Angularly diverse light communication channel
A novel method of improving light communication channel separation through careful placement of the relative fields of view of the transmitter and receiver components to introduce increased channel diversity, limit interference due to unwanted reflections, and so to boost system performance.
- Dense spatial deployments of Li-Fi channels
- Cellular light communication
- Efficient Li-Fi arrays
- Motion tracking
- Li-Fi in the proximity of reflecting surfaces
- Internet of Things
The number of internet connected devices is expected to grow at an 18% CAGR (Compound Annual Growth Rate) to 28 billion units by 2020. Machine to machine data links are multiplying to create an ‘industrial internet’ for airlines, rail, energy companies and hospitals. For the wide deployment of Li-Fi, a multiplicity of transmitter and receiver arrays need to be able to co-exist and form distinct channel pairings sufficient to establish substantive communications.
In light communication, careful arrangement of relative fields of view of the transmitters and receivers introduces channel diversity through control of angular positions. The optimum shape for the plane of the transmitter or receiver array is dependent on the optimum design distance for an application, but may conveniently include arrangement on a concave or convex surface. The introduction of controlled angular offsets between individual transmitter or receiver elements minimises the crosstalk between neighbouring communication channel pairs and allows for net cancellation of interfering cells.
Simulated comparisons with single photodiodes, have shown angularly diverse receivers with the same overall field of view have superior performance characteristics. Several laboratory experiments were also performed with a 4×4 Multiple Input Multiple Output system, which showed that the addition of angular diversity successfully increases the Euclidian distance.
- Improved data rate and reduced intra-channel interference
- High density optical cellular networks
- Increased optical network design flexibility
- Readily fabricated as a transmitter array physical cluster
Chen Z, Tsonev D, Haas H. (2014). Improving SINR in Indoor Cellular Visible Light Communication Networks. IEEEICC 2014 – Optical Networks and Systems