Multi-frequency data transmission channel power allocation

• US 20030084394A1
• Filed: 08/23/2002
• Published: 05/01/2003
• Est. Priority Date: 08/29/2001
• Status: Active Grant

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Erving, Richard Henry, Sankaranarayanan, Lalitha
• Granted Patent: US 7,139,323 B2
• Time in Patent Office: Days
• US Class Current: 714/755
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0016 involving special memory structures, e.g. look-up tables
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A method of controlling a communication device that is operable to transmit digital data over a plurality of frequency channels. The method includes selecting an initial transmission power and a corresponding data rate for each channel. The method also includes identifying in a first channel a first ratio of a first decrement in transmission power to a first data rate decrement that is greater than a second ratio of a second decrement in transmission power to a second data rate decrement. Then, the initial transmission power allocation of the first channel is reduced by the first decrement. The method also includes reallocating the decremented initial transmission power of the first channel to one or more other channels.

Claims

1. A method of controlling a communication device, the communication device including an inner coder and an outer coder, the communication device operable to transmit digital data over a plurality of frequency channels, the method comprising:

obtaining a characteristic of each of the plurality of frequency channels;

selecting performance parameters of the inner coder for each channel and performance parameters of the outer coder for each channel based in part on the obtained characteristic of the channel; and

allocating data to be transmitted to each channel.

2. The method of claim 1 wherein selecting performance parameters of the inner coder for each channel and selecting the performance parameters of the outer coder for each channel further comprises selecting a number representative of parity symbols per payload symbols for the outer coder.

3. The method of claim 1 wherein selecting performance parameters of the inner coder for each channel and selecting the performance parameters of the outer coder for each channel further comprises selecting a constellation symbol size for the inner coder.

4. The method of claim 1 wherein selecting performance selecting performance parameters of the inner coder for each channel and selecting the performance parameters of the outer coder for each channel further comprises:

storing for each of a plurality of combinations of inner coder performance parameters and outer coder performance parameters a corresponding transmission power requirement; and

selecting a combination of inner coder performance parameters and outer coder performance parameters by selecting a transmission power requirement.

5. The method of claim 4 wherein said inner coder performance parameters and said outer coder performance parameters define a data rate for the channel

6. The method of claim 4 wherein selecting the combination of inner coder performance parameters and outer coder performance parameters further comprises:

selecting an initial data rate and transmission power requirement, the initial data rate and transmission power requirement corresponding to a first combination of inner coder performance parameters and outer coder performance parameters; and

selecting an adjusted data rate and transmission power requirement based on a multi-channel efficiency, the adjusted data rate and transmission power requirement corresponding to a second combination of inner coder performance parameters and outer coder performance parameters.

7. The method of claim 1 further comprising employing a linear block coder as the outer coder.

8. The method of claim 7 further comprising employing a Reed-Solomon encoder as the linear block coder

9. The method of claim 1 further comprising employing a trellis encoder as the inner coder.

10. A method of controlling a communication device, the communication device operable to transmit digital data over a plurality of frequency channels, the method comprising:

a) selecting an initial transmission power allocation and a corresponding data rate allocation for each channel;

b) identifying in a first channel a first ratio of a first decrement in transmission power to a first data rate decrement that is greater than a second ratio of a second decrement in transmission power to a second data rate decrement;

c) reducing the initial transmission power allocation of the first channel by the first decrement; and

d) reallocating the reduced initial transmission power allocation of the first channel to one or more other channels.

11. The method of claim 10 further comprising storing information representative of a plurality of data rates and corresponding transmission power requirements, and wherein b) further comprises identifying the first ratio based on the stored information

12. The method of claim 11 wherein the stored information further comprises a stored plurality of combinations of coder parameters from which the plurality of data rates may be derived.

13. The method of claim 11 wherein the communication device further includes an inner coder and an outer coder, and wherein the stored information representative of each of the plurality of data rates and corresponding transmission requirements further comprises a combination of an inner coder parameter and an outer coder parameter.

14. The method of claim 10 wherein b) further comprises identifying in a first channel a first ratio of a first decrement in transmission power to a first data rate decrement that is greater than a second ratio of a second decrement in transmission power to a second data rate in a second channel.

15. The method of claim 10 further comprising repeating b), c) and d) a plurality of times.

16. The method of claim 10, wherein d) further comprises

identifying in a second channel a first increase ratio of a first increment in transmission power to a first data rate increment that is less than a second increase ratio of a second increment in transmission power to a second data rate increment;

and

reallocating at least some of the reduced initial transmission power allocation by increasing the initial transmission power allocation of the second channel by the first increment.

17. An arrangement for use in a communication device, the communication device operable to transmit digital data over a plurality of frequency channels, the arrangement comprising:

a multi-frequency transmission circuit operable to transmit digital data over the plurality of frequency channels, each of the plurality of frequency channels having a channel transmission power;

a processor, the processor operably connected to the multi-frequency transmission circuit to control the channel transmission power of each of the plurality of frequency channels, the processor further operable to,

select an initial transmission power allocation and a corresponding data rate allocation for each channel,

identify in a first channel a first ratio of a first decrement in transmission power to a first data rate decrement that is greater than a second ratio of a second decrement in transmission power to a second data rate decrement,

reduce the initial transmission power allocation of the first channel by the first decrement, and

reallocate the reduced initial transmission power allocation of the first channel to one or more other channels.

18. The arrangement of claim 17 further comprising a memory storing information representative of a plurality of data rates and corresponding transmission power requirements, and wherein the processor is further operable to identifying the first ratio based on the stored information.

19. The arrangement of claim 18 wherein the stored information in the memory further comprises a stored plurality of combinations of coder parameters from which the plurality of data rates may be derived.

20. The arrangement of claim 17, wherein the multi-frequency transmission circuit includes an inner coder and an outer coder, and wherein the processor is operable to change at least one of an inner coder parameter and an outer coder parameter based on the decrement in the initial transmission power

21. The arrangement of claim 20, wherein the processor is further operable to change at least an inner coder parameter and at least an outer coder parameter based on the decrement in the initial transmission power.

22. The arrangement of claim 20 wherein the outer coder comprises a linear block coder, and the outer coder parameter defines a ratio of parity symbols to payload symbols.

23. The arrangement of claim 22 wherein the linear block coder comprises a Reed-Solomon encoder.

24. The arrangement of claim 20 wherein the inner coder parameter defines a constellation size.

25. The arrangement of claim 24 wherein the inner coder comprises a trellis encoder.

26. The arrangement of claim 17 wherein the processor is further operably connected to control the allocation of data bits to the plurality of frequency channels.

27. The arrangement of claim 17, wherein the processor is further operable to:

identify in a second channel a first increase ratio of a first increment in transmission power to a first data rate increment that is less than a second increase ratio of a second increment in transmission power to a second data rate increment; and

reallocate at least some of the reduced initial transmission power allocation by increasing the initial transmission power allocation of the second channel by the first increment.

28. An arrangement for use in a communication device, the communication device operable to transmit digital data over a plurality of frequency channels, the arrangement comprising:

a multi-frequency transmission circuit operable to transmit digital data over the plurality of frequency channels, each of the plurality of frequency channels having a channel transmission power, the multi-frequency transmission circuit further comprising an inner coder and an outer coder; and

a processor, the processor operably connected to the multi-frequency transmission circuit to control the channel transmission power of each of the plurality of frequency channels, the processor further operable to,

obtain a characteristic of each of the plurality of frequency channels;

select performance parameters of the inner coder for each channel and performance parameters of the outer coder for each channel based in part on the obtained characteristic of the channel; and

allocate data to be transmitted to each channel.