3 Distance Measurement – Ranging
The ATA8352 device supports different system modes to be used for distance measurement. The Extended Dual frequency mode listed in the following table is comparable with the LRP mode defined in the IEEE802.15.4z-2020 standard (see Example Application), while the other two modes are the proprietary modes.
- Distance bounding measurement with verifier (VR) and prover (PR) as listed in the following table. The two proprietary modes can be used with the highest security level to prevent physical layer attacks. For more details on these modes, refer to the ATA8352 Impulse-Radio Ultra-Wideband (IR-UWB) Transceiver User’s Guide (DS50003125).
- Ranging modes using the RX and TX modes of the device with enabled TDoA measurement. These modes provide timestamps captured during TX and RX operation to allow two-way-ranging (TWR) or time-difference-of-arrival (TDoA) measurements. For more details on TWR, refer to the ATA8352 Testing and Certifications Application Note (DS00004089).
| System Modes | Data Rate [Mbps] | Modulation | PRF [MHz] | Pulses per Symbol/bit | Preamble Symbols | Postamble Symbols | Application |
|---|---|---|---|---|---|---|---|
| Extended Dual-Frequency mode | 1.0 | PBFSK | 4.0 | 4 | 224/176 | 160/128 | Improved measurement time |
| Proprietary mode1 | 0.5 | PBFSK | 4.0 | 8 | 224/176 | 160/128 | Highest security against physical layer attacks |
| Proprietary mode2 | 0.25 | PBFSK | 4.0 | 16 | 224/176 | 160/128 |
For VR and PR operation, the payload size is limited to 4 bytes, 6 bytes or 8 bytes payload used as nonce data together with the optional 4-byte for the secure-session-identifier (SSID) used as an address filter. In the high security modes VRs/VRso and PRs/PRso, the payload size for the payload data is always 4-byte and requires the exchange or synchronization of security data (index permutation scheme and seed/key data for the Trivium cipher) between the VR and PR nodes. For more details on security mechanisms, refer to the ATA8352 User Guide (DS50003125).
For distance measurement with timestamps and for TDoA, see the system modes listed in Table 2-1. For more details on the TDoA distance measurement scheme and how it uses the RX and TX operations, refer to the Range Measurement using Time-Difference-of-Arrival with ATA8352 Application Note (DS00004113).
These modes do not include the physical security level as available for VRs and PRs modes. Nevertheless, the encryption and coding of the data payload, as described in Recommended Modes for Data Communication, can be applied for the TDoA operation.