检索结果-内蒙古大学图书馆

PAPR reduction in OFDM using scaled particle swarm optimisation based partial transmit sequence technique

JOURNAL OF ENGINEERING-JOE 2019年第5期2019卷 3460-3468页

作者： Prasad, Sanjana Jayabalan, Ramesh PSG Coll Technol Dept Elect & Commun Engn Coimbatore Tamil Nadu India

Partial transmit sequence (PTS) is one of the effective techniques for reducing the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. PTS technique has some issues such as higher computational complexity due to its exhaustive searching of optimal phase factors. In order to overcome this drawback, a scaled particle swarm optimisation algorithm is applied to PTS technique to find the optimal phase factors for reducing the PAPR at a faster convergence rate and lower computational complexity. A scaling factor has been introduced in the velocity updating equation of conventional particle swarm optimisation (PSO) to increase the inertia weight and velocity of the particle, thereby providing faster convergence to the optimum value as well as reducing PAPR effectively. From the simulation results obtained, it can be observed that the proposed scaled PSO-PTS algorithm reduces PAPR effectively and is most suitable for applications with the 64-QAM modulation scheme.

关键词： OFDM modulation quadrature amplitude modulation particle swarm optimisation computational complexity scaled PSO-PTS algorithm PAPR effectively inertia weight conventional particle swarm optimisation velocity updating equation scaling factor lower computational complexity faster convergence rate scaled particle swarm optimisation algorithm optimal phase factors exhaustive searching higher computational complexity PTS technique (OFDM) systems orthogonal frequency division peak-to-average power ratio effective techniques partial transmit sequence technique PAPR reduction

来源：评论

学校读者我要写书评

暂无评论

A Low complexity Space-Time Adaptive Processing with Sparse Constraint based on Conjugate Gradient Techniques 14

A Low Complexity Space-Time Adaptive Processing with Sparse ...

引用

14th IEEE International Conference on Signal Processing (ICSP)

作者： Wang, Xiaoye Yang, Zhaocheng He, Kaixuan Cheng, Yige Shenzhen Univ Coll Informat Engn Shenzhen Peoples R China

ISBN: (纸本)9781538646731

It is known that the knowledge of sparsity of data is valuable to improve the convergence of space-time adaptive processing (STAP) algorithm in airborne radar. Recently, a STAP algorithm was proposed where the sparsity of beam-Doppler pattern is exploited to achieve good performance. However, a matrix inversion operator is involved in this algorithm, which results in high computational burden. In this paper, we present a novel STAP algorithm which is free of matrix inversion. Precisely, the filter weight vector is first expressed by introducing an intermediate vector. The intermediate vector is then derived iteratively by employing CG techniques under some simple assumptions. The filter weight vector can thus be computed by the derived intermediate vector. Therefore, the proposed algorithm avoids the matrix inversion and achieves low computational complexity. Numerical simulation results are provided to illustrate the performance and superiority of the proposed algorithm.

关键词： conjugate gradient sparse constraint space-time adaptive processing limited sample support lower computational complexity

来源：评论

学校读者我要写书评

暂无评论

Wideband Laguerre adaptive array with pre-steering constraints

引用

IET SIGNAL PROCESSING 2015年第7期9卷 529-536页

作者： Ebrahimi, Reza Seydnejad, Saeid R. Shahid Bahonar Univ Kerman Dept Elect Engn Kerman Iran Shahid Bahonar Univ Kerman Dept Elect Engn Commun Syst Grp Kerman Iran

Replacing TDL filters with Laguerre filters in the popular wideband Frost space-time array has resulted in a far better performance, lower computational load and faster convergence rate. Compared with IIR-based arrays, the Laguerre design also offers guaranteed convergence, much simpler design with lower computational complexity and better SINR. However, one limiting factor in all these three broadband space-time beamformers is the quantisation error in the front-end pre-steering delays which are used to compensate for the effect of misalignment between the array geometry and the look direction. To make the Laguerre beamformer robust against the quantisation error, a set of frequency domain constraints is introduced in its linearly constrained minimum variance formulation to replace the pre-steering delays. These constraints are also very flexible in incorporating different requirements such as creating multiple desired beams, placing nulls in interference directions, null broadening and pattern synthesis considerations while all these features can be handled in an adaptive manner. The comprehensive set of simulation results not only shows that the proposed algorithm outperforms the existing TDL or IIR based beamformers but it also demonstrates its great flexibility in achieving the desired pattern.

