A power and spreading gain allocation strategy is considered for effectively providing data services for mobile users with different levels of priorities in a DS-CDMA system supporting real-time and non-real-time services. Specifically, the uplink in the DS-CDMA system is considered subject to a constraint on total power received at the base station caused by non-real-time data services. The constraint is imposed to meet QoS requirements of real-time services. The priority level of a data user is specified by the weighting factor assigned to the data throughput of the user. Our strategy implements a relative prioritization that affords a trade-off between spectral efficiency and strict prioritization.

A clock and data recovery (CDR) circuit using a new half-rate wide-range phase detection technique has been developed. Unlike the conventional three-state phase detectors, the proposed detector is applicable to the Non-Return-to-Zero (NRZ) data stream and also has low jitter and wide capture range characteristics. The CDR circuit was implemented in a 0.35-µm N-well CMOS technique. Experimental results demonstrate that it can achieve the peak-to-peak jitter of the recovered clock and the retimed data about 120 ps and 170 ps, respectively, while operating at the input data rate of 1 Gb/s. The total power dissipation of the CDR is 64.8 mW for the supply 3 V.

The delay characteristics of the MPsLS, a data forwarding scheme used for a core area of the integrated data service network, are discussed and analyzed. MPsLS has the capability of guaranteeing QoS on the per-flow level for time-sensitive applications and simultaneously maintaining the high utilization of network resources. In the MPsLS core area, the forwarding process is implemented with a fine-grain slot synchronization model, and at the ingress edge nodes, the forwarding process is carried with a coarse-grain frame synchronization model. The delay analyses are done according to three service models: the exact synchronization model, the less strict synchronization model for the appointed channels, and an asynchronous model for the filler channels. The authors give estimation equations of mean delay between edge-to-edge nodes in an MPsLS network, and introduce an effective method to determine the reserved bandwidth for given application flows based on numerical calculations from those theory analysis and simple simulation results.

This paper studies the problem of the relations between existence conditions of common quadratic and those of common infinity-norm Lyapunov functions for sets of discrete-time linear time-invariant (LTI) systems. Based on the equivalence between the robust stability of a class of time-varying systems and the existence of a common infinity-norm Lyapunov function for the corresponding set of LTI systems, the relations are determined. It turns out that although the relation is an equivalent one for single stable systems, the existence condition of common infinity-norm type is strictly implied by that of common quadratic type for the set of systems. Several existence conditions of a common infinity-norm Lyapunov functions are also presented for the purpose of easy checking.

In this paper, the performance of Tree-LDPC code [1] is presented based on the min-sum algorithm with scaling and the asymptotic performance in the water fall region is shown by density evolution. We presents that the Tree-LDPC code show a significant performance gain by scaling with the optimal scaling factor [3] which is obtained by density evolution methods. We also show that the performance of min-sum with scaling is as good as the performance of sum-product while the decoding complexity of min-sum algorithm is much lower than that of sum-product algorithm.

In this paper, we give a denotational semantics of imperative programming languages as a CafeOBJ behavioral specification. Since CafeOBJ is an executable algebraic specification language, not only execution of programs but also semi-automatic verification of programs properties can be done. We first describe an imperative programming language with integer and Boolean types, called IPL. Next we discuss about how to extend IPL, that is, IPL with user-defined types. We give a notion of equivalent programs, which is defined by using the notion of the behavioral equivalence of behavioral specifications. We show a sufficient condition for the equivalence relation of programs, which reduces the task to prove programs to be equivalent.

We describe a layer 3 diversity reception scheme that enhances the transmission characteristics of Ku-band mobile satellite communication systems. This scheme can realize high-speed communication for vehicles that experience shadowing caused by terrestrial obstacles such as tunnels, buildings and bridges, especially for trains that frequently experience shadowing from the trolley wire structures. Layer 3 diversity was chosen for long distance diversity to prevent signal shadowing caused by terrestrial obstacles while minimizing the alterations of existing receivers. The technology enables high-speed communication under shadowing conditions in a running train environment.

