In this paper we study the problem of scheduling parallel program modules onto an MPS (message passing multiprocessor system) so as to minimize the total execution time. Each node in the interconnection network of the MPS has buffers at its input ports to store messages waiting for the transmission. An algorithm for finding a route which minimizes the communication delay of a message to be sent between a processor-pair is first given. Next, we present heuristic algorithms for scheduling program modules onto the MPS. These algorithms use the above routing algorithm. The performances of the proposed algorithms are estimated by using simulation experiments.

User capacity of a DS/CDMA cellular mobile radio system employing transmitter power control (TPC) is investigated. Assuming log-normally distributed control error, outage probability is evaluated through computer simulations. The user capacity is dramatically decreased as the power control error increases. If the standard deviation is larger than about 2dB, the user capacity is decreased by more than 60%. It is shown that power control error with a standard deviation of less than or equal to 0.5dB is required to accommodate 90% of the maximum user capacity. The capacity decrease in the reverse and forward link channels due to non-uniform user distributions are also investigated. It is shown that if system users are densely distributed within the zone fringe whose thickness is 80% of the radius, the reverse link capacity is decreased by about 22%. The forward link capacity is comparatively insenstitive to non-uniform user distribution.

A dual transformation incorporating the frequency-dependent scaling factor with the impedance dimension is proposed to synthesize the current-mode counterpart of a voltage-mode original. A general class of current-mode active-RC biquadratic filters and a switched-capacitor low-pass biquad are derived to demonstrate the synthesis procedure. Their simulation and test results show that the current transfer functions are the same as the voltage transfer functions of the originals, and thus confirm the validity of the procedure. The dual trasformation described herein is general in that with the scaling factor chosen appropriately it can meet a wide variety of circuit transformation, and thus useful also for circuit classification and identification.

This paper treats the synthesis of immittance floatator using nullors. Eight sets of circuit equations for realizing immittance floatators and their nullor (nullator-norator) representations are given. By replacing nullors with active elements such as biporlar junction transistors (BJTs), current conveyors (CCIIs), operational amplifiers (OAs) and operational transconductance amplifiers (OTAs), the immittance floatators can be derived. The development is important because it enables one to convert the present wealth of knowledge concerning grounded immittance simulation networks into floating immittance simulation networks. Using immittance floatators, we can obtain not only the floating form of 1-port but also that of 2-port networks. Novel circuits use solely minus-type norators. Using one-type (minus- or plus-type) norators greatly simplifies the simulation circuit. In the case of an immittance floatator using CCIIs as the active elements, the effects of nonideal CCIIs and sensitivities are given. Many circuits can be systematically derived using nullor technique.

General estimation technique using covariance information is proposed for white Gaussian and white Gaussian plus coloured observation noises in linear stationary stochastic systems. Namely, autocovariance data of signal and coloured noise appear in a semi-degenerate kernel, which represents functional expression of the autocovariance data, in the current technique. Then the signal is estimated by directly using autocovariance data of signal and coloured noise. On the other hand, in the previous technique, the covariance information is expressed in the form of a semi-degenerate kernel, but its elements do not include any autocovariance data.

The F-matrix expressions of inverted-L-type four-terminal networks, each involving an element with the power-law conductivity σ(ω)ωa (0a1) connected to a resistance R, an inductance L or a capacitance C, were derived using the standard procedures of Laplace transformation, indicating that the exponents of the complex angular frequency s, so far limited to the integers for the transmission circuits with finite elements, can be extended to the real numbers. The responses to a step voltage calculated show hysteretic behavior reflecting the resistance-capacitance ambivalent nature of the power-law conductivity.

This paper discusses and evaluates, from the viewpoints of definition, analysis, and performance, frequency assignment schemes that enable the efficient assignment of multiple-bandwidth carriers on the transponder in SCPC/FDMA systems with demand assignment operation. The system considered handles carriers of two different bandwidths, and assigns only consecutive slots on the transponder band to broadband carriers. Three types of frequency assignment schemes are proposed, each of which incorporates one or both of two assignment concepts: (1) pre-establishment of assignment priorities on the transponder band, and (2) establishment of broadband slots to guide broadband carrier assignment. Following a definition of the schemes, equations are derived to theoretically analyze performance factors such as call loss for the narrowband and broadband carriers, and system utilization efficiency. Finally, theoretical performance calculated for various traffic and system conditions are presented and evaluated, for the purpose of comparison between the three schemes. Computer simulation results are also presented, to demonstrate the accuracy of the derived equations and to supply data for models too large for theoretical computation. Main results obtained are as follows. (1) Regardless of traffic or system conditions, the assignment scheme incorporating both assignment priorities and broadband slots shows the best performance in terms of broadband call loss and system utilization efficiency. (2) The establishment of broadband slots improves performance when the ratio of broadband traffic to the total traffic volume is high, but worsens performance when the narrowband traffic ratio is higher. (3) All aspects of performance improve with the increase of the total number of assignable slots on the transponder band.

