Space diversity method and system for broadband wireless access

• US 6,498,821 B2
• Filed: 01/26/2001
• Issued: 12/24/2002
• Est. Priority Date: 01/26/2000
• Status: Expired due to Fees

• Current Assignee: Vyyo, Inc. (National Vision Holdings, Inc.)
• Original Assignee: VYYO, Ltd.
• Inventors: Jonas, Ammon, Albo, Claude
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Bayard, Emmanuel
• Application Number:
  US09/771,326
• Publication Number:
  US 20010046271A1
• Time in Patent Office: 697 Days
• Field of Search: 375/347, 375/349, 375/316, 375/337, 375/130, 375/341, 375/267, 375/224, 370/320, 370/335, 370/342, 455/132, 455/133, 455/134, 455/135, 455/137, 455/296, 455/303, 455/277.2, 455/429, 455/54.1
• US Class Current: 375/347
• CPC Class Codes: H04B 7/082 selecting best antenna path
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/02 by diversity reception
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/20 using signal quality detector

Abstract

Spatially diverse signals are simultaneously demodulated and error corrected providing statistically independent data. Statistics for the signals are prepared and available for system management and display to users.

Claims

1. A method of space diversity for broadband wireless access, comprising the steps of:

receiving spatially diverse signals;

separately demodulating each of the spatially diverse signals;

selecting a most correct of the demodulated signals; and

forwarding the selected demodulated signal for further processing;

wherein;

said step of selecting comprises,

performing FEC decoding on codewords contained in each of the spatially divese signals, and

selecting decoded codewords that have been successfully FEC decoded; and

if both of said spatially divese signals contain pairs of codewords that have been successfully FEC decoded, then selecting both decoded codewords.

2. The method according to claim 1, wherein:

said spatially diverse signals include a channel designated as primary, and at least one channel designated as secondary; and

said step of selecting comprises,

selecting codewords decoded from the primary channel of said spatially diverse signals if the primary channel codewords were successfully decoded; and

selecting codewords from a secondary channel of said spatially diverse signals if the primary channel codewords were not successfully decoded and the selected secondary channel codewords were successfully decoded.

3. A method of space diversity for broadband wireless access, comprising the steps of:

receiving spatially diverse signals;

separately demodulating each of the spatially diverse signals;

selecting a most correct of the demodulated signals; and

forwarding the selected demodulated signal for further processing;

wherein said step of selecting includes the steps of;

if said spatially diverse signals are not in burst mode,

performing a FEC on codewords demodulated from the spatially diverse signals; and

if said spatially diverse signals are in burst mode, performing Header, Frame, and PDU CRC.

4. A method of space diversity for broadband wireless access, comprising the steps of:

receiving spatially diverse signals;

separately demodulating each of the spatially diverse signals;

selecting a most correct of the demodulated signals;

forwarding the selected demodulated signal for further processing; and

collecting statistics on at least one of Codeword error rates, selection percentage, header check sequence error rates, and frame check sequence error rates on at least one of a primary and secondary channel in said spatially diverse signals.

5. The method according to claim 4, wherein said statistics are collected for codewords over a sliding window range.

6. The method according to claim 5, wherein said sliding window range is 1000 to 10,000,000 code words in length.

7. The method according to claim 4, wherein said statistics for header check sequence are collected over a sliding window number of frames range.

8. The method according to claim 7, wherein said frames range is 10 to 1,000 frames.

9. The method according to claim 4, wherein said statistics for frame check sequence is calculated over a sliding window of number of frames range.

10. The method according to claim 9, wherein said frames range is 1,000 to 1,000,000.

11. The method according to claim 4, further comprising the step of:

displaying said statistics in response to a statistics display request.

12. The method according to claim 4, further comprising the step of allocating dynamic channels based on at least part of said statistics.

13. The method according to claim 4, further comprising the step of allocating primary and secondary channels based on at least part of said statistics.

