2026-04-17T05:27:15Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/1292152025-07-22T19:09:31Zcom_2072_1033col_2072_452951

Theoretical-practical evaluation of the performance of modulation schemes compatible with VLC technology Ruiz Ruiz, Rocio Zoe Àrees temàtiques de la UPC::Enginyeria electrònica Wireless communications system VLC Wireless Communications Communications Visible Light Communications (VLC) is a technology that has emerged in recent years proposing some improvements over traditional radio communications. The objective of this project is to evaluate the bit error rate of different modulations schemes and the requirements of optical communications are described. It is discussed which of them is better to set VLC transmissions. For this, the work has been divided into three sections. The first section describes the communication systems in visible light, as well as the modulations schemes that could be used, more specifically, those that are based on OFDM. In the second section, the MATLAB simulations performed are detailed, representing the bit error rate graph of each of the modulations, varying an added noise. In the third section, the simulations are moved into a real case. For this, two computers and two USRPs modules are used. One of the PC will act as a transmitter and the other as a receiver. The USRPs work as analog-digital/digital-analog converters and are connected to each other by a cable that introduces attenuation. The objective of this configuration is to estimate the bit error rate, varying the noise. Finally, the system is evaluated by replacing the cable that used to connect both USRPs with a LED and a photodetector. In this way, a real practical case of a system based on visible light communications is shown, its performance is studied, and the conclusions are presented. 2018-10-24 Bachelor thesis Open Access Universitat Politècnica de Catalunya