Previous year question hub

Digital Communications - Communications - Electronics & Communication Engineering Previous Year Questions

Practice Digital Communications - Communications - Electronics & Communication Engineering previous year questions organised from real papers, with year-wise coverage and clear topic navigation.

25Papers

17Years

62Questions

1Topics

Digital Communications question pattern

Every graph below is calculated only from this selection.

Questions by year

Compare question counts across years.

Difficulty distribution

How the classified questions are distributed by difficulty.

62questions

Medium 44 71%

Easy 17 27.4%

Hard 1 1.6%

Question type distribution

MCQ, numerical, multiple-select and other formats found in these papers.

62questions

MCQ 45 72.6%

Numerical Answer Type (NAT) 16 25.8%

Fill in the blanks 1 1.6%

Subject weightage

Top subjects by unique question coverage.

Electronics & Communication Engineering

62 Qs

Most asked topics

Top topics across the included previous year papers.

Communications

62 Qs

Subtopic coverage

Top subtopics inside this exact selection.

Digital Communications

62 Qs

Paper coverage

Question coverage for the most populated papers. Every active PYP paper remains listed below.

Electronics and Communication Engineering (EC) 2026

4 Qs

Electronics & Communication Engineering (EC) 2025

2 Qs

Electronics & Communication Engineering (EC) 2024

2 Qs

Electronics & Communication Engineering (EC) 2022

2 Qs

Electronics & Communication Engineering (EC) 2021

3 Qs

Electronics & Communication Engineering (EC) 2020

2 Qs

Electronics & Communication Engineering (EC) 2019

1 Qs

Electronics & Communication Engineering (EC) 2017 [Session 1]

3 Qs

Electronics & Communication Engineering (EC) 2017

1 Qs

Electronics & Communication Engineering (EC) 2017 [Session 2]

1 Qs

Electronics & Communication Engineering (EC) 2016 [Session 2]

3 Qs

Electronics & Communication Engineering (EC) 2016 [Session 1]

2 Qs

Electronics & Communication Engineering (EC) 2016 [Session 3]

1 Qs

Electronics & Communication Engineering (EC) 2014 [Session 4]

3 Qs

Electronics & Communication Engineering (EC) 2014 [Session 2]

1 Qs

Electronics & Communication Engineering (EC) 2013 [Session 1]

3 Qs

Electronics & Communication Engineering (EC) 2013 [Session 2]

3 Qs

Electronics & Communication Engineering (EC) 2013 [Session 3]

3 Qs

Electronics & Communication Engineering (EC) 2013 [Session 4]

3 Qs

Electronics & Communication Engineering (EC) 2012

2 Qs

Electronics & Communication Engineering (EC) 2011

2 Qs

Electronics & Communication Engineering (EC) 2010

2 Qs

Electronics & Communication Engineering (EC) 2009

1 Qs

Electronics & Communication Engineering (EC) 2008

5 Qs

Electronics & Communication Engineering (EC) 2007

7 Qs

Included previous year papers

Newest papers appear first. Search these papers or sort by year and name.

Paper name	Year	PDF
Electronics and Communication Engineering (EC) 20262026 4 questions in this view	2026	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download Official answer keyOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20252025 2 questions in this view	2025	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download Official answer keyOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20242024 2 questions in this view	2024	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download Official answer keyOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20222022 2 questions in this view	2022	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download Official answer keyOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20212021 3 questions in this view	2021	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download Official answer keyOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20202020 2 questions in this view	2020	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20192019 1 questions in this view	2019	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20172017 1 questions in this view	2017	ExamElite PDFs ExamElite solutions
Electronics & Communication Engineering (EC) 2017 [Session 1]2017 3 questions in this view	2017	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2017 [Session 2]2017 1 questions in this view	2017	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2016 [Session 1]2016 2 questions in this view	2016	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2016 [Session 2]2016 3 questions in this view	2016	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2016 [Session 3]2016 1 questions in this view	2016	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2014 [Session 2]2014 1 questions in this view	2014	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2014 [Session 4]2014 3 questions in this view	2014	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2013 [Session 1]2013 3 questions in this view	2013	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2013 [Session 2]2013 3 questions in this view	2013	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2013 [Session 3]2013 3 questions in this view	2013	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 2013 [Session 4]2013 3 questions in this view	2013	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20122012 2 questions in this view	2012	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20112011 2 questions in this view	2011	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20102010 2 questions in this view	2010	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20092009 1 questions in this view	2009	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20082008 5 questions in this view	2008	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download
Electronics & Communication Engineering (EC) 20072007 7 questions in this view	2007	ExamElite PDFs ExamElite solutions Official documents Official question paperOriginal authority-issued PDF Official Download

All Digital Communications previous year questions

Practice every matching question in batches of 20, with every available option.

