Optimal Spectrum Sharing in MIMO Cognitive Radio Networks via Semidefinite Programming

Abstract--In cognitive radio (CR) networks with multipleinput multiple-output (MIMO) links, secondary users (SUs) can exploit "spectrum holes" in the space domain to access the spectrum allocated to a primary system. However, they need to suppress the interference caused to primary users (PUs), as the secondary system should be transparent to the primary system. In this paper, we study the optimal secondarylink beamforming pattern that balances between the SU's throughput and the interference it causes to PUs. In particular, we aim to maximize the throughput of the SU, while keeping the interference temperature at the primary receivers below a certain threshold. Unlike traditional MIMO systems, SUs may not have the luxury of knowing the channel state information (CSI) on the links to PUs. This presents a key challenge for a secondary transmitter to steer interference away from primary receivers. In this paper, we consider three scenarios, namely when the secondary transm...

• Type: Journal
• Year: 2010
• Where: CORR
• Authors: Ying Jun Zhang, Anthony Man-Cho So
• Keywords: CORR 2010, Education, MIMO, Primary Receivers, Secondary Transmitter