GR/T08593/01 Multiple-Input-Multiple-Output

The explosive growth of the Internet and the continued dramatic increase in demand for all types of advanced multimedia wireless services, may require data rates significantly higher than 2Mb/s, which are unlikely to be supported by the 3rd-generation (3G) systems. For the sake of providing services requiring data rates of tens to hundreds of Mbits per second on the basis of broadband communications, conventional cellular structures, where each cell is covered by a base-station (I3S) having one or more antennas and positioned at the centre of the cell, will encounter substantial problems. For example, in the existing cellular systems 300 mW of transmitted power may be required, in order to transmit at 2 Mb/s in the 2 GHz frequency band. However, for a future system transmitting at a data rate of 100 Mb/s in the 5-GHz frequency band, using similar cellular structures may need a transmitted power of 30 W. Providing such a high power is infeasible both in terms of battery life and the radiation effects on the human body. Since MIMO systems are capable of providing a significantly higher capacity, than conventional single-input-single-output (SISO) systems, the abovementioned problems may be avoided in conjunction with the concept of distributed antenna systems. Distributed antenna systems have conventionally been proposed for enhancing the SINK performance and for improving the integrity and capacity of indoor communications. However, the MIMO principles combined with distributed antenna systems have received insufficient attention, especially, in the context of CDMA systems designed for supporting high data rate communications. Therefore, in this project a range of issues concerning MIMO space-time processing designed for CDMA systems associated with using distributed antennas will be investigated.