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An Error-Correcting Code-Based Robust Watermarking Scheme for Stereolithographic Files 被引量:1
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作者 Zhuorong Li Huawei Tian +2 位作者 Yanhui Xiao Yunqi Tang Anhong Wang 《Computer Systems Science & Engineering》 SCIE EI 2021年第5期247-263,共17页
Stereolithographic(STL)files have been extensively used in rapid prototyping industries as well as many other fields as watermarking algorithms to secure intellectual property and protect three-dimensional models from... Stereolithographic(STL)files have been extensively used in rapid prototyping industries as well as many other fields as watermarking algorithms to secure intellectual property and protect three-dimensional models from theft.However,to the best of our knowledge,few studies have looked at how watermarking can resist attacks that involve vertex-reordering.Here,we present a lossless and robust watermarking scheme for STL files to protect against vertexreordering attacks.Specifically,we designed a novel error-correcting code(ECC)that can correct the error of any one-bit in a bitstream by inserting several check digits.In addition,ECC is designed to make use of redundant information according to the characteristics of STL files,which introduces further robustness for defense against attacks.No modifications are made to the geometric information of the three-dimensional model,which respects the requirements of a highprecision model.The experimental results show that the proposed watermarking scheme can survive numerous kinds of attack,including rotation,scaling and translation(RST),facet reordering,and vertex-reordering attacks. 展开更多
关键词 Three-dimensional watermarking stereolithographic file robust watermarking error-correcting code
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USING ERROR-CORRECTING ENCODERS TO DESIGN LOCAL-RANDOM SEQUENCE GENERATORS
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作者 杨义先 《Journal of Electronics(China)》 1995年第1期9-14,共6页
This paper proved the statement that a good linear block encoder is in fact a good local-random sequence generator. Furthermore, this statement discovers the deep relationship between the error-correcting coding theor... This paper proved the statement that a good linear block encoder is in fact a good local-random sequence generator. Furthermore, this statement discovers the deep relationship between the error-correcting coding theory and the modern cryptography. 展开更多
关键词 error-correcting coding CRYPTOGRAPHY RANDOM SEQUENCES
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Quantum secret sharing based on quantum error-correcting codes
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作者 张祖荣 刘伟涛 李承祖 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第5期91-95,共5页
Quantum secret sharing(QSS) is a procedure of sharing classical information or quantum information by using quantum states. This paper presents how to use a [2k- 1, 1, k] quantum error-correcting code (QECC) to im... Quantum secret sharing(QSS) is a procedure of sharing classical information or quantum information by using quantum states. This paper presents how to use a [2k- 1, 1, k] quantum error-correcting code (QECC) to implement a quantum (k, 2k-1) threshold scheme. It also takes advantage of classical enhancement of the [2k-1, 1, k] QECC to establish a QSS scheme which can share classical information and quantum information simultaneously. Because information is encoded into QECC, these schemes can prevent intercept-resend attacks and be implemented on some noisy channels. 展开更多
关键词 quantum secret sharing quantum error-correcting code classically enhanced quantumerror-correcting code
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Enhancement of Error-Correction Coding of Spatial Watermarks in Gray Code
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作者 Tadahiko Kimoto 《Journal of Signal and Information Processing》 2013年第1期57-63,共7页