14. The method according to claim 13, wherein said primary and secondary channels are configured in at least one of space diversity 1, a primary channel where all PHY parameters are accepted, space diversity 2, a secondary channel that identifies a primary channel and does not have any PHY parameters, and no space diversity, a channel not identified as primary nor secondary, has no associated channel, and accepts all PHY parameters.

15. The method according to claim 4, further comprising the steps of:

splitting each of the spatially diverse signals; and

forwarding each pair of split signals to a pair of demodulators; and

if one of said spatially diverse signals shows up on each arm of the split signal, optimizing said step of selecting by utilizing the split signals are independent events.

16. The method according to claim 4, wherein:

said method is embodied in a set of computer instructions stored on a computer readable media; and

said computer instructions, when loaded into a computer and executed, cause the computer to perform the steps of claim 4.

17. A space diversity device for a wireless hub, comprising:

PHY layer equipment including;

a set of at least two antennas for receiving spatially diverse signals;

a demodulator connected to each of said antennas; and

each demodulator configured to demodulate signals received on the antenna connected to it; and

MAC layer equipment comprising a selection mechanism configured to select a demodulated signal having a largest error free transmission;

an FEC decoding device having a decoding success indicator;

said FEC decoding service connected to said demodulator and configured to perform FEC on codewords transmitted in said signals;

wherein said MAC layer equipment selection mechanism selects the demodulated signal based on said decoding success indicator for each decoded codeword;

said device further comprising;

a header CRC device connected to said demodulator and configured to perform a CRC check on demodulated frame headers;

a frame CRC device connected to said demodulator and configured to perform a CRC check on demodulated frame; and

a PDU CRC device connected to said demodulator and configured to perform a CRC check on demodulated PDUs;

wherein said MAC layer equipment selection mechanism selects the demodulated signal based on said header, frame, and PDU CRC checks.

18. The device according to claim 17, further comprising:

a splitter connected between each antenna and demodulator and configured to split the signal received on the connected antenna into upper and lower frequency ranges; and

a signal optimization device connected to said splitter and configured to optimize the received signal by separately and independently evaluating each split signal if said splitter breaks the received signals into both the upper and lower frequency ranges.

19. The device according to claim 17, further comprising a statistics gathering device configured to track a sliding window of transmission errors in the received signals.

20. The device according to claim 17, further comprising a statistics gathering device configured to track a sliding window of total codewords decoded by said decoding device.

21. A space diversity device for a wireless hub, comprising:

PHY layer equipment including,

a set of at least two antennas for receiving spatially diverse signals,

a demodulator connected to each of said antennas, and each demodulator configured to demodulate signals received on the antenna connected to it;

MAC layer equipment comprising a selection mechanism configured to select a demodulated signal having a largest error free transmission; and

a statistics gathering device configured to track a sliding window of transmission errors in the received signals;

wherein said statistics gather device collects statistics for each of codewords in FEC non burst mode signals received by said antennas, header check sequence in burst mode signals received by said antennas, and frame check sequence in burst mode antennas received by said antennas.

22. The device according to claim 21, further comprising:

a user interface having,

a statistics display invocation mechanism, and

a display mechanism configured to read and display the gathered statistics.

23. The device according to claim 22, wherein said statistics display invocation mechanism in a button.

24. The device according to claim 22, wherein said gathered statistics are at least one of Primary Channel Codeword Error Rate, Secondary Channel Codeword Error Rate, Combined Channel Codeword Error Rate, Primary Channel Selection Percentage, Secondary Channel Selection Percentage, Primary Channel header check sequence, Secondary Channel header check sequence, Primary or Secondary Channel header check sequence Rate, Combined Channel header check sequence Error Rate, Primary Channel frame check sequence, Secondary Channel frame check sequence, Primary or Secondary Channel frame check sequence Error Rate, Combined Channel frame check sequence Error Rate.

25. The device according to claim 21, wherein said sliding window is between 1,000, and 10,000,000 codewords in length.