DefinePK

Abstract

Optical Orthogonal Frequency Division Multiplexing is a bandwidth efficient multicarrier modulation where the available spectrum is divided into subcarriers, with each subcarrier containing a low rate data stream. However, the Peak-to-Average Power Ratio is a major drawback factor of multicarrier transmission system such as Optical Orthogonal Frequency Division Multiplexing. Various methods have been proposed to reduce this factor and one of these methods called Companding Technique and due to their flexibility and low complexity, the Companding Technique is gained great attention. A comparison between the original, companded, and modified companded signal has been implemented in Intensity Modulation/Direct Detection Optical Orthogonal Frequency Division Multiplexing. The proposed Modified A-law Companding technique is guarantees the improved performance in terms of Bit Error Rate and Quality Factor while reducing Peak-to-Average Power Ratio effectively and efficiently by modifying the amplitude of Optical Orthogonal Frequency Division Multiplexing signals. The simulation results allow an optimum companding based on the use of both of (a and A) parameters to be chosen in relation to acceptable or desired Peak-to-Average Power Ratio, Bit Error Rate and Quality Factor requirements. The proposed modified companding scheme can offer better Peak-to-Average Power Ratio reduction, Bit Error Rate, and Quality Factor at A=30 and 87.6 where a=1. The simulation results at the transmission link=900Kmshow that A at 87.6 is the best value measured in term of Peak-to-Average Power Ratio= 5dB at a Complementary Cumulative Distribution Function nearly 1×10-3compared with the original, Quality Factor is 12 and Bit Error Rate is1×10-3.