Impact of distributed antenna systems on inter-cell interference

A distributed antenna diversity system can he effective in combating the effects of shadowing, but this results in some antenna units being closer to adjacent cells. Studying this in a free space propagation environment we show that a distributed antenna has marginally worse iutercell interference than a single antenna at the centre of a cell when the total transmission power in the two systems are equal. We also show that the orientation of the distributed antenna influences the inter-cell interference. However, when downlink transmission power is controlled to produce constant signal-to-noise ratio acrass the cell, the distributed antenna system is seen to yield significantly better interference performance than the single antenna system.