What is the relation between modulation signal and carrier signal?
The modulation signal is the one containing the real information you want to share, whereas the carrier is a signal better suited to be transmitted, because lets you keep small the size both of the transmitter and the receiver, and one of its features(amplitude, phase or frequency)is modified following a particular criteria basing on the modulation signal in a way that lets you to reconstruct the latter by filtering the modified carrier.The reasons you need to do this are in the way aerials work regarding electromagnetic waves receiving and transmission. Without being too much technical, just be aware that the lower is the frequency of the signal you want to transmit, the longer the aerial has to be.For example, transmitting a signal in the range of KHz requires an aerial about a Km long. You surely understand it would be very unpractical.So the idea is this: you use a signal(the carrier) whose frequency lets you keep the aerial's length in the order of centimeters, you modify it as I mentioned above packing to it the real informations you want to share, and finally when you get it in the receiver you filter this modified carrier in order to reconstruct and isolate the original modulation signal. The kind of filtering you will have to apply depends on what kind of modulation you have performed(AM or FM).I hope I have helped you.
What is the difference between signals and information?
Signal is the actual entity that is transmitted from transmitter to receiver while the information is the content of the message signal or we can say knowledge that is communicated by the message signal.Signal carries the informationIn general,When somebody raise thumbs up-it will be a signal while the information is how we interpret it.Here in this case information will be ‘Approval’
What is significance of Modulation index?
significance of modulation index. It is used to determine the strength and quality of transmitted signal. If the modulation index is small, then the amount of variation in the carrier amplitude is small. Thus, the audio signal transmitted willnot be strong. The greater the degree of modulation, die stronger and clearer will be the audio signal during reception.
How can I filter a signal using just the spectrogram information?
It looks to me that your signal is well localized in time. You should be more specific about how you process your signal, how the signal is for different realization or if you can tell or not when your signal starts. Making lots of assumptions here, I will give you some rather naïve solution.If you process your data in fixed time frames, I will assume you have images like that coming and going. If you desire to detect that your signal is present and you are sure that the whole signal spectrum is capture inside your frames, you can fit ellipsoids to your spectrogram (treating it as an image and merging the unconnected regions). Finding a tilted ellipsoid you can say that your signal is present (the tilt can be seen by the non diagonal elements of your covariance matrix, eigenvectors, etc..). This is a very naïve way of using shape fitting for your data. Still, easier and more straightforward methods can be used, but your description of the nature of your problem, at least for me, is not that clear.
Organic-NMR spectra, draw an isomer from the given information?
The NMR spectra of two constitutional isomers having the formula C6H12Cl2 have resonance signals with the same ratio of protons and both show an upfield singlet (with integration of 9). The main difference is in the chemical shift of the multiplets given in the table below. isomer #1--signal @ delta 3.74 - 3.76 ppm, signal @ delta 3.49 ppm, delta 1.06 ppm there's information given about the second isomer, but we're only asked to draw the first one I drew it as having a tert butyl on one end and the 2 Cl on the other end, but it doesnt work....how is it supposed to look like?
From NMR, Find the formula?
Molecular formula is C7H14O , Base on its NMR spectra below , identify the structure At 2.11ppm, a singlet , 3H At 2.32 ppm, a singlet, 2H At 1.01ppm, a singlet , 9H Can you explain how to obtain to get the answer ? Thanks
What is modulation index?
What is Modulation Index?For AM Modulation (Amplitude Modulation): “Modulation Index is defined as the relationship between the amplitude of the Information signal and the amplitude of the carrier signal“.Modulation Index is the ratio.m=Vm/VcWhere:Vm is the amplitude voltage of modulating (Information) signal.Vc is the amplitude voltage of carrier signal.Multiplying the ratio of modulation index by 100 gives the percentage modulation.m=Vm/Vc*100For example, if the carrier voltage is 8 V and the modulating (information) signal voltage is 6.5 V, then the modulation index will be 0.8125Using the above equation it can be seen that a Modulation Index of 0.90 means that the signal will increase by a factor of 0.90 and also decrease to 0.10 of its original level.Importance of Modulation Index in AM Modulation:The modulation index is a ratio and hence the modulation index should be a number between 0 and 1.If the amplitude of the information signal voltage is higher than the carrier voltage, m will be greater than 1, causing distortion in AM wave.Vm>Vc (Distortion will occur)If the distortion is great enough, the information signal becomes not usable. Distortion of voice transmissions produces unnatural sounds or noise in the speaker. Distortion of video signals produces an inaccurate picture on a TV screen.Effect of Modulation Index on AM Modulation:Continue reading…Source: Modulation Index, | Depth of Modulation | and Percentage Modulation
What is the difference between a signal's modulation frequency and its EM wave frequency?
The carrier frequency is always quite a bit higher than the modulation frequency. That carrier is close to a pure sinusoidal tone at that frequency. The information that you want to transmit is used to make very small changes in that almost pure sine wave. That is, the signal is used to modulate the carrier. That modulation can be done in a number of ways. With amplitude modulation (AM), you vary the amplitude of the carrier to in proportion to the information signal you are sending. With frequency modulation (FM), you vary the frequency of the carrier a little bit in proportion to the information signal. It is also possible to vary the phase of the carrier (phase modulation). The receiver is tuned to the carrier frequency. But it takes several cycles of the carrier before the receiver will register the change in the carrier. That's why you have to modulate a lot slower than the carrier frequency. The carrier frequency is the electromagnetic frequency or the radio frequency (RF). If the 10 MHz in your example is referred to as the carrier frequency, then it is the RF frequency and not the modulation frequency. The modulation would be at a much lower frequency - say a factor of 10 lower. So the signal might vary at up to about 1 MHz.
What is the modulation index in amplitude modulation?
Modulation indices are described for various forms of modulation. The amplitude modulation, AM, modulation index can be defined as the measure of extent of amplitude variation about an un-modulated carrier.As with other modulation indices, the modulation index for amplitude modulation, AM, indicates the amount by which the modulated carrier varies around its static un-modulated level.When expressed as a percentage it is the same as the depth of modulation. In other words it can be expressed as: m=M/A.Where:m is the modulation index. A is the carrier amplitude. M is the modulation amplitude and is the peak change in the RF amplitude from its unmodulated value.From this it can be seen that for an AM modulation index of 0.5, the modulation causes the signal to increase by a factor of 0.5 and decrease to 0.5 of its original level.
What is the frequency range for optical signals?
For fiber optics communications we use light in the infrared region. They are 850 nm, 1300 nm, 1550 nm. These are represented in wavelength. To convert this into frequency there is a simple formula.f = c / λWhere f= frequency , c=speed of light (3x10^8 m/s), λ = wavelengthThe frequency of 850 nm is 3.5270x10^8 MHzThe frequency of 1300 nm is 2.3061x10^8 MHzThe frequency of 1550 nm is 1.9341x10^8 MHzBut usually we refer to their wavelength to identify them.