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Measuring the Impact of Beamwidth and Bandwidth on the Wide-Sense Stationarity of Millimeter-Wave Channels



Anmol Bhardwaj, Jack Chuang, Camillo Gentile, Chiehping Lai


A wireless channel is wide-sense stationary (WSS) when the mean and autocorrelation of its small-scale fading are displacement invariant. This occurs when the channel is rich in propagation paths – their complex summation averages out any displacement-specific characteristics. Extensive measurement campaigns have confirmed the microwave channel to be WSS – it is inherently rich in diffracted paths, the 1G to 4G systems that operate there employ omnidirectional antennas which detect paths from all directions, and the systems feature narrow bandwidths which sum paths over long sample periods. Popular millimeter-wave (mmWave) channel models assume the channel is WSS without measured-based confirmation even though the channel is inherently sparse due to weak diffraction and the 5G systems that operate there employ pencilbeam antennas and feature ultra-wide bandwidths. In fact, a recent measurement campaign showed the 60 GHz channel can be non-WSS at certain beamwidths and beamwidths, however the campaign considered only one measured channel and only a discrete set of beamwidths and bandwidths. For comprehensive analysis, we measured 88 channels over three indoor and two outdoor environments with our 60 GHz channel sounder and varied the beamwidth and bandwidth continuously to find the crossover points when the channel transitions from WSS to non-WSS.
IEEE Open Journal of the Communications Society


60 GHz, mmWave, fast fading, small-scale fading


Bhardwaj, A. , Chuang, J. , Gentile, C. and Lai, C. (2023), Measuring the Impact of Beamwidth and Bandwidth on the Wide-Sense Stationarity of Millimeter-Wave Channels, IEEE Open Journal of the Communications Society, [online], (Accessed July 23, 2024)


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Created September 26, 2023, Updated January 22, 2024