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垂直分层空时码(V-BLAST)是贝尔实验室提出的一种基于多入多出(MIMO)传输方式的空时码系统,其检测算法是MIMO系统的有效检测方法。首先介绍V-BLAST系统的信号模型,在此基础上应用不同的信号估计准则推导出不同的检测算法,最后通过仿真实验对各种算法的性能和优缺点进行了分析和比较。 相似文献
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基于MIMO的垂直分层空时码检测算法 总被引:1,自引:0,他引:1
分层空时码(BLAST)是贝尔实验室提出的一种基于多入多出(MIMO)传输方式的空时码系统。本文着重研究了BLAST系统中一类垂直分层空时码的检测算法,依据信号模型,分析推导了基于迫零准则和最小均方误差准则的估计算法,并在此基础上采用了以上算法与判决反馈及最佳排序思想结合的方法,使系统的误码率性能得到了提高。最后通过仿真实验比较了各种算法的性能和特点,结果表明分层空时码用于无线通信具有极大优势。 相似文献
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垂直分层空时码系统(V-BLAST)是贝尔实验室提出的一种基于多输入多输出(MIMO)传输方式的空时码系统。本文介绍了V-BLAST的系统模型、信道容量和Golden检测算法,并把该算法的仿真结果和单发单收系统的性能进行了比较。仿真结果显示V-BLAST系统比传统通信系统的频谱利用率要高。 相似文献
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无线通信系统中的MIMO空时编码技术 总被引:1,自引:0,他引:1
在无线通信系统中,对优质、高效宽带服务的要求不断增加。空时编码(STC)的目的是利用多输入多输出(MIMO)天线系统,提高传输质量,降低误码率,并获得较高的编码增益和分集增益,提高系统容量和频谱利用率。较详细地介绍了MIMO无线通信中的三种空时编码方案:分层空时码、空时格形码、空时分组码,对这三种方案进行了性能分析以及比较。 相似文献
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多输入多输出(MIMO)系统可以有效提高频谱效率和系统容量。基于MIMO系统重点研究了无线光通信垂直分层空时系统(V-BLAST)检测算法。首先分析了最大似然、线性迫零、最小均方误差以及排序干扰抵消等典型的传统检测算法,基于OOK调制和4PPM调制对采用不同检测算法的系统差错性能进行了仿真对比,最后对Turbo码与BLAST技术相结合构成的新系统采用了软输入软输出(SISO)迭代检测译码方案。仿真结果表明,分层空时检测算法中性能最优的是ML,其次是SISO-MAP,ZF算法性能最差;Turbo-BLAST系统可以有效提高无线光通信系统的抗干扰性能。 相似文献
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V-BLAST是一种基于多输入多输出传输的空时码系统,其检测算法是MIMO—OFDM系统的有效检测方法。本文介绍了应用于MIMO—OFDM信号检测的多种V-BLAST检测算法,并根据MATLAB仿真结果对各种算法的性能和优缺点进行了分析和比较。 相似文献
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针对多输入多输出(Multiple Input Multiple Output,MIMO)系统中空时分组码(Space-Time Block Code,STBC)的盲识别问题,提出了一种基于BP神经网络的空时码识别算法。首先对先前学者提出的基于空时相关矩阵的F范数在新的空时码集下的区分性进行了验证,并基于该范数设计了用于空时码识别的六维特征,最后使用BP神经网络对提取的六维特征进行分类以获得识别结果。相比于传统算法,本文算法可识别的空时码集更大;相比于深度学习的算法,本文算法在较为恶劣的瑞利信道下具有更高的识别率。仿真结果表明,所提算法在信噪比为10 dB时可达95%以上的识别率,且算法对不同的调制方式及不同程度的定时同步误差均具有较好的鲁棒性,识别过程无需要对信道信息进行预估计,在电子对抗等非协作场景下具有较好的应用价值。 相似文献
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基于LDPC码和MIMO的无线光通信系统性能 总被引:1,自引:0,他引:1
针对大气湍流严重影响无线光通信系统性能的问题,研究了基于低密度奇偶校验(LDPC)码和多输入多输出(MIMO)无线光通信系统性能,给出了基于LDPC码的空时编码MIMO(ST MIMO)和重复编码MIMO(rep MIMO)系统的解码算法,最后在对数正态模型和K分布模型下进行了仿真分析。仿真结果表明rep MIMO系统性能优于ST MIMO和单输入单输出(SISO)系统,ST MIMO在强湍流情况下性能明显优于SISO系统,基于LDPC码的ST MIMO和rep MIMO能取得10 dB以上的编码增益,并且编码增益随着湍流强度的增大而增加,基于LDPC码和rep MIMO的无线光通信系统差错性能更加优异,可以有效提高系统抗干扰能力。 相似文献
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Anastasopoulos A. Chugg K.M. Colavolpe G. Ferrari G. Raheli R. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2007,95(6):1272-1294
In this paper, we present an overview on the design of algorithms for iterative detection over channels with memory. The starting point for all the algorithms is the implementation of soft-input soft-ouput maximum a posteriori (MAP) symbol detection strategies for transmissions over channels encompassing unknown parameters, either stochastic or deterministic. The proposed solutions represent effective ways to reach this goal. The described algorithms are grouped into three categories: i) we first introduce algorithms for adaptive iterative detection, where the unknown channel parameters are explicitly estimated; ii) then, we consider finite-memory iterative detection algorithms, based on ad hoc truncation of the channel memory and often interpretable as based on an implicit estimation of the channel parameters; and iii) finally, we present a general detection-theoretic approach to derive optimal detection algorithms with polynomial complexity. A few illustrative numerical results are also presented. 相似文献