This paper demonstrates how channel coding can improve the robustness of spatial image watermarks against signal distortion caused by lossy data compression such as the JPEG scheme by taking advantage of the propertie... This paper demonstrates how channel coding can improve the robustness of spatial image watermarks against signal distortion caused by lossy data compression such as the JPEG scheme by taking advantage of the properties of Gray code. Two error-correction coding (ECC) schemes are used here: One scheme, referred to as the vertical ECC (VECC), is to encode information bits in a pixel by error-correction coding where the Gray code is used to improve the performance. The other scheme, referred to as the horizontal ECC (HECC), is to encode information bits in an image plane. In watermarking, HECC generates a codeword representing watermark bits, and each bit of the codeword is encoded by VECC. Simple single-error-correcting block codes are used in VECC and HECC. Several experiments of these schemes were conducted on test images. The result demonstrates that the error-correcting performance of HECC just depends on that of VECC, and accordingly, HECC enhances the capability of VECC. Consequently, HECC with appropriate codes can achieve stronger robustness to JPEG—caused distortions than non-channel-coding watermarking schemes. 展开更多
关键词 error-correctION coding GRAY Code Digital WATERMARK SPATIAL Domain JPEG DCT Compression
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Spatial Image Watermarking by Error-Correction Coding in Gray Codes
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作者 Tadahiko Kimoto 《Journal of Signal and Information Processing》 2013年第3期259-273,共15页
In this paper, error-correction coding (ECC) in Gray codes is considered and its performance in the protecting of spatial image watermarks against lossy data compression is demonstrated. For this purpose, the differen... In this paper, error-correction coding (ECC) in Gray codes is considered and its performance in the protecting of spatial image watermarks against lossy data compression is demonstrated. For this purpose, the differences between bit patterns of two Gray codewords are analyzed in detail. On the basis of the properties, a method for encoding watermark bits in the Gray codewords that represent signal levels by a single-error-correcting (SEC) code is developed, which is referred to as the Gray-ECC method in this paper. The two codewords of the SEC code corresponding to respective watermark bits are determined so as to minimize the expected amount of distortion caused by the watermark embedding. The stochastic analyses show that an error-correcting capacity of the Gray-ECC method is superior to that of the ECC in natural binary codes for changes in signal codewords. Experiments of the Gray-ECC method were conducted on 8-bit monochrome images to evaluate both the features of watermarked images and the performance of robustness for image distortion resulting from the JPEG DCT-baseline coding scheme. The results demonstrate that, compared with a conventional averaging-based method, the Gray-ECC method yields watermarked images with less amount of signal distortion and also makes the watermark comparably robust for lossy data compression. 展开更多
关键词 GRAY CODE error-correcting CODE Digital WATERMARK Spatial Domain JPEG DCT-Based Compression
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Soft Decoding Scheme of Convolution Code Combined with Huffman Coding
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作者 郭东亮 陈小蔷 吴乐南 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期208-211,共4页
This paper proposes a modification of the soft output Viterbi decoding algorithm (SOVA) which combines convolution code with Huffman coding. The idea is to extract the bit probability information from the Huffman codi... This paper proposes a modification of the soft output Viterbi decoding algorithm (SOVA) which combines convolution code with Huffman coding. The idea is to extract the bit probability information from the Huffman coding and use it to compute the a priori source information which can be used when the channel environment is bad. The suggested scheme does not require changes on the transmitter side. Compared with separate decoding systems, the gain in signal to noise ratio is about 0 5-1.0 dB with a limi... 展开更多
关键词 soft output Viterbi decoding a priori information Huffman coding convolution code
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A Quantum Error-Correction Circuit Based on Cyclic Code
