Angular characteristics of multipath propagation in an indoor industrial environment (original) (raw)

A statistical model for angle of arrival in indoor multipath propagation

1997

Abstract Multiple antenna systems are a useful way of overcoming the effects of multipath interference, and can allow more efficient use of spectrum. In order to test the effectiveness of various algorithms such as diversity combining, phased array processing, and adaptive array processing in an indoor environment, a channel model is needed which models both the time and angle of arrival in indoor environments.

A Statistical Model for Indoor Multipath Propagation

IEEE Journal on Selected Areas in Communications, 1987

The results of indoor multipath propagation measurements using 10 ns, 1.5 GHz, radarlike pulses are presented for a medium-size office building. The observed channel was very slowly time varying, with the delay spread extending over a range up to about 200 ns and rms values of up to about 50 ns. The attenuation varied over a 60 dB dynamic range. A simple statistical multipath model of the indoor radio channel is also presented, which fits our measurements well, and more importantly, appears to be extendable to other buildings. With this model, the received signal rays arrive in clusters. The rays have independent uniform phases, and independent Rayleigh amplitudes with variances that decay exponentially with cluster and ray delays. The clusters, and the rays within the cluster, form Poisson arrival processes with different, but fixed, rates. The clusters are formed by the building superstructure, while the individual rays are formed by objects in the vicinities of the transmitter and the receiver.

Analysis of Multipath Propagation based on Cluster Channel Modelling Approach

The computer simulation approach with an emphasis on the propagation modelling for wireless channels for current and future communication systems is a powerful tool to asses the performance of systems without the need of building them. This paper presents a clustering approach geometry-based channel model, and employs it to derive the power density function (PDF) of the Angle of Arrival (AOA) of the multipath signal components. To evaluate the theoretical clusters PDF in angular domain proposed, we make computer simulations for the geometry-based channel model proposed and compared it with experimental results published in the literature showing good agreement. The clusters PDF derived can be used to simulate the power-delay-angle profile (PDAP) and to quantify second order statistics, i.e., power angular spectrums (PAS) and the associated angular spreads (Ass) for a given elliptical shape of the cluster.

Statistical Analysis of Multipath Clustering in an Indoor Office Environment

EURASIP Journal on Wireless Communications and Networking, 2011

A parametric directional-based MIMO channel model is presented which takes multipath clustering into account. The directional propagation path parameters include azimuth of arrival (AoA), azimuth of departure (AoD), delay, and power. MIMO measurements are carried out in an indoor office environment using the virtual antenna array method with a vector network analyzer. Propagation paths are extracted using a joint 5D ESPRIT algorithm and are automatically clustered with the Kpower-means algorithm. This work focuses on the statistical treatment of the propagation parameters within individual clusters (intracluster statistics) and the change in these parameters from one cluster to another (intercluster statistics). Motivated choices for the statistical distributions of the intracluster and intercluster parameters are made. To validate these choices, the parameters' goodness of fit to the proposed distributions is verified using a number of powerful statistical hypothesis tests. Additionally, parameter correlations are calculated and tested for their significance. Building on the concept of multipath clusters, this paper also provides a new notation of the MIMO channel matrix (named FActorization into a BLock-diagonal Expression or FABLE) which more visibly shows the clustered nature of propagation paths.

Indoor wideband time/angle of arrival multipath propagation results

1997

Abstract Most current indoor propagation experiments measure the time of arrival of characteristics of multipath reflections without regard to the angle of arrival. Because of the increasing number of systems that are used indoors and which use multiple antenna systems to combat multipath interference, a need exists for indoor propagation data which takes the angle of arrival into account. A system is described which was used to collect simultaneous time and angle of arrival data in two indoor environments.

Characterization of UHF multipath radio channels in factory buildings

1989

Wide-band multipath measurements at 1300 MHz have been made in five factory buildings in Indiana. Root mean square (rms) delay spread (U) values were found to range between 30 and 300 ns. Median U values were 96 ns for line-of-sight (LOS) paths along aisleways and 105 ns for obstructed paths across aisles. Worst case U of 300 ns was measured in a modern open plan metal-working factory. Delay spreads were not correlated with transmitter-receiver (T-R) separation or factory topography, but were affected by factory inventory, building construction materials, and wall locations. Wide band path loss measurements consistently agreed with continuous wave (CW) measurements made at identical locations. It is shown here that such empirical data suggest independent and identical uniform distributions on the phases of resolvable multipath signal components. Average factory path loss was found to be a function of distance to the 2.2 power. Wide-band factory propagation measurements have not been previously reported in the literature.

