Methods and apparatus for organizing selection of operational parameters in a communication system

• US 6,859,463 B1
• Filed: 11/08/2000
• Issued: 02/22/2005
• Est. Priority Date: 11/08/1999
• Status: Expired due to Fees

• Current Assignee: Stingray IP Solutions LLC (Acacia Research Corporation)
• Original Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Inventors: Mayor, Michael A., Rasmussen, Donald J., Whitehill, Eric A., Simmons, Charles A., McCrady, Dennis
• Primary Examiner(s): Nguyen, Brian
• Assistant Examiner(s): Phan, Tri H.
• Application Number:
  US09/708,189
• Time in Patent Office: 1,567 Days
• Field of Search: 370/230, 370/252, 370/318, 370/445, 370331-333, 370/328, 370447-449, 370461-462, 370/346, 370/338, 375/141, 375/145, 455432-436, 455/456.1, 455/452.1, 709/238, 709/241, 709242-243
• US Class Current: 370/445
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0015 characterised by the adaptation strategy
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo

Abstract

Operational parameters for transmitting a signal over a communication channel of a network are selected by first determining RF conditions on the communication channel from a received signal transmitted over the communication channel. An initial set of parameter values is selected for transmitting the signal based on RF conditions determined from the received signal. The initial set of parameter values is used to identify other sets of parameter values as other potential candidates for transmitting the signal. The parameter values in the other sets of parameter values differ from parameter values in the initial set of parameter values by less than a predetermined amount. The expected performance of the candidate sets of parameter values is compared to determine which set of parameter values has the best expected performance among the candidate sets of parameter values. The signal is transmitted on the communication channel using the selected set of parameter values.

Claims

1. A method of selecting operational parameters for transmitting a signal over a communication channel of a communication network, the method comprising the steps of:

(a) determining RF conditions on the communication channel from a received signal transmitted over the communication channel;

(b) selecting a preliminary set of parameter values for the operational parameters based on the RF conditions determined from the received signal;

(c) using the preliminary set of parameter values to identify candidate sets of parameter values as potential candidates for transmitting the signal, an expected performance value being associated with each of the candidate sets of parameters, wherein determination of the expected performance value is independent of the RF conditions determined from the received signal;

(d) selecting from among the candidate sets of parameter values a selected set of parameter values having the expected performance value indicating a highest expected performance among the candidate sets of parameter values, such that selection of the selected set of parameter values from among the candidate sets of parameter values is independent of the RF conditions determined from the received signal; and

(e) transmitting the signal on the communication channel using the selected set of parameter values.

2. The method of claim 1, further comprising the steps of:

(f) prior to step (d), using a previous set of parameter values with which the received signal was transmitted to identify additional candidate sets of parameter values for transmitting the signal if the previous set of parameter values differs from the preliminary set of parameter values by more than a predetermined amount; and

wherein the candidate sets of parameters in step (d) include the additional candidate sets of parameter values.

3. The method of claim 1, wherein step (b) includes forming a system state vector from the preliminary set of parameter values, and steps (c) and (d) carry out a system state transformation on said system state vector.

4. The method of claim 1, wherein the expected performance values are pre-computed weights stored in a table.

5. The method of claim 1, wherein the preliminary set of parameters includes at least one of:

data rate, packet length, signal bandwidth, frequency channel, code channel, transmit power, multipath profile and forward error correction scheme.

6. The method of claim 1, wherein the determined RF conditions include at least one of:

received signal power, multipath characteristics and interference characteristics.

7. The method of claim 1, wherein the signal being transmitted contains at least one of control, audio, video and data information.

8. The method of claim 1, wherein the candidate sets of parameter values are selected from among possible sets of parameter values based on the preliminary set of parameter values.

9. The method of claim 1, wherein the RF conditions are determined at a same node that transmits the signal with the selected set of parameter values, such that the received signal is received by, not transmitted from, said same node.

10. The method of claim 2, wherein the previous set of parameter values used to transmit the received signal is indicated in the received signal.

11. The method of claim 4, wherein the preliminary set of parameter values is used to index the table of pre-computed weights, such that the candidate sets of parameter values are those within a predetermined number of indices of the preliminary set of parameter values.

12. A communication node for communicating with other nodes in a network over communication channels, comprising:

a receiver configured to process a received signal transmitted over a communication channel to determine RF conditions on the communication channel;

a processor configured to select a preliminary set of parameter values for the operational parameters based on the RF conditions determined from the received signal, and using the preliminary set of parameter values to identify candidate sets of parameter values as potential candidates for transmitting the signal, an expected performance value being associated with each of the candidate sets of parameters, wherein determination of the expected performance value is independent of the RF conditions determined from the received signal, said processor selecting from among the candidate sets of parameter values a selected set of parameter values having the expected performance value indicating a highest expected performance among the candidate sets of parameter values, such that selection of the selected set of parameter values from among the candidate sets of parameter values is independent of the RF conditions determined from the received signal; and

a transmitter configured to transmit the signal on the communication channel using the selected set of parameter values.

13. The communication node of claim 12, wherein said communication node is a mobile communication device.

14. The communication node of claim 12, wherein said communication node communicates with other nodes on a peer-to-peer basis.

15. The communication node of claim 12, wherein said communication node is a multimedia communication device capable of transmitting and receiving audio, video and data messages.