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作者 Lü Hongjun ZHANG Zhike XIE Guangjun 《Wuhan University Journal of Natural Sciences》 CAS 2013年第5期413-417,共5页
In this paper, the cyclic code of the classic circuit is transformed and transplanted; then, the quantum encoding scheme based on cyclic code and quantum error-correction circuit is constructed. The proposed circuit c... In this paper, the cyclic code of the classic circuit is transformed and transplanted; then, the quantum encoding scheme based on cyclic code and quantum error-correction circuit is constructed. The proposed circuit can correct one-bit error, and the use of redundant bits to encode more than one-bit quantum information breaks the previous limitations of many bits encoding a quantum bit. Compared with the existing coding circuits (Shor code, Steane code and five stable subcode), it shows obvious superiority in the quantum coding efficiency and transmission efficiency. 展开更多
关键词 quantum information quantum error-correction code cyclic code redundant bit
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Improved Soft Cancellation Decoding of Polar Codes
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作者 Mingyue You Zhifeng Ma 《Journal of Beijing Institute of Technology》 EI CAS 2020年第3期386-392,共7页
The soft cancellation decoding of polar codes achieves a better performance than the belief propagation decoding with lower computational time and space complexities.However,because the soft cancellation decoding is b... The soft cancellation decoding of polar codes achieves a better performance than the belief propagation decoding with lower computational time and space complexities.However,because the soft cancellation decoding is based on the successive cancellation decoding,the decoding efficiency and performance with finite-length blocks can be further improved.Exploiting the idea of the successive cancellation list decoding,the soft cancellation decoding can be improved in two aspects:one is by adding branch decoding to the error-prone information bits to increase the accuracy of the soft information,and the other is through using partial iterative decoding to reduce the time and computational complexities.Compared with the original method,the improved soft cancellation decoding makes progress in the error correction performance,increasing the decoding efficiency and reducing the computational complexity,at the cost of a small increase of space complexity. 展开更多
关键词 polar codes soft cancellation decoder soft input soft output iterative decoding
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Efficient practical codebook-precoding MIMO scheme based on signal space diversity 被引量:2
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作者 Zhanji Wu Xiang Gao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第1期1-9,共9页
A novel practical codebook-precoding multiple-input multiple-output(MIMO) system based on signal space diversity(SSD) with the minimum mean squared error(MMSE)receiver is proposed.This scheme utilizes rotation m... A novel practical codebook-precoding multiple-input multiple-output(MIMO) system based on signal space diversity(SSD) with the minimum mean squared error(MMSE)receiver is proposed.This scheme utilizes rotation modulation and space-time-frequency component interleaving.A novel precoding matrix selection criterion to maximize the average signal to interference plus noise ratio(SINR) is also put forward for the proposed scheme,which has a larger average mutual information(AMI).Based on the AMI- maximization criterion,the optimal rotation angles for the proposed system are also investigated.The new scheme can make full use of space-time-frequency diversity and signal space diversity,and exhibit high spectral efficiency and high reliability in fading channels.Simulation results show that the proposed scheme greatly outperforms the conventional bit- interleaved coded modulation(BICM) MIMO-orthogonal frequency division multiplexing(OFDM) scheme without SSD,which is up to4.5 dB signal-to-noise ratio(SNR) gain. 展开更多
关键词 signal space diversity(SSD) average mutual information(AMI) Turbo code multiple-input multiple-output(MIMO) minimum mean squared error(MMSE).
