RANDOM OPTICAL CODES FOR OPTICAL CODE-DIVISION MULTIPLE-ACCESS USED IN AN INTRA-SATELLITE OPTICAL WIRELESS NETWORK

摘要

In this paper, we study random optical codes (ROCs), which are intended to be used in Optical Code-Division Multiple-Access (OCDMA) systems. ROCs are codes which are selected randomly from all possible rearrangements. Each bit is transmitted using a different code.rnThe probability of error due to multiple-access interference is computed. It is validated by a comparison between theoretical and simulations results. Moreover the cross-correlation between two codes is also analyzed.rnThe results are satisfactory for a system with long codes and a large number of users. However the simplicity is the main advantage found in ROCs. The random selection of pulse positions out of the length code is easily implementable. Furthermore, the parameter values can be optimized without design restrictions. Besides, this family presents a huge cardinality which permits changing the code for each bit.rnThe main contribution of this paper is the introduction of the dynamical accommodation to the actual number of users. It is possible using the simplicity provided by ROCs. Furthermore a comparison between OCDMA systems using ROCs and Generalized orthogonal optical codes is shown.rnA real application in an intra-satellite optical wireless network where ROCs features are used is also presented.