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.
Q. When input is a triangular wave. When the input fed to differentiating circuit is a triangular wave, the output will be a rectangular wave. During the period OA of
Q. Explain Position servo in a radar system? Figure depicts the essential elements of a position servo system. In a radar system, an electromagnetic pulse is radiated from an a
I can,t connect a new subsystem of solar module with a capacitor and inductor why and how to solve
Explain virtual memory. The term virtual memory considers as to something that appears to be present but in fact it is not. The virtual memory technique permits users to use m
Q. Explain about Register marker? Register marker: Stronger selectors perform searching and counting . Though, the crossbar switch has no ‘intelligence'. Something external to
This example is concerned with steady-state sinusoidal analysis by using mesh equations and MATLAB. Let us consider the circuit shown in Figure and find the input impedance at the
Q. Write down Shockley's equation. What is its importance? I D = I DSS [1-(V GS /V P )]^2 Shockley's equation is used to plot transfer characteristics. The transfer charac
singly excited magnetic systems
Determine phase - voltage and power: A balanced star connected load is supplied from a symmetrical 3-phase 440 Volt system. The current in each of the phase is 40 Amp and lags
Explain Dielectric constant. Dielectric constant: This is also termed as 'Permittivity'. All insulating material possesses an electrical capacitance. Such capacitance of unit d
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