频率载波

基于混合频率载波调制的多电平PWM控制策略研究

Research on the hybrid frequency carrier-based multilevel PWM control strategy

该文在分析混合七电平逆变电路工作原理的基础上，提出了一种适合混合功率单元的混合频率载波PWM调制法。

The hybrid frequency carrier-based PWM control strategy adapted to hybrid power cells is presented in this paper based on the analysis of hybrid seven-level power conversion principle .

新算法可以自适应地调节本振频率跟踪载波频率的阶距，从而很好地缩短了AFC的跟踪时间和改进了频率校正的精度。

It adopts auto adaptive step to track the frequency offset , so that it can shorten the AFC ( Automatic frequency correction ) tracking period and improve frequency precision .

双频接收机可以接收具有L1、L2不同频率的载波信号，利用两个信号穿过电离层的延迟量不同，可以得出其电子含量。

Dual-frequency receiver can receive different frequencies carrier signals with L1 and L2 . Using the different delay amounts between two signals when they pass through the ionosphere , the electron content can be calculated .

对不同数字调制ASK、FSK、PSK、QAM和MSK，分别计算了其特定循环累积量，并证明其仅在循环频率等于载波频率时不为零的结论。

The special cyclic cumulants of various digital modulation formats : ASK , FSK , PSK , QAM and MSK , are calculated and proved to be nonzero only when the cyclo-frequency equals to the carrier frequency .

SCPC（单路载波）方式通过发射不同频率的载波信号来区分不同小站的信息，主要应用于点到点通信和站与站之间的连续比特数据流连接。

SCPC differentials the information from different VSATs by means of transmiting different frequency signals , which is mainly applied to point to point communication and VSAT to VSAT continuous bit connection .

PCM/FM遥测系统中用于去除多谱勒频率和载波频偏的新方法

A New Technique to Remove Doppler Frequency and Carrier Frequency Bias in PCM / FM Telemetry System

在典型的通信系统中，调制过程是数字信号加载在载波的幅度值、载波的频率或者载波的相位上。

In the model communications system , the modulation process also is loaded the digital signal in the carrier scope value , the carrier frequency or on the carrier phase .

然后采用对基带信号的数字预补偿方法来抑制镜像频率和载波泄漏，从而达到应用的目的。

Then we perform digital pre-compensation method , which can be used in the processing of base band signal to reject image frequency and protect carrier leak to meet the application purpose .

在稳态运行时，根据基波频率、载波频率和负载电流来改变电感值，以便获得较好的滤波效果和电气传动效果。

When the motor works in its steady state , the inductance of the output filter can be adjusted according to the inverter fundamental frequency , carrier frequency , and load current . A better filtering effect and better electrical driving effect can thus be achieved .

『正交频分复用（OFDM）是一种将通信信道分成多个等频率间隔子载波信道的通信技术。

Orthogonal Frequency Division Multiplexing ( OFDM ) is a communications technique that divides a communications channel into a number of equally spaced frequency bands .

而构成这种的关键器件之一就是频率锁定多载波光源。

So , the frequency-locked multicarrier is one of the key components .

载波频率同步是载波恢复的重要环节之一。

The most important section of carrier recovery subsystem is carrier frequency synchronization .

在发射端，测距伪码加载到一定频率的无线载波上。

In the transmitter , ranging pseudo-code is loaded into the wireless carrier with a certain frequency .

折射校正载波相位测量是由两组不同的基本频率宽巷载波相位测量组成。

Refraction correction carrier phase measurements is composition of two different sets of fundamental frequency wide-lane carrier phase measurement .

在数字化载波同步环路中，对于具有较大频率偏移的载波的跟踪，可以使用叉积自动频率跟踪算法以及频率开槽技术等，本文研究了它们的工作原理。

The algorithm of cross product automatic frequency control ( CPAFC ) and frequency bin technology is used for tracking larger frequency deviation .