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面向极化编码慢跳频的干扰状态迭代估计及译码算法
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作者 高露琴 吴晓富 +1 位作者 张索非 胡海峰 《电讯技术》 北大核心 2025年第1期103-110,共8页
考虑将循环冗余校验级联极化(Cyclic Redundancy Check Assisted Polar,CA-Polar)码应用于受部分频带干扰的慢跳频通信场景,针对每跳干扰状态未知的挑战,提出了一种基于CA-Polar码软输出解码的迭代干扰状态估计方法。该方法基于广义似然... 考虑将循环冗余校验级联极化(Cyclic Redundancy Check Assisted Polar,CA-Polar)码应用于受部分频带干扰的慢跳频通信场景,针对每跳干扰状态未知的挑战,提出了一种基于CA-Polar码软输出解码的迭代干扰状态估计方法。该方法基于广义似然比(Generalize Ratio Test,GRT)来启动部分频带干扰下的极化解码,然后通过每次迭代译码的可靠度信息来不断提高每一跳干扰状态估计的准确性,基于干扰状态估计更新接收信号的对数似然比(Log-Likelihood Ratio,LLR)并用于CA-Polar码的新一轮迭代译码。仿真结果表明,采用(1024,256+CRC-16)CA-Polar码在块错误率(Block Error Rate,BLER)为1×10^(-4)时,所提出的迭代处理相比于无迭代处理的性能有效提升近2.4 dB;相比于1/2码率的(648,324)LDPC码,同等码率的(512,256+CRC-8)CA-Polar码在相同跳频抗干扰场景下以及BLER为1×10^(-4)时性能增益近0.2 dB。 展开更多
关键词 极化码 慢跳频 脉冲噪声 软输出译码 对数似然比计算
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最小化时变收敛率和节点能耗的功率调度方法
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作者 张豪 闫晶晶 王虎森 《现代电子技术》 北大核心 2025年第10期31-38,共8页
为提高闭环系统的稳定性,并降低传感器节点的能量消耗,针对闭环离散网络化系统,研究以时变收敛率为性能指标的功率优化调度方法。依据网络传输过程的丢包状况和量化输出反馈数据,设计基于状态观测器的控制单元,并设计量化编码策略以实... 为提高闭环系统的稳定性,并降低传感器节点的能量消耗,针对闭环离散网络化系统,研究以时变收敛率为性能指标的功率优化调度方法。依据网络传输过程的丢包状况和量化输出反馈数据,设计基于状态观测器的控制单元,并设计量化编码策略以实现系统在网络带宽约束下的数据传输。同时,从以时变收敛率和节点能耗作为系统性能优化指标的新角度出发,设计功率调度算法,在保证系统均值意义及指数收敛的前提下,最小化给定的性能指标,从而实现提高系统收敛速度和节约能耗的目的。最后,通过实例仿真验证了所提方法的有效性。 展开更多
关键词 功率调度 时变收敛率 节点能耗 量化输出反馈 量化编码 数据丢包
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基于t-SNE和ECOC-ISSA-SVM的变压器故障诊断
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作者 刘蒙 赵晨晓 +4 位作者 朱乔波 李梁 姚旭 李鑫 赵明 《辽宁工程技术大学学报(自然科学版)》 北大核心 2025年第5期606-613,共8页
为解决电力变压器故障诊断中支持向量机(support vector machine,SVM)超参数优化和多分类性能不足的问题,采用t-分布的随机邻居嵌入(t-distributed stochastic neighbor embedding,t-SNE)对26维溶解气体分析(DGA)数据进行非线性降维,引... 为解决电力变压器故障诊断中支持向量机(support vector machine,SVM)超参数优化和多分类性能不足的问题,采用t-分布的随机邻居嵌入(t-distributed stochastic neighbor embedding,t-SNE)对26维溶解气体分析(DGA)数据进行非线性降维,引入纠错输出码(error correction output codes,ECOC),将改进麻雀搜索算法(improved sparrow search algorithm,ISSA)与切比雪夫混沌映射、柯西-高斯变分策略相结合,优化SVM超参数,处理多分类问题。研究结果表明:ECOC-ISSA-SVM(t-SNE)模型的诊断精度、召回率、特异性和F1值分别为95.6%、97.8%、99.6%和97.8%,各项指标较传统模型提升效果显著,诊断时间缩短至11 ms,诊断效率显著提高。研究结论为电力设备智能运维提供技术支持。 展开更多
关键词 故障诊断 变压器 油中溶解气体 支持向量机 麻雀搜索算法 t-SNE降维 纠错输出码
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基于FPGA的Alamouti空时编译码器研究与实现
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作者 黄河 魏志瑾 郑帅 《现代导航》 2025年第2期140-146,共7页
研究了空时编译码算法的原理,提出了基于现场可编程门阵列(FPGA)的Alamouti空时编译码器解决方案,实现了2发2收(2T2R)多输入多输出(MIMO)系统的空时编译码功能,并进行了详细的仿真测试与性能验证。仿真测试结果表明,与传统的1发1收(1T1R... 研究了空时编译码算法的原理,提出了基于现场可编程门阵列(FPGA)的Alamouti空时编译码器解决方案,实现了2发2收(2T2R)多输入多输出(MIMO)系统的空时编译码功能,并进行了详细的仿真测试与性能验证。仿真测试结果表明,与传统的1发1收(1T1R)系统相比,采用空时编译码的2T2R MIMO系统在接收灵敏度性能方面提升了6 dB,验证了解决方案的正确性和有效性。 展开更多
关键词 ALAMOUTI 空时编译码 多输入输出 现场可编程门阵列
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Spatio-temporal evolution of urban innovation structure based on zip code geodatabase: An empirical study from Shanghai and Beijing 被引量:7
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作者 段德忠 杜德斌 +1 位作者 刘承良 Seamus GRIMES 《Journal of Geographical Sciences》 SCIE CSCD 2016年第12期1707-1724,共18页
In today's world, the innovation of science and technology has become the key support for improving comprehensive national strength and changing the mode of social production and lifestyle. The country that posses... In today's world, the innovation of science and technology has become the key support for improving comprehensive national strength and changing the mode of social production and lifestyle. The country that possesses world-class scientific and technological innovation cities maximizes the attraction of global innovation factors and wins a strategic initiative in international competition. Based on the urban zip code geodatabase, an evaluation system of urban innovation with the perspective of innovation outputs, and the spatial evolutionary mode, concerning the structure of innovation space of Shanghai and Beijing from 1991 to 2014, was developed. The results of the research indicated that the zip code geodatabase provided a new perspective for studying the evolving spatial structure of urban innovation. The resulting evaluation of the spatial structure