56 + Interview Questions in Fading Channels in Digital Communications Page 1 InterviewSolution

1.	How can frequency selective distortion be minimized?(a) By using pilot signal(b) By adaptive equalization(c) By spread spectrum(d) All of the mentionedI got this question in my homework.This question is from Effects of Fading and Decision Theory topic in chapter Fading Channels of Digital Communications
Answer» Right CHOICE is (d) All of the mentioned For explanation I would SAY: FREQUENCY selective DISTORTION can be minimized by using adaptive equalization, by using spread SPECTRUM, by using pilot signal and also by using orthogonal FDM modulation.

Discussion

2.	Fading channel has memory.(a) True(b) FalseI had been asked this question in an online quiz.This question is from Effects of Fading and Decision Theory topic in portion Fading Channels of Digital Communications
Answer» Correct option is (a) True The BEST EXPLANATION: FADING channel has memory and the received SAMPLES are correlated with each other in time.

Discussion

3.	What are the parameters calculated for an estimator?(a) Error(b) Mean square error(c) Variance(d) All of the mentionedI have been asked this question during an online exam.My query is from Effects of Fading and Decision Theory in section Fading Channels of Digital Communications
Answer» Correct choice is (d) All of the mentioned To elaborate: Some of the parameters CALCULATED for an estimator are error, mean SQUARE error, VARIANCE, SAMPLING deviation etc.

Discussion

4.	For neyman pearson decision criterion, which are important?(a) Probability of false alarm(b) Probability of miss(c) Probability of false alarm & miss(d) None of the mentionedThe question was asked in exam.Enquiry is from Effects of Fading and Decision Theory topic in section Fading Channels of Digital Communications
Answer» The correct CHOICE is (c) Probability of false alarm & miss Easy EXPLANATION: For neyman pearson decision criterion two probabilities are IMPORTANT – probability of false alarm and probability of miss.

Discussion

5.	Which signal sets are called as equivalent signal sets?(a) Simplex(b) Bi-orthogonal(c) Simplex & Bi-orthogonal(d) None of the mentionedThe question was asked in my homework.This question is from Effects of Fading and Decision Theory topic in chapter Fading Channels of Digital Communications
Answer» Right option is (C) SIMPLEX & Bi-orthogonal The best EXPLANATION: Simplex signals and bi-orthogonal signals are examples of equivalent signal SETS.

Discussion

6.	Symbol error probability can also be determined using upper bound.(a) True(b) FalseThis question was posed to me in an online quiz.My doubt is from Effects of Fading and Decision Theory topic in section Fading Channels of Digital Communications
Answer» RIGHT option is (a) True For explanation: CERTAIN signals lacks symmetry in representation. For those signals SYMBOL error probability can be determined by using upper bound.

Discussion

7.	Which has higher transmission rate?(a) BPSK(b) 16-QAM(c) BPSK & 16-QAM(d) None of the mentionedI had been asked this question in an online interview.This question is from Effects of Fading and Decision Theory topic in section Fading Channels of Digital Communications
Answer» Correct OPTION is (b) 16-QAM The best EXPLANATION: The rate of transmission of bits in 16-QAM is four TIMES that of BPSK.

Discussion

8.	Which needs more signal power?(a) BPSK(b) 16-QAM(c) BPSK & 16-QAM(d) None of the mentionedI got this question by my college professor while I was bunking the class.The query is from Effects of Fading and Decision Theory in chapter Fading Channels of Digital Communications
Answer» The correct CHOICE is (b) 16-QAM Explanation: 16-QAM needs ten times more SIGNAL power than BPSK to attain the same probability of error.

Discussion

9.	In matched filter _______ is performed.(a) Convolution(b) Correlation(c) Convolution & Correlation(d) None of the mentionedThis question was posed to me by my college director while I was bunking the class.My enquiry is from Effects of Fading and Decision Theory topic in section Fading Channels of Digital Communications
Answer» Correct answer is (C) Convolution & Correlation The BEST explanation: In matched filter a known signal is correlated with an unknown signal. It is SIMILAR to convolving a unknown signal with time REVERSED VERSION of it.

