Adaptive Backscatter Modulation

A method for a subordinate wireless apparatus to adaptively modulate backscatter signaling, the method comprising:

• receiving a power transmission from a primary wireless apparatus via an inductive coupling link;
• determining an inductive coupling quality of the inductive coupling link;
• determining a modulation scheme from multiple modulation schemes based on the inductive coupling quality;
• and
• reflecting, based on the modulation scheme, a backscatter signal across the inductive coupling link using the power transmission, including establishing an impedance at the subordinate wireless apparatus in accordance with an impedance point of the modulation scheme.

A wireless apparatus comprising:

• a power store configured to provide or receive power;
• a transceiver assembly configured to receive a power transmission from another wireless apparatus that has an inductive coupling link with the wireless apparatus at some inductive coupling quality, the transceiver assembly configured to provide to the power store power received via the power transmission, the transceiver assembly further configured to reflect a backscatter signal across the inductive coupling link based on an impedance adjusted in accordance with a modulation scheme;
• and
• means for controlling the modulation scheme based on the inductive coupling quality to adjust a communication bandwidth between the wireless apparatus and the other wireless apparatus, the means for controlling the modulation scheme including:
• means for analyzing the inductive coupling link to compute the inductive coupling quality;
• and
• means for determining the modulation scheme from multiple modulation schemes based on the inductive coupling quality.

A wireless apparatus comprising:

• a transceiver assembly configured to generate a power transmission and receive a backscatter signal reflected using the power transmission via an inductive coupling link, the backscatter signal carrying information based on a modulation scheme;
• and
• a transceiver controller configured to:
• analyze the backscatter signal to produce detected impedances respectively corresponding to impedance points in accordance with the modulation scheme;
• and
• process the impedance points based on the modulation scheme to recover the information, wherein:
• the transceiver controller includes modulation control circuitry configured to compute an error indication based on the information recovered by the transceiver controller;
• the transceiver controller is configured to cause the transceiver assembly to generate another power transmission, the other power transmission including the error indication;
• and
• the modulation control circuitry is configured to cause the transceiver controller to change to a different modulation scheme of multiple modulation schemes based on the error indication to process other impedance points from another backscatter signal.