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A BCH error correction scheme applied to FPGA with embedded memory Research Articles

Yang Liu, Jie Li, Han Wang, Debiao Zhang, Kaiqiang Feng, Jinqiang Li,lylyly357@163.com,lijie@nuc.edu.cn

Frontiers of Information Technology & Electronic Engineering 2021, Volume 22, Issue 8, Pages 1127-1139 doi: 10.1631/FITEE.2000323

Abstract: Given the potential for bit flipping of data on a memory medium, a high-speed parallel Hocquenghem (BCHmethod for each part of the system and analyze the realization process of this scheme in the case of the BCH

Keywords：纠错算法；Bose–Chaudhuri–Hocquenghem（BCH）码；现场可编程门阵列（FPGA）；闪存

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A new anti-jamming communication technical system：pre-encoded code hopping spread spectrum

Yao Fuqiang,Zhang Yi

Strategic Study of CAE 2011, Volume 13, Issue 10, Pages 69-75

Abstract:

A kind of pre-encoded code hopping spread spectrum (PCHSS) communication technical system for anti-jamming communication is brought forward and researched after analyzing its necessity based on the deficiency of conventional direct-sequence spread spectrum(DSSS). The main discussions include the basic principle of PCHSS, the differences between PCHSS and self-coded spread spectrum(SCHSS), and some key techniques. The PCHSS basic performance is analyzed finally. The technical system and its basic performance have been proved in practice.

Keywords： anti-jamming communication direct-sequence spread spectrum pre-encoded code hopping spread spectrum self-coded spread spectrum

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Impact of Polarization Mode Dispersion on High-Speed Optical Codes

Rao Min,Sun Xiaohan,Zhang Mingde

Strategic Study of CAE 2002, Volume 4, Issue 11, Pages 67-70

Abstract:

The first and second-order polarization mode dispersion (PMD) effect on the performance of 10 Gbit/s and 40 Gbit/s systems is studied. The statistical behavior of PMD is considered by simulating the nonreturn-to-zero (NRZ) and return-to-zero (RZ) pulses distortion and the system's Q-factor based on principal states of polarization (PSP) theory. It is found that the effect of PMD is significant in higher bit rate systems and the second-order PMD cannot be neglected. Furthermore, the RZ format is more tolerant to PMD than is the NRZ format, and the system performance is improved if the input pulses are appropriately chirped.

Keywords： polarization mode dispersion (PMD) non-return-to-zero (NRZ) return-to-zero (RZ) frequency chirp

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Designing Space-time Trellis Codes in Flat Fast Fading Channels With Large Number of Antennas

Geng Jia,Cao Xiuying,Bi Guangguo

Strategic Study of CAE 2006, Volume 8, Issue 6, Pages 48-54

Abstract:

In recent years space-time trellis codes (STTCs) have attracted a great amount of research interest in wireless communication. However, the design criterion for STTCs is still a difficult problem. In flat fast fading channels, when the number of antennas is large, the space-time trellis codes design criterion, which is based on maximizing the minimum squared Euclidean distance, is better than the traditional distance and product criteria. Nevertheless, the former criterion is still not perfect. In this paper, from the aspects of squared distance distribution and squared distance sum-square square-sum ratio distribution, an improved criterion is presented, and some new codes are also obtained, which are the best codes known. In addition, a new reason is given, which can explain the different performance of a code between in slow fading channels and in fast fading channels. Finally the improved criterion is introduced into the design of smart-greedy codes.

Keywords： space-time trellis code criterion flat fast fading distance distribution

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The V－BLAST Detection for MIMO MC－CDMA System

Yang Jie,Feng Guangzeng

Strategic Study of CAE 2007, Volume 9, Issue 1, Pages 58-62

Abstract:

This paper investigates V-BLAST MC-CDMA down link.A V-BLAST detector per subcarrier is proposed for MIMO MC-CDMA system in this paper and the system performance with var ious numbers of V -BLAST antennas and users for such a system is evaluated throu gh simulations.

