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  • Geographic Routing Algorithm with Location Errors

    Yuanwei JING  Yan WANG  

     
    LETTER-Information Network

      Vol:
    E95-D No:12
      Page(s):
    3092-3096

    Geographic routing uses the geographical location information provided by nodes to make routing decisions. However, the nodes can not obtain accurate location information due to the effect of measurement error. A new routing strategy using maximum expected distance and angle (MEDA) algorithm is proposed to improve the performance and promote the successive transmission rate. We firstly introduce the expected distance and angle, and then we employ the principal component analysis to construct the object function for selecting the next hop node. We compare the proposed algorithm with maximum expectation within transmission range (MER) and greedy routing scheme (GRS) algorithms. Simulation results show that the proposed MEDA algorithm outperforms the MER and GRS algorithms with higher successive transmission rate.

  • Fault-Injection Analysis to Estimate SEU Failure in Time by Using Frame-Based Partial Reconfiguration

    Yoshihiro ICHINOMIYA  Tsuyoshi KIMURA  Motoki AMAGASAKI  Morihiro KUGA  Masahiro IIDA  Toshinori SUEYOSHI  

     
    PAPER-High-Level Synthesis and System-Level Design

      Vol:
    E95-A No:12
      Page(s):
    2347-2356

    SRAM-based field programmable gate arrays (FPGAs) are vulnerable to a soft-error induced by radiation. Techniques for designing dependable circuits, such as triple modular redundancy (TMR) with scrubbing, have been studied extensively. However, currently available evaluation techniques that can be used to check the dependability of these circuits are inadequate. Further, their results are restrictive because they do not represent the result in terms of general reliability indicator to decide whether the circuit is dependable. In this paper, we propose an evaluation method that provides results in terms of the realistic failure in time (FIT) by using reconfiguration-based fault-injection analysis. Current fault-injection analyses do not consider fault accumulation, and hence, they are not suitable for evaluating the dependability of a circuit such as a TMR circuit. Therefore, we configure an evaluation system that can handle fault-accumulation by using frame-based partial reconfiguration and the bootstrap method. By using the proposed method, we successfully evaluated a TMR circuit and could discuss the result in terms of realistic FIT data. Our method can evaluate the dependability of an actual system, and help with the tuning and selection in dependable system design.

  • Wireless Network Coding Diversity Technique Based on Hybrid AF/DF Relay Method Employing Adaptive Power Control at Relay Node for Bidirectional Two-Hop Wireless Networks

    Nobuaki OTSUKI  Takatoshi SUGIYAMA  

     
    PAPER-Fundamental Theories for Communications

      Vol:
    E95-B No:12
      Page(s):
    3772-3785

    In this paper, we propose a wireless network coding diversity technique based on hybrid amplify-and-forward/decode-and-forward relay method employing adaptive power control for two-hop wireless networks in order to improve relay node position flexibility. Wireless network coding diversity based on hybrid relay method selects either modulation symbol level wireless network coding diversity or bit sequence level wireless network coding diversity as its wireless network coding diversity scheme according to the cyclic redundancy check result at the relay node. Moreover, the adaptive power control scheme proposed here controls the relay node's transmit power according to its position. Computer simulations verify that wireless network coding diversity based on hybrid relay method employing the adaptive power control scheme can expand the area wherein the relay node can be located while satisfying the required communication quality by 4.56 times compared to the conventional wireless network coding diversity scheme. Therefore, we confirm that our proposed scheme can increase relay node position flexibility.

  • RazorProtector: Maintaining Razor DVS Efficiency in Large IR-Drop Zones by an Adaptive Redundant Data-Path

