Communicating data between an access point and multiple wireless devices over a link

• US 20060109814A1
• Filed: 11/24/2004
• Published: 05/25/2006
• Est. Priority Date: 11/24/2004
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Karimi, Hamid Reza, Kuzminskiy, Alexandr, Leung, Kin
• Granted Patent: US 7,512,096 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04L 1/1692 Physical properties of the supervisory signal, e.g. acknowledgement by energy bursts
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

The present invention provides a method and an apparatus for communicating data over a network between a communication node, for example, an access point having a first and a second antenna and a first and a second mobile station. The method comprises weighting a first data at the access point to transmit the first data using the first and second antennas so that the first mobile station only receives the first data and weighting a second data at the access point to transmit the second data using the first and second antennas so that the second mobile station only receives the second data. A space division multiple access (SDMA) module may cause a transmission protocol to transmit the first data to the first mobile station on the downlink and transmit the second data to the second mobile station in parallel to the transmission of the first data on the downlink. In a telecommunication system, this substantially simultaneous transmission of the first and second data using a similar carrier frequency in a radio frequency communication over a wireless local area network (WLAN) may increase throughput of a downlink, for example, by a factor nominally equal to the number of antennas at an access point.

Claims

1. A method for communicating data over a network between an access point having a first and a second antenna and a first and a second mobile station, the method comprising:

weighting a first data at said access point to transmit said first data using said first and second antennas so that said first mobile station only receives said first data; and

weighting a second data at said access point to transmit said second data using said first and second antennas so that said second mobile station only receives said second data.

2. A method, as set forth in claim 1, further comprising:

transmitting said first data to said first mobile station on a downlink; and

transmitting said second data to said second mobile station in parallel to the transmission of said first data on said downlink.

3. A method, as set forth in claim 1, further comprising:

transmitting said first and said second data substantially simultaneously at a substantially similar carrier frequency in a radio frequency communication.

4. A method, as set forth in claim 3, further comprising:

causing an increase in a downlink throughput by a factor nominally equal to the number of antennas at said access point.

5. A method, as set forth in claim 1, further comprising:

increasing a first data rate of transmission of said first data and a second data rate of transmission of said second data using a single carrier frequency in a radio frequency communication based on a transmission protocol;

discriminating transmissions of said first and said second data on a downlink in said radio frequency communication based on a spatial dimension; and

applying a space division multiple access based on said transmission protocol to said transmissions to transmit said first and said second data substantially simultaneously from said access point to said first and second mobile stations, respectively.

6. A method, as set forth in claim 5, further comprising:

defining at least one of said access point, said first and second mobile stations, and said downlink at least in part by Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard to establish said network including a wireless local area network; and

coupling said access point to said first and second mobile stations through said wireless local area network.

7. A method, as set forth in claim 6, further comprising:

estimating a first radio channel from said access point to said first mobile station over a pilot interval; and

estimating a second radio channel from said access point to said second mobile station over said pilot interval.

8. A method, as set forth in claim 7, further comprising:

initializing said transmission protocol before starting said transmissions of said first and second data over said downlink.

9. A method, as set forth in claim 8, wherein initializing said transmission protocol further comprising:

exchanging one or more protocol data units and one or more acknowledgement frames between said access point and said first mobile station and said second mobile station.

10. A method, as set forth in claim 9, wherein initializing said transmission protocol further comprising:

offsetting transmission of a first protocol data unit of said one or more protocol data units from said access point to said first mobile station relative to transmission of a second protocol data unit of said one or more protocol data units from said access point to said second mobile station by a predetermined time.

11. A method, as set forth in claim 9, wherein initializing said transmission protocol further comprising:

shifting transmission of said first data relative to transmission of said second data; and

canceling an interference based on synchronization between a first and a second acknowledgement frame of said one or more acknowledgement frames at said access point to recover said first acknowledgement frame that at least partially overlaps said second acknowledgement frame based on the shifted transmissions of said first and second data.

12. A method, as set forth in claim 11, further comprising:

re-estimating said first radio channel associated with the recovered said first acknowledgement frame.

13. A method, as set forth in claim 12, further comprising:

receiving one or more pilot symbols and one or more synchronization symbols of said first acknowledgement frame on a set of uncorrupted sub-carriers of a multiplicity of sub-carriers;

computing estimates of said first radio channel at the uncorrupted sub-carrier frequencies based on at least one of the pilot symbols and the synchronization symbols of said first acknowledgement frame received on the multiplicity uncorrupted sub-carriers; and

computing estimates of said first radio channel at a set of corrupted sub-carriers of said multiplicity of sub-carriers using the computed estimates at the uncorrupted sub-carrier frequencies.

