Performance analysis of CDMA in NLOS ultraviolet communication for UAV swarms

Atmospheric scattered propagation of ultraviolet (UV) light enables non-line-of-sight (NLOS) optical wireless communication and networking, and this paper presents a practical UV-based unmanned aerial vehicle (UAV) cluster network with a seamless grid coverage topology. To address unique channel constraints, we established a novel architecture that quantifies network coverage through joint path loss and bit error rate (BER) modeling, while enabling multi-user access via intensity-modulated Direct-Sequence Spread Spectrum Code Division Multiple Access (DSSS-CDMA) using Walsh-Hadamard coding to suppress multi-user interference during concurrent transmissions. Numerical results confirm system feasibility by comprehensively analyzing node coverage capability and the average multi-user BER.