Channel Measurement and Modeling R&D Topics

The success of the next-generation 5G wireless hinges on a proliferation of ultra-dense networks of massive MIMO antennas sending and receiving millimeter-wave signals. Yet there’s a dearth of channel models at these frequencies, and without channel models and the circuits and protocols they inform, there will be no ultra-dense networks running on massive-MIMO antennas. NIST CTL’s channel measurement and modeling research and development focuses on devising new ways to collect measurement data in challenging gigahertz frequency bands and developing channel models based on statistical analyses of the resulting measurements. Among these efforts include:

• Extending channel models to account for mmWaves, including large-scale path loss and shadowing; small-scale delay characteristics such as power-delay profile, RMS-delay spread, coherence, bandwidth, and fading; as well as for Doppler shifts, which will have significant impact on performance, even at pedestrian speeds.
• Incorporating directional, angle-of-arrival information in mmWave channel models.
• Developing calibrations and uncertainty analyses for inclusion in the NIST Microwave Uncertainty Framework. We will also develop methods to separate channel and antenna effects in channel measurements and models.
• Developing a 28 GHz channel sounder to complement the 83 GHz channel sounder already running. Given industry interest in 38 GHz and 60 GHz bands, we plan to extend our system and channel models to these frequency ranges.
• Extending our channel models to examine signals beyond 100 GHz to support a wireless industry already exploring hardware at 140 GHz.