EC DC 2marksmarks, DIGITAL COMMUNICATION Question Bank, DC Short Answers – ECE 5th SEM Anna University. 0. By vish on. 2. DIGITAL COMMUNICATION. State sampling theorem. If a finite –energy signal satellite communication two marks question and answers QUESTION BANK. Subject Code: EC Subject Name: Digital Communication Techniques. Year/Sem: III/IV. UNIT I PULSE MODULATION. PART A (2 Marks).

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Eye pattern is used to study the effect of ISI in baseband transmission.

Hence higher frequencies take the form of lower frequencies. The output is assigned a discrete value selected from a finite set of representation levels are reconstruction values that are aligned with the treads of the staircase.

Hence a PPM pulse of fixed width is produced after falling. Convolutional codes are difficult to analyze since their andwers is complex. Mention the use of adaptive quantizer in adaptive digital waveform co d ing schemes.

I slow frequency hopping and ii fast frequency hopping. What are the error detection and correction capabilities of hamming co d es?

What is meant by linear code? The sensitivity of the system to timing error is determined by the madks of closure of the eye as the sampling time is varied. I Slow frequency hopping II Fast frequency hopping This is called quantization. The n, k RS code takes the groups of m- bit symbols of incoming binary data stream.


EC Digital Communication – Two Marks and 16 Marks with Answers – All Units

Dirac comb is nothing but a periodic impulse train digitwl which the impulses are spaced by a time interval of Ts seconds. P arameter Direct sequence spread s pectrum F r e qu e n c y hop spread s p ectrum 1 Definition PN sequence of large bandwidth is mulitplied with narrow band data signal Data.

Maximum signal to noise ratio is the ratio of energy to psd of white noise. It also referred as pulse duration modulation or PDM. Most of the comjunication are made up of individual links in switched telephone network,the distortion induced depends upon 1 transmission characteristics of individual links 2 number of links in connection 8.

What is meant by systematic ex2301 non-systematic codes? Mention the merits of DPCM. It sends the information. The h0igher and lower MSK signal frequencies are given as, fH. Because of software implementation of decoding schemes they a re quite flexible compared to hardware implementation of other schemes. KWhat is the period of the maximal length sequence generated using 3 bit shift register.

EC2301 Digital Communication Question Bank – 16 Mark Questions | 5th Semester ECE Anna University

Define the principle of adaptive equalization? Compare between code tree and trellis diagram? Those systems need complex frequency synthesizers 2.

How to request Study Material? KWhat are the application of spread spectrum modulation. Hence it can be used to detect double errors or correct single errors. The pseudo-noise sequence and data sequence are applied to a product modulator.


A baseband signal receiver increases the signal to noise ratio at the instant of sampling. Pseudo noise sequence is a noise like high frequency signal. PN sequence 2 Effect of distance This system is distance relative Effect of distance is less in this system 3 Acquisition time Acquisition time is long Acquisition time is short Define spread spectrum communication Ans: Under such condition, the spectrum of the sampled signal overlaps with itself.

This interference of the frequency components is called as witg effect. This expressed in terms of message bits. T h e decoding schemes of BCH codes can be implemented on digital c o mputer. What is meant by cyclic codes? This ISI is known to. Let communicatkon PAM signal ak represents kth bit. A bandlimited signal of finite energy, which has no frequency components higher than W Hz, may be completely recovered from the knowledge of its samples taken at the rate of 2W samples per second.

What is nyquist Bandwidth? This ISI is known to receiver. Low delectability signal transmission or low probability intercept.