    Yukihiro SASAGAWA  Jun YAO  Takashi NAKADA  Yasuhiko NAKASHIMA  

     
    PAPER-Logic Synthesis, Test and Verification

      Vol:
    E95-A No:12
      Page(s):
    2319-2329

    Recently, the DVS (Dynamic Voltage Scaling) method has been aggressively applied to processors with Razor Flip-Flops. With Razor FF detecting setup errors, the supply voltage in these processors is down-scaled to a near critical setup timing level for a maximum power consumption reduction. However, the conventional Razor and DVS combinations cannot tolerate well error rate variations caused by IR-drops and environment changes. At the near critical setup timing point, even a small error rate change will result in sharp performance degradation. In this paper, we propose RazorProtector, a DVS application method based on a redundant data-path which uses a multi-cycle redundant calculation to shorten the recovery penalty after a setup error occurrence. A dynamic redundancy-adapting scheme is also given to use effectively the designed redundant data-path based on a study of the program, device and error rate characteristics. Our results show that RazorProtector with the adaptive redundancy architecture can, compared to the traditional DVS method with Razor FF, under a large setup rate caused by a 10% unwanted voltage drop, reduce EDP up to 78% at 100 µs/V, 88% at 200 µs/V voltage scaling slope.

  • Linear Transmitter Precoding Design with Matching Weighted SLNR for Multiuser MIMO Downlink Systems

    Chuiqiang SUN  Jianhua GE  Rong SUN  Xinxin BAO  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E95-B No:12
      Page(s):
    3915-3917

    A multiuser precoding algorithm based on matching weighted signal-to-leakage-and-noise ratio (SLNR) is proposed for multiuser MIMO downlink systems. In the proposed algorithm, the matching weight factor is selected based on the effective channel gain, and the leakage power caused by each user is weighted by the factor. The precoding vector is obtained by maximizing the matching weighted SLNR. Simulation results show the superiority of the proposed scheme in terms of bit error rate over the conventional SLNR schemes.

  • All-Digital Wireless Transceiver with Sub-Sampling Demodulation and Burst-Error Correction

    Sanad BUSHNAQ  Makoto IKEDA  Kunihiro ASADA  

     
    PAPER-Circuit Design

      Vol:
    E95-A No:12
      Page(s):
    2234-2241

    In this paper, an all-digital wireless transceiver for near-field communication (NFC) is presented. A novel modulation technique that allows employing only all-digital components in the transceiver is used. The front-end uses all-digital sub-sampling for carrier demodulation, which does not need synchronization circuitry. Burst-errors generated by the front-end are corrected in baseband using hamming code and interleaving techniques. Experimentally, the all-digital transceiver was tested on FPGAs that performed successful wireless communication at range/diameter equal to 1, which is higher than recent NFC research. Our transceiver uses only all-digital components, and consumes less area compared to other research.

  • Alternative Method for Determining Permeability of a Ferrite Core by Using a Combined Microstrip Line-Coaxial Conductor

    Takanobu AOYAMA  Masafumi KATSUDA  Tomohiko KANIE  Takashi TAKEO  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E95-C No:11
      Page(s):
    1769-1775

    An equivalent network analysis for an arrangement that combines a microstrip line and coaxial conductor for the purpose of measuring permeability is discussed in this paper. The measurement circuit used consists of a coaxial conductor with a sample housed inside and a short microstrip line connected to both sides. The coaxial conductor is composed of an electrically grounded coaxial metal pipe with open ends and a center conductor. Equivalent networks for this arrangement are investigated to determine the complex permeability from the impedance of the measurement circuit. We have employed a π network composed of a resistor and an inductor connected in series, and shunt capacitors as the equivalent circuit for the measurement portion. It has been found that the measurement error ratio of less than a few percent can be obtained for most frequency ranges of 10 MHz to 500 MHz.

  • A New Construction of Permutation Arrays

    Jung Youl PARK  Hong-Yeop SONG  

     
    PAPER-Sequences

      Vol:
    E95-A No:11
      Page(s):
    1855-1861

    Let PA(n, d) be a permutation array (PA) of order n and the minimum distance d. We propose a new construction of the permutation array PA(pm, pm-1k) for a given prime number p, a positive integer k < p and a positive integer m. The resulted array has (|PA(p,k)|p(m-1)(p-k))m rows. Compared to the other constructions, the new construction gives a permutation array of far bigger size with a large minimum distance, for example, when k ≥ 2p/3. Moreover the proposed construction provides an algorithm to find the i-th row of PA (pm, pm-1k) for a given index i very simply.

