The research reported in this document/presentation was performed in connection with Contract No. W911NF-04-C-0025 with DARPA and the U.S. Army Research Laboratory. The views and conclusions contained in this document/presentations are those of the authors and should not be interpreted as presenting the official policies or position, either expresses or implied, of the U.S. Government unless so designated by other authorized documents. Citation of manufacturer's or trade names does not constitute an official endorsement or approval of the use thereof. The U.S. Government is authorized to reproduce and distribute reprints for Government purpose not withstanding any copyright notation hereon. Spatial and polarization characterization of MIMO channels in rural environment Dmitry Chizhik, Jonathan Ling, Dragan Samardzija and Reinaldo A.Valenzuela Lucent Bell Laboratories, Crawford Hill, Holmdel NJ 1 Introduction Use of MIMO communication techniques is of particular interest for peer to peer communications, where the nodes are often placed in highly scattering environments. Past measurements have found that large MIMO capacities are supported in urban environments [2], [3]. To demonstrate a real-time, mobile, networked MIMO system in a realistic tactical environment, the Defense Advanced Research Projects Agency (DARPA) has instituted a program called Mobile Network MIMO (MNM) [1]. The first stage of this program is to demonstrate such a system in a rural wooded environment in Lakehurst, NJ using multiple MIMO equipped nodes using an ad hoc network in a bandwidth of up to 25 MHz. Each node is a vehicle with 8 transmit and 10 receive antennas. Some of the key propagation questions addressed here are whether the channels offer enough scattering richness to benefit from MIMO systems in rural environments ranging from densely wooded to open field with large but sparse clutter within Line of Sight. The measurements were conducted at a site in Lakehurst, located in the Pinelands of southern New Jersey. The area shown in Figure 1 is approximately 3.2 km by 4.8 km. Features include several very large hangars around points H,G,V and X, open areas, runways, and mostly single story buildings. The vegetated areas consist primarily of pine trees about 10 m in height. There is some gentle terrain variation, as evident by the 10 foot contour intervals in Figure 1. Capacity enhancement due to polarization is measured. A correlation based spatial channel model is found to result in capacities within 10% of measured ones, with a median error of 3%. 2 Dually polarized MIMO characterization Multi-antenna measurements were conducted at 2.5 GHz using a narrowband 16× 16 sounder used in urban measurements in Manhattan [2]. Here two array Figure 1: Map of Lakehurst, NJ site and MNM demo configuration. arrangements were employed: a vertically polarized array, deploying 16 vertically polarized antennas on both the transmitter and receiver, and a dually polarized array, which had 8 vertically and 8 horizontally polarized antennas at both the transmitter and receiver. The vertically polarized arrays consisted of azimuthally omnidirectional antennas with 8 dBi vertical gain. Both transmit and receive arrays were arranged in a nearly square 4 × 4 grids on the roofs of the vans, with about 20 inches (4 wavelengths) separation between nearest neighbors. A dually polarized array was mounted on both of the measurement vans employing vertically polarized antennas described above and azimuthally omnidirectional horizontally polarized antennas with 9 dBi vertical gain. The sounder reported a 16× 16 H matrix every 3 ms. The vans were driven at 10–20 mph during measurements so as to allow quasi-stationary channel snapshots while collecting statistically diverse H matrix data over longer time records Distribution of measured capacities using only vertically polarized as well as dually polarized arrays are compared in Figure 2. Use of dual polarization is observed