Academic theses (1)
J. Kurjenniemi, “A Study of TD-CDMA and WCDMA radio network enhancements“, Phd. thesis, University of Jyväskylä, Finland, 2005.
The aim of this study is to analyze UMTS terrestrial radio access performance including TDD and FDD modes. 3.84 Mcps TDD Mode of UTRA is based upon a combined time and code division multiple access and it is commonly referred to as TD-CDMA, whereas UTRA FDD mode is based upon a Wideband Code Division Multiple Access (WCDMA).
Conference articles (3)
T. Nihtilä, J. Kurjenniemi, M. Lampinen and T. Ristaniemi, “WCDMA HSDPA Network Performance with Receiver Diversity and LMMSE Chip Equalization“, Proc. of the IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Berlin, Germany, September 11 – 14, 2005.
More advanced receiver structures than the conventional single antenna Rake can be used to improve the signal-to-noise (SNR) ratios, which is especially beneficial in order to utilize the high bit rates provided by the HSDPA concept in WCDMA network.
In WCDMA system, orthogonal Walsh-Hadamard sequences are used as channelization codes. In frequency-selective fading channels the orthogonality of channelization codes disappears and intra-cell multiple access interference (MAI) arises. In order to mitigate the effect of MAI, a chip-level equalization has shown to be a simple and effective solution.
The effectiveness of chip equalization, however, degrades at the cell borders where the inter-cell interference dominates rather than MAI. Dual antenna is a straight-forward solution to mitigate that performance drop.
In this paper we consider receivers equipped with dual antenna and linear minimum mean squared error (LMMSE) chip-level equalizers and present an analysts of the expected gains over conventional single and dual antenna rake receivers in realistic situations by using a dynamic WCDMA system-level tool.
J. Kurjenniemi, T. Nihtilä, M. Lampinen and T. Ristaniemi, “Performance of WCDMA HSDPA Network with Different Advanced Receiver Penetrations“, Proc. of the IEEE Wireless Personal Multimedia Communications, Aalborg, Denmark, September 17 – 22, 2005.
In WCDMA system orthogonal Walsh-Hadamard sequences are used as channelization codes. In frequency-selective fading channels the orthogonality of channelization codes disappears and intra-cell multiple access interference (MAI) arises. In order to mitigate the effect of MAI, a chip-level equalization has shown to be a simple and effective solution.
The effectiveness of chip equalization, however, degrades at the cell borders where the inter-cell interference dominates rather than MAI. Dual antenna is a straight-forward solution to mitigate that performance drop.
A recent study presented an analysis of the expected gains over conventional single and dual antenna Rake receivers in WCDMA HSDPA network when assuming only one type of receivers to be used.
In this paper we study the network performance from a more practical point of view by assuming that the penetration of advanced HSDPA terminal receivers in the network is an increasing factor. Considered advanced receivers include Rake with receive diversity and LMMSE chip level equalizer with/without receive diversity.
The primary interest is to look at the performance gains from the network and end-user perspective with different advanced receiver penetrations.
