets
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26
• CPC Class Codes: H04L 5/26 combined with the use of different frequencies

Abstract

The invention relates to a method and apparatus for digital communications that provides high data rate wireless connections with bandwidth efficiency. The creation of multiple channels (that share the same time-frequency region) between the transmitter and the receiver is achieved by sampling the wavefield space with respect to the spatial domain. The wavefield space is the space spanned by the channel parameters that characterize the multipath fading environment. At the transmitter, symbols are simultaneously modulated and transmitted using signals that occupy the same frequency portion of the spectrum, but are distinguishable because different is their position in the wavefield space. The received signals are optimally processed to extract the digital information. The optimum demodulator estimates the wavefield space parameters without any training sequence or signal and performs optimum separation of the different signals to obtain the multiple streams. The throughput of such communication system is an integer multiple of the throughput that is achievable at each different position in the wavefield space. Given a perfect estimate of the wavefield space parameters, the Maximum Likelihood principle is the optimum strategy for detection. When the wavefield space parameters are a-priori unknown, the Maximum Likelihood detector can not be implemented. The invention describes the use of a focused wavelet-based model in the statistic of the detector which results in an effective approach to wavefield space demodulation without training signals or sequences in frequency selective multipath fading with arbitrarily time-varying fading characteristics.

Claims

1. A digital wireless transceiver comprising:

a digital circuit for detection of a plurality of signals after radio frequency intermediate frequency down-conversion comprising;

a plurality of digital baseband downconversion modules connected to a demodulation module, and

a deinterleaver, with channel decoder function connected to said demodulation module; and

a data extractor connected to said deinterleaver;

wherein

said digital circuit is configured to detect said plurality of signals, and said plurality of signals are afflicted by frequency selective multipath propagation, arbitrarily time-varying fading characteristics, and non Line-Of-Sight communication.

2. The digital wireless transceiver of claim 1, wherein said demodulation module further comprises:

a plurality of pulse shaping filters connected to said plurality of downconversion modules;

a wavefield gradient-based estimator connected to said plurality of pulse shaping filters;

a trellis search processor connected to said wavefield gradient-based estimator, said plurality of pulse-shaping filters, and said deinterleaver; and

a vector symbol synchronizer connected to said trellis search processor and said plurality of pulse-shaping filters.

3. The digital wireless transceiver of claim 2, further comprising a microcontroller.

4. A wideband radio architecture comprising:

a plurality of antennas coupled to an RF distribution network;

a plurality of power amplifiers connected to said RF distribution network;

a wideband digitized spectrum data distribution network;

a user packet data distribution network;

a plurality of wideband receiver modules configured to receive a plurality of signals from said plurality of antennas and route a plurality of digital signals to said wideband digitized spectrum data distribution network;

a plurality of wideband exciter modules configured to extract a plurality of digital signals from said wideband digitized spectrum data distribution network and route a plurality of radio-frequency signals to said plurality of power amplifiers;

a plurality of digital receiver modules configured to extract a plurality of digital signals from said wideband digitized spectrum data distribution network and route a plurality of signals to said user packet data distribution network; and

a plurality of digital transmitter modules configured to extract a plurality of signals from said user packet data distribution network and route a plurality of digital signals to said wideband digitized spectrum data distribution network.

5. The architecture of claim 4, further comprising at least one wideband receiver module configured to receive a plurality of radio-frequency signals from said RF distribution network and route a plurality of signals to said user packet data distribution network.

6. The architecture of claim 4, further comprising at least one wideband exciter module configured to extract a plurality of signals from said user packet data distribution network and route a plurality of radio-frequency signals to said RF distribution network.

7. The architecture of claim 4, further comprising at least one network interface module connected to said user packet distribution network.

8. The architecture of claim 4, wherein said wideband digitized spectrum data distribution network connects said plurality of modules configured to process radio-frequency signals with said plurality of modules configured to process digital signals in a time-division multiplexed, non-blocking manner.

9. The architecture of claim 4, wherein said RF distribution network comprises a plurality of RF signal distribution circuits.

10. The architecture of claim 4, wherein said power amplifiers are configured to amplify said plurality of radio-frequency signals received from said wideband exciter modules to a level sufficient to reach a remote receiver.

11. The architecture of claim 4, wherein said plurality of wideband receiver modules are configured to filter, amplify, down-convert, and digitize a portion of radio-frequency spectrum.

12. The architecture of claim 4, wherein said plurality of wideband receiver modules each comprise an analog-to-digital converter.

13. The architecture of claim 4, wherein said digital receiver modules are configured to perform down-conversion, demodulation, channel decoding and data extraction.

14. The architecture of claim 4, wherein said plurality of wideband exciter modules each comprise a digital-to-analog converter.

15. The architecture of claim 4, wherein said digital transmitter processing modules are configured to perform up-conversion, modulation, channel encoding, and data extraction.

16. The architecture of claim 4, wherein said plurality of wideband receiver modules are driven by said RF distribution network.

17. The architecture of claim 16, wherein said plurality of wideband receiver modules is a plurality equal to said plurality of antennas.

18. The architecture of claim 4, wherein said wideband data distribution network is a high speed time division multiplexed resource.

19. The architecture of claim 4, wherein said RF distribution network is configured to filter and amplify signals received by said plurality of antennas.

20. The architecture of claim 4, wherein each of said plurality of wideband receiver modules is configured to mix signals received from said site RF distribution network down to an intermediate frequency, remove unwanted high frequency components, and to generate a plurality of digital samples of said signals.

