DemoJul 2024

xMASS SDR Demo Shows 8-Channel MIMO Streaming over PCIe

Wavelet Lab demonstrates xMASS SDR carrier board performance with 8-channel MIMO streaming, 12-bit I/Q optimization, PCIe bandwidth utilization, and SoapySDR/GNU Radio support.

Wavelet Lab's xMASS SDR platform is designed for high-channel-count RF systems, including Massive MIMO research, 4G/5G experimentation, beamforming, direction finding, and synchronized multi-channel signal processing.

A recent xMASS carrier board demo highlights the platform's ability to stream high-rate multi-channel I/Q data over PCIe while maintaining practical host-side processing performance.

The demo shows eight channels running at 65 MSPS or four channels running at 130 MSPS on a single CPU without overruns.

Comparison
xMASS multi-channel streaming demo configurations
ConfigurationChannelsSample RateUse Case
8-channel mode865 MSPSSynchronized MIMO capture, beamforming
4-channel mode4130 MSPSWider per-channel bandwidth, wideband DSP

High-throughput MIMO streaming

Multi-channel SDR systems are often limited not by RF capability alone, but by data movement.

As channel count increases, the host interface, driver stack, memory movement, CPU processing, and visualization pipeline all become critical. xMASS is designed to address this by combining synchronized SDR hardware with high-throughput PCIe streaming.

The demo demonstrates that xMASS can sustain demanding multi-channel rates while keeping the system usable for real processing tasks.

12-bit I/Q optimization

To make better use of available PCIe bandwidth, Wavelet Lab optimized xMASS software for complex 12-bit I/Q streaming.

This format improves bandwidth utilization without simply reducing the system to lower dynamic range operation. Efficient packing, unpacking, data conversion, and vectorized processing are important parts of making high-rate SDR workflows practical on standard host computers.

This is especially relevant for MIMO systems where every channel adds data rate, memory pressure, and processing load.

PCIe bandwidth utilization

xMASS uses PCIe to move large amounts of I/Q data from the SDR hardware into the host system. The demo shows high bus utilization while maintaining stable operation.

That matters because many RF applications require continuous streaming rather than short bursts. For ​spectrum monitoring, beamforming, wideband capture, and multi-channel analysis, stable streaming performance is essential.

Real-time host processing

The xMASS demo also highlights host-side processing work, including data transcoding, FFT processing, log conversion, averaging, and visualization.

This shows that the platform is not only moving raw data, but also enabling practical real-time signal analysis workflows.

For developers, this means xMASS can serve as a foundation for more advanced applications such as:

  • Massive MIMO research
  • multi-antenna [​spectrum monitoring]()
  • direction finding
  • beamforming
  • 4G/5G experimentation
  • synchronized signal capture
  • distributed RF sensing
  • high-throughput DSP development

xMASS in the Wavelet Lab ecosystem

xMASS complements Wavelet Lab's smaller SDR modules by scaling the architecture into multi-channel RF systems.

uSDR and xSDR are compact embedded SDR modules.

sSDR extends coverage into higher-frequency applications.

xMASS focuses on synchronized multi-channel operation and high-throughput data movement.

Together, these products support a broad range of RF workflows from portable single-device applications to large MIMO arrays.

See xMASS in action

Watch the carrier-board demo and read the full project update from Crowd Supply.