Date Added: Aug 2011
The authors consider the problem of maximizing the throughput of a Multi-Input Multi-Output (MIMO) Cognitive Radio (CR) network. CR users are assumed to be able to share the available spectrum without disturbing existing Primary Radio (PR) transmissions. For each frequency band, a multi-antenna CR node uses MIMO spatial multiplexing to control its antenna radiation directions and allocate power on each antenna by appropriately adjusting its precoding matrix. Their objective is to design a set of precoding matrices (one for each spectrum band) at each CR node such that power and spectrum are optimally allocated for the node (in terms of throughput) and its interference is steered away from unintended CRs and PRs.