Tobias Tynderfeldt

WCDMA enhanced uplink - test bed and measurements

The WCDMA specification is constantly evolving. In this paper we present results from measurements on a test bed, based on the WCDMA enhanced uplink (UL) concept, which is being introduced in the 6th release of the WCDMA specification. The enhanced UL test bed has been implemented on top of a commercial WCDMA release 99 cellular system and integrated with an existing high speed downlink packet access (HSDPA) test bed. Measurements have been performed over a coaxial network that includes a fading channel emulator. Three transport formats have been measured: 336, 672 and 1344 kbit/s. The measured performance is very close to simulated performance at moderate block error rates (BLER). For high signal-to-noise ratios an error floor causes some degradation.

Transmit diversity options for GSM/EDGE

High system capacity is of utmost importance for future GSM/EDGE networks, with increasing attention given to improved downlink performance. One performance enhancing feature for the downlink is transmit diversity, where the base station transmits from multiple antennas. This paper studies the transmit diversity schemes delay diversity, antenna hopping and phase hopping, which can be used for all existing terminals. Antenna hopping is shown to be very attractive for the non-frequency hopping traffic channels, while delay diversity is an interesting technique for the frequency hopping channels. In an interference limited network, however, it is shown that for terminals with advanced receiver algorithms for interference suppression the performance gains may be reduced if interfered by a base station employing delay diversity.