US 6,044,107 A · Method for interoperability of a T1E1.4 compliant ADSL modem and a simpler modem

Abstract

An MDSL modem is provided that is inter-operable with an ADSL modem. The present invention provides a method for modem operation, by dividing available bandwidth for the modem into a plurality of subsets, selecting at least one of the plurality of subsets for use as a communication path, reducing the SNR value used for bit loading for the selected subsets by a predetermined amount, undersampling any received data, and fast fourier transforming the received data to recover the data transmitted. An MDSL modem is provided having circuitry for dividing available bandwidth for the modem into a plurality of subsets, circuitry for selecting at least one of the plurality of subsets for use as a communication path, circuitry for reducing the SNR value used for bit loading for the selected subsets by a predetermined amount, circuitry for undersampling any received data, and circuitry for fast fourier transforming the received data to recover the data transmitted.

Claims2

Dependent claims

A method for modem operation, comprising:

dividing available bandwidth for said modem into a plurality of subsets,
selecting at least one of said plurality of subsets for use as a communication path,
determining the signal-to-noise (SNR) values for said plurality of subsets,
reducing the SNR value used for bit loading for said selected at least one of said plurality of subsets by a predetermined amount,
reducing the SNR value for said subsets that are not selected to a value preventing bit loading for those subsets,
undersampling any data received over the communication path, and
fast Fourier transforming the received data to recover the data transmitted.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application

08/748,444Filed 13 Nov 1996 · continuation in part

Priority

9 May 1996

Granted

28 Mar 2000

Term ends

Not estimatedThe source records don’t support an estimate.

Classification19 codes

H04L 27/0008
Modulated-carrier systems: arrangements for allowing a transmitter or receiver to use more than one type of modulation
H04L 1/0003
By adapting the transmission rate: by switching between different modulation schemes
H04L 1/0009
Systems modifying transmission characteristics according to link quality, e.g. power backoff: by adapting the channel coding
H04L 1/0016
Characterised by the adaptation strategy: involving special memory structures, e.g. look-up tables

Method for interoperability of a T1E1.4 compliant ADSL modem and a simpler modem

Life of this patent

Method for interoperability of a T1E1.4 compliant ADSL modem and a simpler modem

Life of this patent

Abstract

Claims2