System and method using a gated retro-reflector for visible light uplink communication

A portable device comprising:

• a housing having a first surface and a second surface;
• a first retro-reflector mounted on the first surface of the housing such that a retro-reflecting front face of the first retro-reflector points away from the first surface;
• a second retro-reflector mounted on the second surface of the such that a retro-reflecting front face of the second retro-reflector points away from the second surface;
• a first gating shutter mounted on top of the front surface of the first retro-reflector and a second gating shutter mounted on top of the front surface of the second retro-reflector, wherein the first and second gating shutters are controlled by respective first and second control signals, to be in open and closed states, wherein each of the first and second the gating shutters permits passage of light to and from the retro-reflector in the open state and reduces the passage of light in the closed state;
• a light sensor configured to receive and detect light including visible light communication (VLC) data from a modulated light source, the VLC data being received at regular intervals in which a first VLC light pulse received during a first one of the intervals represents at least a portion of a first VLC data symbol and presence of a second VLC light pulse during a second one of the intervals represents at least a portion of a second VLC data symbol;
• and;
• a controller coupled to the light sensor and to the first and second gating shutters, the controller controlling at least one of the first and second gating shutters to be in the open state during the reception of the first light pulse to upload a first symbol and for controlling at least one of the first and second gating shutters to be in the closed state during the reception of the second light pulse to upload a second symbol.

A system, comprising:

• a visible light communication (VLC) transceiver comprising:
• a VLC light source configured to transmit VLC data at regular intervals in which a light pulse transmitted during one of the intervals represents a first symbol and absence of a light pulse during another one of the intervals represents a second symbol;
• a first light sensor;
• coupled to the VLC light source and configured to receive uplink data symbols during intervals in which the VLC data is transmitted as light pulses;
• a device comprising:
• a second light sensor configured to receive the VLC symbols;
• a retro-reflector having a front face configured to retro-reflect the VLC symbols to the first light sensor;
• a gating shutter coupled between the retro-reflector and the VLC light source, the gating shutter being configured to switch between open and closed states respectively, wherein the gating shutter passes light in the open state and blocks light in the closed state;
• a controller coupled to the second light sensor and to the gating shutter, the controller generating the control signal to control the gating shutter to send the uplink symbols from the device responsive to receiving one of the VLC light pulses;
• wherein the controller opens the gating shutter during the reception of one of the VLC symbols to upload a first symbol and closes the gating shutter during the reception of one of the VLC symbols to upload a second symbol.