1. Multi-cell Multi-user Massive MIMO Systems 

• Spectral efficiency
• Energy Efficiency
• Resource Allocation
• Channel Estimation, Signal Detection and Beamforming (Precoding)
• Channel Charctristics for Milimeter-wave frequency channels
• Pilot Contamination Effects
• Antenaa selection
• ....

2.  Distributed MIMO

3.  Interference Alignment

4.  Cooperative Relaying

• Spectral efficiency
• Energy Efficiency
• Resource Allocation
• .....

5. Signal Processing for RADAR