As autonomous driving and advanced driver-assistance systems (ADAS) evolve, modern vehicles require unprecedented levels of environmental awareness to enhance and ensure driving safety. According to the article “High-Precision Synchronization for 77-GHz Radar Networks via White Rabbit” in Journal of IEEE Transactions on Radar Systems, this demand is driving the deployment of distributed 77GHz automotive radar networks, which rely on coherent data processing to create a precise, real-time map of the vehicle’s surroundings. To achieve this, the distributed sensors must be synchronized with sub-nanosecond accuracy. Existing wired synchronization methods, however, incur high cabling costs and present challenges in complexity and scalability.
White Rabbit (WR) Technology, an Ethernet-based technology providing sub-nanosecond accuracy, enables simultaneous synchronization and data transfer over a standard Ethernet link, thus eliminating the need for a dedicated custom clock distribution network. To implement this technology in FPGAs, it typically requires external voltage-controlled crystal oscillators (VCXOs) for measurement and adjustment. However, such components are often missing on commercially off-the-shelf (COTS) development boards. This forces interested developers to invest inexpensive, specialized hardware just to get started with White Rabbit technology.
MLE supports White Rabbit Technology development in CERN’s White Rabbit Project and provides Dormouse White Rabbit FPGA Mezzanine Card (FMC) to complement (or replace) expensive VCXOs and trade-off BoM cost vs. minor loss of accuracy by using modern on-chip PLL for phase-shifting.
The Dormouse White Rabbit FPGA FMC features tunable oscillators that are required to deploy and operate White Rabbit, an open-source FPGA-based implementation of Precision Time Protocol 2.1 (PTP v2.1), and provides capabilities to generate LF and RF reference clocks derived from a White Rabbit network. For these tasks a high performance OCXO (DOT050V), two programmable and tunable oscillators (SiT3521, Si549) and a flexible PLL (HMC7044) are available for use on the card.
With the Dormouse White Rabbit FPGA FMC, White Rabbit implementation can achieve < 1 ns accuracy and < 100 ps precision of the PTP v2.1 high-accuracy profile for building a time and frequency distributed 77GHz automotive radar networks.
Features of Dormouse White Rabbit FMC:
- Compatible with:
- Zynq UltraScale+ MPSoC ZCU102 Evaluation Kit
- Zynq UltraScale+ MPSoC ZCU106 Evaluation Kit
- Zynq UltraScale+ RFSoC ZCU111 Evaluation Kit
- Other AMD/Xilinx FPGA Development Boards
- IEEE 1588-2019 PTP V2.1
- Typical Accuracy ~ 1 Nanosecond
- ANSI/VITA 57.1 FPGA Mezzanine Card Form Factor
- SFP+ 10 GigE Connector
- Connor-Winfield DOT050V OCXO
- SiTime Tunable Oscillators SiT3521/Si549
- Analog Devices Flexible PLL HMC7044
- TI Wideband Synthesizer LMX2594
- Clock Rates (default): 10 MHz, 62.5 MHz, 125 MHz, 250 MHz
- Designed in Accordance to The CERN Open Hardware License (OHL)
The MLE Dormouse White Rabbit FMC is now available on our partner Trenz’s online shop.
Implementing Sub-Nanosecond Synchronization for a Distributed Automotive Radar Networks?
