6G • RAN
Near-Field Beamforming
Spherical Wavefront Radiative Beamforming
Beamforming algorithms designed for the radiative Fresnel zone where wavefront curvature allows focusing energy onto a specific 3D spatial coordinate.
Technical Explanation
In conventional far-field beamforming, electromagnetic wavefronts arriving at an array are approximated as flat planar waves, limiting beam steering to angular direction (azimuth and elevation). With 6G XL-MIMO and Sub-THz frequencies, the Rayleigh distance (the boundary between near-field and far-field) extends to hundreds of meters. Near-Field Beamforming leverages spherical wavefront curvature, enabling the base station to focus RF energy at a precise 3D point in space (angle plus radial distance), eliminating interference to nearby users.
Key Functions
- Focusing electromagnetic energy at a specific 3D coordinate (angle and distance)
- Spatial user multiplexing along identical angular directions via depth separation
- Mitigating energy leakage to unintended eavesdroppers or interfering receivers
- Exploiting spherical wavefront phase distribution across large aperture arrays
- Accurate 3D range and position estimation integrated into physical layer signaling
Specifications
IEEE Transactions on Signal Processing, ITU-R M.2160
Interfaces
NearField-PHY6G-Uu-NF
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