Non-orthogonal coding techniques for optical sensing

A method for optical sensing, comprising:

• receiving a resulting signal comprising effects corresponding to a first optical coded signal transmitted from a first optical transmitter to a first optical receiver and effects corresponding to a second optical coded signal transmitted from a second optical transmitter to the first optical receiver, wherein the first optical coded signal is transmitted based on a first code, and the second optical coded signal is based on a second code, wherein the first code and the second code are non-orthogonal, and wherein the first optical transmitter and the second optical transmitter transmit at overlapping times;
• determining a first measurement between the first optical transmitter and the optical receiver based on the resulting signal and the first code;
• determining a second measurement between the second optical transmitter and the first optical receiver based on the second code and the resulting signal;
• determining a plurality of positional information for an input object based on the first measurement and the second measurement;
• determining an interference measurement for a first time period;
• and
• adjusting, based on the interference measurement, a number of a plurality of optical transmitters that transmit optical signals at overlapping times,
• wherein the first optical transmitter and the second optical transmitter are in the plurality of optical transmitters.

An input device comprising:

• a plurality of optical transmitters each configured to transmit an optical signal according to a non-orthogonal code of a first plurality of non-orthogonal codes during a first time period, wherein the plurality of optical transmitters transmit the optical signal during overlapping times in the first time period;
• a optical receiver configured to receive an aggregated input signal for the first time period,
• wherein the aggregated input signal comprises the optical signal from the plurality of optical transmitters;
• and
• a processing system configured to:
• determine, for each of the plurality of optical transmitters, an individual input signal from the optical transmitter using the aggregated input signal and the first plurality of non-orthogonal codes, and
• create a second plurality of non-orthogonal codes based on an interference determined from the aggregated input signal, wherein the second plurality of non-orthogonal codes are a different length than the first plurality of non-orthogonal codes.