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. Illustrate Differential phase-shift keying?
In order to eliminate the need of a local carrier, DPSK has been developed in which the receiver uses the received signal to act as its own carrier. Figure shows the functions of a DPSK system in which the leftmost product operation along with 1-bit delay is the differential encoder. The digital signal d(t) is a polar waveform of levels ±1, corresponding to binary digits 1 and 0, respectively. The output signal a(t) from the differential encoder PSK-modulates a carrier to produce the DPSK signal sDPSK(t). The product device followed by the wide-band low-pass filter acts as the coherent detector. The two inputs to the product device are obtained from the output of a filter matched to the input pulse in a single bit interval. Note that the 1-bit delayed input to the product device serves the purpose of the local oscillator for the coherent detector; that is to say, the DPSK waveform in a given bit interval serves as its own local-oscillator signal in the following bit interval.
In Figure, si(t) is the signal component of the matched filter output, and sd(t)isthe signal component of the detector output. If the phases of both si(t) and si(t - Tb) are the same, sd(t) is then a positive voltage; if their phases differ by π radians, sd(t) will then be a negative voltage. These voltages will have maximum amplitudes at the sample time at the end of the bit interval. Because the sign of the voltage at the sampler depends upon the phase relationship between si(t) and its delayed replica, and the sign of sd(t) is of the same form as d(t), the original digital bit sequence can be determined by sampling to decide the sign of the detector output. Figure illustrates an example sequence of message binary digits, modulator wave- forms in DPSK, and phase and polarity relationships as applied to DPSK message recovery.
An ice plant produces 12tonn of ice per day at 0 0 C using water at 300C. The plant operates on reversed Carnot cycle between -15 0 C and 28 0 C. If the actual C.O.P. is 50% of the
Q. A separately excited dc generator with an armature-circuit resistance Ra is operating at a terminal voltage Vt, while delivering an armature current Ia, and has a constant loss
Consider an electromagnet, as shown in Figure, which is used to support a solid piece of steel and is excited by a coil of N = 1000 turns carrying a current i = 1.5 A. The cross-se
Q. Which are the different FET amplifiers? A FET can be used as a small-signal amplifier by connecting one of its lead to signal ground. The other two leads then serve as the i
explian briefly with in diagram and numerical examples
details
Buck Boost Converter The output of buck boost regulator may be less than or greater than the input voltage. Since the polarity of output voltage is opposite to that
do you have a place where I can draw the equation out ?
Research and recommend a sensor for a real full size conveyor system of approximately 1000mm width to detect objects of varying size passing along it. Discuss the suitability of th
Q. What do you know about Input Impedance? Input Impedance : Amplifiers will be quoted as having a specific input impedance. The sort of load it will place on preceding equipm
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