This paper presents a novel power estimation method for large and complex LSIs. The proposed method is based on simulation and is used for analyzing the ways in chip-scale gate-level circuits including processors and memory are affected by gated-clock power reduction and the voltage drop due to electrical resistance. The chip-scale power estimation based on simulation patterns generally takes enormous time. In order to reduce the time to obtain accurate estimation results based on simulation patterns, we introduce three approaches: "partitioning of target LSIs and simulation pattern," "memory modeling," and "processor modeling." After placing and routing, the target LSIs are partitioned into hierarchical blocks, memory, and processors. The power consumption of each hierarchical block is calculated by using the partitioned patterns generated from chip-scale simulation patterns. The power consumption of the processor and memory blocks is estimated by a method considering the static power consumption and the rate of LSI activity ratio. Experimental results for a commercial 0.18 µm-technology media processing chip show that the proposed method is 23 times faster than the conventional method without partitioning and that both the results are almost the same.

In this letter, we focus on non-pilot-symbol assisted integer frequency offset estimation for multicarrier orthogonal frequency division multiplexing (OFDM) systems. We introduce a frequency offset estimator that is based on the guard interval (GI) present in OFDM signals. We show by simulation that the frequency offset estimator can accurately estimate the frequency misalignment at the sacrifice of limited estimation range.

The concept of LR(k) validity is represented as an abstract interpretation of a refinement of the derivation semantics of a given grammar. Also the algorithm of LR(k) parsing is represented as an abstract interpretation of the refined semantics. Such representations of LR formalisms provide us with more intuitive and easier means by which to understand LR parsing.

This paper analyzes the steady-state properties of a CORDIC-based adaptive ARMA lattice filter. In our previous study, the convergence properties of the filter in the non-steady state were clarified; however, its behavior in the steady state was not discussed. Therefore, we develop a distinct analysis technique based on a Markov chain in order to investigate the steady-state properties of the filter. By using the proposed technique, the relationship between step size and coefficient estimation error is revealed.

This letter proves the finish time predictability of EDZL (Earliest Deadline Zero Laxity) scheduling algorithm for multiprocessor real-time systems, which is a variant of EDF. Based on the results, it also shows that EDZL can successfully schedule any periodic task set if its total utilization is not greater than (m+1)/2, where m is the number of processors.

This paper presents a hardware-efficient folding technique for high-order FIR filtering while considering the tradeoff between the number of processing elements and throughput rate. Given the throughput rate, one can always employ the minimum number of processing elements for saving the implementation cost and figure out a folded architecture. However, applying inefficient folding techniques may result in costly switches and registers. Therefore, our work intends to evaluate the efficiency for folding techniques in terms of the number of registers, and the power dissipation of registers. As shown in the estimation results, while comparing with the published folded architectures under the same throughput rate, the proposed folding technique can turn out less power dissipation and low hardware complexity than the others. The proposed design has been implemented using TSMC 0.18 µm 1P6M technology. As seen in the post-layout simulation, our design can meet the requirement of IS-95 WCDMA pulse shaping FIR filter while the power consumption can be as low as 16.66 mW.

This paper proposes a method to determine a single frequency for interconnect RL extraction. Resistance and inductance of interconnects depend on frequency, and hence the extraction frequency strongly affects the modeling accuracy of interconnects. The proposed method determines an extraction frequency based on the transfer characteristic of interconnects. By choosing the frequency where the transfer characteristic becomes maximum, the extracted RL values achieve the accurate modeling of the waveform. Experimental results show that the proposed method provides accurate transition waveforms over various interconnect topologies.

3G must offer high data rates since it should support real-time multimedia services; one performance enhancement, the use of the OVSF code tree, has adopted in 3G WCDMA networks. Unfortunately, this technique allows the link capacity to be set at the base rate times powers of two. This results in wasting bandwidth while the required rate is not powers of two of the basic rate. Several multi-code assignment mechanisms have been proposed to reduce the waste rate, but incur some drawbacks, including high complexity of handling multiple codes and increasing cost of using more rake combiners. Our solution is a dynamic grouping code assignment that allows any rate to be achieved with a single code for any possible rate of traffic. The dynamic grouping approach first forms several calls into a group. It then allocates a subtree to the group and dynamically shares the subtree codes based on time-sharing of slots within a group cycle time. The waste rate and code blocking is thus reduced significantly. Since transmission delay and jitter may occur in such a time-sharing approach, two schemes of cycle interleaving are proposed to minimize delay and jitter. Numerical results demonstrate that the proposed approach reduces the waste rate and increases the system utilization obviously, and the proposed cycle interleaving schemes minimizes delay and jitter significantly.