14. A method, as set forth in claim 13, wherein computing estimates of said first radio channel at a set of corrupted sub-carriers of said multiplicity of sub-carriers using the computed estimates at the uncorrupted sub-carrier frequencies further comprises:

applying interpolation in a frequency domain based on the computed channel estimates to compute estimates of said first radio channel at a set of corrupted sub-carriers of said multiplicity of sub-carriers.

15. A method, as set forth in claim 13, wherein computing estimates of said first radio channel at a set of corrupted sub-carriers of said multiplicity of sub-carriers using the computed estimates at the uncorrupted sub-carrier frequencies further comprises:

computing estimates of said first radio channel at a set of corrupted sub-carriers of said multiplicity of sub-carriers based on the synchronization symbols of said first acknowledgement frame.

16. A method, as set forth in claim 9, further comprising:

using a time division multiple access protocol to partition a radio resource including a channel across a space division multiple access mode and a non-space division multiple access mode of said access point; and

reserving a portion of said channel for a transmission based on said space division multiple access protocol in said space division multiple access mode of said access point.

27. A method, as set forth in claim 9, wherein initializing said transmission protocol further comprises:

delaying transmission of a first one of the protocol data units from said access point to said first mobile station relative to transmission of a second one of the protocol data units from said access point to said second mobile station by a predetermined time during a first period of operation; and

delaying transmission of a third one of the protocol data units from said access point to said second mobile station relative to transmission of a fourth one of the protocol data units from said access point to said first mobile station by a predetermined time during a second period of operation.

28. A method, as set forth in claim 9, wherein initializing said transmission protocol further comprises:

alternately delaying transmissions of the protocol data units from the access point to the first and second mobile stations, respectively.

29. A method, as set forth in claim 9, wherein initializing said transmission protocol further comprises:

transmitting the protocol data units to the first and second mobile stations in a first preselected order during a first period of time and a second preselected order during a second period of time.

17. A communication node associated with a network to communicate data to and from a first and a second mobile station, said communication node comprising:

a first and a second antenna;

a controller; and

a memory storing instructions to cause said controller to weight a first data at said communication node to transmit said first data using said first and second antennas so that said first mobile station only receives said first data and weight a second data at said communication node to transmit said second data using said first and second antennas so that said second mobile station only receives said second data.

18. A communication node, as set forth in claim 17, wherein said communication node is an access point that transmits said first data to said first mobile station on a downlink and transmits said second data to said second mobile station in parallel to the transmission of said first data on said downlink.

19. A communication node, as set forth in claim 17, wherein said memory further storing:

a transmission protocol; and

a module to cause said transmission protocol to transmit said first data to said first mobile station on a downlink and transmit said second data to said second mobile station in parallel to the transmission of said first data on said downlink.

20. A communication node, as set forth in claim 17, further comprising:

a communication interface coupled to said controller and said memory to transmit said first and said second data substantially simultaneously at a same carrier frequency in a radio frequency communication to increase a downlink throughput by a factor nominally equal to the number of antennas at said communication node.

21. A communication node, as set forth in claim 18, wherein said access point is coupled to said first and second mobile stations through said network including a wireless local area network and at least one of said access point, said first and second mobile stations, and said downlink are defined at least in part by Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard.

22. A telecommunication system comprising:

an access point associated with a network to communicate data to and from a first and a second mobile station, said access point including;

a first and a second antenna,

a controller, and

a memory storing instructions to cause said controller to weight a first data at said access point to transmit said first data using said first and second antennas so that said first mobile station only receives said first data and weight a second data at said access point to transmit said second data using said first and second antennas so that said second mobile station only receives said second data.

23. A telecommunication system, as set forth in claim 22, wherein said access point transmits said first data to said first mobile station on a downlink and transmits said second data to said second mobile station in parallel to the transmission of said first data on said downlink to increase throughput on said downlink by a factor nominally equal to the number of antennas at said access point.

24. A telecommunication system, as set forth in claim 23, wherein said memory further storing:

a transmission protocol; and

a module to cause said transmission protocol to transmit said first and said second data substantially simultaneously at a same carrier frequency in a radio frequency communication and increase a first data rate of transmission of said first data and a second data rate of transmission of said second data.

25. A telecommunication system, as set forth in claim 24, wherein said access point is coupled to said first and second mobile stations through said network including a wireless local area network and at least one of said access point, said first and second mobile stations, and said downlink are defined at least in part by Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard.

26. An article comprising a computer readable storage medium storing instructions that, when executed cause a telecommunication system to:

enable a communication node having a first and a second antenna to associate with a network to communicate data to and from a first and a second mobile station;

weight a first data at said access point to transmit said first data using said first and second antennas so that said first mobile station only receives said first data; and

weight a second data at said access point to transmit said second data using said first and second antennas so that said second mobile station only receives said second data.