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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Cyclic codes are the subclasses of linear block codes. A code is linear if modulo-2 sum of any two code vectors produces another code vector. What should be the minimum bandwidth required to transmit a PCM c h a nn e l? The quantization levels are fixed depending upon the number of bits. In adaptive delta markss, the step size is adjusted as per the slope of the input signal. This ecc2301 shows that error probability depends only on energy but not on shape of the signal.

When b t changes level, phase of the carrier is changed.

This code vector is also called block. PDM represents the input signal amplitude in the form of width of the pulse. While converting the communicqtion value from analog to digital, quantization is performed. This ISI is known to receiver. Jamming margin is the ratio of average power of interference J to average power of data signal P.


This special code is known. Environmental science and engineering Two Marks Wi Hence it can be used to detect double errors or correct single errors. State four applications of spread spectrum.

Define constraint length in convolutional code? The bit rate of such schemes is reduced due to adaptive quantization. In coherent detection, the local carrier generated at the receiver is phase locked with the carrier at the mrks. Correlator is the coherent receiver. The distance effect is less. Convolutional codes are not developed much as compared to block codes. K symbols Parity check size: PN sequence of large commmunication is mulitplied with narrow band data signal.

The signal to quantization noise ratio in a PCM system depends on wh a t criteria?

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

A baseband signal receiver increases the signal to noise ratio at the instant of sampling. Quantization is performed in every Analog to Digital Conversion. The sc2301 characteristics keep on changing. Constraint length is the number of shift over which the single message bit can influence the encoder output. This special code is known only.

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

The output is assigned a discrete value selected from commmunication finite set of representation levels are reconstruction values that are aligned with the treads of the staircase. This ISI is known to. In adaptive coding, the quantization step size and prediction filter coefficients are changed as per properties of input signal.


I Slow frequency hopping II Fast frequency hopping They need error correction. Eye pattern is used to study the effect of ISI in baseband transmission. Newer Post Older Post Home. In this method the local carrier generated at the receiver is phase locked with the carrier at the transmitter.

Hence fixed pair of transmit and receive filters will not serve the equalization problem.

Thus pseudo-noise sequence acts as high frequency carrier and data sequence acts as low frequency modulating signal. Therefore adaptive equalization is used. November 19, 0.

A bandlimited signal of finite energy, which ecc2301 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.

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