High-performance Radar Data Recorder Architecture Based on NVMe P2P Transaction and PCIe Switch Network

The radar data recorders need higher data storage performance with the improvement of radar technology. In this paper, we propose a new radar data recorder architecture based on NVMe (Non-Volatile Memory Express) SSD (Solid-State Drive) array on the PCIe (PCI Express) switch network and P2P (peer-to-peer) DMA transaction. We use the cascading capability of PCIe switch to construct NVMe SSD array for data capacity expansion rapidly. The NVMe driver in user-level based on the VFIO framework of the IOMMU function is developed to implement the DMA operation between the NVMe SSD and other PCIe devices. An FPGA, with a PCIe DMA engine and data streaming management logic, acts as the radar data receiver. It is NVMe P2P transaction that makes the radar data directly reach the NVMe SSD efficiently, without passing through CPU memory. The file system format is dissected for building data files in SSD directly. According to the test result, the data recording bandwidth reaches about 5GB/s in PCIe Gen3 x8 mode. We conclude this architecture can greatly improve the radar data storage bandwidth and capacity with simple structure, low cost and high flexibility.