关键词： delay lines stochastic processes space-time adaptive processing adaptive filters array signal processing computational complexity convergence IIR filters quantisation (signal) frequency-domain analysis delay filters TDL filter Laguerre filter design wideband frost space-time array lower computational load faster convergence rate IIR-based arrays wideband Laguerre adaptive array lower computational complexity SINR broadband space-time beamformer quantisation error front-end presteering delay array geometry look direction Laguerre beamformer frequency domain constraints linearly constrained minimum variance formulation tapped delay line filter

来源：评论

学校读者我要写书评

暂无评论

FFT-based parallel encoding algorithm for structured LDPC codes

FFT-based parallel encoding algorithm for structured LDPC co...

引用

11th International Conference on Wireless Communications, Networking and Mobile Computing (WiCOM 2015)

作者： Yanan Fan Xin Meng Xiujuan Yao Yi Yan University of Chinese Academy of Sciences Beijing China National Space Science Center CAS Beijing China

ISBN: (纸本)9781510821279

Structured LDPC, such as RA, IRA, ARA, QC-LDPC etc., are some important LDPC codes, these codes usually have very good performance and facilitate the implementation of encoding and decoding for the structural features they have. A new method for the encoding of the structured LDPC codes has been presented, namely FFT-based parallel encoding algorithm, which uses FFT to realize the parallel encoding of LDPC codes by achieving the circular convolution in the frequency domain. The study shows that the proposed algorithm has lower computational complexity than the previously proposed encoding algorithm. Although transforming to the frequency domain requires complex operations in real domain which increasing the number of the quantization points, the throughput of the encoder has greatly improved because of the increase of the degree of parallelism. The simulation results show that the computational complexity of the FFT-based encoding algorithm has an approximately linear relationship with the size of sub-circulate matrix, and when this size goes larger, the newly proposed algorithm will possess a lower computational complexity and a higher throughput compared with the previously proposed algorithms.

关键词： Circular Convolution FFT-Based High Throughput lower computational complexity Parallel Encoding Structured LDPC parallel encoding low density parity check codes complexity classes Circular Convolution Frequency-domain analysis real number field

来源：评论

学校读者我要写书评

暂无评论

Research on Recognition Algorithm of Digital Modulation by Higher Order Cumulants 4

Research on Recognition Algorithm of Digital Modulation by H...

引用

4th International Conference on Instrumentation and Measurement, Computer, Communication and Control (IMCCC)

作者： Liu Mingzhu Zhao Yue Shi Lin Dong Jingwei Harbin Univ Sci & Technol Sch Measurement & Control Technol & Commun Engn Higher Educ Key Lab Measuring & Control Technol & Harbin Peoples R China

ISBN: (纸本)9781479965755

Modulation identification of communication signals is an important content of wireless communication technology and a hot topic in the research field of the intercepted signal processing. Because the modulation mode is one of the most important characteristics to be used to distinguish various communication signals, in this paper, a new algorithm using feature parameters based on higher order cumulants has been proposed to identify digital modulation signals, which uses the feature of the white Gaussian noise of its greater than second-order cumulants is zero. Based on the analysis of invariant features in cumulant domain of communication signals, the performances of related cumulants have been researched, and at the same time the key cumulants and characteristics of modulation identification have also been determined. The proposed algorithm can identify digital modulation signals of 2ASK, 4ASK, 4PSK, 2FSK, 4FSK and 16QAM effectively under the environment of lower SNR. In addition, the results of simulation show that it can suppress white Gaussian noise effectively and has lower computational complexity and needs less prior information.

关键词： modulation recognition higher order cumulants feature parameter lower computational complexity

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：