Cover
Vol. 7 No. 2 (2011)

Published: December 31, 2011

Pages: 88-93

Original Article

Solving the Near-Far Problem in Dynamic Frequency Hopping-Optical Code Division Multiple Access using Power Control

Wamidh J. M. ALgalbi 1
1 Electrical network dep., Technical Institute Shatra Thi-Qar, Iraq
History
  • Received: October 31, 2011
  • Available Online: December 31, 2011
DOI

https://doi.org/10.37917/ijeee.7.2.1

Abstract

In this study, a distributed power control algorithm is proposed for Dynamic Frequency Hopping Optical-CDMA (DFH-OCDMA) system. In general, the DFH-OCDMA can support higher number of simultaneous users compared to other OCDMA techniques. However, the performance of such system degrades significantly as the received power does lower than its minimum threshold. This may obviously occur in a DFH-OCDMA network with near-far problem which consist of different fiber lengths among the users, that resulting to unequal power attenuation. The power misdistribution among simultaneous active users at the star coupler would degrade the Bit Error Rate (BER) performance for users whose transmitting signals with longer fiber lengths. In order to solve these problems, we propose an adaptive distributed power control technique for DFH-OCDMA to satisfy the target Signal to Noise Ratio (S to R) for all users. Taking into account the noise effects of Multiple Access Interference (MAI), Phase Induced Intensity oise (PII) and shot noise, the system can support 100% of users with power control as compared to 33% without power control when the initial transmitted power was -1dBm with 30 simultaneous users.

Keywords

References

  1. Salehi, J.A., Code division multiple-access techniques in optical fiber networks-Part I: Fundamental principles. IEEE Trans. Commun., 37: 824-833. 1989
  2. Salehi, J.A. and C.A. Brackett,. Code division multiple-access techniques in optical fiber networks-Part performance analysis. IEEE Trans. Commun., 37: 834-842. 1989
  3. Dale, M.R. and R.M. Gagliardi, Channel coding for asynchronous fiber optic CDMA communications. IEEE Trans. Commun., 2485-2492. 1995.
  4. Stok, A. and E.H. Sargent, Lightning the local area: Optical code-division multiple-access and quality of service provisioning. IEEE Network Mag., 42-46. 2000.
  5. Naser G. Tarhuni, Mohamed S. Elmusrati, and Timo O. Korhonen, Nonlinear Power Control for asynchronous fiberoptic CDMA Networks. IEEE Trans. Commun., 6 : 2782 - 2786, 2006.
  6. Mohammad M.N. Hamarsheh, M.H. Hossam Shalaby and Mohamad Khazani Abdullah, Design and Analysis of a Dynamic Code Division Multiple Access Communication System Based on Tunable Optical Filter. J. Light wave Technol., 23: 3959- 3965. 2005.
  7. Yashima, H. and T. Kobayashi, Optical CDMA with time hopping and power control for multimedia network. J. Lightwave Technol., 21: 695-702. 2003.
  8. Zander, J., Distributed cochannel interference control in cellular radio systems. IEEE Trans. Veh. Technol., 41: 305-311. 1992.
  9. E. Inaty,H.M.H. Shalaby, P. Fortier, and L. A. Rusch, Multirate optical fast frequency hopping CDMA system using power control. J. Lightwave Technol., 20: 166-177. 2002.
  10. Wei, Z. and Ghafouri-shiraz, Unipolar Codes with ideal inphase Cross-correlation for spectral Amplitude-Coding Optical CDMA System. IEEE Transact. Commun., 50: 1209-1212. 2002.
  11. Alexander, S.B., Optical Communication Receiver Design. 1st Edn., Spiel Optical Engineering press USA., pp: 328. 1997.
  12. Aylin Yener, Roy D. Yates and Sennur Ulukus, Interference Management for CDMA Systems through Power Control, Multi-user Detection and Beamforming. IEEE Transact. Commun., 49: 1227- 1239. 2001.
  13. Ohtsuki, T. and K. Sato, Direct-detection optical asynchronous. Selected Areas Commun. IEEE J., 14: 1879-1887. 1996.
  14. E. Inaty, H. M. H. Shalaby, and P. Fortier, A new transmitterreceiver architecture for noncoherent multirate OFFH-CDMA system with fixed optimal detection threshold. IEEE J.commun.., 3: 1487-1493. 2001.
  15. E. Inaty, L. A. Rusch, and P. Fortier, Multirate optical fast frequency hopping CDMA system using power control. IEEE J.commun., 3: 1221-1227. 2000.