检索结果-内蒙古大学图书馆

2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011

作者： Li, Heng-Chao Huang, Ping-Ping Fan, Ping-Zhi Sichuan Provincial Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu 610031 China College of Information Engineering Inner Mongolia University of Technology Hohhot 010051 China

ISBN: (纸本)9788993246179

The accurate statistical modeling of synthetic aperture radar (SAR) images is a crucial problem in the context of effective SAR image processing, interpretation and applications. In terms of the heavy-tailed or bi-/ multi-modal characteristics of histograms, it is difficult to apply a single parametric model to accurately describe the statistics of high-resolution SAR images. From the perspective of semi-parametric approach, we choose generalized Gamma distribution (GΓD) as the component of finite mixture model, then exploit generalized Gamma mixture model (GΓMM) to implement an effective statistical analysis of high-resolution SAR images in this paper. And we derive an expectation-maximization (EM) algorithm for estimating the corresponding parameters of GΓMM. Finally, experimental results, carried out on the actual high-resolution SAR images with single- and bi-modal histograms, demonstrate the validity of GΓMM. © 2011 KIEES.

关键词： Mixtures

来源：评论

学校读者我要写书评

暂无评论

Bayesian wavelet-based shrinkage for SAR images despeckling using generalized Gamma distribution

Bayesian wavelet-based shrinkage for SAR images despeckling ...

引用

2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011

作者： Huang, Ping-Ping Li, Heng-Chao Fan, Ping-Zhi College of Information Engineering Inner Mongolia University of Technology Hohhot 010051 China Sichuan Provincial Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu 610031 China

ISBN: (纸本)9788993246179

In this paper, a non-homomorphic wavelet-based maximum a posteriori (MAP) despeckling of SAR images using two-sided generalized Gamma distribution (GΓD) is proposed to suppress speckle. Instead of the logarithmic transformation, the multiplicative speckle model is decomposed into an additive model with signal-dependent noise. And a locally adaptive MAP estimator of noise-free wavelet coefficient is derived by introducing a two-sided GΓD and a local Gaussian distribution as the statistically models for the wavelet coefficients of the additive signal-dependent noise and the reflectance image, respectively. Further, an approximated scheme is provided to estimate the parameters of the involving prior distribution. Finally, experimental results, carried out on the actual SAR image, demonstrate the validity of our proposed despeckling method. © 2011 KIEES.

关键词： Speckle

来源：评论

学校读者我要写书评

暂无评论

A Survey on Low Complexity Detectors for OTFS Systems

引用

ZTE Communications 2021年第4期19卷 3-15页

作者： ZHANG Zhengquan LIU Heng WANG Qianli FAN Pingzhi Key Lab of Information Coding and Transmission Southwest Jiaotong UniversityChengdu 611756China State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China

The newly emerging orthogonal time frequency space(OTFS)modulation can ob⁃tain delay-Doppler diversity gain to significantly improve the system performance in high mobility wireless communication scenarios such as vehicle-to-everything(V2X),high-speed railway and unmanned aerial vehicles(UAV),by employing inverse symplectic finite Fouri⁃er transform(ISFFT)and symplectic finite Fourier transform(SFFT).However,OTFS modu⁃lation will dramatically increase system complexity,especially at the receiver ***,de⁃signing low complexity OTFS receiver is a key issue for OTFS modulation to be adopted by new-generation wireless communication *** this paper,we review low complexity OTFS detectors and provide some insights on future *** firstly present the OTFS system model and basic principles,followed by an overview of OTFS detector structures,classifications and comparative *** also survey the principles of OTFS detection ***,we discuss the design of hybrid OTFS and orthogonal frequency di⁃vision multiplexing(OFDM)detectors in single user and multi-user multi-waveform commu⁃nication ***,we address the main challenges in designing low complexity OT⁃FS detectors and identify some future research directions.

关键词： high mobility wireless communications OTFS ISFFT SFFT delay-Doppler di⁃versity iterative maximum ratio combining(MRC)detection message passing detection

来源：评论

学校读者我要写书评

暂无评论

An inter-cell interference reduction method for downlink cellular networks based on signal autocorrelation

An inter-cell interference reduction method for downlink cel...

