Yosuke Sugita

Empirical Time-Spatial Propagation formula for outdoor LOS environments

In order to accurately evaluate spatial processing techniques such as MIMO for wideband mobile communications, a Time-Spatial Propagation (TSP) model that can simulate the characteristics of both the delay profile and the spatial arrival angular profile for travelling waves at the same time is required. We proposed the TSP model for wideband mobile communication systems using UHF and SHF bands in Non-line of sight (NLOS) environments. Based on field measurement data, this paper extends the TSP model for NLOS environments to create an empirical TSP model for Line of Sight (LOS) environments.

Arrival Angular Profile Modeling at Mobile Station for Outdoor NLOS and LOS Environments

Spatial processing techniques such as Adaptive Array Antenna (AAA) and Multi-Input-Multi-Output (MIMO) are being considered for use in next generation mobile cellular systems. In order to accurately estimate the performance of these spatial processing techniques in wide-band mobile communications, we need an arrival angular profile model at both the base station (BS) and the mobile station (MS). We proposed empirical arrival angular profile model at both the BS and the MS in Non-line of sight (NLOS) environments. Further, we proposed an empirical arrival angular profile model at the BS in Line of Sight (LOS) environments. To complete the arrival angular profile model at the MS, we need to cover LOS environments. Based on field measurement data, this paper extends the arrival angular profile model at the MS in NLOS environments to create a variant that also covers LOS environments. The extended model can predict the arrival angular profile at the MS in both LOS and NLOS environments.

Delay Profile Model for Low Antenna Height Base Stations in Broadband Mobile Communication

Small cells such as micro and pico cells, whose BS antennas are lower than neighboring buildings, are being installed to suppress co-channel interference. Thus a time spatial propagation (TSP) model that predicts, at the same time, the delay profile and spatial arrival angular profile characteristics of the traveling waves for low- antenna-height BSs, is strongly required. This paper proposes an empirical delay profile prediction formula for low-antenna-height BSs that takes account of BS antenna height, distance from BS and city structure.

Carrier Frequency Characteristic of Time-Spatial Profile in Outdoor LOS Environments

In order to evaluate spatial processing techniques such as MIMO for wideband mobile communications, a Time-Spatial Propagation (TSP) model is required. The Time-Spatial profile consists of the delay profile, the spatial arrival angular profiles at the base station (BS) and the mobile station (MS) for traveling waves. One key parameter of the TSP model is carrier frequency. We have proposed a Time-Spatial profile prediction formula for wideband mobile communication systems in Non-line of sight (NLOS) environments and clarified that the Time-Spatial profile does not depend on the carrier frequency. We have also carried out measurements to develop the Time-Spatial profile prediction formula for Line of sight (LOS) environments. In this paper, we evaluate the carrier frequency characteristics of the Time-Spatial profile in Line of sight (LOS) environments based on the measurement data, and show that our proposed Time-Spatial profile prediction formula in LOS environments is valid for various carrier frequencies.