21. The architecture of claim 20, wherein each of said plurality of wideband receiver modules comprise:

a first filter connected to said RF distribution network;

a first amplifier connected to said first filter;

a first mixer connected to said first amplifier configured to mix a signal using a first local oscillator;

a second filter connected to said first mixer;

a second amplifier connected to said second filter;

a second mixer connected to said second amplifier and configured to mix a signal down to intermediate frequency using a second local oscillator;

a third filter connected to said second mixer configured to remove unwanted high frequency components;

a third amplifier connected to said third filter; and

an analog-to-digital converter connected to said third filter.

22. The architecture of claim 4, wherein said plurality of wideband exciter modules each are configured to receive samples from said wideband digitized spectrum data distribution network, convert said samples into analog signals, upconvert said signals, and output signals to said power amplifiers.

23. The architecture of claim 22, wherein said plurality of wideband exciter modules each comprise:

a digital-to-analog converter connected to said wideband digitized spectrum data distribution network;

a first exciter filter connected to said digital-to-analog converter;

a first exciter amplifier connected to said first exciter filter;

a first exciter mixer connected to said first exciter amplifier and configured to mix a signal using said second local oscillator;

a second exciter filter connected to said first exciter mixer;

a second exciter amplifier connected to said second exciter filter;

a second exciter mixer connected to said second exciter amplifier and configured to mix a signal using said first local oscillator;

a third exciter amplifier connected to said second exciter mixer; and

a third exciter filter connected to said third exciter amplifier and said RF distribution network.

24. The architecture of claim 4, wherein said plurality of wideband digital receiver modules each comprise a high-speed ASIC.

25. The architecture of claim 4, wherein said plurality of digital receiver modules are each configured to perform traffic channelization using digital quadrature downconversion.

26. The architecture of claim 4, wherein said plurality of digital receiver modules are each configured to receive samples from said wideband digitized spectrum data distribution network, down convert said samples to baseband by means of a quadrature mixer, where a mixing frequency is generated by a numerically controlled oscillator.

27. The architecture of claim 26, wherein said plurality of digital receiver modules each divide said samples into in-phase and in-quadrature components.

28. The architecture of claim 4, wherein said digital receiver module comprises

a plurality of digital baseband down-conversion modules connected to a demodulation module, and

a deinterleaver with channel decoder function connected to said demodulation module;

and

a data extractor connected to said deinterleaver;

wherein

said digital circuit is configured to detect said plurality of signals, wherein said plurality of signals are afflicted by frequency selective multipath propagation, arbitrarily time-varying fading characteristics, and non Line-Of-Sight communication.

29. The architecture of claim 4, wherein said wideband receiver modules, said wideband exciter modules, said digital receiver processing module, and said digital transmitter processing module are each controlled by a microcontroller, providing an interface with said wideband digitized spectrum data distribution network and said user packet data distribution network.

30. The architecture of claim 4, wherein said plurality of antennas coupled to an RF distribution network comprise a plurality of antennas coupled to a site RF distribution network.

31. The architecture of claim 25, wherein said channelization is performed in software.

32. The architecture of claim 25, wherein said channelization is performed in reconfigurable logic.

33. A wideband radio architecture comprising:

a digital circuit for detection of a plurality of signals after radio frequency intermediate frequency down-conversion comprising;

a plurality of digital baseband downconversion modules connected to a demodulation module, and

a deinterleaver with channel decoder function connected to said demodulation module; and

a data extractor connected to said deinterleaver;

said digital circuit bing configured to detect said plurality of signals when said plurality of signals are afflicted by frequency selective multipath propagation, arbitrarily time-varying fading characteristics, and non-line-of-sight communication.

34. A digital wireless wideband radio transmitter-receiver system comprising:

a wideband digitized spectrum data distribution network;

a user packet data distribution network;

a plurality of digital receiver modules configured to extract a plurality of digital signals from said wideband digitized spectrum data distribution network and route a plurality of signals to said user packet data distribution network; and

a plurality of digital transmitter modules configured to extract a plurality of signals from said user packet data distribution network and route a plurality of digital signals to said wideband digitized spectrum data distribution network.

35. The digital wireless wideband radio transmitter-receiver system in claim 34, further comprising:

a radio-frequency distribution network;

a plurality of power amplifiers connected to said radio-frequency distribution network;

a plurality of antennas coupled to said radio-frequency distribution network;

a plurality of wideband receiver modules configured to receive a plurality of signals from said plurality of antennas and route a plurality of digital signals to said wideband digitized spectrum data distribution network; and

a plurality of wideband exciter modules configured to extract a plurality of digital signals from said wideband digitized spectrum data distribution network and route a plurality of radio-frequency signals to said plurality of power amplifiers.

36. A digital radio architecture comprising:

a wideband digitized spectrum data distribution interface bus;

a user packet data distribution interface bus;

a radio-frequency sub-system comprising at least one wideband receiver module and at least one wideband exciter modules, a site radio-frequency distribution module coupled to the wideband receiver module, and an amplifier coupled between the wideband exciter module and the site radio-frequency distribution;

the wideband receiver module and wideband exciter module interconnecting with a digital receiver processing module and a digital transmitter processing modules through the wideband digitized spectrum data distribution network;

the digital receiver signal processing module and the digital transmitter signal processing module being decoupled from external antenna ports; and

a network interface module coupled with the user packet data distribution network bus.