Multi-tone transmission

• US 7,903,757 B2
• Filed: 04/13/2009
• Issued: 03/08/2011
• Est. Priority Date: 08/06/2001
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Taunton, Mark
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US12/422,714
• Publication Number:
  US 20090257524A1
• Time in Patent Office: 694 Days
• Field of Search: 375/219, 375/222, 375/224, 375/260, 375/262, 375/265, 375/268, 375/295, 375/296, 375/300, 332149-151, 332/160, 332/161
• US Class Current: 375/295
• CPC Class Codes: H04L 27/2614 Peak power aspects
• CPC Class Codes: H04L 27/262 Reduction thereof by selection of pilot symbols

Abstract

A Multi-tone transmission system processes input data through a plurality of intermediate processing stages 12, 14, 16 and corresponding stages of intermediate data 18, 20. A symbol including a number of tones is obtained therefrom by an inverse Fourier transform 24 and stored in a buffer 158. The peak amplitude that the symbol would contain after the subsequent processing in the analogue front end 146 is modelled and compared to a threshold. If the modelled peak amplitude in the symbol exceeds the threshold, the symbol stored in buffer 158 is regenerated. The symbols stored in the buffer are output through analogue front end 146.

Claims

1. A method for peak amplitude reduction, comprising:

processing input data through an intermediate preprocessing stage to generate a symbol;

modeling a predicted peak amplitude in the symbol;

comparing the predicted peak amplitude to a threshold amplitude;

if the predicted peak amplitude is less than the threshold amplitude, transmitting the symbol; and

if the predicted peak amplitude exceeds the threshold amplitude, generating a reprocessed symbol, comprising

(i) amending the input data, and

(ii) reprocessing the input data through the intermediate processing stage.

2. The method of claim 1, wherein amending the input data comprises amending a bit of the input data.

3. The method of claim 1, wherein amending the input data comprises amending a fast byte of the input data.

4. The method of claim 3, wherein amending the fast byte comprises amending an ‘

X’

bit of the fast byte.

5. The method of claim 1, wherein amending the input data comprises amending a sync byte of the input data.

6. The method of claim 5, wherein amending the sync byte comprises amending an ‘

X’

bit of the sync byte.

7. The method of claim 1, wherein amending the input data comprises amending a bit of an idle cell.

8. The method of claim 1, wherein amending the input data comprises amending a bit in an earliest-available idle cell payload byte.

9. The method of claim 1, wherein amending the input data comprises swapping a first ATM cell with a second ATM cell.

10. The method of claim 1, further comprising:

transmitting the reprocessed symbol.

11. The method of claim 1, further comprising:

transmitting the reprocessed symbol if a predicted peak amplitude of the reprocessed symbol is less than the predicted peak amplitude of the symbol; and

transmitting the symbol if the predicted peak amplitude of the symbol is less than the predicted peak amplitude of the reprocessed symbol.

12. A non-transitory computer program product having stored thereon, computer executable instructions that, if executed by a processor, cause the processor to perform a method comprising:

processing input data through an intermediate preprocessing stage to generate a symbol;

modeling a predicted peak amplitude in the symbol;

comparing the predicted peak amplitude to a threshold amplitude;

if the predicted peak amplitude is less than the threshold amplitude, transmitting the symbol; and

if the predicted peak amplitude exceeds the threshold amplitude, generating a reprocessed symbol, comprising

(i) amending the input data, and

(ii) reprocessing the input data through the intermediate processing stage.

13. A transmitter, comprising:

an intermediate preprocessing circuit configured to generate a symbol based on intermediate data;

a symbol buffer coupled to the intermediate preprocessing circuit and configured to store the symbol;

a modeling circuit coupled to the intermediate preprocessing circuit and configured to generate a predicted peak amplitude of the symbol;

a peak detector coupled to the modeling circuit and configured to compare the predicted peak amplitude to a threshold; and

a regeneration controller coupled to the peak detector and configured to amend the intermediate data.

14. The transmitter of claim 13, wherein the regeneration controller is further configured to send the amended intermediate data to the intermediate preprocessing circuit, and wherein the intermediate preprocessing circuit is further configured to generate a reprocessed symbol based on the amended intermediate data.

15. The transmitter of claim 13, further comprising:

an analogue front end configured to output symbols from the symbol buffer.

16. The transmitter of claim 15, wherein the analogue front end is implemented on a chip separate from the symbol buffer.