Multi-antenna cognitive uplink design for spectrum reuse

This paper investigates multi-antenna cognitive radio system, designs signal processing algorithms for cognitive uplink transmission, and proposes an opportunistic spectrum access scheme based on space division multiplexing (SDM-OSA). The proposed algorithms take equipment size and complexity constraints for mobile terminal into account and place main workload at cognitive base station, thus facilitate the design of cognitive terminal. With proper antenna configuration, cognitive transmission could be carried out using SDM even though there is no idle spectrum available. Compared with traditional OSA, throughput of cognitive system with proposed method is notably enhanced. Most important, the design guarantees that cognitive system does not interfere with the primary.