Distance Dependent Model for the Delay Power Spectrum of In-room Radio Channels

Abstract

Abstract-A model based on experimental observations of the delay power spectrum in closed rooms is proposed. The model includes the distance between the transmitter and the receiver as a parameter which makes it suitable for range based radio localization. The experimental observations motivate the proposed model of the delay power spectrum with a primary (early) component and a reverberant component (tail). The primary component is modeled as a Dirac delta function weighted according to an inverse distance power law (d −n ). The reverberant component is an exponentially decaying function with onset equal to the propagation time between transmitter and receiver. Its power decays exponentially with distance. The proposed model allows for the prediction of e.g. the path loss, mean delay, root mean squared (rms) delay spread, and kurtosis versus the distance. The model predictions are validated by measurements: they show good agreement with respect to distance dependent trends.

Reverberation Time and Power Model in Indoor Wireless Scenarios

“…Over the last decade, studies based on room electromagnetics manage to provide more insightful physical understanding for indoor wireless channels [1][2][3][4][5][6][7]. The room electromagnetics theory [1] points out that the electromagnetic waves in indoor wireless scenarios and the acoustic waves in room acoustics share similar behaviors in various aspects.…”

“…The room electromagnetics theory [1] points out that the electromagnetic waves in indoor wireless scenarios and the acoustic waves in room acoustics share similar behaviors in various aspects. The room electromagnetics theory explains the quasi-linear decaying of Power Delay Profile (PDP) in indoor scenarios [1], [4]. In reverberation models, the PDP is interpreted as the superposition of primary component and reverberant component.…”

“…index for free-space propagation) in indoor scenarios. The index describes the decaying of primary component in reverberation models, and it can get closer to 2 than in traditional models [4]. Reverberation time is a key parameter in reverberation models [5][6][7], [9], [10].…”

“…Hence, the modeling of reverberation time is of great importance, as it is a basis of reverberation models. Most reported electromagnetic reverberation time models are based on either Sabine's or Eyring's equation [1], [4][5][6][7], [11], [12]. In analogy with acoustics, it is proposed in the two equations that electromagnetic reverberation time in an indoor wireless scenario is solely dependent on three parameters that are fixed by propagation geometry and materials: volume, surface and average absorption coefficient of the environment [11][12][13][14].…”

“…Also, the small scale fading characteristics including the modeling of PDP are rarely investigated. Meanwhile, most of these studies are limited in enclosed environments like conference rooms and classrooms [1][2][3][4][5][6][7], but semi-enclosed scenarios are rarely studied. Therefore, it is highly desired to develop a novel, accurate and more general reverberation model for indoor wireless scenarios.…”