This paper presents an indoor experiment to verify the battery-less sensor activation via multi-point wireless energy transmission with carrier shift diversity which realizes seamless coverage extension of the sensor activation. The multi-point scheme is employed to overcome path-loss attenuation. The carrier shift diversity has been developed to achieve uniform coverage of power transmission by combating standing-wave problem caused by multi-point transmitters as well as multipath waves, while its effectiveness on activation of battery-less sensors has never been studied in real environments. In this paper, we develop prototype hardware of battery-less sensor and conduct an indoor experiment with the developed sensor node. The experimental results show that the coverage of single-point and simple multi-point wireless energy transmission are limited at 44% and 70% respectively, while that of the proposed multi-point wireless energy transmission with carrier shift diversity achieves 100% to activate the developed sensor node which consumes -4 dBm for a transmission period of 1s.

This paper presents a basic investigation of the power imbalance problem using a dipole array and a handset MIMO model in a browsing situation. Using channel modeling that includes the effects of 3-dimensional angular spectrum and polarization of incident waves, we carried out a Monte Carlo simulation. From the results obtained in this study, estimates of the reduction in channel capacity for different numbers of elements with reduced received power can be made.

In this paper, throughput performance of MIMO-OFDM system in real residential home environment was evaluated by using wideband MIMO channel measurement data. Computer simulations were carried out to compare the performance of MIMO-OFDM systems with various detection methods, i.e. MMSE, VBLAST, QRM-MLD and SVD-MIMO, in addition to that of the SISO-OFDM system. The results showed that the SVD-MIMO transmission can provide the highest average and outage throughput under the assumption of perfect CSI feedback. On the other hand, QRM-MLD yielded the best performance among the systems without CSI available at the transmitter. It was also found that the outage throughput performance of MMSE and VBLAST degrades severely due to the existence of spatial correlation in the real home environment.

An area coverage of 4×4 MIMO-OFDM system was measured in residential home environment at 5GHz band. A novel spatial scanner was fabricated to suit the needs of measurements in environments with household furniture such as beds, sofa and tables. The coverage was calculated based on a total of 55,000 spatial samples in an area of 150m2which includes two rooms, a hallway and living and dining areas. The results shown that the 4×4 MIMO system can greatly increase the area coverage compared to SISO system, especially at high data rate. It was also found that the introduction of optimum power allocation in the MIMO system is effective to increase area boundary with lower data rate.

The process design aid (PDA), a design environment which bridges the gap between design and specification of semiconductor fabrication processes, is presented. The PDA uses a hierarchical process model supporting reuse of well-characterized process fragments; integrates design goals with process and simulation data in a single knowledge base; and provides direct support for the numerical optimization of process parameters and simulator calibration parameters. Details of a hierarchical, object-oriented process representation are discussed. Results of modeling a 0.8- mu m BiCMOS process with the PDA are presented, demonstrating automatic generation of consistent simulation and manufacturing specifications, efficient incremental simulation, and fast, interactive, closed-loop optimization of process parameters.>

In order to analyze short-channel effects of MOS transistor ac characteristics, a two-dimensional device simulator has been used to extract MOS transistor capacitances. The results of simulation and measurements agree well. The causes of short-channel effects have been understood and explained by the simulations. Two-dimensional effects and velocity saturation are the main causes of short-channel effects in MOS transistor capacitances. Two-dimensional simulation was found to be a useful tool for studying mobility models, as well as for obtaining capacitance models for circuit simulation.