If you are a technical expert in computer skills and have interests in marketing as well, then you can build up a career in digital communication. Today a number of companies require the efforts of Digital communication professionals to help them coordinate their online marketing efforts. Wisdomjobs provides you with all the digital communication job opportunities available such as digital content management, content marketing expert and digital media operators. As a digital communication operator you will be able to publish your content on websites, provide online information about the products and can also work on blog postings and make information videos. All the information regarding the qualification, training and answers to job related queries are available to you on our wisdomjobs page. A list of digital communication job interview questions and answers, have been provided to you, to help you find your dream job easily.
Answer :
For a given bit rate 1/Tb, a QPSK wave requires half the transmission bandwidth of the corresponding binary PSK wave. Equivalently for a given transmission bandwidth, a QPSK wave carries twice as many bits of information as the corresponding binary PSK wave
Question 2. Give The Equation For Average Probability Of Symbol Error For Coherent Binary Psk?
Answer :
Average probability of signal error,
Pe = 1 / 2 erfc? Eb / No
Answer :
QPSK is Quadriphase –shift keying. In QPSK the phase of the carrier takes on one of the four equally spaced values Such as ?/4 , 3?/4, 5?/4 and 7?/4.
Answer :
dibits 10, 00, 01 & 11
Question 5. Give The Two Basic Operation Of Dpsk Transmitter?
Answer :
Question 6. Define Information Capacity?
Answer :
Information capacity represents the number of independent symbols that can be carried in the system for a given time.
Question 7. What Is The Unit Of Information Capacity?
Answer :
Unit is bits per second
Question 8. Why Digital Amplitude Modulation Is Commonly Called On –off Keying?
Answer :
Carrier is either in ON or Off state so it is called as On Off Keying.
Question 9. Why Digital Amplitude Modulation Is Called As Continuous Wave Modulation?
Answer :
When the carrier is being transmitted it has constant amplitude, constant frequency and constant phase.
Answer :
The rate of change at the input to the modulation is called bit ra and is expressed in bits per second.
Answer :
Baud is the rate of change and is equal to the reciprocal of one signaling element.
Question 12. Define Phase Reversal Keying?
Answer :
Since Phase of the output carrier shifts between two phases PSK is also called as Phase reversal keying.
Question 13. What Is Offset Qpsk?
Answer :
IT is a modified form of QPSK where the bit waveforms on the I and Q channels are offset or phase shifted in phase from each other one by one half of a bit time.
Question 14. What Is Eight Phase Psk?
Answer :
Eight Phase PSK (8-PSK) is an M-ary encoding technique where M=8.
Question 15. What Is The Need Of Maximum Distance Code?
Answer :
It is used to reduce the number of transmission errors.
Question 16. What Is Quad Bits?
Answer :
A 16 bit PSK modulator acts on the incoming data in groups of four bit is called Quad bits.
Answer :
DPSK is the difference between two successive signalling elements rather than the absolute phase.
Question 18. What Is The Need For Ber?
Answer :
Bit error Rate is the empirical record of Systems actual bit error performance.
Digital Communication Practice Test
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