RESEARCH OF MODULATION METHODS FOR DATA TRANSMISSION VIA VISIBLE LIGHT

The emergence of new directions based on the optical range in the field of communications is explained by existing problems in organizing modern wireless infrastructure. Currently, the radio frequency band widely used for data transmission is overloaded and cannot meet the rapidly growing traffic and demand for wireless data services. Additional implementation of wireless systems based on the use of optical range can help solve existing problems. Visible light communication, as an integral part of optical wireless communication, can realize the requirements for data transmission speed in the network, and reduce the load on the bandwidth of existing wireless networks. The article discusses modulation methods in a wireless optical communication network. Modulation characteristics that are important for system performance are studied. For types of pulse modulation, the power spectral density is calculated and studied to obtain time waveforms with a given signal-to-noise ratio. A model of an ideal transmission and reception system for OOC-NRZ in the presence of additive white Gaussian noise is constructed, which is suitable for indoor visible light data transmission systems. Signal shapes and the influence of instrumental and external noise were studied. Calculated values of the bit error probability based on experimental data are given. The proposed simulation model can be used in the design of real transmitting and receiving devices for a visible light communication system.