引用

4th International Workshop on Signal Design and Its Applications in Communications, IWSDA'09

作者： Kai, Yu Pingzhi, Fan Li, Hao Key Lab. of Information Coding and Transmission Institute of Mobile Communications Southwest Jiaotong University Chengdu Sichuan 610031 China

ISBN: (纸本)9781424443802

Since the intra-cell interference can be nearly eliminated by OFDM, the inter-cell interference (ICI) has dominated the cellular networks and greatly degraded the system performance. In this paper, an ICI reduction method based on signal autocorrelation is proposed. In this method, the transmission signals from different cells may overlap in time and frequency, but they are processed to have linearly independent autocorrelation function by adopting a distinguishing pre-filter in each cell. Hence the downlink ICI from adjacent cells can be significantly eliminated by autocorrelation matched filter. To ease the requirement of multiple receiving antennas at the mobile stations, a modified method is proposed to suppress the strongest ICI from the nearest adjacent cell, which only requires 2 antennas equipped at the mobile station. The modified method is especially efficient for the edge cell users. ©2009 IEEE.

关键词： Autocorrelation

来源：评论

学校读者我要写书评

暂无评论

Sensing error aware delay-optimal channel allocation scheme for cognitive radio networks

Sensing error aware delay-optimal channel allocation scheme ...

引用

作者： Wang, Wei Wu, Kejian Luo, Haiyan Yu, Guanding Zhang, Zhaoyang Department of Information Science and Electronic Engineering Zhejiang Provincial Key Laboratory of Information Network Technology Zhejiang University Hangzhou 310027 China Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu 610031 China

Spectrum sensing is not always perfect in practical cognitive radio networks. In this paper, two kinds of sensing errors are considered into the channel allocation scheme. Our work focuses on the cases that the channel availability varies fast during a channel allocation period, in which case the channel dynamics needs to be considered. The sensing errors are modeled to derive the metric of mean delay for each user-channel combination using the vacation queueing model. Further, the optimal resource allocation is determined based on the mean delay metric by bipartite graph matching. The simulation results indicate that the proposed mean delay metric can represent the transmission performance successfully, and the proposed resource allocation scheme is robust to sensing errors. © 2011 Springer Science+Business Media, LLC.

关键词： Cognitive radio

来源：评论

学校读者我要写书评

暂无评论

Efficient Priority Packet Recovery Based on Network coding in DVB-IPDC System

引用

China Communications 2015年第7期12卷 167-178页

作者： WANG Lian PENG Daiyuan LIANG Hongbin Provincial Key Laboratory of Information Coding and Transmission School of Information Science and TechnologySouthwest Jiaotong University College of Computing Science and Technology Chongqing University of Posts and Telecommunications School of Transportation and Logistics Southwest Jiaotong University Secure Networking and Computing Institute School of Computing Informatics and Decision Systems EngineeringArizona State University

In DVB-IPDC system, due to the constraints of handheld devices and the broadcast nature of wireless network, packet loss is inevitable. ECDR-NC proposed is a retransmission encoding packet selection algorithm based on the dynamic information updating, which can find the current most effective complete decoding packet. ECDR-NC can not only avoid the redundant encoding packets due to the overlapping among encoding packets, but also reduce the computational complexity compared with the traditional encoding schemes. Furthermore, the retransmission upper bound of ECDR-NC is fully controlled. In time-sensitive applications, to maximize the aggregate number of recovery packets while minimizing the total number of discarded packets due to the time limit according to the priority preference, the adaptive priority scheme EPNC is formulized, and the weighted relation graph is constructed to find the maximum-weighted encoding packets sequence according to the decoding gains. In the same network environment, the performances comparisons between PNC and EPNC show that EPNC is more efficient and more rational, and the average discarded packets ratios ofEPNC can be reduced about 18%~27%. The main contributions of this paper are an effective retransmission encoding packet selection algorithm ECDR-NC proposed, and a new adaptive priority recovery scheme EPNC introduced into DVB-IPDC system.

关键词： digital video broadcasting(DVB) retransmission network coding(NC) longterm evolution(LTE) wireless network

来源：评论

学校读者我要写书评

暂无评论

Improved singleton bound on frequency hopping sequences

Lecture Notes in Computer Science (including subseries Lectu...

引用

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2014年 8865卷 305-314页

作者： Liu, Xing Peng, Daiyuan Han, Hongyu Provincial Key Lab of Information Coding and Transmission Institute of Mobile Communications Southwest Jiaotong University Chengdu China

In this paper, a new bound on the frequency hopping (FH) sequences with respect to the size of the frequency slot set, the sequence length, the family size, and the maximum periodic Hamming correlation is established. The new bound is tighter than the Singleton bounds on the FH sequences derived by Ding et al. (2009) and Yang et al. (2011) and the bound derived by Liu and Peng (2013). © Springer International Publishing Switzerland 2014.

