Effect of co-phasing diversity on CDMA downlink capacity

The impact of distributed antennas using co-phasing transmission diversity on downlink CDMA channels is examined. An expression is derived that demonstrates that uniform downlink signal-to-interference ratio across users can be achieved by appropriately weighting the distribution of transmit powers across distributed antennas. The capacity of a downlink CDMA system employing distributed antennas with optimum power allocation is then found by simulation.