Systems And Methods For Pulse Width Encoded Data Communications

A method of operating a wireless power transfer system comprising (1) a wireless power receiver comprising (i) a receiver antenna that is operable to (a) couple with a transmission antenna, (b) receive a wireless power signal, and (c) produce an alternating current (AC) power signal based on the wireless power signal, (ii) a rectifier circuit that is operable to (a) receive the AC power signal from the receiver antenna, and (b) output a direct current (DC) power signal for a load based on the AC power signal, and (2) a wireless power transmitter comprising (i) a DC input that is operable to provide a DC voltage signal having a voltage level, (ii) a driver that is operable to output a drive signal having an operating frequency, (iii) an inverter coupled to the DC input and the driver and that is operable to (a) receive the DC voltage signal and the drive signal, and (b) output an AC signal based on the DC voltage signal and the drive signal, (iv) a tuning circuit that is operable to (a) receive the AC signal from the inverter and (b) tune the AC signal for wireless power transfer, and (v) a transmission antenna that is operable to (a) receive the tuned AC signal from the tuning circuit, and (b) generate the wireless power signal based on the tuned AC signal, the method comprising:

• determining, by the wireless power receiver, a message signal including one or more message words;
• encoding, by the wireless power receiver, the one or more message words into an encoded message signal including one or more encoded message words in accordance with a coding format that correlates each of a plurality of correlated ratios, respectively, with a format word of a plurality of format words, wherein each correlated ratio is a ratio of (i) a duty cycle of a modulation interval used for in-band communications to (ii) a period of the modulation interval, and wherein each encoded message word is encoded as one of the plurality of correlated ratios;
• communicating, by the wireless power receiver, the encoded message signal from the wireless power receiver to the wireless power transmitter, as in-band communications, by modulating the wireless power signal;
• receiving, by the wireless power transmitter, the encoded message signal including the one or more encoded message words;
• decoding, by the wireless power transmitter, the one or more encoded message words into one or more decoded message words in accordance with the coding format by referencing the one or more encoded message words against the plurality of correlated ratios;
• determining, by the wireless power transmitter, the message signal based on the one or more decoded message words;
• and
• configuring, by the wireless power transmitter, at least one operating parameter of the wireless power signal based on the message signal.