Abstract
A significant problem that deteriorates the performance of 3G W-CDMA systems is code blocking. The complete elimination of this phenomenon is accomplished only if a code reassignment procedure is employed. However, the relatively high total signaling delay for a single OVSF code reassignment combined with the strict delay requirements of some services makes the reassignment of some OVSF codes impractical. In other words, that a reassignment procedure cannot always be performed and therefore code blocking cannot be eliminated. In this paper, we introduce a new code selection scheme, named Delay Sensitivity Based Assignment (DSBA), which takes into account the different delay requirements of the incoming calls. The performance of the proposed scheme is evaluated through event driven simulation and the results show a significant decrease in code blocking probability, especially for high rate calls, compared to other previously proposed schemes.
Chapter PDF
Similar content being viewed by others
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
References
F. Adashi, M. Sawahashi, and K. Okawa: Tree structured generation of orthogonal spreading codes with different lengths for forward link of DS-CDMA mobile radio. Electronic Letters, vol. 33, pp. 27–28, Jan 1997.
3GPP, Technical Specification 25.213 V5.2.0 (2002–09), Spreading and Modulation (FDD).
T. Minn, K.Y. Siu: Dynamic Assignment of Orthogonal Variable Spreading Factor Codes in W- CDMA. IEEE Journal on Selected Areas in Communications, Vol. 18, No. 8, August 2000, pages 1429–1440.
Harri Holma and Antti Toskala: WCDMA for UMTS Radio Access For Third Generation Mobile Communications. John Wiley and Sons, 2001.
3GPP, Technical Specification TR 25.848 V4.0.0 (2001–03), Physical layer aspects of UTRA High Speed Downlink Packet Access.
Paolo Goria, Claudio Guerrini, Alessandro Vaillant: Signaling delay of code allocation strategies. In Proc. of IST Mobile & Wireless Telecommunications Summit 2002.
3GPP Technical Specification 22.105 V6.2.0 (2003–2006) Services and service capabilities.
3GPP Technical Report 25.853 V4.0.0 (2001–2003) Delay Budget within the Access Stratum.
Y.-C. Tseng, C.-M. Chao, and S.-L. Wu: Code placement and replacement strategies for wideband CDMA OVSF code tree management, in Proc. of IEEE GLOBE-COM, vol. 1, pp. 562–566, 2001.
A. Rouskas and D. Skoutas: OVSF code assignment and reassignment at the forward link of W- CDMA 3G systems. In Proc. of IEEE PIMRC, vol. 5, pp. 2404–2408, 2002
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2004 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Skoutas, D.N., Rouskas, A.N. (2004). Delay Sensitivity Based Assignment of OVSF Codes for the Downlink DCH in WCDMA. In: Mitrou, N., Kontovasilis, K., Rouskas, G.N., Iliadis, I., Merakos, L. (eds) Networking 2004. NETWORKING 2004. Lecture Notes in Computer Science, vol 3042. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-24693-0_38
Download citation
DOI: https://doi.org/10.1007/978-3-540-24693-0_38
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-21959-0
Online ISBN: 978-3-540-24693-0
eBook Packages: Springer Book Archive