Discussion

10.	The inter-leaver is more effective if the vehicle is(a) Fast(b) Slow(c) Fast & Slow(d) None of the mentionedThe question was posed to me during an interview for a job.The question is from Effects of Fading and Decision Theory topic in portion Fading Channels of Digital Communications
Answer»

Discussion

11.	Which noise component plays a role in decision making?(a) Relevant noise(b) Non relevant noise(c) Relevant & Non relevant noise(d) None of the mentionedThe question was asked in final exam.My enquiry is from Effects of Fading and Decision Theory topic in chapter Fading Channels of Digital Communications
Answer» The correct option is (a) Relevant NOISE For EXPLANATION: Only the relevant noise components PLAY an important role in decision making. It does not DEPEND on NON relevant noise components.

Discussion

12.	Channel noise is(a) Additive(b) White and stationary(c) Has infinite bandwidth(d) All of the mentionedI have been asked this question in an interview for internship.The origin of the question is Effects of Fading and Decision Theory in division Fading Channels of Digital Communications
Answer» RIGHT OPTION is (d) All of the mentioned Easiest explanation: Channel noise is stationary, ADDITIVE and white with infinite bandwidth.

Discussion

13.	Decision making needs(a) Priors(b) Likelihoods(c) Priors & Likelihoods(d) None of the mentionedThis question was addressed to me in exam.Asked question is from Effects of Fading and Decision Theory in portion Fading Channels of Digital Communications
Answer» Right answer is (c) Priors & Likelihoods To ELABORATE: Decision making NEEDS both priors and likelihoods and Bayes decision RULE COMBINES them to achieve minimum PROBABILITY of error.

Discussion

14.	The ISI and adjacent channel interference is removed by(a) Cancelling filter(b) Port processing equalizer(c) Cancelling filter & Port processing equalizer(d) None of the mentionedI got this question during an interview for a job.Enquiry is from Effects of Fading and Decision Theory topic in section Fading Channels of Digital Communications
Answer» CORRECT option is (C) CANCELLING FILTER & Port processing equalizer Easiest EXPLANATION: The known ISI which is introduced deliberately and the adjacent channel interference is removed by cancelling filter and post processing equalizer.

Discussion

15.	Fast fading can be minimized by(a) Robust modulation(b) Coding and interleaving(c) Robust modulation, Coding and interleaving(d) None of the mentionedThis question was posed to me in a national level competition.The origin of the question is Effects of Fading and Decision Theory in division Fading Channels of Digital Communications
Answer» Correct OPTION is (c) ROBUST modulation, Coding and interleaving The explanation is: Fast fading can be MINIMIZED by using coding and interleaving, by using robust modulation and by introducing signal REDUNDANCY to increase signalling RATE.

Discussion

16.	The decision feedback equalizer has a linear traversal filter which is(a) Feed forward section(b) Feedback section(c) Feed forward section & Feedback section(d) None of the mentionedI got this question in quiz.This is a very interesting question from Effects of Fading and Decision Theory topic in section Fading Channels of Digital Communications
Answer» Right option is (a) Feed FORWARD section To explain I would SAY: The decision FEEDBACK filter has a feed forward section which is a linear TRAVERSAL filter.

Discussion

17.	How can slow fading be minimized?(a) By diversity technique(b) Error correcting codes(c) By diversity technique & Error correcting codes(d) None of the mentionedI have been asked this question in an international level competition.I would like to ask this question from Effects of Fading and Decision Theory topic in chapter Fading Channels of Digital Communications
Answer» Correct CHOICE is (c) By DIVERSITY technique & Error correcting codes Easiest EXPLANATION: Slow fading can be minimized by using error correcting codes and also by using diversity technique to GET additional uncorrelated estimates of a signal.

Discussion

18.	The rake receivers functions are similar to(a) Equalizer(b) Matched filter(c) Equalizer & Matched filter(d) None of the mentionedThis question was addressed to me in quiz.I would like to ask this question from Diversity Technique and Rake Receivers in section Fading Channels of Digital Communications
Answer» The correct answer is (C) Equalizer & MATCHED FILTER Best EXPLANATION: The functionality of rake receiver resembles that of the equalizer and matched filter.