This paper presents a family of rate-one quasi-orthogonal space-time block codes (QO-STBCs) for any number of transmit antennas. Full diversity of the proposed QO-STBCs is achieved via the use of constellation rotation. When the number of transmit antennas is even, these codes are delay "optimal." This property along with the quasi-orthogonality one allows the codes to have low decoding complexity. Besides, by applying lookup tables into the detection methods presented in [1] and generalizing them, two low-complexity maximum-likelihood (ML) decoders for the proposed QO-STBCs and for other existing QO-STBCs, called PMLD and QMLD, are obtained. Simulation results are provided to verify the bit error rate (BER) performances and complexities of both the proposed QO-STBCs and the proposed decoders.

We succeeded to fabricate p-n heterojunction and bulkheterojunction small-molecular-weight organic thin-film solar cells by combination of dry (p-type = zinc phthalocyanine, n-type = fullerene) and wet (p-type = tetra-tert-butyl zinc phthalocyanine, n-type = [6,6]-phenyl-C61-buteric acid methyl ester) processes. Relationship between morphologies of semiconducting layers and photovoltaic properties was investigated. The p-n heterojunction organic thin-film solar cells based on dry process, where surface roughness was approximately 2 nm, showed the highest power conversion efficiency of 1.3% in this paper.

To make the best use of the known characteristics of the alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method such as unconditional stability and modeling accuracy, an efficient time domain solution with variable time-step size is proposed. Numerical results show that a time-step size for a given mesh size can be increased preserving a desired numerical accuracy over frequencies of interest.

The selection of motion vectors plays an important role in the error propagation process between inter-frames. In this letter, an end-to-end prediction error calculation method is proposed and is used for the rate-distortion optimized selection of motion vectors. Simulation results show that the robustness of encoded video streams under error-prone environment is improved.

This paper considers the optimal generator matrices of a given binary cyclic code over a binary symmetric channel with crossover probability p→0 when the goal is to minimize the probability of an information bit error. A given code has many encoder realizations and the information bit error probability is a function of this realization. Our goal here is to seek the optimal realization of encoding functions by taking advantage of the structure of the codes, and to derive the probability of information bit error when possible. We derive some sufficient conditions for a binary cyclic code to have systematic optimal generator matrices under bounded distance decoding and determine many cyclic codes with such properties. We also present some binary cyclic codes whose optimal generator matrices are non-systematic under complete decoding.

Frequency-variation method (FVM), reported in [1], was further studied for simultaneously measuring the both complex permittivity and complex permeability by intentionally changing the test frequency to obtain different reflections. An enhanced coaxial-probe-based in-situ measurement system has been established. The spectral domain full-wave model is derived to take place of the quasi-static one. A novel coaxial probe is designed so that the one-port calibration could be performed with Agilent-supplied precise cal-kit instead of the liquid standard. Criterions for a right order of the interpolation polynomial used to approximate the frequency-dependent EM parameters; measures to reduce the residual mismatch errors and random error in reflection measurements and to suppress the ambiguities in solving the transcendent equation system were experimentally studied to resolve the problems and improve the accuracy in dispersive absorbing materials' test. Several typical dispersive absorbing coatings have been tested via FVM. The good comparison between the measured results and reference ones validate the feasibility of the proposed improved technique.

A new approach to low-complexity rate allocation scheme in closed loop MIMO-OFDM system is proposed. The new scheme utilizes ordered statistics of channel matrix's singular values to simplify the ideal scheme which uses water filling in both frequency and space domain. Unlike the conventional simplified algorithm called FFC [1] ("frequency flat constraint"), the proposed scheme has no restrictions of the numbers of antennas. The improvement of SNR gain with this new scheme is about 0.8 dB in 2-antenna systems with a little more complexity than FFC.

