Security enhancement of OCDMA system against eavesdropping using code-switching scheme

In this paper, the security enhanced OCDMA system based on spectral encoding using code-switching scheme is analyzed. The security issues are investigated by measuring eye diagrams and received signals for various cases. It has been observed; an eavesdropper based on a simple energy detector can easily read the information being transmitted by a single user using on-off keying. In order to increase the security a code-switching scheme is implemented on OCDMA. It is shown that the eye diagram at the eavesdropper becomes true noise waveform due to code-switching scheme and at the receiver end a clear eye diagram is observed. Hence, it is concluded that the code-switching scheme shows an immunity of the OCDMA system against eavesdropping and like conventional OCDMA schemes an authorized user clearly decodes an original data when a single user is active in the network.