关键词： Frequency hopping

来源：评论

学校读者我要写书评

暂无评论

The Waveform analysis and signal processing for space-borne MIMO-SAR 9

The Waveform analysis and signal processing for space-borne ...

引用

9th European Conference on Synthetic Aperture Radar, EUSAR 2012

作者： Ping-Ping, Huang Heng-Chao, Li Fan, Feng Mo, Huang College of Information Fngineering Tnner Mongolia University of Technology China Sichuan Provincial Key Laboratory of Information Coding and Transmission Southwest Jiaotong University China Institute of Electronics Chinese Academy of Sciences China

ISBN: (纸本)9783800734047

For the urgent need of waveform suitable for Multiple-Input and Multiple-Output SAR, three kinds of waveforms, which are representative for the Multiple-Input and Multiple-Output SAR, are investigated and compared in this paper. The practicality of these waveforms are evaluated by performing the imaging simulation with the distribute target. The waveform separation and energy separation rules for echoes of Multiple-Input and Multiple-Output SAR are proposed On the basis of this, we arrive the conclusion that multiple aperture sub-band synthetic technique is an appropriate method to Multiple-Input and Multiple-Output SAR at the state-of-The-Art level. The principle and implementation steps are presented in detail, the corresponding filter is derived and the image algorithm is proposed. The effectiveness and feasibility of the method were demonstrated with computer simulaticns.

关键词： Synthetic aperture radar

来源：评论

学校读者我要写书评

暂无评论

Two Frequency Reuse Schemes in OFDMA-TDD Based Two-Hop Relay Networks

Two Frequency Reuse Schemes in OFDMA-TDD Based Two-Hop Relay...

引用

IEEE Conference on Wireless Communications and Networking

作者： Zhengguang Zhao Xuming Fang Ying Zhu Yan Long Provincial Key Lab of Information Coding & Transmission Southwest Jiaotong University Chengdu China

ISBN: (纸本)9781424463961;9781424463985

Frequency reuse scheme is extremely important in multi-hop relay networks (MRNs), because some extra frequency resource should be elaborately allocated to Relay Stations (RSs). However the time and spatial reuse characteristics of RS should be taken into account in order to mitigate the co-channel interference. This paper presents two adaptive frequency reuse schemes for MRN by using different reuse patterns in different time zones of the same frame. In our schemes, reuse pattern of 1×3×1 is applied in the Relay Zone (RZ), and 1 × 3 × 3 is applied in the Access Zone (AZ). The former allows only the two RSs which are located farthest apart in one cell to share the same frequency portion; while in the latter two adjacent RSs may share the same resources. Analysis and simulation results show that both schemes improve the system throughput greatly. The comparison of coverage and throughput between the two schemes indicates that the latter scheme has better performance and an aggressive full reuse scheme could be utilized to all RSs.

关键词： Relays Frequency Radio spectrum management Interchannel interference Analytical models Throughput WiMAX Land mobile radio cellular systems Communications Society Spread spectrum communication

来源：评论

学校读者我要写书评

暂无评论

Frequency hopping sequences with optimal partial Hamming correlation by interleaving techniques

Frequency hopping sequences with optimal partial Hamming cor...

引用

International Workshop on Signal Design and Its Applications in Communications (IWSDA)

作者： Xing Liu Daiyuan Peng Provincial Key Lab of Information Coding and Transmission Southwest Jiaotong University Chengdu China

In order to evaluate the goodness of frequency hopping (FH) sequence design, the periodic Hamming correlation function is used as an important measure. Usually, the length of correlation window is shorter than the period of the chosen FH sequence, so the study of the partial Hamming correlation of FH sequence is particularly important. In this paper, we first prove that there does not exist a strictly optimal FH sequence set of family size M and length N over a frequency slot set of size q with respect to the partial Hamming correlation bound when N > q 2 over M and q ≥ 2. In addition, we give a construction of FH sequences with optimal partial Hamming correlation by utilizing interleaving techniques.

关键词： Correlation Manganese Spread spectrum communication Frequency modulation Bluetooth Interference Encoding

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：