RadioStream: A Wideband Multi-Antenna SDR Platform

Abstract

Software-defined radios are central to wireless systems research, but their host-centric streaming interfaces grow fragile exactly where modern experiments push hardest: wide bandwidth, many antennas, and fine slot-level control. The root difficulty is a timing-domain mismatch: the FPGA and RF front-end run on a deterministic, sample-clock-driven timeline, while the host operates asynchronously under operating-system scheduling, and traditional stacks resolve this by forcing the host to keep pace with the radio, producing late packets, underflows, and overflows at wideband rates. We present RadioStream, a radio-centric, slot-synchronous SDR architecture that makes the slot, rather than the raw sample stream, the unit of coordination across the host-radio boundary. The FPGA owns slot timing and time-critical radio actions and exports slot boundaries to the host as explicit slot-tick Ethernet packets, while the host runs asynchronously behind slot-aligned buffers over a lightweight fronthaul, with a two-slot look-ahead for control. A DPDK-based host path integrates directly with frameworks such as GNU Radio, Python, and MATLAB. On a 100G interface, RadioStream sustains 90 Gbps concurrently on uplink and downlink with no packet drops, streams 2 GHz of aggregated RF bandwidth, bounds slot-tick jitter below 600 ns at the 99th percentile, and applies per-slot control reaching the RF output in under 500 ns. We demonstrate RadioStream across communication, mmWave beam sweeping, and sub-6 GHz multi-antenna sensing workloads, showing that reliable, high-throughput streaming and deterministic fine-grained control hold together in practice.