Abstract
In this paper, we study the use of shifted carrier-hopping prime codes (CHPC) for multicode keying in wavelength-time optical code-division multiple-access (O-CDMA) systems. By using the code's good properties of zero autocorrelation sidelobes and cross-correlation functions of at most one, each user is assigned M = 2m shifted copies of its own code matrix to represent m data bits per symbol with minimal interference. The advantages of our scheme are that: 1) a lower baud rate O-CDMA system can now support a higher bit rate; 2) no network synchronization is required; 3) no M-fold increase in code cardinality is needed, as compared with standard M-code keying; 4) the numbers of optical encoders and decoders can be reduced from M to one per user, a major hardware cost savings; and 5) user code confidentiality is enhanced, as compared with the transmission of one code matrix for each data-bit one in conventional "on-off keying" O-CDMA schemes. Finally, our performance analysis shows that there is a tradeoff between the error probability and the choice of M.
Original language | English (US) |
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Pages (from-to) | 2150-2156 |
Number of pages | 7 |
Journal | IEEE Transactions on Communications |
Volume | 53 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2005 |
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering
Keywords
- Multicode keying
- Optical code-division multiple-access (O-CDMA)
- Optical codes
- Wavelength-hopping time-spreading