This paper aims at developing forward link power control methods for CDMA cellular systems. The purpose is to allocate available power to as many mobiles as possible. When a power allocation in the network is fixed, the power assigned to the cell where rare mobiles communicate is wasting, and moreover, is prohibitive if other cells fall short of transmitting power. In this case, re-allocation is necessary. Power control in this paper takes the form of allocating pilot and traffic power according to the different needs from each cell. Especially, the pilot power control method tends to balance nonuniformly imposed load through the network, and hence helps the network resources be utilized equally. With the proposed pilot control method, the number of simultaneously communicating mobiles increases by 10-25% over the reference methods.

Highly miniaturization technology in front-end GaAs Hybrid IC for mobile communication equipment will be presented. A combination of MBB (micro bump bonding) technology and the new GaAs IC fabrication process using high dielectric constant (εr) thin film technology has achieved a super small HIC with low cost and low power consumption. The new HIC was constructed of only a ceramic substrate in which the spiral inductors were formed on it and the GaAs IC chip that was bonded by using MBB technology. The MBB technology lead the HIC to a lower temperature process without soldering, a smaller bump diameter, at shorter intervals and the lowest parasitic in the bump. The advantage of the small bonding pad of the IC contributes to miniaturize the IC chip and reduces the chip cost. The GaAs IC process technology using high-εr thin film achieves the integration of all capacitors in the IC without increasing the chip size. Furthermore, low power consumption was achieved by 0. 5-µm LDD BP-MESFET with a high k-value. Although capacitors were integrated on the IC, all of the inductors were formed on the top of the ceramic substrate using a thin film metal process. This was used due to its large occupation area when it was integrated on the IC, and produced a low Q-factor. As a results, the chip was minimized to a size of 0. 81. 0 mm2 and achieved a low-cost chip. Two types of HICs were fabricated for 880 MHz cellular band and 1. 9 GHz PHS (Personal Handy phone System) band. The HIC at 880 MHz measures only 5. 05. 01. 0 mm3, and offered a conversion gain of 25 dB, a noise figure of 4. 2 dB and an image rejection ratio of 12 dB at 2. 7 V and at a power supply of 3. 5 mA. The HIC for 1. 9 GHz measures only 3. 54. 01. 0 mm3, and showed a conversion gain of 16. 0 dB, a II P3 of -16. 0 dBm, and an image rejection ratio of over 20 dBc at 3. 0 V and at power supply of 4. 5 mA.

This paper describes new IC design concepts using flip-chip bonding technologies for microwave and millimeter-wave circuit integration. Two types of bonding technologies, stud bump bonding (SBB) and micro bump bonding (MBB) are introduced, and their applications to microwave and millimeter-wave ICs are presented. Receiver front-end hybrid IC (HIC) for cellular and PHS handsets using SBB and new millimeter-wave ICs on Si substrate called millimeter flip-chip IC (MFIC) using MBB have been designed and fabricated to prove their advantages. These flip-chip bonding technologies are experimentally proven to provide excellent solutions for high performance and compact-sized ICs with low-cost. The HIC concept is applicable consistently over a wide range of devices from RF/microwave to millimeter-wave region.

This paper describes new millimeter-wave ICs based on flip-chip bonding using micro bumps on a low cost silicon substrate, named millimeter-wave flip-chip ICs (MFICs). They have significant advantages such as good performance, low cost and excellent flexibility in the active device selection which makes them superior to conventional monolithic microwave integrated circuits (MMICs). In order to demonstrate these advantages, a K-band front-end block for a broadband wireless communication equipment was designed and fabricated. This front-end block consists of four MFIC chips: a low noise amplifier (LNA), a down converter and two medium power amplifiers. These chips are designed to satisfy stable operation conditions using a simplified model derived for micro bump bonding (MBB). In experimental measurements; the LNA using heterojunction field-effect transistors (HFETs) had an 18 dB gain, the down converter using an HFET had a 9. 5 dB conversion loss, and two power amplifiers using heterojunction bipolar transistors (HBTs) had saturated powers of 13. 0 dBm and 11. 7 dBm, respectively. The performance for each of the developed ICs agreed with the designed values, and satisfied circuit requirements. These results show that the MFIC technique is a potential technology for manufacturing multi-functional millimeter-wave ICs.

