Beam selection for ambient backscatter communication in beamspace mmWave symbiotic radio

The Internet of Things revolution has profoundly impacted wireless communication systems. Access to high data rates is now just as important as low power operation. The use of incident millimeter-wave (mmWave) signals for ambient backscatter communication (AmBC) has shown significant promise for delivering high data rates. However, due to channel sparsity, incident signal availability to backscatter devices (BDs) at mmWave is erratic. In order to address the incident signal inaccessibility problem and enable high data-rate AmBC, this letter presents an efficient beam selection method in the beamspace millimeter-wave symbiotic radio system. The proposed method improves the overall system's sum-rate performance by up to 30% while ensuring signal accessibility to BDs.