Keywords： multiple input multiple output(MIMO) orthogonal frequency division multiplexing(OFDM) layered space唱time code(LST) zero force(ZF)algorithm minimum mean square error(MMSE)

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ShortTail: taming tail latency for erasure-code-based in-memory systems Research Article

Yun TENG, Zhiyue LI, Jing HUANG, Guangyan ZHANG

Frontiers of Information Technology & Electronic Engineering 2022, Volume 23, Issue 11, Pages 1646-1657 doi: 10.1631/FITEE.2100566

Abstract:

s with erasure coding (EC) enabled are widely used to achieve high performance and data availability. However, as the scale of clusters grows, the server-level fail-slow problem is becoming increasingly frequent, which can create long . The influence of long is further amplified in EC-based systems due to the synchronous nature of multiple EC sub-operations. In this paper, we propose an EC-enabled in-memory storage system called ShortTail, which can achieve consistent performance and low latency for both reads and writes. First, ShortTail uses a lightweight request monitor to track the performance of each memory node and identify any fail-slow node. Second, ShortTail selectively performs degraded reads and redirected writes to avoid accessing fail-slow nodes. Finally, ShortTail posts an adaptive write strategy to reduce write amplification of s. We implement ShortTail on top of Memcached and compare it with two baseline systems. The experimental results show that ShortTail can reduce the P99 by up to 63.77%; it also brings significant improvements in the median latency and average latency.

Keywords： Erasure code In-memory system Node fail-slow Small write Tail latency

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Performance research on anti-noise FM jamming of pseudo-random code phase modulation and sine FM combined fuze

Tu Youchao,Zhao Huichang,Zhou Xingang

Strategic Study of CAE 2009, Volume 11, Issue 9, Pages 68-73

Abstract:

Development and application of pseudo-random code combined fuze can be guided in theory by researching its anti-jamming performance. The anti-noise FM jamming performance of pseudo-random code phase modulation and sine FM combined fuze is analyzed based on the criterion of signal to jamming ratioin (SJR) gain in this paper. First, the principle of the combined fuze was introduced, and its overall SJR gain is reduced in detail under the noise FM jamming, then, the factors affecting its anti-noise FM jamming performance were analyzed, such as the nth order Bessel function of the first kind, Doppler frequency, pseudo-random code period, pulse width, and spot error. The results provide the important theoretic foundation for the improvement on anti-noise FM jamming performance of the combined fuze. At the same time, the studying method put forward in this paper may be used as the reference for analyzing anti-jamming performance of other type of fuzes.

Keywords： pseudo-random code fuze sine FM SJR gain anti-jamming

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ApipelinedReed-Solomon decoder based on a modified step-by-step algorithm Article

Xing-ru PENG,Wei ZHANG,Yan-yan LIU

Frontiers of Information Technology & Electronic Engineering 2016, Volume 17, Issue 9, Pages 954-961 doi: 10.1631/FITEE.1500303

Abstract: We propose a pipelined Reed-Solomon (RS) decoder for an ultra-wideband system using a modified stepby-step algorithm. To reduce the complexity, the modified step-by-step algorithm merges two cases of the original algorithm. The pipelined structure allows the decoder to work at high rates with minimum delay. Consequently, for RS(23,17) codes, the proposed architecture requires 42.5% and 24.4% less area compared with a modified Euclidean architecture and a pipelined degree-computationless modified Euclidean architecture, respectively. The area of the proposed decoder is 11.3% less than that of the previous step-by-step decoder with a lower critical path delay.

Keywords： Reed-Solomon codes Step-by-step algorithm Ultra-wideband Pipelined structure

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Performance Optimization Analysis of 2D - OOSC Codeword for OCDMA System

Li Chuanqi,Sun Xiaohan,Zhang Mingde,Ding Dong

Strategic Study of CAE 2003, Volume 5, Issue 4, Pages 50-54

Abstract:

The scheme of 2-dimensions optical orthogonal square codes (2D - OOSC) in optical code-division multiple-access (OCDMA) networks is given in this paper. The influence of coding parameters to the performance of the system is mainly discussed. It is proved that the relativity of the codeword satisfies the system requirement, and the system BER based on multiple user interference is ascertained. The results indicate that the number of simultaneous users that can be contained in this system will be much larger than that in the system with ID-OOC under the same conditions, the total transmitting capacity of the system will reach the level of Tb/s, and the performance of 2D — OOSC system will be largely enhanced, especially under the heavy transmitting traffic.