This paper proposes a multiple-input multiple-output (MIMO) eigenmode transmission technique which transmits different data streams on eigenmodes of different multi-path components while suppressing intra and inter-eigenmode interferences by means of a turbo equalization technique. This paper also evaluates the effectiveness of the proposed system in frequency selective fading conditions. Computer simulation results confirms the proposed technique is effective even in high spatial correlation cases.

Our investigation is presented into analysis of the co-channel interference (CCI) statistic in orthogonal frequency-division multiple access (OFDMA) uplink systems. The derived statistic is then used to analyze the performance of reuse partitioning (RP)-based dynamic channel allocation (DCA). Analysis and simulation results show that the performance of DCA in multi-cell environments is noticeably dependent on the CCI. Finally, the results of the analysis yield the optimum RP area for achieving the maximum spectral efficiency.

A compact on-chip signal monitor circuit uses voltage mode sensing by a source follower circuit with small input device geometry, followed by a current-mode sample and a hold circuit that is connected to a shared current output bus. A prototype signal monitor circuit demonstrated a 1.1-GHz effective bandwidth for 1.0-V full-swing digital signals in a 90-nm CMOS technology, where the monitor used 2.5-V I/O CMOS transistors and occupied a 30 µm120 µm silicon area. We also showed that such signal monitor circuits can be tailored to sense of power-supply, ground, as well as full-swing logic signal wirings, and form an array with a single current output. Therefore, an on-chip multi-channel signal monitor enables multiple-points as well as multiple-voltage domain waveform acquisition for the purpose of the in-depth study of digital signal integrity.

Analog-to-Digital converters (ADCs) for video applications have made exciting progress in miniaturization and power reduction in the past 20 years. This paper mainly describes the key technologies for miniaturization and power reduction of 10-bit video-frequency ADCs. By reviewing useful architectures and circuit schemes for video-frequency ADCs, self-calibration techniques and interleaving techniques are surveyed. The subranging pipeline look-ahead ADC architecture is introduced. It has a potential for reducing power consumption and improving conversion rate when minute deep submicron CMOS devices are used with low supply voltage.

This paper presents a novel gain boosted and bandwidth enhanced CMOS Op-Amp based on the well-known folded cascode structure. In contrast with the conventional methods which increase output resistance for gain boosting, the transconductance of the circuit is increased, therefore the -3 dB frequency is the same as for folded cascode structure. With negligible extra power consumption, the unity gain bandwidth is increased considerably. In this method, a new node is created in the circuit which introduces a pole to the transfer function with a frequency lower than cascode pole; feed-forward compensation is employed to reduce the effect of this pole on the frequency response. The input common mode range is limited slightly by 0.2-0.3 V with respect to folded cascode which is insensible. HSPICE simulations using level 49 parameters (BSIM3v3) in a typical 0.35 µm CMOS technology result in three times gain boosting and 60% enhancement in unity gain bandwidth compared to folded cascode, while the power consumption is increased by 10%.

We extend the adaptive-order rational Arnoldi algorithm for multiple-inputs and multiple-outputs (MIMO) interconnect model order reductions. Instead of using the standard Arnoldi algorithm for the SISO adaptive-order reduction algorithm (AORA), we study the adaptive-order rational global Arnoldi (AORGA) algorithm for MIMO model reductions. In this new algorithm, the input matrix is treated as a vector form. A new matrix Krylov subspace, generated by the global Arnoldi algorithm, will be developed by a Frobenius-orthonormal basis. By employing congruence transformation with the matrix Krylov subspace, the one-sided projection method can be used to construct a reduced-order system. It will be shown that the system moment matching can be preserved. In addition, we also show that the transfer matrix residual error of the reduced system can be derived analytically. This error information will provide a guideline for the order selection scheme. The algorithm can also be applied to the classical multiple point MIMO Pade approximation by the rational Arnoldi algorithm for multiple expansion points. Experimental results demonstrate the feasibility and the effectiveness of the proposed method.

