Performance Analysis of Coded OFDM for Optical Wireless Communication System

Background/Objectives: Orthogonal Frequency Division Multiplexing (OFDM) is an efficient multicarrier modulation technique suitable for optical communication due to high data rate, high spectrum efficiency. A serious problem of this system is the large dynamic range of the transmitted signal due to the nonlinear Power Amplifier (PA). To achieve high power efficiency, Peak to Average Power Ratio (PAPR) value has to be reduced. Methods/Statistical Analysis: In OFDM system, error correction code is an essential for transmission of high data rate. Recently, Low-Density Parity-Check (LDPC) is commonly used as error correcting code. Findings: Here, we present LDPC coded OFDM system to analyze the performance metrics such as Complementary Cumulative Distribution Function (CCDF), Bit Error Rate (BER), Error Vector Magnitude (EVM), Modulation Error Rate (MER) on AWGN channel with and without irregular LDPC codes. Simulation results show that the LDPC code on OFDM system to improve CCDF as well as BER performance than that of uncoded OFDM system. Simulation results also show that by modulating a signal at fixed subcarriers, the EVM decreases and MER increases as the function of Signal to Noise Ratio (SNR) increases. Application/Improvements: Hence, the advantage of LDPC, which makes it possible work in application with low BER, such as wire communication, deep space communication and disk storage industry, etc.