分别分析了锁相环频率合成器，载波调制器和功率放大器的原理和指标，完成了电路搭建，版图绘制和发射测试。

Analyze the theory and parameters of PLL , modulator and amplifier . Finish building the circuits , plotting the layout and testing . 3 .

结果表明，射频信号的驱动电压，系统中偏振态的变化是影响频率锁定多载波光源产生的主要因素。

The results show that the radio frequency drive voltage , the variation of states of polarization are main factors to affect the generation of the frequency-locked multi-carrier source .

该解调器由载波频率恢复、载波相位恢复、符号同步3个环路为主要部分构成，具有良好的抗噪声性能、较低的系统差损和适中的算法复杂度。

This demodulator includes three sub-components as carrier frequency recovery loop , carrier phase recovery loop and symbol synchronization loop . This demodulator has a good performance at low SNR , low system loss and reasonable complexity .

该方法利用信号的瞬时频率来估计载波频率，并通过定位非微弱信号段和中值滤波有效地抑制了噪声和调制引起的瞬时频率的波动和冲激，来提高估计精度。

The method estimates carrier frequency from the signal 's instantaneous frequency , and improves the estimation precision by decreasing the wave and impulse of the signal 's instantaneous frequency through detecting signal 's better segments and median filtering .

讨论相控阵纤维光学信号分配网络的三个任务，这些任务是：（1）分配发射/接收（T/R）组件频率同步的载波参考信号；

Emphasis is put on the discussion of three tasks of fiber optic sig - nal distribution network for phased array , I , e. ,( 1 ) distribution of the car - rier reference signal for T / R modules with synchronous frequency ;

本文分析研究该系统的同步原理，其中包括接收机参考信号与所接收信号的定时同步的识别、定时同步的跟踪、载波频率跟踪及载波相位跟踪。

The basic principle of synchronization of the FD / SSMA system is studied in this paper , where recognizing and tracking of timing synchronization between the local reference signal and the received signal , tracking and locking of the frequency and phase of carrier are included .

在OFDM系统中，宽带子载波通过快速傅里变换（FFT）被分割为若干频率正交的子载波，每个用户可以分配到多个子载波同时进行数据传输。

In OFDM system , Broadband carrier is divided into a number of frequency orthogonal sub-carriers for data transmission by Fast Fourier Transform ( FFT ), each user can be assigned to a plurality of subcarriers .

针对等幅且各子载波等频率间隔的多载波信号，从瞬时包络功率出发，采用代数方法推导了一种降低峰值平均功率比（PAPR）的新相位方案。

For a multicarrier signal with equal amplitudes and equally spaced frequencies , a new phasing scheme to reduce the peak-to-average power ratio ( PAPR ) is derived from the instantaneous envelope power in an algebraic method in this paper .

地震检波器谐振频率频谱元件，载波频率。可指定频率类型。

Frequency spectrum element , carrier frequency . Frequency type can be specified .

频率选择性信道下单载波空时分组编码传输系统中的信道估计技术

Channel estimation in single-carrier systems with space-time block coded transmission over frequency-selective fading channels

频率同步分为载波频率同步和采样时钟同步两个部分。

Frequency synchronization is divided into two parts : the carrier frequency synchronization and the sampling clock synchronization .

最后用这些变量调节本地振荡频率，以跟踪载波频率。

Finally , these judged variables adjust the local oscillating frequency to track the carrier frequency by NCO .

考虑了两种情况：其一是取样频率与彩色副载波频率为非同步的，其二是取样频率为副载波频率的三倍。

One is that the sampling frequency and the color subcarrier frequency are non-synchronized and the other is that the sampling frequency is three times the subcarrier frequency .

当干扰信号和目标回波信号同时作用于引信时，只要干扰信号的载波频率同引信的载波频率，有可能使引信瞎火。

When the fuze receives the jamming along with the target echo signal , the jamming signal that has the same carrier frequency will have big influence on fuze .