FPGA implementation of QPSK visible light communication system

Abstract

According to the principle of digital modulation and demodulation system, the Quadrature Phase Shift Keying (QPSK) modulation and demodulation module is implemented with Verilog HDL language, and the error caused by incoherent demodulation is reduced by compensating the circuit carrier error. In the process of development, intellectual property core (IP) is used to develop the communication system, including bit synchronization technology, baseband signal generator, phase-locked loop, etc., which greatly increases the convenience of development. The reception performance of visible light receiving circuit is improved by combining three-stage amplifier circuit, and the communication and anti-noise performance of visible light communication system are enhanced by using high-order modulation mode with multi-stage photoelectric conversion receiving circuit. Through the FPGA (Field Programmable Gate Array) development board for on-board testing, the whole set of visible light communication system is designed with photoelectric conditioning circuit