Patent ID: 8766931

Claim:
A method performed by a data processing apparatus associated with a sensor, the sensor comprising a plurality of trace lines oriented in a matrix configuration, a front end interface, a plurality of transmitters coupled with the front end interface, and a plurality of receivers, wherein respective transmitters correspond to and are coupled with a first location of respective trace lines, and respective receivers are coupled with a second location of the respective trace lines, the method comprising: determining orthogonal excitation waveforms having an orthogonal waveform sequence, wherein the orthogonal excitation waveforms are orthogonal to each other and define an integration period that is longer than a time constant of a feedback resistor and a feedback capacitor connected in parallel between an input of a transimpedance amplifier and an output of the transimpedance amplifier; simultaneously transmitting, on each of at least two of the transmitters, one of the orthogonal excitation waveforms such that at least two of the transmitters are configured to transmit respective orthogonal waveform sequences for a duration equal to an integration time, wherein the transmitting occurs on less than all transmitters in the sensor, and wherein a length of the integration time is determined based on a number of transmitters simultaneously transmitting the one of the orthogonal excitation waveforms, the length of the integration time increasing as the number of transmitters simultaneously transmitting increases; receiving at least two of the orthogonal excitation waveforms at least at two of the receivers, wherein each of the at least two orthogonal excitation waveforms are received at one of the respective receivers; receiving information for at least an expected received waveform; and for each of the at least two receivers, correlating the received excitation waveform against the expected received waveform.