Outbound Interference Reduction in a Broadband Powerline System
AssigneeAT&T Intellectual Property II, L.P.
InventorPaul Shala Henry
Life of this patent
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Abstract
Disclosed is a method and apparatus for reducing outbound interference in a broadband powerline communication system. Data is modulated on first and second carrier frequencies and is transmitted via respective first and second lines of the powerline system. A characteristic of at least one of the carrier signals (e.g., phase or amplitude) is adjusted in order to improve the electrical balance of the lines of the transmission system. This improvement in electrical balance reduces the radiated interference of the powerline system. Also disclosed is the use of a line balancing element on or more lines of the powerline system for altering the characteristics of at least one of the power lines in order to compensate for a known imbalance of the transmission system.
Claims20
A method for reducing interference radiated by a powerline transmission system, the method comprising:
- determining characteristics of a modulated first carrier signal on a first line of the powerline transmission system;
- determining characteristics of a modulated second carrier signal on a second line of the powerline transmission system;
- and
- adjusting one of the characteristics of the modulated first carrier signal or the modulated second carrier signal based on a determined imbalance between the first line and the second line to improve an electrical balance of the first line and the second line of the powerline transmission system.
A transmitter for use in a powerline communication system having a first transmission line and a second transmission line, the transmitter comprising:
- at least one modulator for modulating first data onto a first carrier signal and for modulating second data onto a second carrier signal;
- and
- a differential driver connected to the at least one modulator for adjusting a characteristic of one of the first carrier signal or the second carrier signal to improve an electrical balance of the powerline communication system based on a determined imbalance between the first transmission line and the second transmission line.
A method for reducing interference radiated by a powerline transmission system comprising:
- generating respective modulated first and second carrier signals having characteristics which compensate for a determined imbalance between respective first and second transmission lines of the powerline transmission system;
- and
- transmitting first and second data via the respective modulated first and second carrier signals on the respective first and second transmission lines of the powerline transmission system using differential excitation.
Dependencies are inferred from the claim text.