ALL OPTICAL CDMA CONFIDENTIALITY ENHANCEMENT USING 16 CODE KEYING by Prabhjot Kaur
Abstract
As we know OCDMA is a coding technique which is used to spread optical pulses with respect to time wavelength. This technique can support simultaneous users to access optical channels. Now the concept of multi-code keying encryption has been used to enhance received power, confidentiality and security of the OCDMA system. In order to solve the above mentioned purpose hardware implementation is done by using Optical exclusive XOR gate and codeword multiplexer CMUX. This optical design is highly scalable. The basically for the input sequence of data bits and the sequence of encryption keys NRZ modulation format is used. Thus 16 code keying has been constructed using XOR of 2 code, 4 code and 8 code keying. Using optisystem software, this has been observed that on increasing coding from 2 keying to 16 keying, power improves and trails enhance. Thus, as a result security and confidentiality improves, it has been possible due to the XOR gate and NRZ generator with CMUX. There is successive improvement of 52% using 16 coding technique as it improves due to 2� � codewords. Since the proposed system is based on XOR gate and NRZ pulses, this is the best system to improve confidentiality or to improve encryption. The latency of XOR gate is very high and because if this feature, MAI is also reduced. Since number of code words being used in 16 code keying is more than any other system, it will make difficult for the eavesdropper to recognize the data symbols. Also the system is providing with another benefit of more power received which will make the system highly secure as the transmission is being done at 1550 nm. Hence the confidentiality and the power improvement is best in case of 16 code keying.
