Radar functions inside a communication network
When a 6G network operates in radar mode, it illuminates the environment and processes the returning echoes to detect objects, estimate their range and radial velocity, and in some configurations form images or maps. Unlike a dedicated automotive or defense radar, the 6G radar mode must coexist with data traffic, share the same spectrum license and often reuse the same waveform family. The result is a set of performance trade-offs that pure radar systems do not face and that pure communication systems ignore.
Detection performance is characterized by probability of detection and probability of false alarm under specified signal-to-noise and clutter conditions. Range resolution is set primarily by the effective bandwidth of the sensing waveform. Velocity resolution is set by the coherent processing interval and the carrier frequency. Angular resolution depends on the array aperture and the beamforming or direction-of-arrival algorithm employed.
Range-Doppler processing
Most practical 6G radar pipelines form a range-Doppler map. After pulse compression or matched filtering in the range dimension, a Fourier transform across successive pulses or OFDM symbols extracts Doppler (velocity) information. Communication-centric OFDM waveforms can be adapted for this purpose by treating the cyclic prefix and pilot structure carefully and by ensuring phase continuity across the coherent interval. Sensing-centric chirps or phase-coded pulses remain attractive when maximum range resolution or Doppler clarity is required and communication rate can be temporarily reduced.
Clutter—returns from ground, buildings and slow-moving foliage—must be suppressed or modeled. Moving-target indication, space-time adaptive processing and learning-based clutter maps are all candidates for 6G implementations. The presence of many communication users adds structured interference that the sensing processor must either null or treat as known signals.
Imaging and high-resolution modes
Beyond point detection, 6G sensing can support imaging. Synthetic aperture techniques, when platform motion or multi-static geometries provide sufficient baseline, yield finer cross-range resolution. Tomographic approaches that combine multiple views can reconstruct three-dimensional structure. These modes consume more resources and are typically scheduled as background or on-demand tasks rather than continuous real-time services.
Material sensing and micro-Doppler analysis extend the information extracted from a single target. Micro-Doppler signatures from rotating machinery, human gait or respiratory motion enable classification and biometric applications. Bandwidth and phase stability requirements rise accordingly.
Waveform and resource considerations
Communication waveforms optimized solely for spectral efficiency are rarely optimal for sensing. Designers therefore introduce sensing-oriented pilots, reserved symbols or dual-purpose sequences whose autocorrelation and ambiguity properties support both functions. Power allocation between communication streams and sensing illumination is another degree of freedom; boosting sensing power improves detection range but reduces the power available for data and may increase interference to neighboring cells.
Scheduling algorithms must decide when to prioritize a sensing dwell versus a latency-sensitive communication burst. Safety-critical automotive or industrial use cases may require guaranteed sensing update rates, which in turn constrain the communication capacity that can be promised in the same cell.
Metrics and evaluation
Standardization efforts define sensing key performance indicators that complement traditional communication KPIs. These include maximum detectable range at a given radar cross-section, range and velocity resolution, localization accuracy, update rate and the impact of sensing on communication throughput. Evaluation methodologies combine link-level waveform studies with system-level simulations that capture multi-user interference, mobility and multi-cell coordination. Field trials ultimately validate whether the radar-mode performance predicted in simulation holds under real clutter, weather and traffic conditions.
6G radar sensing is therefore not a simple add-on. It is a mode of network operation that reuses infrastructure for environmental awareness while imposing new requirements on waveform design, resource management and performance measurement.