This paper describes the experimental performance of eigenbeam multi-input multi-output with orthogonal frequency division multiplexing (MIMO-OFDM) systems as measured in a testbed implemented with field programmable gate arrays (FPGAs). The FPGA-testbed, characterized by the software-defined radio (SDR) technique, offers 1/5-scale real time signal processing. Extensive experiments on the testbed confirm the basic operation and performance of eigenbeam MIMO-OFDM with quadrature phase-shift keying (QPSK) and 16 quadrature amplitude modulation (QAM). From the packet error rate (PER) performance, we confirm that the eigenbeam 16QAM/MIMO-OFDM scheme with permutation matrix and three transmit antennas (Mt=3) drastically improves the required carrier-to-noise power ratio (CNR) by approximately 5.6 dB over the scheme without eigenbeam with Mt=2. Furthermore, to determine the impact of Doppler frequency fd, we focus on the transmission interval between the MIMO channel estimation and data transmission. To suppress the required CNR degradation to within 1.5 dB, it is found that the eigenbeam 16QAM/MIMO-OFDM scheme with permutation matrix and Mt=3 permits a transmission interval of approximately 68.5 ms when fd=1 Hz for a 1/5-scale model.

A nonlinear optical fiber loop mirror (NOLM) adapted for all-optical 2R operation at ultrahigh bit-rates was experimentally and theoretically investigated. The proposed NOLM was created by adding inline/external fiber polarizers and also an inline optical phase-bias compensator (OPBC) to a standard NOLM. A theoretical investigation revealed that the operation of the standard NOLM became unstable due to residual polarization crosstalk of the polarization-maintaining optical components making up the NOLM, and that it could be dramatically improved with the inline/external polarizers. The NOLM with the polarizers ensured stable switching operation with high switching-dynamic-range (>30 dB) against the change of the wavelength of the input clock pulses, and the change of the environment temperature. We also experimentally verified that the OPBC played a dramatic role to ensure excellent dynamic switching performance of the NOLM, and to achieve signal-Q-recovery of the regenerated signals. All optical 2R experiments at 40 Gb/s and 160 Gb/s were performed with the modified NOLM. Signal regeneration with improved extinction ratio and signal Q value was successfully demonstrated. Q-recovery to the input of the control pulses degraded with ASE noise accumulation was also successfully achieved.

In the design of an active integrated antenna, it is necessary to analyze problems such as unwanted emissions or mutual coupling between elements. In this paper, we clarify the problems in implementing S-parameters for an FDTD analysis. Cubic spline interpolation is suitable for the construction of the S-parameter data. The implementation methods of terminal resistors and vias are examined. The proposed FDTD analysis becomes stable after correcting the discrete time lag in the formation of the incident wave. The validity of the proposed method is verified in its application to the low pass filter and the frequency tunable band pass filter.

We demonstrate single electron counting on an alkanethiol-protected Au nanodot in a double-barrier tunneling structure by noncontact atomic-force spectroscopy (nc-AFS). The Coulomb step width dependence on the Au nanodot diameter is observed. Evaluation of fractional charge Q0 and contact potential difference by nc-AFS reveals a Vd-independent voltage shift due to Q0.

Set Partitioning in Hierarchical Trees (SPIHT) is a highly efficient technique for compressing Discrete Wavelet Transform (DWT) decomposed images. Though its compression efficiency is a little less famous than Embedded Block Coding with Optimized Truncation (EBCOT) adopted by JPEG2000, SPIHT has a straight forward coding procedure and requires no tables. These make SPIHT a more appropriate algorithm for lower cost hardware implementation. In this paper, a modified SPIHT algorithm is presented. The modifications include a simplification of coefficient scanning process, a 1-D addressing method instead of the original 2-D arrangement of wavelet coefficients, and a fixed memory allocation for the data lists instead of a dynamic allocation approach required in the original SPIHT. Although the distortion is slightly increased, it facilitates an extremely fast throughput and easier hardware implementation. The VLSI implementation demonstrates that the proposed design can encode a CIF (352288) 4:2:0 image sequence with at least 30 frames per second at 100-MHz working frequency.