Efficient spectrum sensing for aeronautical LDACS using low-power correlators

Air traffic has seen tremendous growth over the last decade pushing the need for enhanced air traffic management schemes. L-band Digital Aeronautical Communication System (LDACS) is gaining traction as a scheme of choice, and aims to exploit the capabilities of modern digital communication techniques and computing architectures. Cognitive radio based approaches have also been proposed for LDACS to improve spectrum efficiency and communication capacity; however, these require intelligent compute capability in aircrafts that enforce limited space and power budgets. This paper proposes the use of multiplierless correlation to enable spectrum sensing in LDACS air-to-ground links, and its integration into the on-board LDACS system. The proposed architecture offers improved performance over traditional energy detection even at low signal to noise ratio (SNR) with lower energy consumption than a multiplier-based correlator, while also assisting in receiver synchronisation. We evaluate the proposed architecture on a Xilinx Zynq FPGA and show that our approach results in 28.3% reduction in energy consumption over the multiplier-based approach. Our results also show that the proposed architecture offers 100% accuracy in detection even at -12dB SNR without requiring additional circuitry for noise estimation, which are an integral part of energy detection based approaches