Application of Linear Inserting-Values Arithmetic and so on in UWA OFDM System's Frequency Field Equalization 线性插值算法等在OFDM水声通信系统频域均衡中的应用研究
An UWA spread-spectrum communication system was designed and realized by using the good performances of anti-multipath, anti-jamming and low SNR diction of spread-spectrum communication technology. 针对水下声信道的独特环境,利用扩频通信技术的抗多途、抗干扰、低信噪比检测等优良性能,设计并实现了一个水声扩频通信系统。
The ice cap on Uganda's highest peak has split because of global warming, Uganda's Wildlife Authority ( UWA) says. 乌干达野生动物保护局称,因为全球变暖,其国内最高峰的冰盖已经破裂。
In the fading channel with high noise, e.g.mobile communication channel and UWA channel, JSCC gets better performance than separated coding. 在严重噪声的衰落信道(移动通信信道、水声信道等)中,采用联合编码技术比采用分离编码技术更能获得令人满意的效果。
This article focuses on UWA channel modeling and simulation research. 本文主要进行水声信道的建模与仿真的研究工作。
Design and Implementation of an Adaptive High Speed UWA Voice Communication System 高速自适应水声语音系统的设计与实现
In addition, combined with OFDM technology, the image transmission system in UWA channel is set up. 并进一步结合OFDM技术,初步实现了水下图像的传输。
Underwater acoustic ( UWA) communication technology is the primer tool to study and develop the ocean. 火声通信技巧非研讨和开收海土的从要工具之一。
Channel equalization is of great necessary for the successful UWA communications because of the complexity of underwater acoustic channels. 由于海洋信道的复杂性,要实现可靠的水下声通信,必须进行有效的信道匹配。
With the LFM pulse frame synchronization method, the performance of UWA communication system based on DPSK is apparently improved. 同时运用线性调频脉冲帧同步法,改善了基于差分相移键控的水声数字通信系统的性能。
With the developments of advanced equalization and carrier synchronization techniques, the applications of high-speed phase coherent UWA communications seem more feasible. 随着性能更佳的均衡技术和载波同步技术的出现,使得相位相干通信技术在高速水声通信中的应用已成为可能。
A UWA channel model including the time-varying fading, multipath and additive noise is built. 建立了包括时变衰落、多途和加性干扰的水声信道模型。
A UWA communication system is designed, lake experiments are also conducted with several equalization methods being employed. One key of the techniques in underwater acoustic communication-synchronization technique is studied. 在吉林松花湖作了水声通信试验,验证了上述算法的仿真结论,并对水声通信的关键技术之一的相关同步技术进行了分析研究。
Discusses the unfavorable effects of the shallow water acoustic channels on data transmission, and objectively introduces recent certain advanced in UWA communication. 论文主要进行了以下几个方面的研究工作:1.分析了浅海声传输特点和对水声数据传输的不利影响,并较客观和全面地综述了浅海域水声通信技术的研究概况;
In this subject the PDS system is used to realize UWA communication. 在本课题中采用了PDS(Pattern-时延差编码)体制来实现水声通信。
Whereas, based on the principle that the sound intensity can cancel the isotropic noise and increase signal to noise ratio, the frequency modulation UWA communication technique by using acoustic vector sensor has also been studied. 基于声矢量传感器声强处理可以抵消各向同性干扰、提高信噪比的原理,研究了在频率调制的水声通信系统中,利用声强解码代替声压解码的方法。
A method of high resolution frequency estimation based on a single vector sensor using ESPRIT algorithm is proposed and applied to the underwater acoustic ( UWA) communication system of frequency modulation. 本文给出了基于矢量传感器的ESPRIT频率估计算法,并将其应用于频率调制水声通信系统中。
We deduce from theory that this method can reduce the time of acquisition, then the dissertation designs and implements a method of synchronization with correlated detection for UWA FH communication. 论文还设计并实现了一种采用相关检测方法的同步头方案实现水声跳频通信中的同步捕获;
The dissertation begins with the introduction of the underwater acoustic communication system, and is compactly devoted to the study on the synchronization and coding techniques in underwater acoustic communication, based on the analysis of the characteristics of UWA channels. 本文从介绍水声数字通信系统出发,基于对水声信道特性的分析,紧密围绕水声通信系统同步和编码技术展开研究。
The technology shows a good application promise on UWA communications. 仿真计算结果表明该技术在水下声通信中有很好的应用前景。
The limited channel bandwidth and ISI introduced by channel multipath propagation are the obstacles for underwater acoustic ( UWA) communications. Intersymbol interference ( ISI) caused by multipath propagation is one of the main challenges in high speed underwater acoustic communication. 受限的信道带宽和信号多途传输造成的码间干扰一直是水声通信的主要障碍。信号的多途传输引起的码间干扰是影响高速水声通信的主要障碍之一。
Along with the application field of underwater acoustic ( UWA), communication has expanded. How to realize the data transmission with high speed and to overcome intersymbol interference introduced by channel multipath propagation is very important. 随着水声通信应用领域的不断扩展,实现数据的高速传输和克服水声信道的码间干扰,成为水声通信技术研究的重点。
Firstly, the basic model and express form are introduced, also the necessity of channel estimation and equalization in OFDM UWA communication is discussed. 论文首先介绍了OFDM的基本模型和表示形式,在此基础上讨论了在OFDM水声通信中进行信道估计和均衡的必要性。
Underwater acoustic channel ( UWA) is a complex time-space-frequency varying environment. Multipath channel caused by ray bending and reflection at the boundaries is fundamental mechanism of intersymbol interference ( ISI). 水声信道是一种极其复杂多变的时-空-频变参信道,声线弯曲和界面反射引起的多途扩展导致了码间干扰。
Underwater acoustic ( UWA) communication which is not only used in military, but also used in commercial and civilian areas is an important field in underwater acoustic research. 水声通信一直是水声研究中的一个重要领域,它不但具有强烈的军事应用背景,更是商业和民用领域中不可或缺的水下数据传输手段。
In the future high-tech research fields, UWA communications technology has become an active research field. 在未来的高科技研究领域中,水声通信技术已成为研究热点之一。
In recent years, the efficiency and the quality of UWA is improved by introducing blind equalization and spread spectrum techniques. 近年来,将盲均衡和扩频技术引入到水声通信中,有效的提高了复杂水声信道的通信效率和质量。
The study of the key technologies for OFDM in high-speed UWA communication: In this paper, parts of the technologies for OFDM in high-speed UWA communication have been studied by simulations, and tested by the data collected on the lake and sea. 论文针对高速水声通信中OFDM的部分关键技术进行了仿真研究,并通过湖上和海上试验数据进行了验证。
These characteristics seriously affect the data transmission rate, reliable data communication, available radio range, the throughput of network and energy expended in UWA. 这些干扰严重影响了水声传感器网络的数据传输速率、数据通信的可靠性、有效的通信距离、网络的吞吐量和能量消耗。
However, poor conditions of transmission, serious noise background, time and frequency selective fading, the limited bandwidth of channel result in serious distortion of UWA communication signals. 但由于水声通信传输条件恶劣,存在严重的噪声背景,并且水下声信道的带宽十分有限,再加上复杂的多径传播和时间、频率选择性衰落,导致水声通信信号严重畸变。