This letter addresses the sensor selection problem for spectrum sensing in cognitive radio networks. Hereby, an energy-efficient cooperative spectrum sensing is proposed, which is based on sensing node selections in multiantenna structures. In this letter, the sensor selection problem is solved utilizing two methods: convex optimization and genetic algorithm. Simulation results indicate that the convex optimization with cooperative multiple antennas sensing improves the performance of a network in comparison with genetic algorithm while suffers from complexity and implementation costs.