On the Ergodic Capacity of Fading Cognitive Radio MIMO Z-Interference Channel

In this letter, the ergodic capacity maximization problem is first studied in the fading cognitive multiple-input multiple-output (MIMO) Z-interference channel (ZIC), where the interference from the primary transmitter (PT) to the secondary receiver (SR) is omitted. With the statistical channel state information (CSI) feedback, we find the optimal and the low complexity sub-optimal power strategies for fading cognitive MIMO ZIC to maximize its ergodic capacity under total power constraint, interference power constraint and rank constraint. Simulation results show that the proposed sub-optimal scheme is very efficient and almost achieves the optimal performance.