CIR improvement in a cellular mobile system using beamforming and power control

摘要

Cochannel interference is the most important issue in cellular mobile systems. It can be reduced by increasing the frequency re-use distance among the cochannel cells while keeping constant cell radius which improves the quality of a cellular mobile system. But this will decrease the overall network capacity because cluster size, which is inversely proportional to network capacity, also increases. Beamforming using antenna arrays is an effective technique to reduce cochannel interference while cluster size remains the same. Here first we use beamforming technique at the base station to reduce uplink cochannel interference and hence improvement in uplink carrier to interference ratio (CIR). Then we use power control together with the beamforming technique for further improvement in CIR and hence increase in network capacity. Both beamforming and power control parameters are updated iteratively in our proposed algorithm so that they jointly increase the network capacity. There are many other advantages of beamforming and power control such as saving in power of mobile station but here we focus only on CIR Improvement because it is the most common parameter in all access schemes like FDMA, TDMA, CDMA and SDMA.