2007 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2007

In delta modulation, the slope overload distortion can be reduced by

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2007 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2007

The raised cosine pulse \(p(t)\) is used for zero ISI in digital communications. The expression for \(p(t)\) with unity roll-off factor is given by \(p(t) = \frac{\sin 4\pi Wt}{4\pi Wt(1-16W^2t^2)}\). The value of \(p(t)\) at \(t = \frac{1}{4W}\) is

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2007 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2007

During transmission over a certain binary communication channel, bit errors occur independently with probability \(p\). The probability of AT MOST one bit in error in a block of \(n\) bits is given by

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2007 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2007

In a Direct Sequence CDMA system the chip rate is \(1.2288 \times 10^6\) chips per second. If the processing gain is desired to be AT LEAST 100, the data rate

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2007 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2007

The ratio of the average energy of Constellation 1 to the average energy of Constellation 2 is

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2007 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2007

If these constellations are used for digital communications over an AWGN channel, then which of the following statements is true?

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2007 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2007

Assuming that the reconstruction levels of the quantizer are the mid-points of the decision boundaries, the ratio of signal power to quantization noise power is

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2008 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2008

Consider a Binary Symmetric Channel (BSC) with probability of error being p. To transmit a bit, say 1, we transmit a sequence of three 1s. The receiver will interpret the received sequence to represent 1 if at least two bits are 1. The probability that the transmitted bit will be received in error is

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2008 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2008

Four messages band limited to W, W, 2W and 3W respectively are to be multiplexed using Time Division Multiplexing (TDM). The minimum bandwidth required for transmission of this TDM signal is

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2008 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2008

A speech signal, band limited to 4 kHz and peak voltage varying between +5V and -5V, is sampled at the Nyquist rate. Each sample is quantized and represented by 8 bits.
If the bits 0 and 1 are transmitted using bipolar pulses, the minimum bandwidth required for distortion free transmission is

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2008 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2008

Assuming the signal to be uniformly distributed between its peak to peak value, the signal to noise ratio at the quantizer output is

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2008 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2008

The number of quantization levels required to reduce the quantization noise by a factor of 4 would be

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2009 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2009

If the positive values of the signal are uniformly quantized with a step size of 0.05 V, and the negative values are uniformly quantized with a step size of 0.1 V, the resulting signal to quantization noise ratio is approximately

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2010 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2010

Consider the pulse shape s(t) as shown. The impulse response h(t) of the filter matched to this pulse is

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2010 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2010

The probability of bit error is

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2011 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2011

For the constraint that the minimum distance between pairs of signal points be d for both constellations, the radii r₁ and r₂ of the circles are

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2011 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2011

Assuming high SNR and that all signals are equally probable, the additional average transmitted signal energy required by the 8-PSK signal to achieve the same error probability as the 4-PSK signal is

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2012 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2012

In a baseband communications link, frequencies upto 3500 Hz are used for signaling. Using a raised cosine pulse with 75% excess bandwidth and for no inter-symbol interference, the maximum possible signaling rate in symbols per second is

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2012 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2012

A BPSK scheme operating over an AWGN channel with noise power spectral density of \( N_0/2 \), uses equiprobable signals \( s_1(t) = \sqrt{\frac{2E}{T}} \sin(\omega_c t) \) and \( s_2(t) = -\sqrt{\frac{2E}{T}} \sin(\omega_c t) \) over the symbol interval (0, T). If the local oscillator in a coherent receiver is ahead in phase by 45° with respect to the received signal, the probability of error in the resulting system is

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2013 · Electronics & Communication Engineering · Communications · Digital Communications

Electronics & Communication Engineering (EC) 2013 [Session 1]

The bit rate of a digital communication system is \( R \) kbits/s. The modulation used is 32-QAM. The minimum bandwidth required for ISI free transmission is

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Digital Communications - Communications - Electronics & Communication Engineering Previous Year Questions