Practical design procedure of a four-pole dual-mode cavity filter is explained in the details. Coupling matrix M of an elliptic function filter is derived analytically. The effects of septum thickness is studied experimentally. The dimensions of the aperture have to be modified due to the effects. This attempt had made the filter design very elegant, because no complicated calculation is required. A four-pole filter and a multiplexer are designed and constructed experimentally. They show very excellent performances in the 23 GHz band.

This paper describes design approach and power performance of a single 1. 5 V operation two-stage power amplifier MMIC for 2. 4 GHz wireless local area network applications. The MMIC with 0. 760. 96 mm2 area includes SrTiO3 (STO) capacitors with a high capacitance density of 8. 0 fF/µm2 and double-doped AlGaAs/InGaAs/AlGaAs heterojunction FETs with a shallow threshold voltage of -0. 24 V. Utilizing a series STO capacitor and a shunt inductor as an output matching circuit, the total chip size was reduced by 40% as compared with an MMIC utilizing SiNx capacitors. Under single 1.5 V operation, the developed MMIC delivered an output power of 110 mW (20.4 dBm) and a power-added efficiency (PAE) of 36.7% with an associated gain of 20.0 dB at 2.4 GHz. Even operated at a drain bias voltage of 0.8 V, the MMIC exhibited a high PAE of 31.0%.

This paper describes a calculation method of large-signal characteristics of multi-stage power amplifier modules using source-pull and load-pull data. An output power, a power-added efficiency, and a phase deviation of multi-stage power amplifier modules are calculated based on the source-pull and load-pull data, which are comprised of input and output reflection coefficients, an input power, an output power, a phase deviation and a drain voltage and current, taking into account the source and load impedance of each stage FET. Applying this method to a 900 MHz two-stage Si-MOSFET power amplifier module, the calculated and measured results are in good agreement.

Properties of a quarter-wavelength coplanar waveguide resonator such as resonant frequency, external quality factor (Qe) are characterized by a theoretical approach and verified by the experiment. The unloaded quality factor (Q0) of the resonator is also examined experimentally. After new types of combline bandpass filter (BPF) made of these resonators are realized, their transmission and reflection characteristics are examined theoretically and experimentally. A new combline BPF having attenuation poles are also realized. A simple method to produce two-port equivalent circuit of these BPF is presented in this paper. The transmission characteristics including such as the control of attenuation poles of these filters are explained by the created equivalent circuit with the concept of even and odd modes. A new method of describing attenuation poles is established.

This paper describes the evaluation of the Voltage Down Converter (VDC) with low ratio of consuming current to load current in DC/AC operation mode. The stability, response and power consumption are investigated. First, for the stability and response, the VDC can operate in the condition that the bounce of the down voltage (dVDL) is no more than 10% of the setting voltage and the maximum load operation frequency (fmax) is 100 MHz at the average load current 70 mA (the maximum load current 140 mA). Secondly, for the power consumption, by using this VDC technology, the value of IC/IL can be suppressed to 5.1E-4 (IC: total consuming current in VDC, IL: average load current) in the condition that dVDL is no more than 10% of the setting voltage and fmax is 10 MHz at the average load current 70 mA. Thus, it is made clear that the VDC can realize high stability, good response and low power consumption at the same time. This technology is suitable for high performance ULSIs which require large load current and low-power consumption.

This paper is concerned with Wiener-Hopf solutions to the electromagnetic wave scattering by a conducting finite thin plate when the incident wave is not a plane wave. The incident wave is approximated in terms of a piece-wise plane wave on a divided small section of the conducting plate. The final expressions are given in an analytically compact form and the results are accurate as long as the plate width is greater than the wavelength and the divided section is so small that we can expand the incident wave by a piece-wise plane wave. A criterion for the ray tracing method is also proposed.

