Performance of an indoor optical wireless communication system employing convolutional encoding

The optical wireless communication attracts much attention as an option for the indoor mobile communication technology. It utilizes the optical transmitter as a carrier source and photodiodes in the transmitted wavelength range as a signal detector. An indoor optical wireless communication system using convolutional coding is demonstrated by computer simulation. The data stream is coded into a convolutional code and then modulates the light from a optical transmitter. In this paper, we consider the convolutional encoding with k=1, n=2, K=3. In the receiver, a photodiode senses the optical signals transmitted from the optical transmitter and the received electrical signal is amplified. And then, the digital data is decoded. The simulation results show that the BER performance is improved by the convolutional encoding/decoding algorithm. The soft decision algorithm provides the BER improvement of approximately 2 dB compared to the hard decision algorithm.