| Author | Sharma, Sanjaya Raj |
| Call Number | AIT RSPR no.TC-97-6 |
| Subject(s) | Fiber optics
|
| Note | A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Advanced Technologies |
| Publisher | Asian Institute of Technology |
| Series Statement | Research studies project report ; no. TC-97-6 |
| Abstract | Intended for optical CDMA applications, construction of a new family of code
sequences based on hybrid wavelength hopping/ time spreading scheme is presented in this
research study. The different types of hybrid system named ep/ prime sequence (using
extended prime code sequence for spreading and prime code sequence for hopping pattern),
tel prime sequence (using truncated costas OOC for spreading and prime sequence for
hopping pattern), and bmc/ prime sequence (using block multiplexing code sequence for
spreading and prime sequence for hopping pattern) are introduced. Moreover, performance of
the newly constructed codes is analyzed by using a Gaussian approximation for optical
multiple-access interference and the bit error rate (BER) in terms of the code length and the
number of simultaneous users are discussed. It is shown that the newly constructed code
sequences exhibit excellent auto correlation and cross correlation properties (i.e., auto
correelation sidelobes not existing).
Analysis of the security aspects of the newly constructed hybrid systems is presented.
It is shown that, system security can be increased by increasing the number of discrete
wavelength or employing asymmetric system (with different number for spreading pattern and
hopping pattern). The system can be configured so that even in the pessimistic case of
incomplete detection with only half wavelengths, many years would be needed to penetrate
the network.
Because of the increased number of station and the number of simultaneous users that
can be supported (for given BER), proposed scheme is suitable for truly asynchronous optical
LANs with increased security. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Research studies project report ; no. TC-97-6 |
| Type | Research Study Project Report (RSPR) |
| School | School of Advanced Technologies (SAT) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Zhang, Jian-Guo |
| Examination Committee(s) | Sharma, A. B.;Makelainen, Kimmo |
| Degree | Research Studies Project Report (M. Eng.) - Asian Institute of Technology, 1997 |