Access control is a key technology for providing data security in database management systems (DBMSs). Recently, various authorization models for object-oriented databases (OODBs) have been proposed since authorization models for relational databases are insufficient for OODBs because of the characteristics of OODBs, such as class hierarchies, inheritance, and encapsulation. Generally, an authorization is modeled as a set of rights, where a right consists of at least three components s, o, t and means that subject s is authorized to perform operation t on object o. In specifying authorizations implicitly, inference rules are useful for deriving rights along the class hierarchies on subjects, objects, and operations. An access request req=(s,o,t) is permitted if a right corresponding to req is given explicitly or implicitly. In this paper, we define an authorization model independent of any specific database schemas and authorization policies, and also define an authorization specification language which is powerful enough to specify authorization policies proposed in the literature. Furthermore, we propose an efficient access control method for an authorization specified by the proposed language, and evaluate the proposed method by simulation.

This paper describes a complete Mandarin text-to-speech system on time domain. We take advantage of the advancement of memory technology, which achieves ever-increasing capacity and ever-lower price. We try to collect as more as possible the synthesis units in a Mandarin text-to-speech system. With such an effort, we developed simpler speech processing techniques and achieved faster processing speed by using only an ordinary personal computer. We also developed delicate methods to measure the intelligibility, comprehensibility, and naturalness of a Mandarin text-to-speech system. Our system performs very well compared with existing systems. We first develop a set of useful algorithms and methods to deal with some features of the syllables, such as duration, amplitude, fundamental frequency, pause, and so on. Based on these algorithms and methods, we then build a Mandarin text-to-speech system. Given any Chinese text in some computerized form, e. g. , in BIG-5 code representation, our system can pronounce the text in real time. Our text-to-speech system runs on an IBM 80486 compatible PC, with no special hardware for signal processing. The evaluation of our text-to-speech system is based on a proposed subjective evaluation method. An evaluation was made by 51 undergraduate students. The intelligibility of our text-to-speech system is 99. 5%, the comprehensibility of our text-to-speech system is 92. 6%, and the naturalness of our text-to-speech system is 81. 512 points in a percentile grading system (the highest score is 100 points, and the lowest score is 0 point). Other 40 Ph. D. students also did the same evaluation about naturalness. The result shows that the naturalness of our text-to-speech system is 82. 8 points in a percentile grading system.

Machine learning in real-world situations sometimes starts from an initial collection of training instances; learning then proceeds off and on as new training instances come intermittently. The idea of two-phase learning has then been proposed here for effectively solving the learning problems in which training instances come in this two-stage way. Four two-phase learning algorithms based on the learning method PRISM have also been proposed for inducing rules from training instances. These alternatives form a spectrum, showing achievement of the requirement of PRISM (keeping down the number of irrelevant attributes) heavily dependent on the spent computational cost. The suitable alternative, as a trade-off between computational costs and achievement to the requirements, can then be chosen according to the request of the application domains.

The matrix decomposition of transformation associated with the Kronecker product not only provides a thoughtful structure in hardware realization but also bestows a skillful tool for complexity evaluation. Hence, there are several fast algorithms developed to achieve efficient computation of two-dimensional (2-D) discrete cosine transform (DCT) with matrix decomposition techniques. However, we found that their derivations associated with their computation structures were not shown formally. In this paper, we propose formal derivations to remedy their deficiencies to achieve more structural 2-D DCT and inverse DCT (IDCT) algorithms. Furthermore, we also show that the remedied algorithms are with less computational complexity and more regular structure for realization.

A technique for generating the standard EM fields with arbitrary wave impedance at the center of a TEM cell is proposed in this letter. We can realize the experimental system and obtain the measured results to agree well with the calculated results. This technique is useful for the EMS test and the calibration of EM probe because the wave impedance can be easily adjusted only with step attenuator.

