Performance enhancement using decentralised cooperative transmission in an MISO‐VLC system

Abstract

In this study, the authors propose a decentralised cooperative transmission in a multiple-input–single-output visible light communication (VLC) system to deal with the co-channel interference (CCI) converting the interference between adjacent light-emitting diode (LED) lamps into the desired signal and to overcome link blockage recovering the data when the obstruction is not severe. VLC uses the LED lamps already installed for illumination and can alleviate the growing data traffic in the existing wireless communications without interfering. However, CCI and link blockage must be considered to improve performance. The proposed scheme decentralises a cooperative transmission employing a randomised coding rule since each LED sends a random linear combination of the columns of a deterministic code matrix whose coefficients are independent and identically distributed and the decoding is performed by ignoring the number of cooperative LEDs that is unknown and time varying at the receiver. Through computer simulations, the proposed scheme outperforms a centralised scheme when the random coefficients are real and positive. Although the performance deteriorates as decreasing the received links, it does not require to exchange information among the LEDs before transmission or receive all data before decoding as in a centralised scheme.