60GHz Channel Characterization using a Scatterer Mapping Technique A. Papió * , A. Grau + , J. Balcells # , J. Romeu # , L. Jofre # , F. De Flaviis * * Electrical Engineering and Computer Sciences Dept., University of California Irvine (UCI) Room 2233 Engineering Gateway, UCI, 92697-7625 Irvine, CA, USA apapioto@uci.edu , franco@uci.edu # Signal Theory and Communications Department, Technical University of Catalonia (UPC) Campus Nord D3-210, Jordi Girona 1-3, 08034 Barcelona, Spain jofre@tsc.upc.es + Broadcom Corporation 5300 California Ave., Irvine, CA 92617, USA Abstract—In this paper, a Scatterer Mapping Technique based on a Multi-Frequency Bi-focusing operator with good imaging capabilities is used to characterize the 60GHz wireless channel in an office environment. The measurement data is also processed to extract the effective number of communication channels. The relation between the 60GHz office scatterer map and the effective number of communication channels is highlighted. I. INTRODUCTION Since the past few years, the telecommunications industry has been driving a growing interest for new wireless applications, such as WPAN. As a result, there is a strong interest in having a good understanding of the propagation characteristics of 60GHz wireless indoor channels. More precisely, it is of particular interest to determine the predominance of either a scattering or specular phenomena within the wireless channel. This information is critical to determine whether the 60GHz communications need to be encoded using MIMO diversity techniques (if the channel is rich in scattering) or using beamforming techniques (if a few specular paths are available between the transmitter and the receiver). The wireless propagation channel may be in general characterized by either the transfer function of the channel [1], or alternatively by a more compact way based on the description of the positions and shape of the main scatterers contributing to the creation of the different wave-paths. The advantages of using one or the other depend on the particular scattering/specular characteristics of the channel. If the channel contains a large number of scatterers/paths, the traditional transfer function may be a more appropriate way to describe it. However, when the number of significant scatterers reduces, the scatterer mapping technique [2] becomes more convenient and intuitive because it allows us to physically identify the location of the scatters within the channel. In this paper, a 2D Scatterer Mapping technique based on a Multi-Frequency Bi-focusing (MF-BF) operator with good imaging properties is applied to the characterization of the 60GHz channel in a realistic indoor scenario. The proposed real indoor scenario (RIS) is that of an office (RIS-Office- Table) consisting on a rectangular office with a central table, wall covering furniture and two different obstacles (RIS- Office-Laptop and RIS-Office-Wall) separating a Tx and Rx located at both ends of the office as represented in Fig.1. In addition, the effective number of communication channels between the transmitter and the receiver is also extracted by following traditional methods [3] for the characterization of MIMO communication channels. The relation between the two characterization methods is illustrated. The remainder of the paper is organized as follows. In section II the Scatterer Mapping Technique is presented. Section III provides a description of the measurement system. Section IV presents mapping results of canonical objects at 10GHz and 60GHz for imaging friendly scenarios. The effective number of communication channels for such scenarios is also computed. A relation between both is established. Results for the RIS-Office scenarios are also presented here. Section V is devoted to conclusions. Fig. 1: 60GHz Channel Characterization Geometry. II. 2D SCATTERER MAPPING TECHNIQUE The general idea for the Scatterer Mapping technique consists on distributing a certain number of microwave T x R x Obstacle