The most of conventional information services are based on the implicit premise that the users has already defined their desired information. This study proposes a mobile information service that allows the users who have not yet defined their desired information or whose desired information varies according to the situation to get appropriate information. When the user can specify their desired information to the system explicitly, the authors develop a "Pull" service. Conversely, when the user cannot verbally specify their desired information to the system, this study provides "Push" service and "Don't disturb" option for the user who does not welcome this service. This study considers the characteristics of the environment of mobile terminal to focus on "Time", "Place" and user's "Preference": long term and short term preference. This study also creates rules, algorithms and filtering to the service. Furthermore, the results of experiments have been discussed to verify the idea that different of user desired requires different information services.

Uncertainty within one-wavelength (λ) is inevitable in an ultrasound positioning system that measures the time of flight of ultrasound pulses especially when a simple comparator is used for pulse detection. This paper proposes a compensation scheme based on pulse period adjustment. The test results show that the proposed scheme efficiently eliminates the 1λ-deviation and provides improved distance measurement.

The purpose of the study is to obtain the automatic and optimal matching between a motion-measurement device such as a data glove and an output device such as a dexterous robot hand, where there are many differences in the numbers of degree of freedom, sensor and actuator positions, and data format, by means of motion imitation by the humans. Through the algorithm proposed here, a system engineer or user need no labor of determining the values of gains and parameters to be used. In the system, a subject with data glove imitated the same motion with a dexterous robot hand which was moving according to a certain mathematical function. Autoregressive models were adapted to the matching, where each joint angle in the robot and data glove data of the human were used as object and explanatory variables respectively. The partial regression coefficients were estimated by means of singular value decomposition with a system-noise reduction algorithm utilizing statistical properties. The experimental results showed that the robot hand was controlled with high accuracy with small delay, suggesting that the method proposed in this study is proper and easy way and is adaptive to many other systems between a pair of motion-measurement device and output device.

In this letter, we derive an efficient audio/video synchronization method for video telephony. For synchronization, this method does not require any further RTCP packet processing except for the first one. The derived decision rule is far more compact than the conventional method. This decision rule is incorporated in an actual video telephony system adopting Texas Instruments (TI) OMAP 1510 processor and Qualcomm MSM 5500. The computational requirement was compared with the conventional method and through simulations the superiority of the proposed method is proved.

A low-noise CMOS amplifier operating at a low supply voltage is developed using the two noise reduction techniques of autozeroing and chopper stabilization. The proposed amplifier utilizes a feedback with virtual grounded input-switches and a multiple-output switched op-amp. The low-noise amplifier fabricated in a 0.18-µm CMOS technology achieved 50-nV/Hz input noise at 1-MHz chopping and 0.5-mW power consumption at 1-V supply voltage.

The RC mismatch among S/H stages for time-interleaved ADCs causes a phase error and a gain error and the phase error is dominant. The paper points out that clock skew and the phase error caused by the RC mismatch have similar effects on the sampling error and then can be compensated with the clock skew compensation. Simulation results agree well with the theoretical analysis. With the phase error compensation of RC mismatch, the SNDR in 14b ADC can be improved by more than 15 dB in the case that the bandwidth of S/H circuits is 3 times the sampling frequency. This paper also proposes a method of clock skew and RC mismatch compensation in time-interleaved sample-and-hold (S/H) circuits by sampling clock phase adjusting.

Two schemes for fast identification of JPEG coded images are proposed in this paper. The aim is to identify the JPEG images that are generated from the same original image and have equivalent or different compression ratios. Fast identification can be achieved since the schemes work on the quantized Discrete Cosine Transform (DCT) domain. It is not required to inverse the quantization and the DCT. Moreover, only a few coefficients are commonly required for identification. The first approach can avoid identification leakage or false negative (FN), and probably result in a few false positives (FP). The second approach can avoid both FN and FP, with a slightly higher processing time. By combining the two schemes, a faster and a more perfect identification can be achieved, in which FN and FP can be avoided.