跳时

传统的抗干扰技术例如高速跳频，扩频编码以及跳时技术都是分别以频率域，时间域上的自由度资源为基础来获得抗干扰性能的提升的。

The traditional anti-jamming techniques - such as High-speed Frequency Hopping Technology , Spread Spectrum Coding Technology and Time Hopping Technology - are based on the degree of freedom in the frequency domain , or time domain to get the improvement of the anti-jamming performance .

UWB伪混沌跳时多帐篷映射及DSP实现方法研究

Pseudo-Chaotic Time Hopping with Multi-tent Map and DSP Scheme for UWB

跳时序列对UWB系统多址性能的影响

Effects of Time-Hopping Sequences on Multiple-Access Performance of Ultra-wideband Impulse Radio

UWB系统的一种改进型伪混沌跳时多址接入技术

An improved pseudo-chaotic time hopping scheme for UWB multiple access

而TH技术中的跳时序列的设计与其性能的分析则是它的一个关键方面。

The design of time-hopping sequence and performance analysis in TH technology is an important component of its aspects .

研究了基于跳时多址的UWB系统在多径环境中的多址接入干扰分析模型。

An analytical method of Multiple Access Interference ( MAI ) of the TH-UWB in the multipath circumstance is studied .

接着，在分析了基本的UWB波形的情况下，研究比较了采用跳时调制不同的数据调制方案。

Then , this dissertation analyses the basic UWB waveform and compares two different data modulation schemes which adopting time-hopping modulation .

提出了在跳时（TH）脉冲位置调制（PPM）通信系统中的同步相关算法，主要对仿真链路中的接收机进行设计和实现，其中包括信号检测、伪随机序列捕获、数据同步等。

And it presents the synchronization-correlation algorithm in TH PPM communication systems , including UWB signal detection , PN sequences acquisition , and data synchronization .

通过分析比较：采用高斯信号波形，进行脉冲位置调制方式及跳时技术，UWB能够在误码率、系统实现等方面取得较好的性能。

At last , it concludes that the performance is good and realization is easy for UWB with pulse position modulation , gauss waveform and TH technology .

通过分析脉冲的各个多径分量与之后发送的脉冲的时间差的分布，得到了跳时UWB的码间干扰估算公式。

Based on analysis of the probability distribution of the time between the reflections of former pulse and the latter one , an estimated formula of ICI is derived .

与采用等间距发送脉冲时的码间干扰对比，结果显示，随着脉冲重复周期增大，跳时UWB的码间干扰的改善的速度比等间距发送脉冲时缓慢。

The analysis shows that the improvement of ICI from increasing the pulse repetition period is slower than equidistance transmitting pulse when the manner of transmitting pulse is time hopping .

直到1993年，美国学者R.A.Scholtz发表论文论证了采用冲激脉冲进行跳时调制的多址技术，使UWB技术的发展重新繁荣。

Until 1993 , the American scholar R. A. Scholtz published a famous paper in Milcom '93 proposed the multiple access technology using the impulse radio to implement the Time-Hopping modulation .

为了使脉冲均匀的分布在时域上，IR-UWB系统一般采用跳时序列控制脉冲发送的时刻，不同的跳时序列确定了不同的跳时逻辑信道，数据传输可以在不同的跳时信道上同时进行。

In order to transmit pulse signal uniformly on the time domain , IR-UWB system uses the time-hopping sequence to control the transmission of pulse .

结果：分别在F1和F2点测得光击穿及空化气泡闭合与反跳时产生的声压脉冲信号；用石膏小球进行了碎石演示性实验，取得初步结果。

Results : We measured the pulse sound pressure from water broken down and bubble collapse near F 1 and F 2 respectively and made the simulated lithoclastic experiments for a small plaster ball .

跳时-脉冲位置调制方式（TH-PPMTime-HoppingPulsePositionModulation）是IR-UWB系统中最常用的多址调制方式之一，针对该多址方式的性能分析一直是UWB技术研究的一个热点。

The Time-Hopping Pulse Position Modulation ( TH-PPM ) is one of the most popular approaches for IR-UWB multi-user systems , and a lot of research efforts have been devoted on its performance analysis .

在此基础上，比较了在PPM调制方式下基于这几类二次跳时序列的UWB系统的误码率，并给出了数值结果。

Based on the discussion and comparison , the error rate of the ultra-wide band ( UWB ) systems with these quadratic time-hopping sequences and pulse position modulation ( PPM ) were compared , and the numerical results were presented .

然后，确定跳时UWB通信系统的信道模型，选定接收端的判决信号的判决方法，建立相关接收的数学模型，分析相关接收的抗噪声性能。

Then , the channel model of time-hopping UWB communication system is established and the decision method of signal in the receiver is selected . Besides , math model of correlation receiving is established and antinoise performance of correlation receiving is analyzed .

THMA技术对不同用户采用伪随机跳时序列区分，实现了多址接入。

THMA technique uses varied pseudo-random TH sequences to distinguish the corresponding users to realize the multiple access .

分析跳时序列在跳时脉冲位置调制（TH-PPM）超宽带无线电系统中的作用及对系统性能的影响。

This paper investigates the specific role of time-hopping sequences in the time-hopping pulse position modulation ultra-wideband system and its effect on the BER performance of the system .

该方案采用正交可变扩频因子（OVSF）与跳时相结合，使系统支持可变速率要求。

The hybrid multiple access scheme , OVSF-TH , was presented based on the orthogonal variable spread factor ( OVSF ), and a corresponding correlation mask for this scheme was designed .

改变了Merton期权定价模型的基本假设，认为股票价格的跳跃过程为一类特殊的复合Poisson过程且无跳时的波动率为时间的函数，建立了股票价格服从跳扩散过程的行为模型。

By changing basic assumption of Merton option pricing model to the assumption that jump process is a kind of special compound Poisson process and volatility without jump is the function of time , it is established that the behavior model of the stock pricing process is jump-diffusion process .

针对跳时脉位调制（TH-PPM）的超宽带系统信号离散功率谱分量集中、易引起多址干扰的缺点，引入了基于Tent映射的混沌脉位调制（CPPM）UWB系统。

Using Time-Hopping pulse position modulation ( TH-PPM ), an UWB system has some disadvantages that the discrete power spectral density ( PSD ) is centralized and may arouse multiple-access interference . An UWB system utilizing chaotic pulse position modulation ( CPPM ) based on Tent map was introduced .

该文简要说明了JTIDS的工作方式，从JTIDS系统的数据模型入手，完成了包括RS编码、交织编码、软扩频、MSK调制、跳频、跳时在内的整个JTIDS系统仿真。

The brief working process is illuminated in the paper . The simulation of whole working process , including Reed Solomon encoding , tamed spread spectrum , MSK modulation and demodulation , frequency hopped and time hopped , is introduced in this paper starting with the data model of JTIDS .

跳时脉位调制超宽带信号的功率谱密度分析

The power spectrum density analysis of TH-PPM ultra-wide band signals

在第三次跳时，那个跳高运动员跳过了2.34米。

At his third attempt , the high jumper cleared 2.34 meters .

混沌跳时脉冲调幅超宽带系统设计与分析

Design and analysis of a chaotic time-hopping PAM UWB system

第二跳时，则犯规更严重。

On the second jump , I fouled even worse .

他从汽车往下跳时手臂受了伤。

He injured his arm as he jumped clear of the car .

两段式双稳半导体激光器上跳时参量的变化

Changes of operation parameters of two-contact bistable laser diodes at switch-on currents

跳时序列在超宽带系统中的应用

The application of some time-hopping sequences for ultra wideband radio