Achieving Long Range Ambient Scatter Communication Networks: A Primary User Interference Perspective

Ambient Scatter Communications (ASC) is an emergent field of scatter-based-radio which promises low-power, low-cost, and 'regulation-free' wireless communications. Ambient Scatter Communication Systems (ASCS) uniquely employ previously modulated and transmitted ambient RF energy as its RF carrier, creating non-trivial complexity in matters of signal processing and RF propagation. This paper provides a comprehensive analysis of past ASC works, demonstrating how Primary User Interference (PUI) -- the non-scattered signal which travels directly from the ambient source to the ambient receiver -- limits the operating range for current ASCS's. Firsttime theoretical descriptions are developed for the PUI Power Differential in ambient bistatic links and for describing bistatic radio topologies. A large survey of current devices in the field of ASC's is compiled and compared to each other using these new metrics as reference, illustrating ways to greatly enhance the range of ASCs in the future.