Radio propagation modeling in indoor stairwell: A K-means clustering approach

Abstract

The propagation characteristics in indoor stairwell differ from those of the conventional indoor signal propagation across different floors and hence, deserve independent scrutiny. In this work, the propagation characteristics in four indoor stairwells have been examined by means of extensive field measurements at two frequency bands -2.4 and 5.8 GHz respectively. It has been found the values of the path loss exponent n for stairwell are higher than those for other indoor environments. More importantly, the standard deviation of the nvalues are high, leading to less accurate propagation models. This paper proposes the use of K-means clustering for the path loss data and values of path loss exponent n of stairwells are subsequently computed. The newly-computed path loss exponents n are lowered and their standard deviation values are significantly reduced. The path loss characteristics are useful for understanding radio propagation in pico-or femto-cells that have great potential in increasing the capacity and reducing the operational cost for wireless communications systems.

Path loss and delay spread for the stairwell channel at 5 GHz

“…The path loss was 35 to 85 dB with link distance ranging from approximately 2 m (with line-of-sight (LOS)) to two floors apart (in non-LOS (NLOS) conditions). In [6][7][8][9], ray tracing simulations and empirical measurements along two types of stairwells in four buildings were conducted at both 2.4 and 5.8 GHz. The transmitter (Tx) was outside the building, and the receiver (Rx) was in the stairwell from the first floor (with LOS) to the third floor (without LOS).…”

“…In contrast, we have found that the polarizations have significant effect in both LOS and NLOS conditions in our measurements where both Tx and Rx are indoors in the stair-wells. No models for floor attenuation factor (FAF) or data on small-scale fading were reported in [6][7][8][9]. We provide a FAF path loss model in this paper, which can be more accurate than traditional log-distance path loss models in multi-floor indoor environments.…”

Antenna‐height‐dependent delay spread model under indoor stair environment for small cell deployment in future mobile communications

“…Thus, the propagation characteristics under such an environment are essentially important to the indoor coverage of the 5G communication system. The propagation properties under stair environment have been studied . Basic propagation mechanisms are analyzed by using ray‐tracing method and verified by employing measurements .…”

“…Basic propagation mechanisms are analyzed by using ray‐tracing method and verified by employing measurements . More recently, a sectional path loss model of multi‐floor stair was proposed . The path loss model using “walking distance” instead of the separation of the transmitting and receiving antennas was proposed in a recent paper .…”

Path Loss Model with Antenna Height Dependency under Indoor Stair Environment

“…In order to satisfy the increasing demands, especially for indoor application, the dense small cell deployment becomes a main direction for the traditional and next-generation communication systems [3,4]. Therefore, site-specific propagation models for different indoor environments with the features of low power and short distance, for example, office rooms [5,6], corridors [7,8], and stairs [9,10], are needed to describe the channel characteristics more accurately. As a basic part of the indoor environments, stair environment plays an important role in our daily life.…”