The performance difference between a simple equal subchannel#R##N#power allocation and the optimal water-filling subchannel#R##N#power allocation schemes is studied for a multiuser OFDM-based#R##N#cognitive radio (CR) system. It is shown that this difference#R##N#depends on the average subchannel gain variations among#R##N#the CR users as well as the activity levels of the primary users.
['Yonghong Zhang', 'Cyril Leung']
Performance of Equal Power Allocation in Multiuser OFDM-Based Cognitive Radio Systems