  • Burst Error Resilient Channel Coding for SVC over Mobile Networks

    GunWoo KIM  Yongwoo CHO  Jihyeok YUN  DougYoung SUH  

     
    LETTER-Multimedia Environment Technology

      Vol:
    E95-A No:11
      Page(s):
    2032-2035

    This paper proposes Burst Error Resilient coding (BRC) technology in mobile broadcasting network. The proposed method utilizes Scalable Video Coding (SVC) and Forward Error Correction (FEC) to overcome service outage due to burst loss in mobile network. The performance evaluation is performed by comparing PSNR of SVC and the proposed method under MBSFN simulation channel. The simulation result shows PSNR of SVC equal error protection (EEP), unequal error protection (UEP) and proposed BRC using Raptor FEC code.

  • Effects of Channel Estimation Error and Interference on BER in the MIMO Zero-Forcing Receiver

    Sang Goo KIM  Dongweon YOON  Janghoon OH  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E95-B No:11
      Page(s):
    3605-3608

    The Multiple-Input Multiple-Output (MIMO) Zero-Forcing (ZF) receiver requires accurate Channel State Information (CSI), which is impacted by channel estimation error, to perform properly. Moreover, interference occurs due to the change of channel coefficients between the channel estimation events in fading channels. Thus, in practice, both channel estimation error and interference greatly influence Bit Error Rate (BER) performance. In this letter, we derive an Signal-to-Interference-and-Noise Ratio (SINR) expression considering both channel estimation error and interference and develop approximate closed-form BER expressions of M-PSK and M-QAM for the MIMO ZF receiver in Nakagami-m fading channels. We then analyze the effects of channel estimation error, interference, and the numbers of transmit and receive antennas.

  • Balanced Switching Schemes for Gradient-Error Compensation in Current-Steering DACs

    Xueqing LI  Qi WEI  Fei QIAO  Huazhong YANG  

     
    PAPER-Electronic Circuits

      Vol:
    E95-C No:11
      Page(s):
    1790-1798

    This paper introduces balanced switching schemes to compensate linear and quadratic gradient errors, in the unary current source array of a current-steering digital-to-analog converter (DAC). A novel algorithm is proposed to avoid the accumulation of gradient errors, yielding much less integral nonlinearities (INLs) than conventional switching schemes. Switching scheme examples with different number of current cells are also exhibited in this paper, including symmetric arrays and non-symmetric arrays in round and square outlines. (a) For symmetric arrays where each cell is divided into two parallel concentric ones, the simulated INL of the proposed round/square switching scheme is less than 25%/40% of conventional switching schemes, respectively. Such improvement is achieved by the cancelation of linear errors and the reduction of accumulated quadratic errors to near the absolute lower bound, using the proposed balanced algorithm. (b) For non-symmetric arrays, i.e. arrays where cells are not divided into parallel ones, linear errors cannot be canceled, and the accumulated INL varies with different quadratic error distribution centers. In this case, the proposed algorithm strictly controls the accumulation of quadratic gradient errors, and different from the algorithm in symmetric arrays, linear errors are also strictly controlled in two orthogonal directions simultaneously. Therefore, the INLs of the proposed non-symmetric switching schemes are less than 64% of conventional switching schemes.

  • No-Reference Quality Estimation for Video-Streaming Services Based on Error-Concealment Effectiveness

    Toru YAMADA  Yoshihiro MIYAMOTO  Takao NISHITANI  

     
    PAPER-Multimedia Environment Technology

      Vol:
    E95-A No:11
      Page(s):
    2007-2014

    This paper proposes a video-quality estimation method based on a no-reference model for realtime quality monitoring in video-streaming services. The proposed method analyzes both bitstream information and decoded pixel information to estimate video-quality degradation by transmission errors. Video quality in terms of a mean squared error (MSE) between degraded video frames and error-free video frames is estimated on the basis of the number of impairment macroblocks in which the quality degradation has not been possible to be concealed. Error-concealment effectiveness is evaluated using motion information and luminance discontinuity at the boundaries of impairment regions. Simulation results show a high correlation (correlation coefficients of 0.93) between the actual MSE and the number of macroblocks in which error concealment has not been effective. These results show that the proposed method works well in reatime quality monitoring for video-streaming services.