Discussion

19.	Rake receivers are used in(a) Radio astronomy(b) CDMA(c) W-CDMA(d) All of the mentionedThe question was posed to me in an online quiz.I would like to ask this question from Diversity Technique and Rake Receivers topic in portion Fading Channels of Digital Communications
Answer» The CORRECT answer is (d) All of the mentioned To explain: RAKE receivers are used in RADIO astronomy, CDMA, W-CDMA, wireless LAN networks ETC.

Discussion

20.	A rake receiver uses multiple(a) Delay circuits(b) Correlators(c) Detectors(d) None of the mentionedThe question was posed to me in an internship interview.This intriguing question originated from Diversity Technique and Rake Receivers topic in portion Fading Channels of Digital Communications
Answer» The CORRECT option is (b) Correlators Easy explanation: A rake RECEIVER uses multiple correlators to separately DETECT multiple strongest COMPONENTS.

Discussion

21.	Information reliability depends on(a) Magnitude of each component(b) Time of arrival of each component(c) Magnitude & Time of arrival of each component(d) None of the mentionedI got this question in an internship interview.Question is from Diversity Technique and Rake Receivers in chapter Fading Channels of Digital Communications
Answer» The correct option is (c) Magnitude & Time of ARRIVAL of each COMPONENT Best EXPLANATION: The INFORMATION reliability can be improved by computing the amplitude and time of arrival of each component.

Discussion

22.	Rake receiver does(a) Counter effects multi-path fading(b) Resembles equalizer(c) Resembles equalizer & Counter effects multi-path fading(d) None of the mentionedThe question was asked during an interview.I'm obligated to ask this question of Diversity Technique and Rake Receivers in portion Fading Channels of Digital Communications
Answer» The correct choice is (C) Resembles equalizer & Counter effects multi-path FADING The best I can explain: RAKE RECEIVER resembles equalizers and it is used to counter the effects of multipath fading and is also used to exploit the path diversity.

Discussion

23.	Interleaving does(a) Forward error correction(b) Backward error correction(c) Forward & Backward error correction(d) None of the mentionedI had been asked this question during an internship interview.This interesting question is from Diversity Technique and Rake Receivers in chapter Fading Channels of Digital Communications
Answer» The correct answer is (a) FORWARD ERROR correction Explanation: INTER LEAVER does forward error correction.

Discussion

24.	Uncorrelated fading occurs when(a) Time span is small(b) Time span is large(c) Does not depend on time span(d) None of the mentionedI had been asked this question in a job interview.My doubt is from Diversity Technique and Rake Receivers topic in section Fading Channels of Digital Communications
Answer» Right OPTION is (b) Time span is large To ELABORATE: As the time span increases, the fading is more UNCORRELATED and effectiveness ALSO increases.

Discussion

25.	Which signalling scheme is preferred for fading channel?(a) Frequency based modulation(b) Phase based modulation(c) Frequency & Phase based modulation(d) None of the mentionedI got this question in a national level competition.This intriguing question comes from Diversity Technique and Rake Receivers in division Fading Channels of Digital Communications
Answer» Correct choice is (c) FREQUENCY & Phase BASED modulation Easiest explanation: Frequency based modulation and phase based modulation is PREFERABLE for FADING channel than amplitude based modulation.

Discussion

26.	What are the modes of adaptive equalizer?(a) Training mode(b) Tracking mode(c) Training & Tracking mode(d) None of the mentionedI have been asked this question by my school teacher while I was bunking the class.This intriguing question comes from Diversity Technique and Rake Receivers in division Fading Channels of Digital Communications
Answer» Correct answer is (c) Training & TRACKING mode For explanation I WOULD SAY: Adaptive EQUALIZER operates on two modes – training mode and tracking mode.

Discussion

27.	Which is more effective and commonly preferred technique?(a) Time diversity(b) Spatial diversity(c) Frequency diversity(d) None of the mentionedThe question was posed to me during a job interview.My doubt is from Diversity Technique and Rake Receivers in section Fading Channels of Digital Communications
Answer» The CORRECT choice is (b) Spatial diversity For explanation I WOULD SAY: Most COMMONLY used and more EFFECTIVE diversity technique is spatial diversity technique.

