Statistics of short time and spatial variations measured in wideband indoor radio channels

Abstract

In an indoor environment, channel variations which occur most frequently are due to the movement of personnel near the transmitting or receiving antennas and/or local movements of the terminals around a given location. Such spatial and short time variations in the indoor radio channel are studied and determined by performing wideband propagation experiments in line of sight and nonline of sight environments at 910MHz. The database is divided into two classes: spatial and short time variations. Spatial variations deal with the changes in the radio channel, observed over a short time and space, at different locations in an environment. The short time variations address changes induced over time, by human traffic close to the fixed transmitter/receiver or by manually shaking the antenna on its base. The statistics of RMS delay spread and the received power in the multipath profiles are computed and compared for these experimental variations.

Modeling the statistical time and angle of arrival characteristics of an indoor multipath channel

“…This results in the addition of an angle-of-arrival term to the channel impulse response given in (1). The combined impulse reponse is thus taken to be (6) The time-only model assumed the cluster times to be statistically independent of the ray times . Likewise, we will assume that the cluster statistics (the distributions of and ) are independent of the ray statistics (distributions of and ).…”

“…The papers by Ganesh and Pahlavan [6] and Todd et al [7] were initial attempts at addressing the spatial aspects of indoor propagation. Both presented data that were collected with small variations in the location of the receiving antenna, and both also addressed the effects of the movement of people near the transmitting and receiving antennas.…”

A worst-case analysis of direct-sequence spread-spectrum in multipath channels

“…Bernoulli random variables that take on values + I and -I with equal prob ability. Hence, the signal from transmitter k has the form [7] Sk(t) = ~ak(t)bk(t)COS(Wot+ek)' (5) where P k is the power and e k is phase angle of transmitter k, and Wo is the carrier frequency with Wo » T-…”

“…Many aspects of SSMA and indoors environment, such as multiuser average error probabilities and propagation measurements have been considered in the literature [1][2][3][4][5][6]. Worst-case performance measures, however, have received much less attention compared with the work on the average probability of error.…”

Indoor temporal variations at 800 MHz band

“…In an indoor environment, channel variations which occur most frequently are due to the movement of personal near the transmitting or receiving antenna andor local movements of terminals around a given location [2]. In general, the types of variations may be classified into two classes: Small Spatial Variation: this kind of variations deals with the changes in the radio channel observed over a short time around a given area at different locations of the terminal, such variations are induced by slowly moving the antenna around 0.5 m at various locations of the transmitter in one LOS and one OLOS environments.…”