5G • 5G-Advanced (Rel-18)
Ambient IoT Coexistence
Interference Mitigation Between High-Power 5G and Weak Ambient Backscatter
Advanced gNodeB receiver algorithms that detect weak micro-volt backscatter signals in the presence of high-power multi-megabit smartphone traffic.
Technical Explanation
Because backscatter reflections are extremely faint (often 80 dB below thermal noise), direct leakage from the base station transmitter can easily drown them out. Rel-18 employs self-interference cancellation, frequency-offset subcarrier reflection (shifting the backscattered signal away from the carrier tone), and spreading codes to detect ambient tags reliably.
Key Functions
- Detects micro-volt backscatter signals situated deep below the thermal noise floor
- Applies frequency-offset reflection, shifting tag signals away from direct carrier leakage
- Uses orthogonal pseudo-noise spreading codes to separate thousands of overlapping tags
- Prevents high-power smartphone data traffic from jamming ambient inventory operations
Specifications
3GPP TR 38.848, TS 38.211 (Rel-18)
Interfaces
gNodeB Receiver
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