Estimating local mean signal strength of indoor multipath propagation

IEEE Transactions on Vehicular Technology, 1997

We explore techniques for the measurement of local mean signal strength at 900 MHz and 2 GHz. In particular, we characterize the impact of transmitter and receiver antenna rotation on the estimated local mean. Then, we explore collecting high resolution data while moving along a linear trajectory and using linear averaging techniques to estimate the local mean. With this information, the best measurement techniques can be chosen depending on the required speed versus accuracy tradeoff. Finally, we use a ray tracing propagation model to evaluate different methods of calculating the local mean signal strength for indoor environments. Reinaldo A. Valenzuela (M'85-SM'89) received the B.Sc. (E.Eng.) from the University of Chile, and the DIC and Ph.D. degrees from the Imperial College of Science and Technology, University of London, U.K. His doctoral work introduced novel digital filter architectures with applications in transmultiplexer design. At Databit Ltd. (U.K.) he worked on a full-duplex echo cancelling system for the transmission of data over voice signals in the subscriber loop. Later, he joined AT&T Bell Laboratories, where he studied indoor microwave propagation and modeling, packet reservation multiple access techniques for indoor wireless systems, and optical WDM networks. During 1988 and 1989, he was Manager, Voice Research Department, at Motorola Codex, involved in the real time implementation of low-bit-rate voice coding for integrated voice and data packet systems. He is currently the Department Head at the Wireless Communications Research Laboratory, Lucent Technologies, Holmdel, NJ, where he is engaged in research on wireless systems for personal communication networks. His interests include wireless system design, propagation measurements, and site-specific propagation models for indoor and microcellular systems. He has led a multidisciplinary team effort to create a software tool for Wireless System Engineering (WiSE), now in widespread use in AT&T and Bell Laboratories. Dr. Valenzuela recently received the AT&T Bell Laboratories Distinguished Member of Technical Staff award. Orlando Landron (M'90) was born in Washington, D.C., in 1967. He received the B.S. and M.S. degrees in electrical engineering from the Virginia Polytechnic and State University (Virginia Tech), Blacksburg, in 1990 and 1992, respectively.

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

1996

Abstract Most previously proposed statistical models for the indoor multipath channel include only time of arrival characteristics. However, in order to use statistical models in simulating or analyzing the performance of systems employing spatial diversity combining, information about angle of arrival statistics is also required. Ideally, it would be desirable to characterize the full spare-time nature of the channel. In this paper, a system is described that was used to collect simultaneous time and angle of arrival data at 7 GHz.

Experimental Analysis of Dense Multipath Components in an Industrial Environment

IEEE Transactions on Antennas and Propagation, 2000

This work presents an analysis of Dense Multipath Components (DMC) in an industrial workshop. Radio channel sounding experiments with a vector network analyzer and virtual antenna arrays were carried out. The specular and dense multipath components were estimated from channel sounding data by means of an iterative maximum-likelihood algorithm (RiMAX). The DMC covariance structure of the RiMAX data model was validated for the industrial environment under consideration. Two main DMC parameters are studied: the distribution of radio channel power between specular and dense multipath, and the DMC reverberation time in the time-delay domain. The DMC power is found to account for 23 to 70% of the total channel power. A statistically significant difference between DMC powers in line-of-sight and non-line-of-sight situations is discovered, and this difference can be largely attributed to the power of the lineof-sight multipath component. In agreement with the theory of room electromagnetics, the DMC reverberation time is found to be nearly constant. Overall, DMC in the industrial workshop is more important than in office environments: it occupies a fraction of the total channel power that is 4 to 13% larger. The industrial environment absorbs on average 29% of the electromagnetic energy compared to 45-51% for office environments in literature: this results in a comparatively larger reverberation time in the former environment. These findings are explained by the highly cluttered and metallic nature of the workshop.