Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Measuring the Impact of Beamwidth on the Correlation Distance of 60 GHz Indoor and Outdoor Channels



Aidan Hughes, Sung Yun Jun, Camillo Gentile, Derek Caudill, Jack Chuang, Jelena Senic


Due to high antenna directionality and channel sparseness, millimeter-wave receivers will detect much less multipath then their microwave counterparts, fundamentally changing the small-scale fading observed. In particular, the de facto Rayleigh-Rice model, which assumes a rich multipath environment interpreted by the Clarke-Jakes omnidirectional ring of scatterers, does not provide an accurate representation for this fading, nor for the coherence distance that it predicts. Rather, in the recent, seminal work by Va et al., a model interpreted by a directional ring of scatterers, theoretically demonstrated a strong dependence of coherence distance on beamwidth. To support Va's model through actual measurement, we conducted an exhaustive measurement campaign for fading in five different environments - three indoor and two outdoor - with our state-of-the-art 60 GHz 3D double-directional channel sounder, compiling a total of 36,000 channel captures. By exploiting the super-resolution capabilities of our system, with average angular error of only about 2.5°, we were the first, to our knowledge, to measure coherence distance as a function of beamwidth. We showed that for narrow beamwidths, coherence was maintained for much longer distances than predicted by the Rayleigh-Rice model, supporting Va's model, however as the beamwidth approached omnidirectionality, with more and more multipath detected, the behavior was represented well by the Rayleigh-Rice model.
IEEE Open Journal on Vehicular Technology


Millimeter-wave, mmWave, small-scale fading, fast fading, 5G, Sum of Cisoids model, SOC model


Hughes, A. , Jun, S. , Gentile, C. , Caudill, D. , Chuang, J. and Senic, J. (2021), Measuring the Impact of Beamwidth on the Correlation Distance of 60 GHz Indoor and Outdoor Channels, IEEE Open Journal on Vehicular Technology, [online], , (Accessed July 13, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created March 22, 2021, Updated October 12, 2021