Multitone power spectral density

• US 7,391,820 B2
• Filed: 07/03/2003
• Issued: 06/24/2008
• Est. Priority Date: 07/08/2002
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Redfern, Arthur J.
• Primary Examiner(s): Ghayour; Mohammad H.
• Assistant Examiner(s): Williams; Lawrence B
• Application Number:
  US10/613,145
• Publication Number:
  US 20040037216A1
• Time in Patent Office: 1,818 Days
• Field of Search: 375/222, 375/227, 375/260, 375/295, 375/346, 375/316, 375/350, 375/225, 370/201, 370/203, 370/235, 370/278, 370/282, 370/480, 370/286, 455/507, 455/517, 455/522, 455/130, 379/22.08, 379/395.01, 379/416, 379/93.05, 348/607, 348/659, 708/313
• US Class Current: 375/295
• CPC Class Codes: H04L 27/2614 Peak power aspects

Abstract

A method of transmit power adjustment in multitone communication systems is performed by changing a power spectral density for each subchannel k the power spectral density to the minimum of the power spectral density and a miximum of the power spectral density REFPSD(k)=min(NOMPSD(k), NOMPSD−PCB) where REFPSD(k) is the transmitted PSD at tone k, NOMPSD(k) is the maximum transmit PSD allowed at each tone k, NOMPSD is the maximum value of NOMPSD(k) over all k and PCB is a power cutback level.

Claims

1. A method of transmit power adjustment in a multitone communication system, comprising:

adjusting transmit power by changing a power spectral density PSD for each subchannel k to a minimum of the power spectral density and a maximum of a reference power spectral density REFPSD(k)=min(NOMPSD(k), NOMPSD−

PCB) where REFPSD(k) is the transmitted PSD at subchannel k, NOMPSD(k) is the maximum transmit PSD allowed at each subchannel k, NOMPSD is the maximum value of NOMPSD(k) over all k and PCB is a power cutback level.

2. The method of claim 1, wherein:

said PCB is selected from the range 0 dB to 40 dB.

3. The method of claim 1, wherein:

said multitone system is an asymmetrical digital subscriber line system; and

said PCB is selected as the larger of a power cutback selected by a central office transceiver and a power cutback selected by a customer transceiver.

4. A system including at least one processor, said processor configured to perform for a power spectral density where k indexes subchannels of a multitone system, for each subchannel k:

adjusting transmit power by changing a power spectral density for each subchannel k to the minimum of a power spectral density and a maximum of a reference power spectral density REFPSD(k)=min(NOMPSD(k), NOMPSD−

PCB) where REFPSD(k) is the transmitted PSD at tone k, NOMPSD(k) is the maximum transmit PSD allowed at each tone k, NOMPSD is the maximum value of NOMPSD(k) over all k and PCB is a power cutback level.

5. A computer readable medium storing instructions to configure a processor to perform for a power spectral density PSD where k indexes subchannels of a multitone system, for each subchannel k:

adjusting transmit power by changing a power spectral density for each subchannel k to a minimum of the power spectral density and a maximum of a reference power spectral density REFPSD(k)=min(NOMPSD(k), NOMPSD−

PCB) where REFPSD(k) is the transmitted PSD at subchannel k, NOMPSD(k) is the maximum transmit PSD allowed at each subchannel k, NOMPSD is the maximum value of NOMPSD(k) over all k and PCB is a power cutback level.