Masahiro Motoyoshi

High-speed estimation of MIMO system capacity using a hierarchical approach and preprocessing digital maps

We propose a high-speed and highly-accurate estimation method for area-dependent MIMO system capacity. The proposed method employs a hierarchical approach, in which the evaluation area is divided into two groups based on the contribution of diffracted components estimated by a simple ray-launching method without considering the effect of diffraction, and then appropriate estimation method is applied for each group. The method also employs a novel digital map preprocessing that combines adjacent structured objects with similar heights and treats them as one object, which enabled to reduce the number of objects used in a ray-launching analysis. It has been confirmed that the proposed method calculated 58 times faster than the conventional full ray-launching method, enabling efficient radio planning of upcoming MIMO-based wireless communication systems.

A framework for enterprise SLA in W-CDMA networks

With the increase in cell-phone business communications, SLA-based contracts with cellular network operators assure the consumer of better quality communications. However, todays cellular networks can only differentiate the service quality amongst user groups in emergency situations. This paper presents a mobile SLA framework that provides a service quality guarantee for corporate cellular phone users. We propose a multi-stage dynamic partitioning (MSDP) call admission control scheme to allocate radio resources efficiently amongst the different users and service types. The simulation results demonstrate that MSDP can maintain the service quality at the level required in a typical SLA cycle, and that service is always available for all user types