16. The communication node of claim 12, wherein said processor uses a previous set of parameter values with which the received signal was transmitted to identify additional candidate sets of parameter values for transmitting the signal if the previous set of parameter values differs from the preliminary set of parameter values by more than a predetermined amount;

and

wherein the additional candidate sets of parameter values are among the candidate sets of parameter values from which the selected set of parameter values is chosen.

17. The communication node of claim 12, wherein said processor forms a system state vector from the preliminary set of parameter values, and carries out a system state transformation on said system state vector to choose the selected set of parameter values.

18. The communication node of claim 12, wherein the expected performance values are pre-computed weights, the node further comprising a memory for storing the pre-computed weights in a table, wherein the selected set of parameter values has a pre-computed weight corresponding to a highest performance among the candidate sets of parameter values.

19. The communication node of claim 12, wherein the preliminary set of parameters includes at least one of:

data rate, packet length, signal bandwidth, frequency channel, code channel, transmit power, multipath profile and forward error correction scheme.

20. The communication node of claim 12, wherein the determined RF conditions include at least one of:

received signal power, multipath characteristics and interference characteristics.

21. The communication node of claim 12, wherein said communication node communicates on the communication channel using carrier sense multiple access with collision avoidance.

22. The communication node of claim 12, wherein said communication node defines the communication channel using code division multiple access and frequency division multiple access.

23. The communication node of claim 12, wherein said communication node transmits a direct sequence spread spectrum signal.

24. The communication node of claim 12, wherein said communication node selects a set of parameter values for each message transmitted by said communication node.

25. The node of claim 12, wherein the processor selects the candidate sets of parameter values from among possible sets of parameter values based on the preliminary set of parameter values.

26. The node of claim 16, wherein the previous set of parameter values used to transmit the received signal is indicated in the received signal.

27. The node of claim 18, wherein the processor uses the preliminary set of parameter values to index the table of pre-computed weights, such that the candidate sets of parameter values are those within a predetermined number of indices of the preliminary set of parameter values.

28. A communication system, comprising:

a plurality of nodes communicating over communication channels, each of said nodes including;

a receiver configured to process a received signal transmitted over a communication channel to determine RF conditions on the communication channel;

a processor configured to select a preliminary set of parameter values for the operational parameters based on the RF conditions determined from the received signal, and using the preliminary set of parameter values to identify candidate sets of parameter values as potential candidates for transmitting the signal, an expected performance value being associated with each of the candidate sets of parameters, wherein determination of the expected performance value is independent of the RF conditions determined from the received signal, said processor selecting from among the candidate sets of parameter values a selected set of parameter values having the expected performance value indicating a highest expected performance among the candidate sets of parameter values, such that selection of the selected set of parameter values from among the candidate sets of parameter values is independent of the RF conditions determined from the received signal; and

a transmitter configured to transmit the signal on the communication channel using the selected set of parameter values.

29. The communication system of claim 28, wherein each node is a mobile communication device.

30. The communication system of claim 28, wherein nodes in said communication system communicate with each other on a peer-to-peer basis.

31. The communication system of claim 28, wherein each node is a multimedia communication device capable of transmitting and receiving audio, video and data messages.

32. The communication system of claim 28, wherein said processor uses a previous set of parameter values with which the received signal was transmitted to identify additional candidate sets of parameter values for transmitting the signal if the previous set of parameter values differs from the preliminary set of parameter values by more than a predetermined amount;

and

wherein the additional candidate sets of parameter values are among the candidate sets of parameter values from which the selected set of parameter values is chosen.

33. The communication system of claim 28, wherein said processor forms a system state vector from the preliminary set of parameter values, and carries out a system state transformation on said system state vector to choose the selected set of parameter values.

34. The communication system of claim 28, wherein the expected performance values are pre-computed weights and each node further comprises a memory for storing the pre-computed weights in a table, wherein the selected set of parameter values has a pre-computed weight corresponding to a highest performance among the candidate sets of parameter values.

35. The communication system of claim 28, wherein the preliminary set of parameters includes at least one of:

data rate, packet length, signal bandwidth, frequency channel, code channel, transmit power, multipath profile and forward error correction scheme.

36. The communication system of claim 28, wherein the determined RF conditions include at least one of:

received signal power, multipath characteristics and interference characteristics.

37. The communication system of claim 28, wherein said communication system employs carrier sense multiple access with collision avoidance.

38. The communication system of claim 28, wherein said communication system employs code division multiple access and frequency division multiple access to define communication channels.

39. The communication node of claim 28, wherein said node transmit direct sequence spread spectrum signals.

40. The communication node of claim 28, wherein each node selects a set of parameter values for each message transmitted.

41. The system of claim 28, wherein the processor selects the candidate sets of parameter values from among possible sets of parameter values based on the preliminary set of parameter values.

42. The system of claim 28, wherein the RF conditions are determined at a same node that transmits the signal with the selected set of parameter values, such that the received signal is received by, not transmitted from, said same node.

43. The system of claim 32, wherein the previous set of parameter values used to transmit the received signal is indicated in the received signal.

44. The system of claim 34, wherein the processor uses the preliminary set of parameter values to index the table of pre-computed weights, such that the candidate sets of parameter values are those within a predetermined number of indices of the preliminary set of parameter values.