Performance analysis of threshold value estimation methods in visible light communication systems

The design of modulator and demodulator design in VLC is one of the most important issues because it affects features such as error performance, bandwidth efficiency, power efficiency. Systems where the artificial light intensity in the environment changes or the distance between the receiver-transmitter changes, adversely affects the error performance of the modulation techniques using threshold values. Therefore, a separate threshold value should be determined for variable systems according to the traditional method, and this situation is impossible in practical applications. In this study, threshold value estimation methods have been developed in Digital Intermittent Pulse Modulation (DPIM) technique in order to eliminate the situations that may negatively affect the error performance. Thanks to the developed methods, the threshold value is updated software according to changing conditions. This is the biggest advantage of the proposed method over the traditional method. Performance analysis of the methods developed under varying conditions was made. The Symbol Error Rates (SER) of the traditional system and the proposed system in the simulation studies were compared. Simulation studies were carried out in MATLAB program. From the results obtained, it was seen that the proposed methods showed a very good SER performance compared to the system with a fixed threshold value, very close to the traditional method.