This paper analyzes the performance of the capacity controlled digital radio system, which controls the number of modulation levels according to the amount of traffic. These analyses are performed under thermal noise and co-channel interference. As a result, the throughput improvement is approximately 16 times comparing with the fixed capacity system which has the designed outage probability of 0.1%. Theoretical results are applied to the future mobile communication system which utilizes TDMA access method or burst co-dec, and it is found that the reuse distance can be improved to 1/5 times when the designed outage probability is 0.1%.

Noise characteristics of InAlAs/InGaAs HEMT's passivated by SiN are investigated to ascertain their suitability for practical applications in circuit such as MMIC's. A 0.18-µm-gate-length device with 125-µm-gate width and 8-gate fingers showed the lowest minimum noise figure of 0.43 dB at 26 GHz with an associated gain of 8.5 dB of any passivated device ever reported. This value is also comparable to the lowest reported minimum noise figure obtained by bare InAlAs/InGaAs HEMT's in spite of increased parasitic capacitances due to the SiN passivation. Thes excellent noise performance was achieved by employing non-alloyed ohmic contact, a T-shaped gate geometry and a multi-finger gate pattern. To reduce the contact resistance of the non-alloyed ohmic contact, a novel n+-InGaAs/n+-InAlAs cap layer was used resulting in a very low contact resistance of 0.09 Ωmm and a low sheet resistance for all layers of 145 Ω/sq. No increase in these resistances was observed after SiN passivation, and a very low source resistance of 0.16 Ωmm was obtained. An analysis of equivalent circuit parameters revealed that the T-shaped gate and multi-finger gate pattern drastically decrease gate resistance.

The optimal coding strategy for signal detection in the correlated gaussian noise is established for the distributed sensors system with essentially zero transmission rate constraint. Specifically, we are able to obtain the same performance as in the situation of no restriction on rate from each sensor terminal to the fusion center. This simple result contrasts with the previous ad hoc studies containing many unnatural assumptions such as the independence of noises contaminating received signal at each sensor. For the design of optimal coder, we can use the classical Levinson-Wiggins-Robinson fast algorithm for block Toeplitz matrix to evaluate the necessary weight vector for the maximum-likelihood detection.

A new Elastic-Block Matching Algorithm using bilinear space warping is proposed. In this scheme a convex quadrilateral, which minimizes a distortion measure against the current square block, is searched to compensate the shape deformation caused by a rigid body's 3 dimensional depth motion or rotation. The proposed algorithm gives a remarkable improvement in motion-compensated prediction compared with the conventional algorithm.

This paper proposes parallel VLSI processors for robotics based on multiple processing elements organized around multiple bus interconnection networks. The advantages of multiple bus interconnection networks are generality, simplicity of implementation and capability of parallel communications between processing elements, therefore it is considered to be suitable for parallel VLSI systems. We also propose the optimal scheduling formulated in an integer programming problem to minimize the delay time of the parallel VLSI processors.

For a realization of a DC-DC converter using no magnetic devices, a new switched capacitor (SC) transformer is introduced, which gives voltage ratios by Fibonacci series corresponding to the stages. This transformer is connected in cascade by each basic block which is assembled by a capacitor and three MOSFET switches. This operates on a simple two-phase clock and has a large step-up or step-down voltage ratio in spite of its simple configuration. The characteristics of this transformer with n stages of basic block are derived and calculated by means of a 4 4 cascade matrix. The optimal arrangement of each stage's capacitances is shown to reduce the SC resistance by about 20%. The simulation results are compared with the characteristics of a prototype transformer with four stages (8 times step-up ratio). Its power efficiency achieves 88% in case of 97 V output voltage, 0.2 A output current, and 100 kHz switching frequency. Lastly, the proposed SC transformer is compared and discussed with other typical SC transformers.

