Open-loop MIMO Extensions for HSDPA with Practical Constraints

Abstract:
In this paper, we investigate three different open-loop multi antenna schemes and compare their performance to the traditional receive diversity in high speed downlink packet access (HSDPA) system, which is a packet enhancement to the third generation wideband code division multiple access (WCDMA) mobile communication system. The studied schemes are per antenna rate control (PARC), space time transmit diversity (STTD) and matrix modulation (MaMo) each with 2x2 antenna configuration. In this study a chip equalizer based receiver is used, because the optimal receiver is prohibitively complex for practical implementation. The link throughput results show that multiple-input multiple-output (MIMO) schemes outperform the traditional receive diversity in low delay spread channels especially, if up-to-date and error free link adaptation feedback is available. However, with practical constraints on the link adaptation feedback , geometry distribution and delay spread, the receive diversity performs almost as well as the studied MIMO schemes.