  • Performance of Spatial and Temporal Error Concealment Method for 3D DWT Video Coding in Packet Loss Channel

    Hirokazu TANAKA  Sunmi KIM  Takahiro OGAWA  Miki HASEYAMA  

     
    PAPER-Image Processing

      Vol:
    E95-A No:11
      Page(s):
    2015-2022

    A new spatial and temporal error concealment method for three-dimensional discrete wavelet transform (3D DWT) video coding is analyzed. 3D DWT video coding employing dispersive grouping (DG) and two-step error concealment is an efficient method in a packet loss channel [20],[21]. In the two-step error concealment method, the interpolations are only spatially applied however, higher efficiency of the interpolation can be expected by utilizing spatial and temporal similarities. In this paper, we propose an enhanced spatial and temporal error concealment method in order to achieve higher error concealment (EC) performance in packet loss networks. In the temporal error concealment method, structural similarity (SSIM) index is employed for inter group of pictures (GOP) EC and minimum mean square error (MMSE) is used for intra GOP EC. Experimental results show that the proposed method can obtain remarkable performance compared with the conventional methods.

  • Active Learning Using Phone-Error Distribution for Speech Modeling

    Hiroko MURAKAMI  Koichi SHINODA  Sadaoki FURUI  

     
    PAPER-Speech and Hearing

      Vol:
    E95-D No:10
      Page(s):
    2486-2494

    We propose an active learning framework for speech recognition that reduces the amount of data required for acoustic modeling. This framework consists of two steps. We first obtain a phone-error distribution using an acoustic model estimated from transcribed speech data. Then, from a text corpus we select a sentence whose phone-occurrence distribution is close to the phone-error distribution and collect its speech data. We repeat this process to increase the amount of transcribed speech data. We applied this framework to speaker adaptation and acoustic model training. Our evaluation results showed that it significantly reduced the amount of transcribed data while maintaining the same level of accuracy.

  • Channel Modeling and Performance Analysis of Diversity Reception for Implant UWB Wireless Link

    Jingjing SHI  Daisuke ANZAI  Jianqing WANG  

     
    PAPER-Antennas and Propagation

      Vol:
    E95-B No:10
      Page(s):
    3197-3205

    This paper aims at channel modeling and bit error rate (BER) performance improvement with diversity reception for in-body to on-body ultra wideband (UWB) communication for capsule endoscope application. The channel characteristics are firstly extracted from 3.4 to 4.8 GHz by using finite difference time domain (FDTD) simulations incorporated with an anatomical human body model, and then a two-path impulse response channel model is proposed. Based on the two-path channel model, a spatial diversity reception technique is applied to improve the communication performance. Since the received signal power at each receiver location follows a lognormal distribution after summing the two path components, we investigate two methods to approximate the lognormal sum distribution in the combined diversity channel. As a result, the method matching a short Gauss-Hermite approximation of the moment generating function (MGF) of the lognormal sum with that of a lognormal distribution exhibits high accuracy and flexibility. With the derived probability density function (PDF) for the combined diversity signals, the average BER performances for impulse-radio (IR) UWB with non-coherent detection are investigated to clarify the diversity effect by both theoretical analysis and computer simulation. The results realize an improvement around 10 dB on Eb/No at BER of 10-3 for two-branch diversity reception.

  • Cumulative Differential Nonlinearity Testing of ADCs

    Hungkai CHEN  Yingchieh HO  Chauchin SU  

     
    PAPER-Measurement Technology

      Vol:
    E95-A No:10
      Page(s):
    1768-1775

    This paper proposes a cumulative DNL (CDNL) test methodology for the BIST of ADCs. It analyzes the histogram of the DNL of a predetermined k LSBs distance to determine the DNL and gain error. The advantage of this method over others is that the numbers of required code bins and required samples are significantly reduced. The simulation and measurements of a 12-bit ADC show that the proposed CDNL has an error of less than 5% with only 212 samples, which can only be achieved with 222 samples using the conventional method. It only needs 16 registers to store code bins in this experiment.