Keywords： optical code division multiple access (OCDMA) 2-dimensions optical orthogonal square codes (2D-OOSC) multi-users interfering (MUI) based bit-error-ratio (BER)

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Areliable and energy-efficient storage systemwith erasure coding cache Article

Ji-guang WAN, Da-ping LI, Xiao-yang QU, Chao YIN, Jun WANG, Chang-sheng XIE

Frontiers of Information Technology & Electronic Engineering 2017, Volume 18, Issue 9, Pages 1370-1384 doi: 10.1631/FITEE.1600972

Abstract: In modern energy-saving replication storage systems, a primarygroup of disks is always powered up to serve incoming requests whileother disks are often spun down to save energy during slack periods.However, since new writes cannot be immediately synchronized intoall disks, system reliability is degraded. In this paper, we developa high-reliability and energy-efficient replication storage system,named RERAID, based on RAID10. RERAID employs part of the free spacein the primary disk group and uses erasure coding to construct a codecache at the front end to absorb new writes. Since code cache supportsfailure recovery of two or more disks by using erasure coding, RERAIDguarantees a reliability comparable with that of the RAID10 storagesystem. In addition, we develop an algorithm, called erasure codingwrite (ECW), to buffer many small random writes into a few large writes,which are then written to the code cache in a parallel fashion sequentiallyto improve the write performance. Experimental results show that RERAIDsignificantly improves write performance and saves more energy thanexisting solutions.

Keywords： Reliability Energy-efficient Storage system Erasure coding Cache management

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High efficiency spreading spectrum modulation based on double orthogonal complex sequences

Shi Xiaohong

Strategic Study of CAE 2012, Volume 14, Issue 3, Pages 108-112

Abstract:

This paper presents a kind of high efficiency spreading spectrum modulation scheme using double orthogonal complex sequences (DoCS). In this scheme, input data bit-stream is split into many groups with length M. Each group is then mapped into a word of width M and then utilized to select one sequence from 2M-2 DoCS sequences each with length L. After that, the selected sequence is modulated on carrier in QPSK(quadrature phase shift keying) mode. In addition, a novel method named forward phase correction (FPC) is put forward for carrier recovery.

Keywords： modulation and demodulation high efficiency spreading spectrum modulation forward phase correction double orthogonal complex sequences

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SA-RSR: a read-optimal data recovery strategy for XOR-coded distributed storage systems Research Articles

Xingjun ZHANG, Ningjing LIANG, Yunfei LIU, Changjiang ZHANG, Yang LI

Frontiers of Information Technology & Electronic Engineering 2022, Volume 23, Issue 6, Pages 858-875 doi: 10.1631/FITEE.2100242

Abstract:

To ensure the reliability and availability of data, redundancy strategies are always required for s. Erasure coding, one of the representative redundancy strategies, has the advantage of low storage overhead, which facilitates its employment in s. Among the various erasure coding schemes, are becoming popular due to their high computing speed. When a occurs in such coding schemes, a process called takes place to retrieve the failed node's lost data from surviving nodes. However, data transmission during the process usually requires a considerable amount of time. Current research has focused mainly on reducing the amount of data needed for to reduce the time required for data transmission, but it has encountered problems such as significant complexity and local optima. In this paper, we propose a random search recovery algorithm, named SA-RSR, to speed up recovery of . SA-RSR uses a simulated annealing technique to search for an optimal recovery solution that reads and transmits a minimum amount of data. In addition, this search process can be done in polynomial time. We evaluate SA-RSR with a variety of in simulations and in a real storage system, Ceph. Experimental results in Ceph show that SA-RSR reduces the amount of data required for recovery by up to 30.0% and improves the performance of by up to 20.36% compared to the conventional recovery method.

