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Copyright of Journal of South China Normal University (Natural Science Edition) / Huanan Shifan Daxue Xuebao (Ziran Kexue Ban) is the property of Journal of South China Normal University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Heilongjiang University of Science & Technology is the property of Journal of Heilongjiang University of Science & Technology Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

MIMO technology has been applied to PLC to meet the demand of PLC for larger capacity and wider coverage, and it can achieve high-speed data transmission. However, the channel of MIMO-PLC system has the characteristics of serious multipath effect and frequency selective fading, and the channel quality of different subcarriers is quite different. Therefore, the existing signal detection algorithms cannot achieve good performance. This paper proposed a detection algorithm based on condition number threshold selection, and used the condition number of the channel matrix to measure the quality of the channel and set the threshold of the optimal condition number. It selected the CLLL-MMSE-SQRD detection algorithm when the condition number of channel was less than or equal to the threshold, and the selected QRD-M detection algorithm when the condition number of channel was greater than the threshold. The simulation results prove that the proposed algorithm can reach the performance of optimal detection algorithm. In the 16QAM modulation mode, the complexity of the proposed algorithm is reduced by 44% compared with the QRD-M detection algorithm, and with the increase of modulation order, the complexity is reduced more obviously. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Posts & Telecommunications (Natural Science Edition) is the property of Chongqing University of Posts & Telecommunications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The ambiguity resolution is one of the primary problems in GNSS carrier phase measurement. To acquire carrier phase integer ambiguity rapidly and accurately, we often take advantage of integer least-squares (ILS) estimation criterion to resolve ambiguity. Due to ILS problem can be regarded as closest vector problem (CLP) in lattice theory, therefore, lattice reduction could help to accelerate ambiguity enumeration process, shorten the search time, and further to improve the computation efficiency of ambiguity resolution. Among many of lattice reduction algorithms, Lenstra-Lenstra-Lovász (LLL) is a most popular and widely used reduction algorithm in many fields. It includes two reduction conditions, size reduction and basis vector swapping. However, size reduction is aimed at all matrix elements and basis vector swapping is only limited to two adjacent vectors, that will result in the unnecessary elements size reduction and excessive basis vector swapping times. Hence, both of them are not conducive to improving the ambiguity reduction efficiency, especially for high-dimensional ambiguity resolution. To overcome this problem, we adopt the greedy algorithm and partial column vector reduction to reduce the number of basis swapping and size reduction, in this contribution the computing complexity of LLL reduction algorithm is reduced, where LLL reduction algorithm has a long time-consuming under high-dimensional conditions. Simulations and real data validations have clearly shown that the modified LLL reduction algorithm can significantly improve the computational efficiency. Therefore our modified LLL algorithm has a certain useful value for fast resolution under high-dimensional case. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new lattice reduction method is introduced to solve the problem of integer ambiguity resolution in GNSS carrier phase precise positioning. The current LLL reduction algorithm is improved based on a orthogonal Householder transformation with systematic rotation. The comparative range is extended to n. The reduction base vectors are preordered and a HE-LLL reduction algorithm is proposed. Experiments with different time intervals and baseline lengths were executed and a comparison was made between the HE-LLL algorithm and other algorithm concerning condition number, non-orthogonal index, reduction time, and changing trend of the length of orthogonal row vector. The results show that the HE-LLL algorithm has improved reduction efficiency, and can well restrict the length of orthogonal row vector. [ABSTRACT FROM AUTHOR]

Considering a single-user multiple-input multiple-output (MIMO) wireless system, this paper puts forward a novel sorted lattice reduction (SLR) algorithm for integer forcing (IF) linear receiver, which reduces the 2-norm of each lattice basis using a series of column-addition operations. The lower complexity and excellent performance of IF receivers are from the closed-loop property of integer domain and the optimization techniques of maximizing the signal-to-interference-noise-ratio (SINR) of each layer, which is equivalent to a famous NP-Hard problem, referred to as shortest independent vector problem (SIVP), in lattice theory. Thesorted lattice reduction algorithm in this paper can effectively alleviate the complexity of this problem in spite of a little orthogonality performance loss, which goes especially well with large MIMO systems. Computer simulations show that the proposed algorithm not only outperforms the famous LLL algorithm in terms of the length of the maximal lattice basis, but also has a relative lower practical complexity. Moreover, the integer forcing receiver based on the sorted lattice reduction algorithm defeats most linear receivers in terms of the bit-error-ratio (BER) performance and is closed to that of the optimal maximal likelihood (ML) receiver. [ABSTRACT FROM AUTHOR]

This paper analyzed a class of weak keys of NTRU. According to the similarity between the structures of the CS lattice in NTRU and the generation matrix of cyclic code, when the degree of the greatest common divisor of NTRU public key and (xn - 1) was great than zero, generation matrix of CS lattice was not reversible and NTRU could be broken by the decoding technique of cyclic code and lattice reduction algorithm. Finally it proposed a method to protect NTRU against this flaw. [ABSTRACT FROM AUTHOR]

After analyzing the way to attack RSA system and NTRU system based on the lattice reduction, this paper presented a method how to generate the lattice in the lattice reduction. The method was mainly used in the cry ptosystems which had the vectors, polynomials or find the small solutions to the equation of the higher degree. In the end, the method was realized in the Regev’s cryptosystem which was based on the LWE,and gave the way how to generate the lattice in this cryptosystem. This application proves the useful of this method. [ABSTRACT FROM AUTHOR]