Novel Load-Free SSB Modulation for LoRa Backscatter Communication

To optimize the link budget for wearable backscatter communication system, a load-free single-sideband modulation architecture for LoRa backscatter communication is proposed. It eliminates the requirement for a complex impedance network by utilizing the transmission-line-based in-phase quadrature (IQ) radio frequency (RF) front-end to implement the Hilbert transform of the reflection coefficients. We establish a quantitative analysis framework for energy efficiency, and experimental results validate 10 dB target-sideband enhancement (vs 12 dB). Link measurements confirm a 4.2× improvement in indoor and a 2.6× enhancement in outdoor communication distance compared to legacy LoRa backscatter methods, achieving over 400% link budget enhancement with only 16% additional power overhead.