Method and apparatus for efficient use of communication resources in a CDMA communication system

• US 6,779,147 B2
• Filed: 09/25/2001
• Issued: 08/17/2004
• Est. Priority Date: 09/25/2001
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Tao
• Primary Examiner(s): Lamarre, Guy J.
• Application Number:
  US09/965,189
• Publication Number:
  US 20030058831A1
• Time in Patent Office: 1,057 Days
• Field of Search: 714/748, 714/749, 370/349, 370/476, 370/468, 455/69, 455/88, 455/62
• US Class Current: 714/748
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0015 characterised by the adaptation strategy
• CPC Class Codes: H04L 1/0033 arrangements specific to the transmitter
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end

Abstract

A method and accompanying apparatus provides for efficient use of communication resources in a CDMA communication system by controlling a transmitting source (300) for transmitting a packet of data over a data frame at a first data rate and at a power level and re-transmitting the packet of data at a second data rate over at least two frames of data at the power level when a receiving destination fails to decode the packet of data. A data rate and power level selector (303) selects the second data rate lower than the first data rate. The data rate and power level selector (303) determines energy per bit of the packet of data at a ratio of the first and second data rates, and selects the second data rate from the ratio such that the determined energy per bit is at a minimum level.

Claims

1. In a communication system, a method comprising:

transmitting a packet of data over a data frame at a first data rate and at a power level from a transmitting source;

receiving said packet of data at a receiving destination;

failing to decode said packet of data;

transmitting a negative acknowledgment to said transmitting source; and

re-transmitting said packet of data at a second data rate over at least two frames of data at said power level;

determining energy per bit of said packet of data at a ratio of said first and second data rates;

determining said second data rate from said ratio such that said determined energy per bit is at a minimum level.

2. The method as recited in claim 1 wherein said second data rate is lower than said first data rate.

3. The method as recited in claim 1 further comprising:

selecting said second data rate from a predetermined group of data rates for transmission.

4. The method as recited in claim 1 wherein a number of said at least two frames of data depends on a ratio of said first and second data rates.

5. In a communication system, an apparatus comprising:

a transmitting source for transmitting a packet of data over a data frame at a first data rate and at a power level; and

a data rate and power level selector coupled to said transmitting source for re-transmitting said packet of data at a second data rate over at least two frames of data at said power level when a receiving destination fails to decode said packet of data;

wherein said data rate and power level selector determines energy per bit of said packet of data at a ratio of said first and second data rates, and selects said second data rate from said ratio such that said determined energy per bit is at a minimum level.

6. The apparatus as recited in claim 5 wherein said data rate and power level selector selects said second data rate at a rate lower than said first data rate.

7. The apparatus as recited in claim 5 wherein said data rate and power level selector selects said second data rate from a predetermined group of data rates for transmission.

8. The apparatus as recited in claim 5 wherein said data rate and power level selector selects a number of said at least two frames of data based on a ratio of said first and second data rates.

9. A communication system comprising:

a transmitting source for transmitting a packet of data over a data frame at a first data rate and at a power level;

a receiving destination for receiving said packet of data, and for transmitting a negative acknowledgment to said transmitting source when said receiving destination fails to decode said packet of data; and

wherein said transmitting source is configured for re-transmitting said packet of data at a second data rate over at least two frames of data at said power level;

a data rate and power level selector for determining energy per bit of said packet of data at a ratio of said first and second data rates, selecting said second data rate from said ratio such that said determined energy per bit is at a minimum level.

10. The system as recited in claim 9 wherein said transmitting source includes a data rate and power level selector for selecting said second data rate lower than said first data rate.

11. The system as recited in claim 9 further comprising:

a data rate and power level selector for selecting said second data rate from a predetermined group of data rates for transmission.

12. The system as recited in claim 9 wherein a number of said at least two frames of data depends on a ratio of said first and second data rates.

13. A processor for use in a communication system comprising:

a data rate and power level selector for controlling a transmitting source for transmitting a packet of data over a data frame at a first data rate and at a power level from said transmitting source and re-transmitting said packet of data at a second data rate over at least two frames of data at said power level when a receiving destination fails to decode said packet of data;

wherein said data rate and power level selector is configured for determining energy per bit of said packet of data at a ratio of said first and second data rates, and selecting said second data rate from said ratio such that said determined energy per bit is at a minimum level.

14. The processor as recited in claim 13 wherein said data rate and power level selector is configured for selecting said second data rate lower than said first data rate.

15. The processor as recited in claim 13 wherein said data rate and power level selector is configured for selecting said second data rate from a predetermined group of data rates for transmission.

16. The processor as recited in claim 13 wherein said data rate and power level selector is configured for selecting a number of said at least two frames of data based on a ratio of said first and second data rates.

17. An apparatus for use in a communication system comprising:

means for a data rate and power level selector for controlling a transmitting source for transmitting a packet of data over a data frame at a first data rate and at a power level from said transmitting source and re-transmitting said packet of data at a second data rate over at least two frames of data at said power level when a receiving destination fails to decode said packet of data, wherein said means for said data rate and power level selector is coupled to said transmitting source;

wherein said means for said data rate and power level selector is configured for determining energy per bit of said packet of data at a ratio of said first and second data rates, and selecting said second data rate from said ratio such that said determined energy per bit is at a minimum level.

18. The apparatus as recited in claim 17 wherein said means for said data rate and power level selector is configured for selecting said second data rate lower than said first data rate.

19. The apparatus as recited in claim 17 wherein said means for said data rate and power level selector is configured for selecting said second data rate from a predetermined group of data rates for transmission.

20. The apparatus as recited in claim 17 wherein said means for said data rate and power level selector is configured for selecting a number of said at least two frames of data based on a ratio of said first and second data rates.