Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. Explain Multiplexing Systems?
A multiplexing system is one in which two or more signals are transmitted jointly over the same transmission channel. There are two commonly used methods for signal multiplexing. In frequency-division multiplexing (FDM), various signals are translated to nonoverlapping frequency bands. The signals are demultiplexed for individual recovery by bandpass filtering at the destination. FDM may be used with either analog or discrete signal transmission. Time - division multiplexing (TDM), on the other hand, makes use of the fact that a sampled signal is off most of the time and the intervals between samples are available for the insertion of samples from other signals. TDM is usually employed in the transmission of discrete information. Let us now describe basic FDM and TDM systems.
Figure (a) shows a simple FDM system which is used in telephone communication systems. Each input is passed through a low-pass filter (LPF) so that all frequency components above 3 kHz are eliminated. It is then modulated onto individual subcarriers with 4-kHz spacing. While all subcarriers are synthesized from a master oscillator, the modulation is achieved with single sideband (SSB). The multiplexed signal, with a typical spectrum as shown in Figure (b), is formed by summing the SSB signals and a 60-kHz pilot carrier. The bandpass filters (BPFs) at the destination separate each SSB signal for product demodulation. Synchronization is achieved by obtaining the local oscillator waveforms from the pilot carrier. Telephone signals are often multiplexed in this fashion.
A basic TDM system is illustrated in Figure (a). Let us assume for simplicity that all three input signals have equal bandwidths W. A commutator or an electronic switch subsequently obtains a sample from each input every Ts seconds, thereby producing a multiplexed waveform with interleaved samples, as shown in Figure (b). Another synchronized commutator at the destination isolates and distributes the samples to a bank of low-pass filters (LPFs) for individual signal reconstruction.More sophisticated TDM systems are available inwhich the sampled values are converted to pulse modulation prior to multiplexing and carrier modulation is included after multiplexing. Integrated switching circuits have made the TDM implementation much simpler than FDM.
Stack Operation Stack is a group of memory locations which are part of the same read write memory used for storing data temporarily during the execution of the progra
advantages of constant current bias
Q. What is Frequency Translation and Product Modulation? The basic operation needed to build modulators is the multiplication of two signals. Whenever sinusoids are multiplied,
Q. What is a clipper circuit? Clipping circuits are linear wave shaping circuits. The main function of 'clipper' is that it clips off a part of input waveform i.e., it cut off
advantages and disadvantages
When recording infrasound waves or microwaves how do they vary from one another? Ans) By microwaves, do you mean "radio signals", like in a microwave oven? These have nothing t
Transmission And Distribution Losses - Electrical Energy Previously, you have learnt that there are inherent losses in transmission and distribution of electrical energy from
Q. A60-Hz, 100-kVA, 2400/240-V(rms) transformer is used as a step-down transformer from a transmission line to a distribution system. Consider the transformer to be ideal. (a) F
Q. Consider the circuit of Figure. Determine and sketch i L (t) and v C (t) for capacitance values of (a) 1/6 F, (b) 1/8 F, and (c) 1 / 26 F. Note that the capacitance values ar
You are given a binary image consisting of only zeros and ones, see image-A. Apply required morphological operations and give the output images on the grid.
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd