A MISO UCA beamforming dimmable LED system for indoor positioning.
The use of a multiple input single output (MISO) transmit beamforming system using dimmable light emitting arrays (LEAs) in the form of a uniform circular array (UCA) of transmitters is proposed in this paper. With this technique, visible light communications between a transmitter and a receiver (LED reader) can be achieved with excellent performance and the receiver's position can be estimated. A hexagonal lattice alignment of LED transmitters is deployed to reduce the coverage holes and the areas of overlapping radiation. As a result, the accuracy of the position estimation is better than when using a typical rectangular grid alignment. The dimming control is done with pulse width modulation (PWM) to obtain an optimal closed loop beamforming and minimum energy consumption with acceptable lighting.
Wireless Information Security and Eco-Electronics Research Unit/National Electronics and Computer Technology Center, Bangkok 12120, Thailand. attaphongse.taparugssanagorn@nectec.or.th.
Attaphongse
A
Taparugssanagorn
Wireless Information Security and Eco-Electronics Research Unit/National Electronics and Computer Technology Center, Bangkok 12120, Thailand. siwaruk.siwamogsatham@nectec.or.th.
Siwaruk
S
Siwamogsatham
Radio Frequency (RF) Communications, Purdue University, Fort Wayne, IN 46805, USA. cpomalaz@purdue.edu.
Carlos
C
Pomalaza-Ráez