A study on the limitation of optical communication systems has received much attention. A method to overcome the standard quantum limit is to apply non-standard quantum state, especially squeezed state. However, the advantage of the non-standard quantum state is degraded by the transmission energy loss. To cope with this problem, we have proposed a concept of the received quantum state control (RQSC), but the realization has some difficulties. In this paper, we propose a new system to realize the received quantum state control system, employing injection locked laser (ILL) system. Then we show that our new system can overcome the standard quantum limit.

In this letter, introducing a highly accurate model for a real current mode DC-DC converter, an innovative design strategy is proposed in order to optimize circuit behavior in cases in which chaotic effects are present.

An intermediate-frequency-combining (IF-combining) polarization diversity using frequency conversion is proposed. The proposed diversity requires no phase controller as opposed to the conventional IF-combining diversity. It has been theoretically clarified that this diversity has polarization insensitive bit-error-rate (BER) characteristics. The effectiveness has been confirmed by experiments in which the sensitivity dependence on the polarization is suppressed to within 0.8dB and a stable 101km fiber transmission at 600Mbit/s is achieved.

In this paper, voltage-input current-output Membership Function Circuit (MFC) and Normalization Locked Loop (NLL) are proposed. They are useful building blocks for the current-mode analog fuzzy hardware. The voltage-input current-output MFC consists of one source coupled type Operational Transconductance Amplifier (OTA). The MFC is used in the input parts of the analog fuzzy hardware system. The fuzzy hardware system can execute the singleton fuzzy control algorithm. In the algorithm, the weighted average operation is processed. When the weighted average operation is directly realized by analog circuits, a divider must be implemented. Here, the NLL circuit, which can process the weighted average operation without the divider, is implemented using one source coupled type OTA. The proposed circuits were designed by using 2 µm CMOS design rules and its operations were confirmed using SPICE simulations.

Novel, very small-size multilayer MMIC's using miniature microstrip lines on a thin dielectric film, as well as the features of the multilayer structure, are presented. Very narrow-width thin-film transmission lines, meander-like configurations, line crossovers, and vertical connections, which are effective for significant chip-size reduction and flexible layout, are realized and utilized in a 2.5-3 µmN-layer dielectric film structure. 180-degree and 90-degree hybrids and umltiport Wilkinson dividers, which are implemented in small areas of 0.1 mm2 and 1.7 mm2, are presented. Furthermore, layout flexibility in the multilayer structure is demonstrated by implementing distributed amplifiers into the layers.

Recently much attention has been devoted to the problem of translating a set of geometrical objects in a given direction, one at a time, without allowing collisions between the objects. This paper studies the translation problem in three dimensions on a set of c-oriented faces", that is, the faces whose bounding edges have a constant number c of orientations. We solve the problem in O(N log2 NK) time and O(N log N) space, where N is the total number of edges of the faces and K is the number of edge intersections in the projection plane. As an intermediate step, we also solve a problem related to ray-shooting. The algorithm for translating c-oriented faces finds uses in computer graphic systems.

High-speed digital land mobile communications suffer from frequency-selective fading due to a long delay difference. Several techniques have been proposed to overcome the multipath propagation problem. Among them, an adaptive array antenna is suitable for very high-speed transmission because it can suppress the multipath signal of a long delay difference significantly. This paper describes the LMS adaptive array antenna for frequency-selective fading reduction and a new diversity technique. First, we propose a method to generate a reference signal in the LMS adaptive array. At the beginning of communication, we use training codes for the reference signal, which are known at a receiver. After the training period, we use detected codes for the reference signal. We can generate the reference signal modulating a carrier at the receiver by those codes. The carrier is oscillated independently of the incident signal. Then, the carrier frequency of the reference signal is in general different from that of the incident signal. However, the LMS adaptive array works in such a way that the carrier frequency of the array output coincides with that of the reference signal. Namely, the frequency difference does not affect the performance of the LMS adaptive array. Computer simulations show the proper behavior of the LMS adaptive array with the above reference signal generator. Moreover, we present a new multipath diversity technique using the LMS adaptive array. The LMS adaptive array reduces the frequency-selective fading by suppressing the multipath components. This means that the transmitted power is not used sufficiently. We propose a multiple beam antenna with the LMS adaptive array. Each antenna pattern receives one of the multipath components, and we combine them adjusting the timing. Then, we realize the multipath diversity. In addition to the multipath fading reduction, we can improve a signal-to-noise ratio by the diversity technique.