BER Performance Analysis of an LDPC Coded OFDM Optical Wireless Communication System with Intensity Modulation and a Direct Detection Receiver

摘要

Optical wireless (OW) that is also known as free space optical (FSO) communication system are impaired by adverse weather conditions, such as rain, fog, cloud, snow and atmospheric turbulences. To reduce the destructive effect of atmospheric turbulence, OFDM technique itself have already been reported in several publications which is not sufficient to improve the performance. So channel coding with OFDM in OW havebeen proposed in literature. LDPC-coded OFDM enhances the immunity to the atmospheric turbulence in optical wireless communication systems. In this paper we provide a logical way to evaluate the exhibitions of LDPC coded OFDM OW correspondence framework with the impact of solid air disturbance. The scientific perception demonstrates that the framework endures penalty due to atmospheric turbulence and the degradations of BER are evaluated for several values of system parameters like number of OFDM subcarriers, code word length, interface separate, information rate and quality of the disturbance which is spoken to through refractive list structure parameter. Examination likewise demonstrates that the framework exhibitions enhances due to LDPC code and the coding addition of the LDPC coded OFDM framework with 64 sub-bearers are investigated. It is seen that LDPC coded OFDM OW framework gives 12 to 15 dB improvements over uncoded OFDM OW frame work at a BER of 10~(-9).