Indoor signal tests show antenna type affects 6 GHz channel behavior
Directional and Quasi-Omnidirectional Indoor Channel Measurements at Upper 6 GHz
Emerging TechnologiesInformation Theory
Summary
Wireless signals inside buildings behave differently depending on the type of antennas used. The authors compared focused (directional) antennas to wide-angle (quasi-omnidirectional) antennas at frequencies above 6 GHz inside halls and corridors. They found that directional antennas pick up less delayed signal reflections, showing clearer and more stable paths especially in line-of-sight settings. This affects measurements like signal delay and fading, which are important for designing indoor wireless networks.
What this means in practice
- •For indoor wireless network engineers: Improve indoor signal models by selecting antenna types that better reflect real-world signal delays and fading at upper 6 GHz frequencies.
- •For antenna designers: Design antennas for indoor 6 GHz systems that balance directional gain and sensitivity to delayed multipath signals for better network performance.
Authors
Chengsong Fu, Hongbo Zhao, Jianer Zhou, Xiongbin Yu, Weichao Li, Chen Zhuang, Meng Li, Wenquan Feng, Xiaofeng Tao
Abstract
Physical directional and quasi-omnidirectional antenna pairs are compared at 6.425--7.125 GHz over 32 position-matched indoor links per configuration: 23 line-of-sight (LOS) and nine non-LOS (NLOS) links in an open hall and an L-shaped corridor. Peak-gain normalization retains antenna-pattern weighting in the measured path loss, shadow-fading residuals, RMS delay spread (DS), and PDP-equivalent $K$ factor. Hall LOS close-in exponents are nearly identical at 2.10/2.11 for directional\slash quasi-omnidirectional pairs, yet median DS values differ markedly at 1.78/36.52 ns. Directional DS is lower at all LOS positions, with smaller fitted shadow-fading residuals and higher $K$ factors. Representative PDPs associate these differences with reduced off-axis delayed energy. In corridor NLOS, the directional floating-intercept slope is negative, consistent with distance-dependent antenna-pattern weighting under the fixed pointing rule, whereas the quasi-omnidirectional slope is positive and DS ordering varies by position. These results quantify practical antenna-filtered channels without angular-scan synthesis, with unequal weak-path sensitivity contributing to the observed differences.