A channel estimation scheme for space time HSDPA services

The Third Generation Partnership Project (3GPP) is currently considering suitable systems for the high-speed downlink packet access (HSDPA) service. One of the systems currently under consideration is a space-time coding (STC) architecture using the vertical-Bell-Labs-layered-space-time (V-BLAST) system on the downlink-shared channel (DSCH), which allows simultaneous transmissions over multiple channels destined for a single user. Although link level results for flat fading channels indicate significant performance advantages over conventional single antenna systems, it is less successful for frequency-selective fading. The majority of results thus far assume that perfect channel estimation is available and do not consider a suitable method of channel estimation or its effect on system performance. We present a simple pilot based estimation scheme for this system and illustrate its performance in a frequency selective fading environment.