Wireless access system using selectively adaptable beam forming in TDD frames and method of operation

• US 7,230,931 B2
• Filed: 09/05/2001
• Issued: 06/12/2007
• Est. Priority Date: 01/19/2001
• Status: Active Grant

• Current Assignee: Access Solutions, Ltd. (LOXAM SAS)
• Original Assignee: Raze Technologies, Inc.
• Inventors: Struhsaker, Paul F.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Ahmed, Salman
• Application Number:
  US09/948,059
• Publication Number:
  US 20020136170A1
• Time in Patent Office: 2,106 Days
• Field of Search: 370/280, 370/252, 370/350, 370347-348
• US Class Current: 370/280
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 1/0005 applied to payload information
• CPC Class Codes: H04L 1/0006 by adapting the transmission format
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0042 Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape H04L1/0067 takes precedence
• CPC Class Codes: H04L 1/007 Unequal error protection for format H04L1/0078; for codes per se H03M13/35
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 2001/0098 Unequal error protection
• CPC Class Codes: H04L 2001/125 Arrangements for preventing errors in the return channel
• CPC Class Codes: H04L 5/1453 : of modulation type
• CPC Class Codes: H04L 5/1469 : using time-sharing
• CPC Class Codes: H04M 2207/206 : composed of PSTN and wireless network
• CPC Class Codes: H04M 2242/04 : for emergency applications
• CPC Class Codes: H04M 2242/06 : Lines and connections with preferential service
• CPC Class Codes: H04M 3/42 : Systems providing special services or facilities to subscribers specially adapted for wireless communication networks H04W4/00
• CPC Class Codes: H04W 16/28 : using beam steering
• CPC Class Codes: H04W 28/04 : Error control
• CPC Class Codes: H04W 28/18 : Negotiating wireless communication parameters
• CPC Class Codes: H04W 72/0446 : Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/00 : Wireless channel access
• CPC Class Codes: H04W 84/042 : Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 84/12 : WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/14 : WLL [Wireless Local Loop]; RLL [Radio Local Loop]
• CPC Class Codes: H04W 88/021 : adapted for Wireless Local Loop operation
• CPC Class Codes: H04W 88/08 : Access point devices

Abstract

A transceiver for use in a wireless access network comprising a plurality of base stations, each of the plurality of base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises in a corresponding cell site of the wireless access network. The transceiver is associated with a first base station and comprises transmit path circuitry associated with a beam forming network for transmitting directed scanning beam signals in a sector of a cell site of the first base station. The transmit path circuitry transmits at a start of a TDD frame a broadcast beam signal comprising a start of frame field and subsequently transmits downlink data traffic in a downlink portion of the TDD frame to at least one of the wireless access devices using at least one directed scanning beam.

Claims

1. For use in a wireless access network comprising a plurality of base stations, each of said plurality of base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises in an associated cell site of said wireless access network, a transceiver associated with a first of said plurality of base stations comprising:

transmit path circuitry associated with a beam forming network capable of transmitting directed scanning beam signals each directed to substantially only wireless access devices within a different one of a plurality of sectors of a cell site associated with said first base station, wherein said transmit path circuitry

transmits, at a start of a TDD frame, a broadcast beam signal to wireless access devices within more than one of said sectors, the broadcast beam signal comprising a start of frame field, and

subsequently transmits, in a downlink portion of said TDD frame, first downlink data traffic to substantially only wireless access devices within one of said sectors using one of said directed scanning beam signals.

2. The transceiver as set forth in claim 1 wherein said broadcast beam signal further comprises a first beam map containing scanning beam information usable by said wireless access devices to detect said directed scanning beam signals.

3. The transceiver as set forth in claim 2 wherein said scanning beam information identifies a downlink time slot in said downlink portion during which said one of said directed scanning beam signals transmits said downlink data traffic.

4. The transceiver as set forth in claim 3 wherein said scanning beam information identifies at least one modulation format associated with said one of said directed scanning beam signals.

5. The transceiver as set forth in claim 3 wherein said scanning beam information identifies at least one forward error correction code level associated with said one of said directed scanning beam signals.

6. The transceiver as set forth in claim 2 further comprising receive path circuitry associated with said beam forming network capable of receiving uplink data traffic transmitted by at least one wireless access device in an uplink portion of said TDD frame.

7. The transceiver as set forth in claim 6 wherein said first beam map further contains uplink transmission information identifying an uplink time slot in said uplink portion during which said at least one wireless access device transmits said uplink data traffic.

8. The transceiver as set forth in claim 7 wherein said uplink transmission information further identifies at least one modulation format used by said at least one wireless access device to transmit said uplink data traffic.

