MIMO antenna systems for DS/CDMA communications

Abstract

The rapid growth of wireless voice subscribers, the growth of the Internet, and the increasing use of portable computing devices suggest that high-speed, high-capacity and high-quality wireless communications will grow to be a major area of telecommunications services. In this thesis, we propose a multiple-input multiple-output (MIMO) antenna system with pre-Rake and Rake adaptive filters (FIR filters) for the downlink of DS/CDMA communications, of which multiple-input single-output (MISO) antenna system is a special case. In order to find the optimal solution to a general MIMO DS/CDMA antenna system, a MIMO DS/CDMA antenna system model is first developed. Then, by using this model, we derive an optimal MIS0 system solution, which reduces to a Pre-Rake maximum ratio combining (MRC) transmit diversity system under the assumption that a simple one finger matched filter is used at the receiver. This system combines the advantages of pre-Rake diversity and transmit antenna diversity. We also obtain another system by attempting to find the optimal solution to a MIMO antenna system. A single user joint optimum scenario and a multi-user signal-to-interference plus noise ratio (SINR) enhancement scenario are derived. This system can be used to enhance SINR in frequency selective fading environment, and therefore can increase system capacity beyond current levels. In addition, a simple one finger receiver structure is introduced.

Date of Award	2000
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology