Common mode signal reduction in powerline communication devices
AssigneeQUALCOMM Incorporated
InventorFaisal M. Shad
Life of this patent
Estimating the term…
Abstract
An active common mode current limiting mechanism limits common mode currents in a powerline communication device. A powerline coupler determines a common mode signal component of an output signal of the powerline communication device. The powerline coupler provides voltage estimates of the common mode signal component to a signal processing unit. The signal processing unit generates samples of the voltage estimates of the common mode signal component. The signal processing unit adjusts transmit voltage levels of the powerline communication device based on the samples of the voltage estimates of the common mode signal component to limit the common mode signal component of the output signal.
Claims31
A method for limiting a common mode signal component of a powerline communication device, comprising:
- determining, using a feedback loop of the powerline communication device, a common mode signal component of an output signal of the powerline communication device;
- providing, via the feedback loop, voltage estimates of the common mode signal component to a signal processing unit of the powerline communication device;
- generating samples of the voltage estimates using an analog-to-digital converter of the signal processing unit, in response to the signal processing unit receiving the voltage estimates;
- and
- adjusting a transmit voltage of the powerline communication device based, at least in part, on the samples of the voltage estimates, wherein said adjusting comprises,
- determining a common mode voltage level of a carrier frequency associated with the samples;
- and
- adjusting a differential mode voltage gain associated with the carrier frequency to maintain the common mode signal component below a threshold limit.
A method for limiting a common mode signal component of a powerline communication device, comprising:
- determining estimates of a common mode current of a differential output signal at first and second terminals of the powerline communication device, wherein the common mode current is associated with a carrier frequency;
- determining a first frequency dependent carrier weight and a second frequency dependent carrier weight for the carrier frequency based, at least in part, on the estimates;
- and
- adjusting a transmit voltage associated with the differential output signal, wherein said adjusting the transmit voltage comprises applying the first frequency dependent carrier weight and the second frequency dependent carrier weight to the carrier frequency.
A network device comprising:
- a powerline communication (PLC) coupler operable to:
- determine, using a feedback loop of the network device, a common mode signal component of an output signal of the network device, wherein said determining the common mode signal comprises,
- providing the output signal to a common mode choke on the feedback loop;
- and
- generating the common mode signal component using the common mode choke;
- provide, via the feedback loop, voltage estimates of the common mode signal component to a PLC processing unit of the network device;
- and
- the PLC processing unit operable to,
- generate samples of the voltage estimates of the common mode signal component using an analog-to-digital converter of the PLC processing unit, in response to receiving the voltage estimates;
- and
- adjust a transmit voltage of the network device based, at least in part, on the samples of the voltage estimates.
A network device comprising:
- a memory unit;
- and
- a powerline communication (PLC) processing unit operable to,
- determine estimates of a common mode current of a differential output signal at first and second terminals of the network device, wherein the estimates are associated with a carrier frequency;
- determine a first frequency dependent carrier weight and a second frequency dependent carrier weight for the carrier frequency based, at least in part, on the estimates of the common mode current;
- and
- adjust a transmit voltage associated with the differential output signal, wherein
- the PLC processing unit operable to adjust the transmit voltage comprises the PLC processing unit further operable to apply the first frequency dependent carrier weight and the second frequency dependent carrier weight to the carrier frequency.
A method comprising:
- determining a carrier frequency dependent current to inject into a wire of a powerline communication medium that is not being utilized for powerline communications;
- and
- injecting the carrier frequency dependent current into the wire to limit a net common mode current.
Dependencies are inferred from the claim text.