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系统地分析了Shearlet变换系数分布模型,提出了基于Shearlet变换的数字水印算法。将水印检测转化为二元假设检测问题,推导出了水印局域最优非线性检测的通用算法。分别采用拉普拉斯分布、柯西分布和广义高斯分布来对Shearlet变换系数统计分布进行拟合,推导出三种分布下水印检测算法并进行实验。结果显示,与传统的线性相关检测算法相比,这三种检测算法均获得好的检测性能,其中基于广义高斯分布的检测算法性能最佳。 相似文献
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We propose a general framework for trellis-based detection over channels with infinite memory. A general truncation assumption enables the definition of a trellis diagram, which takes into account a considered portion of the channel memory and possible coding memory at the transmitter side. It is shown that trellis-based maximum a posteriori (MAP) symbol detection algorithms, in the form of forward-backward (FB) algorithms, can be derived on the basis of this memory-truncation assumption. A general approach to the design of truncated-memory (TM) FB algorithms is proposed, and two main classes of algorithms, characterized by coupled and decoupled recursions, respectively, are presented. The complexity of the derived TM-FB algorithms is analyzed in detail. Moreover, it is shown that MAP sequence detection algorithms, based on the Viterbi algorithm, follow easily from one of the proposed classes. Looking backward at this duality between MAP symbol detection algorithms and MAP sequence detection algorithms, it is shown that previous solutions for one case can be systematically extended to the other case. The generality of the proposed framework is shown by considering various examples of stochastic channels. New detection algorithms, as well as generalizations of solutions previously published in the literature, are embedded in the proposed framework. The obtained results do suggest that the performance of the proposed detection algorithms ultimately depends on the truncation depth, almost regardless of the specific detection strategy. 相似文献
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介绍了当前网络舆情话题检测所广泛使用的算法,讨论了当前网络技术发展环境下海量网络信息对网络舆论突发事件中话题发现造成的影响。结合舆情监控系统的设计,详细阐述了热点发现的过程中几种算法的实现过程,并对几种算法进行了比较分析。 相似文献
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强噪声背景下车辆震动信号检测算法研究 总被引:1,自引:0,他引:1
针对强噪声背景下车辆震动信号检测问题,结合车辆震动信号特点,提出了2种检测算法:基于功率谱分布的检测算法和基于负熵的检测算法,并将小波去噪用于强噪声背景下地震动信号的提取。该算法与一般检测算法相比具有环境适应性强、检测准确率高和运算量小的特点,这些优点使得该算法更适用于能量受限、工作环境复杂的无线传感网络。仿真结果表明该算法具有很高的检测准确率。 相似文献
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The real-time measurement of various traffic parameters including queue parameters is required in many traffic situations such as accident and congestion monitoring and adjusting the timings of the traffic lights. In case of the queue detection, at least two algorithms have been proposed by previous researchers. Those algorithms are used for queue detection and are unable to measure queue parameters. The authors propose a method based on applying the combination of noise insensitive and simple algorithms on a number of sub-profiles (a one-pixel-wide key-region) along the road. The proposed queue detection algorithm consists of motion detection and vehicle detection operations, both based on extracting edges of the scene, to reduce the effects of variation of lighting conditions. To reduce the computation time, the motion detection operation continuously operates on all the sub-profiles, but the vehicle detection is only applied to the tail of the queue. The proposed algorithms have been implemented on an 80386-based microcomputer system and the whole system works in real-time 相似文献