Four way handshake for robust channel estimation and rate prediction

• US 20070093209A1
• Filed: 03/28/2006
• Published: 04/26/2007
• Est. Priority Date: 10/25/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Agrawal, Avneesh, Julian, David, Prakash, Rajat
• Granted Patent: US 8,125,961 B2
• Time in Patent Office: Days
• US Class Current: 455/63.1
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

Systems and methodologies are described that facilitate enabling communication over a time varying channel with time varying interference. According to various aspects, systems and methods are described that facilitate selecting appropriate channels and identifying rates that yield optimal capacity for the selected channels. Such systems and/or methods can evaluate a signal to interference noise ratio (SINR) at a receiving node within a multinode network to facilitate selecting the rates.

Claims

1. A method of wireless communication that estimates channel interference, comprising:

sending a request;

receiving a grant of a channel assignment responsive to the request;

sending a pilot utilizing the granted channel assignment;

receiving a rate assignment based on a signal to interference noise ratio; and

transmitting data at the assigned rate.

2. The method of claim 1, the grant includes a channel identification to assign the channel.

3. The method of claim 1, the channel assignment being one or more of a frequency band, a time slot, and a spreading code assignment.

4. The method of claim 1, the grant provides hybrid automatic repeat request (HARQ) information including at least one of a HARQ fragment number, data indicating whether a transmitter should transmit a new packet, and a HARQ retransmission of an old packet.

5. The method of claim 1, the grant of the channel assignment includes an assigned power.

6. The method of claim 5, sending the pilot at the assigned power.

7. The method of claim 5, transmitting the data at the assigned power.

8. The method of claim 1, sending the request to an intended recipient.

9. The method of claim 1, further comprising pipelining the data by sending the request to an intermediate node within a multihop topology.

10. The method of claim 1, transmitting the data on a substantially similar channel and at a substantially similar power as compared to sending of the pilot.

11. The method of claim 1, the rate assignment includes at least one of a modulation format and a coding format.

12. The method of claim 1, further comprising interlacing a second data transmission.

13. The method of claim 12, interlacing the second data transmission further comprising:

sending a second request during a first time slot during which the pilot is sent;

receiving a second grant during a second time slot during which the rate assignment is received;

transmitting a second pilot according to the second grant during a third time slot during which the data is transmitted;

receiving a second rate assignment; and

transmitting a second data block based upon the second rate assignment.

14. The method of claim 1, the pilot being sent prior to transmitting the data to obtain rate information at a receiver.

15. An apparatus that optimizes capacity in a wireless communication system, comprising:

a memory that stores information associated with estimating a channel; and

a processor, coupled to the memory, that is configured to transmit a grant, receive a pilot transmitted based upon the grant, and estimate a signal to interference noise ratio (SINR) associated with the received pilot.

16. The apparatus of claim 15, the processor being further configured to determine a strength of the pilot and a strength of inference.

17. The apparatus of claim 15, the processor being further configured to analyze the SINR based upon the pilot obtained from a sender node during a time slot and interference caused by at least one disparate node concurrently transmitting a disparate pilot during the time slot.

18. The apparatus of claim 15, the processor being further configured to utilize the SINR to transmit a rate assignment.

19. The apparatus of claim 18, the rate assignment includes at least one of a coding format and a modulation format.

20. The apparatus of claim 15, the processor being further configured to transmit the grant in response to obtaining a request.

21. The apparatus of claim 15, the processor being further configured to transmit the grant that includes an assigned channel and an assigned power.

22. The apparatus of claim 21, the processor being further configured to evaluate the SINR of the received pilot transmitted with the assigned channel and the assigned power.

23. The apparatus of claim 22, the processor being further configured to estimate a SINR of data transmission based upon the SINR of the pilot by employing the assigned channel and the assigned power for both data transmission and pilot transmission for simultaneously transmitting nodes.

24. A wireless communication apparatus for estimating a channel and predicting a rate based upon a signal to interference noise ratio (SINR), comprising:

means for transmitting a request;

means for receiving a grant in response to the request;

means for transmitting a pilot based on the grant;

means for receiving a rate assignment based on the SINR associated with the pilot; and

means for transmitting data at the assigned rate.

25. The apparatus of claim 24, the grant includes at least one of an assigned channel and an assigned power.

26. The apparatus of claim 24, the rate assignment includes at least one of a coding format and a modulation format.

27. A computer-readable medium having a computer program stored thereon with computer-executable instructions for:

receiving a request;

transmitting a grant of a channel assignment;

receiving a pilot on the granted channel;

determining a signal to interference noise ratio (SINR) during transmission of the pilot;

transmitting a rate based on the SINR; and

obtaining data at the assigned rate.

28. The computer-readable medium of claim 27, further comprising instructions for terminating a hybrid automatic repeat request (HARQ).

29. The computer-readable medium of claim 28, further comprising instructions for correcting errors associated with the obtained data.

30. The computer-readable medium of claim 29, further comprising instructions for determining whether an error is unable to be corrected.

31. The computer-readable medium of claim 30, further comprising instructions for retransmitting the grant upon determining the error is unable to be corrected.

32. The computer-readable medium of claim 31, further comprising instructions for repeating the transmission of the grant, receipt of the pilot, determination of the SINR, transmission of the rate, receipt of the data, and attempt to correct of the errors until all errors are corrected.

33. The computer-readable medium of claim 27, further comprising instructions for pipelining the obtained data.

34. The computer-readable medium of claim 33, further comprising instructions for pipelining the data by initiating a transmission by sending a disparate request while transmitting the grant.

35. The computer-readable medium of claim 33, further comprising instructions for pipelining the obtained data further comprising:

sending a second request to a disparate node during a first time slot during which the grant is transmitted;

receiving a second grant from the disparate node during a second time slot during which the pilot is received;

transmitting a second pilot according to the second grant during a third time slot during which the rate assignment is transmitted;

receiving a second rate assignment during a fourth time slot during which the data is obtained; and

transmitting the data to the disparate node based upon the second rate assignment.

36. The computer-readable medium of claim 33, further comprising instructions for mitigating end to end latency associated with data transmission through a plurality of nodes by transmitting a disparate request to a disparate node while transmitting the grant to a sending node.