Packet service in UMTS: effects of the radio interface parameters on the performance of the downlink shared channel
The UMTS W-CDMA radio interface is characterized by great flexibility and a variety of different physical and logical channel types. For example, on the downlink, the DCH offers circuit switching, the FACH uses packet switching and the DSCH uses packet switching with closed loop power control. Furthermore, several user rates and protections are possible, by choosing suitable parameters, such as spreading factors, code rates and ARQ schemes. In this paper we present the results, obtained by a detailed simulation, about the effect of several parameters and system alternatives on the capacity of the downlink segment of the W-CDMA interface with packet service. In particular, we investigate the effect of the spreading factor and the code rate on the DSCH capacity and delay-throughput performance.
KeywordsPower Control Code Rate Spreading Factor Universal Mobile Telecommunication System Radio Interface
Unable to display preview. Download preview PDF.
- J. Y. N. Hui, Throughput analysis for Code Division Multiple Access of the Spread Spectrum Channel, IEEE Journal on Selected Areas in Communications, vol. 2, no. 4, July 1984.Google Scholar
- R.J. McEliece, W.E. Stark, Channels with block interference, IEEE Trans. on Information Theory, Vol. 30, No. 1, January 1984.Google Scholar
- F. Borgonovo, A. Capone, L. Fratta, Retransmissions Versus FEC Plus Interleaving for Real-Time Applications: A Comparison Between CDPA and MC-TDMA Cellular Systems, IEEE Journal on Selected Areas in Communications, vol. 17, no. 11, Nov. 1999.Google Scholar
- UMTS 30.03, Annex B: Test environments and deployment models, TR 101 1112 v.3. 2. 0, April 1998.Google Scholar
- rd Generation Partnership Project, RLC Protocol Specification, 3G TS 25. 322, December 2001.Google Scholar
- rd Generation Partnership Project, MAC protocol specification, 3G TS 25. 321, December 2001.Google Scholar
- A. Bellini, M. Ferrari, Personal communication, Politecnico di Milano, 2000.Google Scholar
- rd Generation Partnership Project, RF system scenarios, 3G TR. 25. 942, December 2001.Google Scholar
- rd Generation Partnership Project, Physical channels and mapping of transport channels onto physical channels (FDD), 3G TS 25. 211, December 2001.Google Scholar