通信原理-绪论(Principles of communication - Introduction) Television has dramatically changed people's lives, transmitting and communicating information from single voices to real-time images. Transfer and exchange information from single sound to real time images. (5) electronic computer. Computers are ...
In amplitude modulation, the amplitude of a high-frequency wave is varied in accordance with the signal to be transmitted. This variation may, in the most simple case (which is, in fact, a quite complicated case), consist of an on and off condition of the carrier, representing the ...
However, the spectrum of the modulated signal actually has seven different tones. In the center is the 1340 kHz carrier wave. The amplitude modulation process creates three new tones at frequencies just above the carrier wave, as well as a mirror image of these tones just below the carrier ...
It describes the basic principles of PCM, namely one channel and video transmission. In a PCM system, the primary signal function with its subtle amplitude variations is transformed into a secondary signal. This signal is merely a sequence of on-off pulses, or marks and spaces where the pulse...
UNIT I AMPLITUDE MODULATIONPrinciples of amplitude modulation - AM envelope - frequency spectrum and bandwidth modulation index and percent modulation - AM... DYSE Iii/V 被引量: 0发表: 0年 Introduction to Communication Systems, 3rd edition This textbook presents an introduction to communication system...
Pulse code modulation (PCM) is a digital representation of analog signals whose amplitude is sampled at regular intervals. Each sample is then quantized to the nearest value within a range of digital steps. PCM is widely used for processing digital audio s...
Lock-in amplifiers for phase detection also have the added benefit of measuring the signal amplitude. This can be used for other control mechanisms, such as automatic gain control (AGC). The amplitude R and the phase θ can be easily derived from the measured in-phase X and quadrature Y th...
Pulse code modulation (PCM) is a digital representation of analog signals whose amplitude is sampled at regular intervals. Each sample is then quantized to the nearest value within a range of digital steps. PCM is widely used for processing digital audio signals. TDM After analog signals are con...
Chapter3 ModulationTechniqueswith EmphasisonAnalogSystems 3.1Problems Problem3.1 Thedemodulatedoutput,ingeneral,is y D (t)=Lpfx c (t)2cos[! c t+ (t)]g whereLpf gdenotesthelowpassportionoftheargument.With x c (t)=A c m(t)cos[! c t+ 0 ] thedemodulatedoutputbecomes y D (t)=Lpf2A...
3 Amplitude Modulation Fundamentals 4 Amplitude Modulator and Demodulator Circuits 5 Fundamentals of Frequency Modulation 6 FM Circuits ··· (更多) 我来说两句 短评 ··· 热门 还没人写过短评呢 我要写书评 Principles of Electronic Communication Systems的书评 ··· ( 全部0 条 ) 论坛 ·...