To support the development of high-capacity airto-ground links for range extension, measurements of the lowaltitude air-to-ground channel were made at 915 MHz. Two transmit antennas were mounted on a UAV, which was flown in loops at an altitude of approximately 200 m above ground level. The received signals were recorded at each of eight antenna elements mounted on a van, at locations outside and inside the flight loop. Analysis of the measurements shows that there are regions where the spatial diversity is significant, despite the sparse multipath environment, indicating spatial decorrelation at both the ground and air terminals. The variations in spatial correlation across the receiver array indicate the presence of nonplanar wavefronts produced by the signals' interaction with objects in the array near-field, in particular, the measurement vehicle. A similar effect is probable at the UAV, and it is expected that more significant near-field effects would arise on a more conventional air platform. These support significant reductions in outage probability at both receiver locations: with appropriate signalling strategies, an airborne platform could provide a viable relay or broadcast node for high capacity communications using MIMO.

Exploiting the full spatial diversity available in mobile wireless channels is most effective when some information about the channel is available at the transmitter. In many practical applications, such information is rapidly outdated and has limited realizable benefits. This note investigates the feasibility of linear fading prediction, applied to noisy channel estimates. The predictions are then used for antenna subset selection for space-time block coding. It is shown, using synthesized and measured channel data, that multidimensional prediction from short channel snapshots is unreliable for dense scattering channels. However, the use of parallel predictors can provide a significant increase in the diversity, and hence performance, achievable with antenna subset selection relative to outdated or no channel information at the transmitter.

This study documents a low incidence of both acute and RUTIs in the female population undergoing MUS operations. These results support the current recommendations for perioperative prophylactic antibiotics for anti-incontinence procedures.

Measured channel data are used to analyze the throughput of V-BLAST systems with transmit selection based on limited feedback from the receiver. The achievable throughput is found to be very dependent on the channel conditions in particular its spatial diversity, which may vary significantly with location indicating the need for adaptivity. The rate at which the subsets must be updated is also investigated and related to the differing channel conditions.

In this paper we describe a series of urban measurements designed to characterize the MIMO channel when antenna arrays with dual-polarized elements are placed on the sides of the mobile receiver. It is seen that the received signal power is highly dependent on the physical environment local to the receiver and on the position of the vehicular mounted array elements relative to the transmitter. These factors, combined with the channel's propagation characteristics, result in a spatial power imbalance across the arrays as well as cross polarization discrimination (XPD). When the spatial array power imbalance (API) exceeds the XPD polarization diversity can be exploited to improve the system performance. However, when the XPD is greater than the API spatial diversity results in improved performance.