Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC...Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC） scheme based on multi-user detection for the multiple unicast transmission is proposed.Theoretic analysis and simulation results demonstrate that,compared with the conventional cooperation（CC） scheme and network-coded cooperation（NCC） scheme,CFNCC would obtain higher network throughput and consumes less time slots.Moreover,a further investigation is made for the symbol error probability（SEP） performance of CFNCC scheme,and SEPs of CFNCC scheme are compared with those of NCC scheme in various scenarios for different signal to noise ratio（SNR） values.展开更多
The capabilities of decoding beyond the bound of the Complex-Rotary code （CRcodes） and its dual code are analyzed. It is obtained that the CR codes with normal error-correcting ability t = （p+1）/2 can correct （t+...The capabilities of decoding beyond the bound of the Complex-Rotary code （CRcodes） and its dual code are analyzed. It is obtained that the CR codes with normal error-correcting ability t = （p+1）/2 can correct （t+1）-errors up to C<sub>p<sup>2</sup>+p（p+1）</sub><sup>t+1</sup>-p<sup>2Ct</sup><sub>2t+1</sub> and itsdual code can correct （t<sub>1</sub>+1）-errors up to C<sub>p<sup>2</sup>+2tp</sub><sup>t<sub>1</sub>+1</sup>-2tpC<sub>p+1</sub><sup>t<sub>1</sub>+1</sup> where t<sub>1</sub>=（p+1）/2-1 and pis a prime.展开更多
Firstly,the Fourier transforms in finite fields and the concept of linear complexityof sequences are described.Then several known lower bounds on the minimum distance of cycliccodes are outlined.Finally,the minimum di...Firstly,the Fourier transforms in finite fields and the concept of linear complexityof sequences are described.Then several known lower bounds on the minimum distance of cycliccodes are outlined.Finally,the minimum distance of cyclic codes is analyzed via linear complexityof sequences,and new theorems about the lower bounds are obtained.展开更多
This paper investigates a peak to average power ratio （PAPR） reduction method in multicarrier code division multiple access （MC-CDMA） system. Variable code sets （VCS）, a spreading codes selection scheme, can imp...This paper investigates a peak to average power ratio （PAPR） reduction method in multicarrier code division multiple access （MC-CDMA） system. Variable code sets （VCS）, a spreading codes selection scheme, can improve the PAPR property of the MC-CDMA signals, but this technique requires an exhaustive search over the combinations of spreading code sets. It is observed that when the number of active users increases, the search complexity will increase exponentially. Based on this fact, we propose a low complexity VCS （LC-VCS） method to reduce the computational complexity. The basic idea of LC-VCS is to derive new signals using the relationship between candidature signals. Simulation results show that the proposed approach can reduce PAPR with lower comtational pucomplexity. In addition, it can be blindly received without any side information.展开更多
Recent research challenges in the wireless communication include the usage of diversity and efficient coding to improve data transmission quality and spectral efficiency. Space diversity uses multiple transmitting and...Recent research challenges in the wireless communication include the usage of diversity and efficient coding to improve data transmission quality and spectral efficiency. Space diversity uses multiple transmitting and/or receiving antennas to create independent fading channels without penalty in bandwidth efficiency. Space-time block coding is an encoding scheme for communication over Rayleigh fading channels using multiple transmitting antennas. Space-time block codes from complex orthogonal designs exist only for two transmitting antennas. This paper generalizes a new complex orthogonal space-time block code for four transmitting antennas, whose decoding complexity is very low. Simulations show that the generalized complex orthogonal space-time block code has low bit error rate, full rate and possibly large diversity.展开更多
A code developed recently by the authors, for counting and computing the eigenvalues of a complex tridiagonal matrix, as well as the roots of a complex polynomial, which lie in a given region of the complex plane, is ...A code developed recently by the authors, for counting and computing the eigenvalues of a complex tridiagonal matrix, as well as the roots of a complex polynomial, which lie in a given region of the complex plane, is modified to run in parallel on multi-core machines. A basic characteristic of this code (eventually pointing to its parallelization) is that it can proceed with: 1) partitioning the given region into an appropriate number of subregions;2) counting eigenvalues in each subregion;and 3) computing (already counted) eigenvalues in each subregion. Consequently, theoretically speaking, the whole code in itself parallelizes ideally. We carry out several numerical experiments with random complex tridiagonal matrices, and random complex polynomials as well, in order to study the behaviour of the parallel code, especially the degree of declination from theoretical expectations.展开更多
阐述广播电视播出中的码流自适应调整技术的现状,介绍基于超文本传输协议(Hyper Text Transfer Protocol,HTTP)的动态自适应流媒体技术的广泛应用及优势。同时,分析高精度码流自适应调整技术面临的挑战,涵盖算法复杂度与实时性冲突、视...阐述广播电视播出中的码流自适应调整技术的现状,介绍基于超文本传输协议(Hyper Text Transfer Protocol,HTTP)的动态自适应流媒体技术的广泛应用及优势。同时,分析高精度码流自适应调整技术面临的挑战,涵盖算法复杂度与实时性冲突、视频编码技术局限性以及设备性能与兼容性问题,并提出相应的对策,旨在为高精度码流自适应调整技术的发展提供理论支持和实践指导。展开更多
随着样品种类和检验需求的日益多样化,传统的检验方法面临信息采集滞后、流程烦琐等问题,需要一种更加高效的技术手段。二维码与无线射频识别(Radio Frequency Identification,RFID)技术融合通过结合各自的优势,在样品的全生命周期内提...随着样品种类和检验需求的日益多样化,传统的检验方法面临信息采集滞后、流程烦琐等问题,需要一种更加高效的技术手段。二维码与无线射频识别(Radio Frequency Identification,RFID)技术融合通过结合各自的优势,在样品的全生命周期内提供了精确的追踪、信息管理和数据交换方案,优化了检验流程。二维码在信息存储与读取速度上的高效性与RFID技术的自动识别、远程数据传输特性相结合,可以实现样品的实时监控和数据精准采集,提高了检验结果的自动化处理能力。二维码与RFID技术融合在复杂样品检验中的应用前景广阔,具有广泛的行业推广价值与应用潜力。展开更多
基金supported by the National Natural Science Foundation of China(6104000561001126+5 种基金61271262)the China Postdoctoral Science Foundation Funded Project(201104916382012T50789)the Natural Science Foundation of Shannxi Province of China(2011JQ8036)the Special Fund for Basic Scientific Research of Central Colleges (CHD2012ZD005)the Research Fund of Zhejiang University of Technology(20100244)
文摘Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC） scheme based on multi-user detection for the multiple unicast transmission is proposed.Theoretic analysis and simulation results demonstrate that,compared with the conventional cooperation（CC） scheme and network-coded cooperation（NCC） scheme,CFNCC would obtain higher network throughput and consumes less time slots.Moreover,a further investigation is made for the symbol error probability（SEP） performance of CFNCC scheme,and SEPs of CFNCC scheme are compared with those of NCC scheme in various scenarios for different signal to noise ratio（SNR） values.
