Enhanced communications for wireless power transfer

A wireless power transmitter comprising:

• an inverter that receives a DC input voltage and produces an AC output voltage;
• a wireless power transmitter coil that receives the AC output voltage from the inverter and delivers power to a wireless power receiver by magnetic coupling;
• controller and communications circuitry that controls the inverter and provides in-band communications with the wireless power receiver via the wireless power transmitter coil, wherein the controller and communications circuitry that:
• receives the results of a characterizing signal transmitted by the wireless power receiver;
• computes at least two parameters of a model characterizing an in-band communications channel based on the received results of the characterizing signal transmitted by the wireless power receiver, wherein a first parameter corresponds to a time constant of the channel, and a second parameter corresponds to a damping value of the communications channel;
• computes a plurality of equalizing filter taps from the at least two parameters;
• and
• applies the computed equalizing filter taps to subsequent signals received by the wireless power transmitter via the in-band communications channel.

A wireless power receiver comprising:

• a wireless power receiver coil that receives power from a wireless power transmitter by magnetic coupling;
• a rectifier that receives an AC voltage from the wireless power receiver coil and produces a DC output voltage to power a load;
• controller and communications circuitry that controls the rectifier and provides in-band communications with the wireless power transmitter via the wireless power receiver coil, wherein the controller and communications circuitry transmit a characterizing signal to the wireless power transmitter;
• wherein the characterizing signal is selected to allow the wireless power transmitter to:
• receive the results of a characterizing signal transmitted by the wireless power receiver;
• compute at least two parameters of a model characterizing an in-band communications channel based on the received results of the characterizing signal transmitted by the wireless power receiver, wherein a first parameter corresponds to a time constant of the channel, and a second parameter corresponds to a damping value of the communications channel;
• compute a plurality of equalizing filter taps from the at least two parameters;
• and
• apply the computed equalizing filter to subsequent signals received by the wireless power transmitter via the in-band communications channel.

A wireless power transfer system comprising a wireless power transmitter and a wireless power receiver:

• wherein the wireless power transmitter further comprises:
• an inverter that receives a DC input voltage and produces an AC output voltage;
• a wireless power transmitter coil that receives the AC output voltage from the inverter and delivers power to a wireless power receiver by magnetic coupling;
• controller and communications circuitry that controls the inverter and provides in-band communications with the wireless power receiver via the wireless power transmitter coil, wherein the controller and communications circuitry that:
• receives the results of a characterizing signal transmitted by the wireless power receiver;
• computes at least two parameters of a model characterizing an in-band communications channel based on the received results of the characterizing signal transmitted by the wireless power receiver, wherein a first parameter corresponds to a time constant of the channel, and a second parameter corresponds to a damping value of the communications channel;
• computes a plurality of equalizing filter taps from the at least two parameters;
• and
• applies the computed equalizing filter taps to subsequent signals received by the wireless power transmitter via the in-band communications channel;
• and wherein the wireless power receiver further comprises:
• a wireless power receiver coil that receives power from a wireless power transmitter by magnetic coupling;
• a rectifier that receives an AC voltage from the wireless power receiver coil and produces a DC output voltage to power a load;
• controller and communications circuitry that controls the rectifier and provides in-band communications with the wireless power transmitter via the wireless power receiver coil, wherein the controller and communications circuitry transmit a characterizing signal to the wireless power transmitter.

A method performed by one or more processing elements of a wireless power transfer system, the method comprising:

• using a wireless power receiver to transmit a characterizing signal to the wireless power receiver via a communication channel in-band with the wireless power transfer;
• using a wireless power transmitter to:
• receive the results of a characterizing signal transmitted by the wireless power receiver;
• compute at least two parameters of a model characterizing an in-band communications channel based on the received results of the characterizing signal transmitted by the wireless power receiver, wherein a first parameter corresponds to a time constant of the channel, and a second parameter corresponds to a damping value of the communications channel;
• compute a plurality of equalizing filter taps from the at least two parameters;
• and
• apply the computed equalizing filter to subsequent signals received by the wireless power transmitter via the in-band communications channel.