Symbiotic Communication: Concurrent Transmission for Multi-Users Based on Backscatter Communication

As backscattering technology has become more widely used in the Internet of Things, how to correctly recover multiple reflected signals has become a hot research in the field of reverse communication. In the background of backscatter communication (BackCom), this paper proposes a symbiotic communication system for multi-user random access. By using a simple coding algorithm that does not require strict synchronization, we propose a method to avoid interference between multiple reflected signals. Passive users use mutually orthogonal chips to encode, so that the interference between the reflected signals is the orthogonal interference, which achieving the parallel transmission for multiple users. Meanwhile, this study designs the coding and decoding algorithms to achieve two orthogonal chips, which are used with different chip lengths and different chip transmission rate. We compares with the parallel transmission scheme based on code division multiple access (CDMA). After the verification of orthogonal interference among multiple reflected signals, we make the simulation analysis of the random access multi-user symbiotic system. The simulation results verify the feasibility and effects of the proposed algorithm.