A system includes a transmitter to transmit a set of bits associated with signaling having one or more levels. The system includes a receiver coupled to the transmitter, the receiver to receive the set of bits and generate a first plurality of digital values, each digital value generated at a first timing value and a plurality of reference voltages, the reference voltage incremented based at least in part on generating a digital value of the first plurality of digital values. The receiver is to generate a second plurality of digital values at a second timing value and the plurality of reference voltages, the first timing value incremented to the second timing value based at least in part on generating the first plurality of digital values. The system includes a controller to determine an amplitude associated with each the first and second plurality of digital values.

Provided is an electronic apparatus comprising a main body and a kit connected to the main body, wherein the main body comprises a battery, a first motor, an electric wire connected to the battery and a first controller connected to the electric wire, wherein the kit comprises a second motor supplied with power through the electric wire and a second controller connected to the electric wire, wherein the first controller comprises a first signal generator configured to generate a signal to be transmitted to the kit and a first modulator configured to modulate the signal generated by the first signal generator, and wherein the signal modulated by the first modulator is transmitted to the second controller through the electric wire.

Provided is an electronic apparatus comprising a main body and a kit connected to the main body, wherein the main body comprises a battery, a first motor, an electric wire connected to the battery and a first controller connected to the electric wire, wherein the kit comprises a second motor supplied with power through the electric wire and a second controller connected to the electric wire, wherein the first controller comprises a first signal generator configured to generate a signal to be transmitted to the kit and a first modulator configured to modulate the signal generated by the first signal generator, and wherein the signal modulated by the first modulator is transmitted to the second controller through the electric wire.

A wireless power transmitter can 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, 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 first parameter can correspond to a time constant of the channel, and a second parameter can correspond to a damping value of the communications channel. The wireless power transmitter can transmit to a wireless power receiver a request to transmit a characterizing signal through the in-band communication channel, wherein the characterizing signal transmitted by the wireless power receiver is sent in response to the transmitted request.

A wireless power transmitter can 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, 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 first parameter can correspond to a time constant of the channel, and a second parameter can correspond to a damping value of the communications channel. The wireless power transmitter can transmit to a wireless power receiver a request to transmit a characterizing signal through the in-band communication channel, wherein the characterizing signal transmitted by the wireless power receiver is sent in response to the transmitted request.

A method of reducing transmission power for an encoded data stream includes the steps of receiving an incoming data stream having equal probability for a plurality of incoming data bits, assigning a symbol scheme to the received data bits of the incoming data stream according to probabilities of occurrence of individual ones of the received data bits, and transmitting an outgoing data stream according to the assigned symbol scheme having a second average transmit power, different than the first average transmit power, for a plurality of outgoing symbols.

A method of reducing transmission power for an encoded data stream includes the steps of receiving an incoming data stream having equal probability for a plurality of incoming data bits, assigning a symbol scheme to the received data bits of the incoming data stream according to probabilities of occurrence of individual ones of the received data bits, and transmitting an outgoing data stream according to the assigned symbol scheme having a second average transmit power, different than the first average transmit power, for a plurality of outgoing symbols.

A polar transmitter provided for transmitting a phase/frequency modulated and amplitude modulated transmit signal and a method for generating a transmit signal using a polar transmitter are described. An example polar transmitter comprises a phase locked loop for generating a phase/frequency modulated precursor of the transmit signal. The phase locked loop comprises at its input a phase error detection unit for detecting a phase error of the precursor fed back from the output of the phase locked loop to the phase error detection unit as a feedback signal. The polar transmitter comprises a digital amplitude modulator for amplitude modulation of the precursor, resulting in the transmit signal. The digital amplitude modulator is arranged within the phase locked loop for amplitude modulation of the precursor before being output by the PLL. The phase error detection unit is further provided for detecting the amplitude of the feedback signal.

A communication device according to the disclosure includes: a signal generator that generates, on the basis of the first signal received from a communication partner through a coil, a second signal that synchronizes with the first signal; a first modulator configured to be able to modulate the first signal on the basis of the second signal; a second modulator configured to be able to modulate the first signal; and a communication controller that selects, on the basis of the first signal, whichever modulator is to be operated, from the first modulator and the second modulator.

A communication device according to the disclosure includes: a signal generator that generates, on the basis of the first signal received from a communication partner through a coil, a second signal that synchronizes with the first signal; a first modulator configured to be able to modulate the first signal on the basis of the second signal; a second modulator configured to be able to modulate the first signal; and a communication controller that selects, on the basis of the first signal, whichever modulator is to be operated, from the first modulator and the second modulator.