of urban innovation using the urban zip code geodatabase established by connecting random edge points, was relatively effective. The study illustrates the value of this methodology. During the study period, the spatial structure of innovation of Shanghai and Beijing demonstrated many common features: with the increase in urban space units participating in innovation year by year, the overall gap of regional innovation outputs has narrowed, and the trend towards spatial agglomeration has strengthened. The evolving spatial structure of innovation of Shanghai and Beijing demonstrated differences between the common features during the 25 years as well: in the trend towards the suburbanization of innovation resources, the spatial structure of innovation of Shanghai evolved from a single-core to a multi-core structure. A radiation effect related to traffic arteries as spatial diffusion corridors was prominent. Accordingly, a spatial correlation effect of its innovation outputs also indicated a hollowness in the city center; the spatial structure of innovation of Beijing had a single-core oriented structure all the way. Together with the tendency for innovation resources to be agglomerated in the city center, the spatial correlation effect of innovation outputs reflected the characteristics of the evolutionary feature where "rural area encircles cities". The innovation spatial structure of Shanghai and Beijing have intrinsic consistency with the spatial structure of their respective regions(Yangtze River Delta urban agglomeration and Beijing-Tianjin-Hebei metropolitan region), which suggested that the principle of proportional and disproportional distribution of a city-scale pattern of technological and innovational activities is closely related to its regional innovation pattern. 展开更多
关键词 innovation outputs zip code spatio-temporal evolution agglomeration and dispersion
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A Novel Deterministic Quantum Communication Scheme Using Stabilizer Quantum Code 被引量:3
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作者 GUO Ying CHEN Zhi-Gang +1 位作者 HUANG Da-Zu ZENG Gui-Hua 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第1期93-99,共7页
Exploiting the encoding process of the stabilizer quantum code [[n, k, d]], a deterministic quantum communication scheme, in which n - 1 photons are distributed forward and backward in two-way channel, is proposed to ... Exploiting the encoding process of the stabilizer quantum code [[n, k, d]], a deterministic quantum communication scheme, in which n - 1 photons are distributed forward and backward in two-way channel, is proposed to transmit the secret messages with unconditional security. The present scheme can be implemented to distribute the secret quantum (or classical) messages with great capacity in imperfect quantum channel since the utilized code encodes k-qubit messages for each scheme run. 展开更多
关键词 quantum key distribution quantum error-correction code quantum information
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ON CLASSICAL BCH CODES AND QUANTUM BCH CODES 被引量:3
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作者 Xu Yajie Ma Zhi Zhang Chunyuan 《Journal of Electronics(China)》 2009年第1期64-70,共7页
It is a regular way of constructing quantum error-correcting codes via codes with self-orthogonal property, and whether a classical Bose-Chaudhuri-Hocquenghem (BCH) code is self-orthogonal can be determined by its des... It is a regular way of constructing quantum error-correcting codes via codes with self-orthogonal property, and whether a classical Bose-Chaudhuri-Hocquenghem (BCH) code is self-orthogonal can be determined by its designed distance. In this paper, we give the sufficient and necessary condition for arbitrary classical BCH codes with self-orthogonal property through algorithms. We also give a better upper bound of the designed distance of a classical narrow-sense BCH code which contains its Euclidean dual. Besides these, we also give one algorithm to compute the dimension of these codes. The complexity of all algorithms is analyzed. Then the results can be applied to construct a series of quantum BCH codes via the famous CSS constructions. 展开更多