In this paper, we apply the Semi-markov Memory and Cache coherence Interference (SMCI) model, which we had proposed for invalidating based cache coherent parallel computers, to an updating based protocol. The model proposed here, the SMCI/Dragon model, can predict performance of cache coherent parallel computers with the Dragon protocol as well as the original SMCI model for the Synapse protocol. Conventional analytic models by stochastic processes to describe parallel computers have the problem of numerical explosion in the number of states necessary as the system size increases. We have already shown that the SMCI model achieved both the small number of states to describe parallel computers with the Synapse protocol and the inexpensive computation cost to predict their performance. In this paper, we demonstrate generality of the SMCI model by applying it to the another cache coherence protocol, Dragon, which has opposite characteristics than Synapse. We show the number of states required by constructing the SMCI/Dragon model is only 21 which is as small as SMCI/Synapse, and the computation cost is also the order of microseconds. Using the SMCI/Dragon model, we investigate several comparative experiments with widely known simulation results. We found that there is only a 5. 4% differences between the simulation and the SMCI/Dragon model.

Field experiments using the 2 GHz carrier frequency band were conducted nearby Tokyo to evaluate the effect of joint use of Rake combining and antenna diversity and also the effect of spreading chip rate (or bandwidth) on the achievable bit error rate (BER) performance and the mobile station transmit power distribution of power controlled coherent DS-CDMA reverse-link (mobile-to-base). Four chip rates, 0. 96, 1. 92, 3. 84, and 7. 68 Mcps, were used. The command interval and power step size of the fast transmission power control (TPC) used in the experiments, 1. 25 ms and 1 dB, respectively, were based on measurements of signal-to-interference plus background noise power ratio (SIR) after Rake combining. The field experiments demonstrate that the joint use of antenna diversity and Rake combining significantly improves the BER performance and, furthermore, that increasing the chip rate improves the BER performance and decreases the transmit power because of enhanced Rake combining through an increase in the number of resolved paths.

The conventional method requires a centerline of a vessel to estimate the vessel diameter. Two methods of estimating the centerline of vessels have been reported: One is to manually define the centerline of the vessel. This potentially contributes to inter- and intra-observer variability. The orientation of the centerline has an effect on the diameter function since diameters are computed perpendicular to the centerline. And the other is to automatically detect the centerline of the vessel. But this is a very complicated method. In this paper, we propose a new method of estimating vessel diameter using direction codes without detecting centerline. Since this method detects the vessel boundary and direction code at the same time, it simplifies the procedure and reduces execution time in estimating the vessel diameter. Compared to a method that automatically estimates the vessel diameter using centerline, a proposed method provides an improved accuracy in image with poor contrast, branching or obstructed vessels. Also, this provides a good compression of boundary description. Our experiments demonstrate the usefulness of the technique using direction code for quantitative angiography. Experimental results justify the validity of the proposed method.

This paper demonstrates a polyimide/alumina-ceramic multilayer MIC analog phase shifter with a large phase shift. First, a novel active inductor, similar to the previously reported active inductor but with a shunt variable resistor inserted in the feedback loop, is proposed for miniaturizing the circuit. The chip size of the fabricated GaAs MESFET active inductor is less than 0. 52 mm2. Next, a low-loss analog phase shifter with a large phase shift is presented. This is constructed in an MIC structure with the active inductors, the varactor diodes and the low-loss polyimide/alumina-ceramic multilayer broad-side coupler. Furthermore, since the amount of the phase shift is the sum of the two individual tuning ranges attributed to the active inductors and varactor diodes, a large phase shift is obtained compared to the case where only the varactor diodes are tunable. Thus, a phase shift of more than 270 within 2-dB insertion loss from 2. 1 to 2. 4 GHz is obtained with the fabricated single-stage reflection-type analog phase shifter. The total power consumption is less than 80 mW.

In this paper, we consider the selection of analysis filters used in the delayless subband adaptive digital filter (SBADF) and propose to use simple analysis filters to reduce the computational complexity. The coefficients of filters are determined using the components of the first order Hadamard matrix. Because coefficients of Hadamard matrix are either 1 or -1, we can analyze signals without multiplication. Moreover, the conditions for convergence of the proposed method is considered. It is shown by computer simulations that the proposed method can converge to the Wiener filter.