Design of 2D-WH/TS OCDMA PON ONU Receiver with FLC Technique

Abstract

This paper exercises fuzzy logic for the prediction of channel response to a two dimensional-wavelength hopping /time spreading optical code division multiple access (2D-WH/TS OCDMA) code in a passive optical network (PON). A fuzzy logic control (FLC) is employed for the reduction of bit error rate of 2D-WH/TS OCDMA PON at the receiver. This FLC predicts the environmental temperature variation effects that occur in the transmission links which impact the expected magnitude of the autocorrelation peak of 2D-WH/TS OCDMA code at the receiver. The FLC system, uses propagation distance and the temperature changes in channel which is estimated by sensors, as input variables, to predict the auto-correlation peak at the receiver. This information on the reduction of auto correlation requires to dynamically adjust the threshold level of threshold detector at the receiver. The design of the FLC demands a priory knowledge of the analytic response of the 2D-WH/TS OCDMA channels. The simulation of FLC was done by using membership functions in MATLAB using fuzzy libraries. The simulation results show that the effect of environmental temperature can be predicted with the accuracy of 92.1% from the analytic model available for channel response.