US 9,866,323 B2 · Techniques for optical wireless communication

Abstract

Optical wireless communication techniques are described and claimed. In one embodiment, the disclosure relates to method and apparatus to provide optical signaling with visible light having variable pulse position modulation (VPPM). The optical signal includes a Start Frame Delimiter (SFD) which indicates beginning of an asynchronous optical signaling. The VPPM signaling includes a lower frequency time varying amplitude component that when subsampled by a low frame rate camera results in alias induced flicker or blinking. Such signals are quickly recognizable as signals with modulated data. In another embodiment, the disclosure provides a system, device and method for decoding a Start Frame Delimiter (SFD) to indicate arrival of incoming VPPM optical data.

Claims11

Dependent claims

A receiver circuitry to decode asynchronous optical data from a pixel, the receiver comprising:

a shift register having a plurality of storage cells, each storage cell configured to receive and store one byte of data per clock cycle, each byte of data representing a pixel state;
a first plurality of comparator logic gates to correspond to a first group of the shift register storage cells and a second plurality of comparator logic gates to correspond to a second group of the shift register storage cells, each of the plurality of the first and the second logic gates to determine the pixel state at a respective clock cycle;
and
a Start Frame Delimiter (SFD) combinational logic to communicate with the first and the second plurality of comparator logics, the SFD combinational logic configured to implement a Boolean expression to identify receipt of an SFD signal at the pixel.

1 more element

Dependencies are inferred from the claim text.

Techniques for optical wireless communication

Life of this patent

Techniques for optical wireless communication

Life of this patent

Abstract

Claims11