关键词 Quantum error-correcting codes Bose-Chaudhuri-Hocquenghem (BCH) codes Self-orthogonal Euclidean dual Hermitian dual
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Absolute multi-pole encoder with a simple structure based on an improved gray code to enhance the resolution 被引量:1
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作者 刘勇 《Journal of Chongqing University》 CAS 2009年第3期181-187,共7页
We developed a novel absolute multi-pole encoder structure to improve the resolution of the multi-pole encoder, realize absolute output and reduce the manufacturing cost of the encoder. The structure includes two ring... We developed a novel absolute multi-pole encoder structure to improve the resolution of the multi-pole encoder, realize absolute output and reduce the manufacturing cost of the encoder. The structure includes two ring alnicos defined as index track and sub-division track, respectively. The index track is magnetized based on the improved gray code, with linear halls placed around the track evenly. The outputs of linear halls show the region the rotor belongs to. The sub-division track is magnetized to N-S-N-S (north-south-north-south), and the number of N-S pole pairs is determined by the index track. Three linear hall sensors with an air-gap of 2 mm are used to translate the magnetic filed to voltage signals. The relative offset in a single N-S is obtained through look-up. The magnetic encoder is calibrated using a higher-resolution incremental optical encoder. The pulse output from the optical encoder and hall signals from the magnetic encoder are sampled at the same time and transmitted to a computer, and the relation between them is calculated, and stored in the FLASH of MCU (micro controller unit) for look-up. In the working state, the absolute angle is derived by looking-up with hall signals. The structure is simple and the manufacturing cost is very low and suitable for mass production. 展开更多
关键词 signal encoding magnetic encoder improved gray code absolute output
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单端高速接口DDR PHY IP的一种综合性系统设计方法学
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作者 潘中平 吴伟 高小芳 《中国集成电路》 2025年第6期40-48,共9页
随着数字化转型浪潮的加速推进,智能化时代背景下,半导体行业的数据存储需求正经历前所未有的变革。特别是针对智能化时代的核心资产——数据的安全存储与高效利用/管理,成为制约行业发展的关键因素之一。本研究针对与数据存储密切关联... 随着数字化转型浪潮的加速推进,智能化时代背景下,半导体行业的数据存储需求正经历前所未有的变革。特别是针对智能化时代的核心资产——数据的安全存储与高效利用/管理,成为制约行业发展的关键因素之一。本研究针对与数据存储密切关联的数据传输环节的存储器访问单端高速接口技术,以GDDR5 PHY IP(速率达5.5Gbps)设计为例,深入探讨了在高数据速率下,如何克服电源噪声(PSN)、串扰(crosstalk)、码间干扰(ISI)等关键技术挑战。鉴于现有设计方法学在处理单端高速接口设计时的局限性,特别是其对电源噪声效应的忽略及对串扰简化处理,可能导致系统性能评估的不精确与设计资源的过度预留。本文提出了一种创新的综合性系统仿真方法学,不仅全面考虑了上述挑战,还通过引入多边沿响应(MER)概念,有效捕捉了系统非线性及数据相关时钟抖动效应,为实现更准确的低位误码率(BER)评估提供了有力工具。本研究的核心贡献在于,通过集成脉冲响应卷积、理想PRBS格式下的ISI与crosstalk分析,构建了更为真实的信号波形模型,并结合Q-调节方法学优化了差分统计眼图的推导过程。实际硅验证结果显示,新方法学预测的眼图特性与测试芯片数据之间的误差控制在10%以内,显著提升了设计的可靠性和效率,为半导体企业在“云-边-端”架构中的存储系统智能化升级提供了科学依据。本研究/实践成果也为行业同仁面对数据存储与数据传输中涉及的棘手问题提供了一个可行的解决方案框架,促进了存储技术及系统效应的自适应优化和智能化演进。 展开更多
关键词 高速接口(电路) 一种较新的图形显示高速DDR5高速接口标准 电源噪声 同步开关输出 多边沿响应 Q-调节 输入输出接口 锁相环 一种常用的时钟校准电路 单个(时间)间隔 错误检测码 码间干扰 位误码率
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Performance of MIMO Systems Using Space Time Block Codes (STBC) 被引量:1
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作者 Christopher M. Lau 《Open Journal of Applied Sciences》 2021年第3期273-286,共14页
Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multipl... Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas. 展开更多
关键词 Computer Analysis Digital Communications MATLAB MIMO Modulation Techniques Multiple Input Multiple output Systems Orthogonal Space Time Block Codes OSTBC Rayleigh Fading Channels Space Time Block Codes STBC Wireless Communications Wireless Networks
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Turbo Decoding中BCJR算法的应用及改进
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作者 张浩 郑建宏 《重庆邮电学院学报(自然科学版)》 2000年第3期42-46,共5页
并行级连卷积码 (Turbo Codes)是近年来在编码理论上的一个重大突破 ,其性能与信道容量极限的差距可小于 1d B,有着极其广阔的应用前景 ,而其独特的迭代译码方法更成了编码界和通信界讨论的热点。讨论了 Turbo Codes的编译码原理及 BCJ... 并行级连卷积码 (Turbo Codes)是近年来在编码理论上的一个重大突破 ,其性能与信道容量极限的差距可小于 1d B,有着极其广阔的应用前景 ,而其独特的迭代译码方法更成了编码界和通信界讨论的热点。讨论了 Turbo Codes的编译码原理及 BCJR算法 ,比较了 SOVA,M- BCJR及T- BJCR等几种简化译码算法的性能 ,并对后两者的工程应用进行了探讨。 展开更多
关键词 并行级连卷积码 BCJR算法 纠错码 编码 TURBO码
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