Multitone power spectral density

• US 20040037216A1
• Filed: 07/03/2003
• Published: 02/26/2004
• Est. Priority Date: 07/08/2002
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Redfern, Arthur J.
• Granted Patent: US 7,391,820 B2
• Time in Patent Office: Days
• US Class Current: 370/203
• CPC Class Codes: H04L 27/2614 Peak power aspects

Abstract

ADSL systems with a power cutback by imposition of a power ceiling; this reduces the range of transmitted power across frequencies.

Claims

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

(a) for a power spectral density P(i) expressed in terms of dBm/Hz where i indexes subchannels of a multitone system, for each subchannel k changing P(k) to the minimum of P(k) and P_max−

PCB where P_max is the maximum of the P(i) and PCB is a power cutback level in terms of dB.

2. The method of claim 1, wherein:

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

3. The method of claim 1, wherein:

(a) said multitone system is an asymmetrical digital subscriber line system; and

(b) 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.