  • Multiple-Bit-Upset and Single-Bit-Upset Resilient 8T SRAM Bitcell Layout with Divided Wordline Structure

    Shusuke YOSHIMOTO  Takuro AMASHITA  Shunsuke OKUMURA  Hiroshi KAWAGUCHI  Masahiko YOSHIMOTO  

     
    PAPER-Electronic Circuits

      Vol:
    E95-C No:10
      Page(s):
    1675-1681

    This paper presents a new 8T (8-transistor) SRAM cell layout mitigating multiple-bit upset (MBU) in a divided wordline structure. Because bitlines along unselected columns are not activated, the divided wordline structure eliminates a half-select problem and achieves low-power operation, which is often preferred for low-power/low-voltage applications. However, the conventional 8T SRAM with the divided wordline structure engenders MBUs because all bits in the same word are physically adjoining. Consequently, it is difficult to apply an error correction coding (ECC) technique to it. In this paper, we propose a new 8T cell layout pattern that separates internal latches in SRAM cells using both an n-well and a p-substrate. We saw that a SEU cross section of nMOS is 3.5–4.5 times higher than that of pMOS (SEU: single event upset; a cross section signifies a sensitive area to soft error effects). By using a soft-error simulator, iRoC TFIT, we confirmed that the proposed 8T cell has better neutron-induced MBU tolerance. The simulator includes soft-error measurement data in a commercial 65-nm process. The MBU in the proposed 8T SRAM is improved by 90.70% and the MBU soft error rate (SER) is decreased to 3.46 FIT at 0.9 V when ECC is implemented (FIT: failure in time). Additionally, we conducted Synopsys 3-D TCAD simulation, which indicates that the linear energy transfer (LET) threshold in SEU is also improved by 66% in the proposed 8T SRAM by a common-mode effect.

  • Computing the k-Error Linear Complexity of q-Ary Sequences with Period 2pn

    Zhihua NIU  Zhe LI  Zhixiong CHEN  Tongjiang YAN  

     
    LETTER-Cryptography and Information Security

      Vol:
    E95-A No:9
      Page(s):
    1637-1641

    The linear complexity and its stability of periodic sequences are of fundamental importance as measure indexes on the security of stream ciphers and the k-error linear complexity reveals the stability of the linear complexity properly. Recently, Zhou designed an algorithm for computing the k-error linear complexity of 2pn periodic sequences over GF(q). In this paper, we develop a genetic algorithm to confirm that one can't get the real k-error linear complexity for some sequenes by the Zhou's algorithm. Analysis indicates that the Zhou's algorithm is unreasonable in some steps. The corrected algorithm is presented. Such algorithm will increase the amount of computation, but is necessary to get the real k-error linear complexity. Here p and q are odd prime, and q is a primitive root (mod p2).

  • Quantization Error-Aware Tomlinson-Harashima Precoding in Multiuser MISO Systems with Limited Feedback

    Yanzhi SUN  Muqing WU  Jianming LIU  Chaoyi ZHANG  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E95-B No:9
      Page(s):
    3015-3018

    In this letter, a quantization error-aware Tomlinson-Harashinma Precoding (THP) is proposed based on the equivalent zero-forcing (ZF) criterion in Multiuser Multiple-Input Single-Output (MU-MISO) systems with limited feedback, where the transmitter has only quantized channel direction information (CDI). This precoding scheme is robust to the channel uncertainties arising from the quantization error and the lack of channel magnitude information (CMI). Our simulation results show that the new THP scheme outperforms the conventional precoding scheme in limited feedback systems with respect to Bit Error Ratio (BER).

  • A Numerical Evaluation of Entanglement Sharing Protocols Using Quantum LDPC CSS Codes

    Masakazu YOSHIDA  Manabu HAGIWARA  Takayuki MIYADERA  Hideki IMAI  

     
    PAPER-Information Theory

      Vol:
    E95-A No:9
      Page(s):
    1561-1569

    Entangled states play crucial roles in quantum information theory and its applied technologies. In various protocols such as quantum teleportation and quantum key distribution, a good entangled state shared by a pair of distant players is indispensable. In this paper, we numerically examine entanglement sharing protocols using quantum LDPC CSS codes. The sum-product decoding method enables us to detect uncorrectable errors, and thus, two protocols, Detection and Resending (DR) protocol and Non-Detection (ND) protocol are considered. In DR protocol, the players abort the protocol and repeat it if they detect the uncorrectable errors, whereas in ND protocol they do not abort the protocol. We show that DR protocol yields smaller error rate than ND protocol. In addition, it is shown that rather high reliability can be achieved by DR protocol with quantum LDPC CSS codes.

301-320hit(1060hit)