Keywords： Distributed storage system Data reliability and availability XOR-based erasure codes Single-node failure Data recovery

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& Research Article

Yaofeng TU, Rong XIAO, Yinjun HAN, Zhenghua CHEN, Hao JIN, Xuecheng QI, Xinyuan SUN,tu.yaofeng@zte.com.cn,xiao.rong1@zte.com.cn,han.yinjun@zte.com.cn,chen.zhenghua@zte.com.cn,jin.hao1@zte.com.cn,qi.xuecheng@zte.com.cn,sun.xinyuan@zte.com.cn

Frontiers of Information Technology & Electronic Engineering 2023, Volume 24, Issue 5, Pages 716-730 doi: 10.1631/FITEE.2200466

Abstract: In s, replication and (EC) are common methods for data redundancy. Compared with replication, EC has better storage efficiency, but suffers higher overhead in update. Moreover, and reliability problems caused by s bring new challenges to applications of EC. Many works focus on optimizing the EC solution, including algorithm optimization, novel data update method, and so on, but lack the solutions for and reliability problems. In this paper, we introduce a storage system that decouples data updating and EC encoding, namely, decoupled data updating and coding (DDUC), and propose a data placement policy that combines replication and parity blocks. For the () EC system, the data are placed as groups of +1 replicas, and redundant data blocks of the same stripe are placed in the parity nodes, so that the parity nodes can autonomously perform local EC encoding. Based on the above policy, a two-phase data update method is implemented in which data are updated in replica mode in phase 1, and the EC encoding is done independently by parity nodes in phase 2. This solves the problem of data reliability degradation caused by s while ensuring high concurrency performance. It also uses persistent memory (PMem) hardware features of the byte addressing and eight-byte atomic write to implement a lightweight logging mechanism that improves performance while ensuring data . Experimental results show that the concurrent access performance of the proposed storage system is 1.70–3.73 times that of the state-of-the-art storage system Ceph, and the latency is only 3.4%–5.9% that of Ceph.

Keywords： Concurrent update High reliability Erasure code Consistency Distributed storage system

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Level-direction decomposition analysis with a focus on image watermarking framework Article

M. F. KAZEMI,M. A. POURMINA,A. H. MAZINAN

Frontiers of Information Technology & Electronic Engineering 2016, Volume 17, Issue 11, Pages 1199-1217 doi: 10.1631/FITEE.1500165

Abstract: This research addresses the new level-direction decomposition in the area of image watermarking as the further development of investigations. The main process of realizing a watermarking framework is to generate a watermarked image with a focus on contourlet embedding representation. The approach performance is evaluated through several indices including the peak signal-to-noise ratio and structural similarity, whereby a set of attacks are carried out using a module of simulated attacks. The obtained information is analyzed through a set of images, using different color models, to enable the calculation of normal correlation. The module of the inverse of contourlet embedding representation is correspondingly employed to obtain the present watermarked image, as long as a number of original images are applied to a scrambling module, to represent the information in disorder. This allows us to evaluate the performance of the proposed approach by analyzing a complicated system, where a decision making system is designed to find the best level and the corresponding direction regarding contourlet embedding representation. The results are illustrated in appropriate level-direction decomposition. The key contribution lies in using a new integration of a set of subsystems, employed based upon the novel mechanism in contourlet embedding representation, in association with the decision making system. The presented approach is efficient compared with state-of-the-art approaches, under a number of serious attacks. A number of benchmarks are obtained and considered along with the proposed framework outcomes. The results support our ideas.

Keywords： Level-direction decomposition analysis Watermarking framework Contourlet embedding representation Scrambling module Simulated attacks

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Combinational Evaluation Method Based on Projection Pursuit Algorithm

Wang Shuo, Yang Shanlin, Hu Xiaoxuan

Strategic Study of CAE 2008, Volume 10, Issue 8, Pages 60-64

Abstract:

The combinational evaluation method which combines TOPSIS with gray correlation degree analysis can improve validity of the evaluation result. In such method, a usual way to assign combinational weight of index is subjective weighting, to assign combinational preference coefficient and identification coefficient is manual weighting. The advantages of combinational evaluation method are not fully mined. Aim at this problem, a method uses projection pursuit algorithm to establish combinational evaluation model is presented. The real coded accelerating genetic algorithm is used to dispose those non-linear problems. The gained index weights are objective. In the same time, a new method of confirms combinational preference coefficients and identification coefficients of gray correlation degree is presented. The example shows the combinational evaluation method based on projection pursuit algorithm is scientific and objective.

Keywords： combinational evaluation projection pursuit algorithm real code daccelerating enetic algorithm identification coefficient combinational preference coefficient