文摘The capabilities of decoding beyond the bound of the Complex-Rotary code （CRcodes） and its dual code are analyzed. It is obtained that the CR codes with normal error-correcting ability t = （p+1）/2 can correct （t+1）-errors up to C<sub>p<sup>2</sup>+p（p+1）</sub><sup>t+1</sup>-p<sup>2Ct</sup><sub>2t+1</sub> and itsdual code can correct （t<sub>1</sub>+1）-errors up to C<sub>p<sup>2</sup>+2tp</sub><sup>t<sub>1</sub>+1</sup>-2tpC<sub>p+1</sub><sup>t<sub>1</sub>+1</sup> where t<sub>1</sub>=（p+1）/2-1 and pis a prime.
文摘Firstly,the Fourier transforms in finite fields and the concept of linear complexityof sequences are described.Then several known lower bounds on the minimum distance of cycliccodes are outlined.Finally,the minimum distance of cyclic codes is analyzed via linear complexityof sequences,and new theorems about the lower bounds are obtained.
文摘This paper investigates a peak to average power ratio （PAPR） reduction method in multicarrier code division multiple access （MC-CDMA） system. Variable code sets （VCS）, a spreading codes selection scheme, can improve the PAPR property of the MC-CDMA signals, but this technique requires an exhaustive search over the combinations of spreading code sets. It is observed that when the number of active users increases, the search complexity will increase exponentially. Based on this fact, we propose a low complexity VCS （LC-VCS） method to reduce the computational complexity. The basic idea of LC-VCS is to derive new signals using the relationship between candidature signals. Simulation results show that the proposed approach can reduce PAPR with lower comtational pucomplexity. In addition, it can be blindly received without any side information.
文摘Recent research challenges in the wireless communication include the usage of diversity and efficient coding to improve data transmission quality and spectral efficiency. Space diversity uses multiple transmitting and/or receiving antennas to create independent fading channels without penalty in bandwidth efficiency. Space-time block coding is an encoding scheme for communication over Rayleigh fading channels using multiple transmitting antennas. Space-time block codes from complex orthogonal designs exist only for two transmitting antennas. This paper generalizes a new complex orthogonal space-time block code for four transmitting antennas, whose decoding complexity is very low. Simulations show that the generalized complex orthogonal space-time block code has low bit error rate, full rate and possibly large diversity.
文摘A code developed recently by the authors, for counting and computing the eigenvalues of a complex tridiagonal matrix, as well as the roots of a complex polynomial, which lie in a given region of the complex plane, is modified to run in parallel on multi-core machines. A basic characteristic of this code (eventually pointing to its parallelization) is that it can proceed with: 1) partitioning the given region into an appropriate number of subregions;2) counting eigenvalues in each subregion;and 3) computing (already counted) eigenvalues in each subregion. Consequently, theoretically speaking, the whole code in itself parallelizes ideally. We carry out several numerical experiments with random complex tridiagonal matrices, and random complex polynomials as well, in order to study the behaviour of the parallel code, especially the degree of declination from theoretical expectations.
文摘阐述广播电视播出中的码流自适应调整技术的现状,介绍基于超文本传输协议(Hyper Text Transfer Protocol,HTTP)的动态自适应流媒体技术的广泛应用及优势。同时,分析高精度码流自适应调整技术面临的挑战,涵盖算法复杂度与实时性冲突、视频编码技术局限性以及设备性能与兼容性问题,并提出相应的对策,旨在为高精度码流自适应调整技术的发展提供理论支持和实践指导。
文摘随着样品种类和检验需求的日益多样化,传统的检验方法面临信息采集滞后、流程烦琐等问题,需要一种更加高效的技术手段。二维码与无线射频识别(Radio Frequency Identification,RFID)技术融合通过结合各自的优势,在样品的全生命周期内提供了精确的追踪、信息管理和数据交换方案,优化了检验流程。二维码在信息存储与读取速度上的高效性与RFID技术的自动识别、远程数据传输特性相结合,可以实现样品的实时监控和数据精准采集,提高了检验结果的自动化处理能力。二维码与RFID技术融合在复杂样品检验中的应用前景广阔,具有广泛的行业推广价值与应用潜力。
