Skip to main content

Overloading Cellular DS-CDMA: A Bandwidth-Efficient Scheme for Capacity Enhancement

  • Conference paper
Distributed Computing and Networking (ICDCN 2008)

Part of the book series: Lecture Notes in Computer Science ((LNTCS,volume 4904))

Included in the following conference series:

Abstract

Overloading is a technique to accommodate more number of users than the spreading factor N. This is an efficient way to increase the number of users in a fixed bandwidth, which is of practical interest to mobile system operators. In this paper we have reviewed the different overloading schemes proposed in the literature for the DS-CDMA systems. The performance of an Orthogonal/Orthogonal (O/O) overloading scheme, using two sets of orthogonal codes (O/s-O) has been evaluated. Iterative multistage detector (IMSD) is used to reduce the multiple access interference between the users of two sets. The BER performance of IMSD is evaluated with hard and soft decisions functions using Monte-Carlo simulations. It is found that, this scheme provides 19% and 11% channel overloading for synchronous DS-CDMA system in an AWGN channel, with a SNR degradation of less than 0.5 dB at a BER of 10− 5 compared to single user bound for N=16 and 64 respectively.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Similar content being viewed by others

References

  1. Adachi, F., Sawahashi, M., Suda, H.: Wideband DS-CDMA for Next- Generation Mobile Communication Systems. IEEE Commun. Mag. 36, 56–59 (1998)

    Article  Google Scholar 

  2. Hara, S., Prasad, R.: Overview of multicarrier CDMA. IEEE Commun. Mag. 35, 126–133 (1997)

    Article  Google Scholar 

  3. Verdu, S.: Multi - user Detection. Cambridge University Press, Cambridge (1998)

    Google Scholar 

  4. Verdu, S., Shamai, S.: Spectral Efficiency of CDMA with Random Spreading. IEEE Trans. Inform. Theory. 55, 622–640 (1999)

    Article  MathSciNet  Google Scholar 

  5. Viswanath, P., Anantharam, V.: Optimal Sequences and Sum Capacity of Synchronous CDMA Systems. IEEE Trans. Inform. Theory. 45, 1984–1991 (1999)

    Article  MATH  MathSciNet  Google Scholar 

  6. Ulukus, S., Yates, R.D.: Iterative Construction of Optimum Signature Sequence Sets in Synchronous CDMA Systems. IEEE Trans. Inform. Theory 47, 1989–1998 (2001)

    Article  MATH  MathSciNet  Google Scholar 

  7. Learned, R.E., Willisky, A.S., Boroson, D.M.: Low complexity joint detection for oversaturated multiple access communications. IEEE Trans. Signal Processing 45, 113–122 (1997)

    Article  Google Scholar 

  8. Ross, J.A.F., Taylor, D.P.: Multiuser Signaling in the Symbol- Synchronous AWGN Channel. IEEE Trans. Inform. Theory 41, 1174–1178 (1995)

    Article  MATH  Google Scholar 

  9. Sari, H., Vanhaverbeke, F., Moeneclaey, M.: Extending the Capacity of Multiple Access Channels. IEEE Commun. Mag. 38, 74–82 (2000)

    Article  Google Scholar 

  10. Sari, H., Vanhaverbeke, F., Moeneclaey, M.: Increasing the Capacity of CDMA using Hybrid Spreading Sequences and Iterative Multistage Detection. In: Proc. IEEE VTC, pp. 1160–1164 (1999)

    Google Scholar 

  11. Vanhaverbeke, F., Moeneclaey, M., Sari, H.: DS/CDMA with Two Sets of Orthogonal Sequences and Iterative - Detection. IEEE Commun. Lett. 4, 289–291 (2000)

    Article  Google Scholar 

  12. Sari, H., Vanhaverbeke, F., Moeneclaey, M.: Multiple access using two sets of orthogonal signal waveforms. IEEE Commun. Lett. 4, 4–6 (2000)

    Article  Google Scholar 

  13. Kumar, P., Chakrabarti, S.: A New Overloading Scheme for DS- CDMA System. In: National Conference on Communication, IIT Kanpur, pp. 285–288 (2007)

    Google Scholar 

  14. Djonin, D., Bhargava, V.K.: New results on low complexity detectors for oversaturated CDMA systems. In: Proceedings of Globecom 2001, pp. 846–850 (2001)

    Google Scholar 

  15. Paavola, J., Ipatov, V.: Oversaturating Synchronous CDMA Systems on the Signature Per User Basis. In: Proc. 5th European Personal Mobile Communications Conf., pp. 427–430 (2003)

    Google Scholar 

  16. Yang, K., Kim, Y.K., Kumar, P.V.: Quasi-orthogonal Sequences for Code-division Multiple-Access Systems. lEEE Trans. Inform. Theory. 46, 982–993 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  17. Vanhaverbeke, F., Moeneclaey, M.: Binary signature sets for increased user capacity on the downlink of a CDMA systems. IEEE Trans. on Wireless Communication 05, 1795–1804 (2006)

    Article  Google Scholar 

  18. Vanhaverbeke, F., Moeneclaey, M.: Performance Evaluation of Three Different Types of Channel overloading. In: IEEE PIMRC, pp. 569–572 (2003)

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Editor information

Shrisha Rao Mainak Chatterjee Prasad Jayanti C. Siva Ram Murthy Sanjoy Kumar Saha

Rights and permissions

Reprints and permissions

Copyright information

© 2007 Springer-Verlag Berlin Heidelberg

About this paper

Cite this paper

Kumar, P., Ramesh, M., Chakrabarti, S. (2007). Overloading Cellular DS-CDMA: A Bandwidth-Efficient Scheme for Capacity Enhancement. In: Rao, S., Chatterjee, M., Jayanti, P., Murthy, C.S.R., Saha, S.K. (eds) Distributed Computing and Networking. ICDCN 2008. Lecture Notes in Computer Science, vol 4904. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-77444-0_55

Download citation

  • DOI: https://doi.org/10.1007/978-3-540-77444-0_55

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-77443-3

  • Online ISBN: 978-3-540-77444-0

  • eBook Packages: Computer ScienceComputer Science (R0)

Publish with us

Policies and ethics