5G • 5G-Advanced (Rel-18)
Digital Baseband SIC
Digital Domain Non-Linear Self-Interference Cancellation
High-speed DSP algorithm that models non-linear power amplifier distortion and phase noise to cancel residual self-interference after analog cancellation.
Technical Explanation
After analog RF cancellation reduces self-interference below LNA saturation, up to 50 dB of residual interference remains in the digital domain, compounded by Power Amplifier (PA) nonlinearities and phase noise. Digital Baseband SIC reconstructs non-linear Volterra series models of the transmitted signal in real time, subtracting the exact distortion waveform from digitized baseband samples.
Key Functions
- Eliminates residual 40 to 50 dB of self-interference in the digital baseband domain
- Models non-linear power amplifier harmonics, intermodulation, and phase noise
- Brings total gNodeB self-interference cancellation to over 130 dB (below thermal noise floor)
- Enables clean detection of microvolt-level uplink signals from distant edge UEs
Specifications
3GPP TR 38.858 (Rel-18)
Interfaces
gNodeB Baseband Processing
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