9. The transceiver as set forth in claim 8 wherein said uplink transmission information further identifies at least one at least one forward error correction code level used by said at least one wireless access device to transmit said uplink data traffic.

28. The transceiver as set forth in claim 1 wherein said transmit path circuitry transmits, in said downlink portion of said TDD frame, second downlink data traffic to substantially only wireless access devices within an other of said sectors using an other of said directed scanning beam signals.

10. A fixed wireless access network comprising:

a plurality of base stations, each of said base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises in a cell site associated with said each base station, wherein said each base station comprises;

transmit path circuitry associated with a beam forming network capable of transmitting directed scanning beam signals each directed to substantially only wireless access devices within a different one of a plurality of sectors of a cell site associated with said first base station, wherein said transmit path circuitry

transmits, at a start of a TDD frame, a broadcast beam signal to wireless access devices within more than one of said sectors, the broadcast beam signal comprising a start of frame field, and

subsequently transmits, in a downlink portion of said TDD frame, first downlink data traffic to substantially only wireless access devices within one of said sectors using one of said directed scanning beam signals.

11. The fixed wireless access network as set forth in claim 10 wherein said broadcast beam signal further comprises a first beam map containing scanning beam information usable by said wireless access devices to detect said directed scanning beam signals.

12. The fixed wireless access network as set forth in claim 11 wherein said scanning beam information identifies a downlink time slot in said downlink portion during which said one of said directed scanning beam signals transmits said downlink data traffic.

13. The fixed wireless access network as set forth in claim 12 wherein said scanning beam information identifies at least one modulation format associated with said one of said directed scanning beam signals.

14. The fixed wireless access network as set forth in claim 12 wherein said scanning beam information identifies at least one forward error correction code level associated with said one of said directed scanning beam signals.

15. The fixed wireless access network as set forth in claim 11 wherein said each base station further comprises receive path circuitry associated with said beam forming network capable of receiving uplink data traffic transmitted by at least one wireless access device in an uplink portion of said TDD frame.

16. The fixed wireless access network as set forth in claim 15 wherein said first beam map further contains uplink transmission information identifying an uplink time slot in said uplink portion during which said at least one wireless access device transmits said uplink data traffic.

17. The fixed wireless access network as set forth in claim 16 wherein said uplink transmission information further identifies at least one modulation format used by said at least one wireless access device to transmit said uplink data traffic.

18. The fixed wireless access network as set forth in claim 17 wherein said uplink transmission information further identifies at least one at least one forward error correction code level used by said at least one wireless access device to transmit said uplink data traffic.

19. For use in a wireless access network comprising a plurality of base stations, each of said plurality of base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises in an associated cell site of said wireless access network, a method of communicating with a first of said plurality of base stations comprising the steps of:

transmitting, at a start of a TDD frame, a broadcast beam signal to wireless access devices within more than one of a plurality of sectors within said associated cell site, the broadcast beam signal comprising a start of frame field capable of synchronizing receivers in said wireless access devices; and

transmitting, in a downlink portion of said TDD frame, first downlink data traffic to substantially only wireless access devices in a first of said sectors using a first directed scanning beam signal.

20. The method as set forth in claim 19 wherein said broadcast beam signal further comprises a first beam map containing scanning beam information usable by said wireless access devices to receive said first directed scanning beam signal.

21. The method as set forth in claim 20 wherein said scanning beam information identifies a downlink time slot in said downlink portion during which said first directed scanning beam signal transmits said downlink data traffic.

22. The method as set forth in claim 21 wherein said scanning beam information identifies at least one modulation format associated with said first directed scanning beam signal.

23. The method as set forth in claim 21 wherein said scanning beam information identifies at least one forward error correction code level associated with said directed scanning beam signal.

24. The method as set forth in claim 20 further the step of receiving uplink data traffic transmitted by at least one wireless access device in an uplink portion of said TDD frame.

25. The method as set forth in claim 24 wherein said first beam map further contains uplink transmission information identifying an uplink time slot in said uplink portion during which said at least one wireless access device transmits said uplink data traffic.

26. The method as set forth in claim 25 wherein said uplink transmission information further identifies at least one modulation format used by said at least one wireless access device to transmit said uplink data traffic.

27. The method as set forth in claim 26 wherein said uplink transmission information further identifies at least one at least one forward error correction code level used by said at least one wireless access device to transmit said uplink data traffic.

29. The method as set forth in claim 19, further comprising:

transmitting, in said downlink portion of said TDD frame, second downlink data traffic to substantially only wireless access devices in a second of said sectors using a second directed scanning beam signal.