Discussion

28.	Diversity technique(a) Provides significant link improvement(b) Needs training overhead(c) All of the mentioned(d) None of the mentionedThis question was posed to me in homework.This question is from Diversity Technique and Rake Receivers in chapter Fading Channels of Digital Communications
Answer» The correct answer is (a) Provides SIGNIFICANT link improvement To explain I would SAY: DIVERSITY TECHNIQUE does not require training overhead at the TRANSMITTER and also provides significant link performance.

Discussion

29.	Diversity technique is used for combating(a) Fading(b) Error bursts(c) Co-channel interference(d) All of the mentionedThe question was posed to me in an interview for job.The above asked question is from Diversity Technique and Rake Receivers in portion Fading Channels of Digital Communications
Answer» The correct option is (d) All of the mentioned Explanation: Diversity technique is a COMMON method used for combating FADING, co-channel INTERFERENCE and error bursts.

Discussion

30.	Diversity technique is applied at(a) Base station(b) Mobile receiver(c) Base station & Mobile receiver(d) None of the mentionedThe question was asked in a job interview.My question comes from Diversity Technique and Rake Receivers in section Fading Channels of Digital Communications
Answer» Right OPTION is (c) Base station & Mobile receiver Explanation: DIVERSITY TECHNIQUE can be APPLIED at both base station and at mobile receivers.

Discussion

31.	The technique for combining diversity signals are(a) Feedback(b) Maximal ratio(c) Equal gain(d) All of the mentionedThis question was posed to me during an internship interview.The query is from Diversity Technique and Rake Receivers in portion Fading Channels of Digital Communications
Answer»

Discussion

32.	Frequency tracking loop can minimize irreducible error rate by using(a) GMSK(b) DMSK(c) MSK(d) QAMThis question was addressed to me in homework.This intriguing question originated from Signal Time Spreading topic in division Fading Channels of Digital Communications
Answer» Correct answer is (b) DMSK To explain: FREQUENCY tracking LOOP can MINIMIZE the irreducible error rate in a mobile system by using DIFFERENTIAL MINIMUM shift keying modulation.

Discussion

33.	If signalling rate is less than fading rate, _____ fading occurs.(a) Slow(b) Fast(c) Time selective(d) None of the mentionedI have been asked this question during an online interview.I would like to ask this question from Signal Time Spreading topic in chapter Fading Channels of Digital Communications
Answer» Right answer is (B) Fast For EXPLANATION: A CHANNEL is SAID to be fast fading if symbol rate or signalling rate is LESS than fading rate.

Discussion

34.	When transmitter and receiver moves towards each other, the magnitude of frequency shift is(a) Positive(b) Negative(c) Zero(d) InfinityI have been asked this question by my school principal while I was bunking the class.This key question is from Signal Time Spreading in division Fading Channels of Digital Communications
Answer» Right option is (a) POSITIVE Explanation: When transmitter and RECEIVER moves TOWARDS each other, the magnitude of frequency shift is positive, where as if it moves away from each other then it is negative.

Discussion

35.	Flat fading can be avoided or stopped by(a) Error coding(b) Equalization(c) Adaptive bit loading(d) All of the mentionedI have been asked this question in unit test.My question comes from Signal Time Spreading topic in division Fading Channels of Digital Communications
Answer» Correct ANSWER is (d) All of the mentioned To EXPLAIN: Flat FADING can be combated by MEANS of error coding, equalization and adaptive bit loading.

Discussion

36.	The effect of Doppler shift can be counterattacked by(a) OFDM(b) By using two receivers with separate antennas(c) By using diversity receiver(d) All of the mentionedThis question was addressed to me in an internship interview.I want to ask this question from Signal Time Spreading topic in portion Fading Channels of Digital Communications
Answer» The correct option is (d) All of the mentioned The EXPLANATION: The effect of Doppler shift can be removed by using diversity SCHEME such as orthogonal frequency division multiplexing, by using TWO receivers with separate ANTENNAS or by using specially designed diversity RECEIVER.

Discussion

37.	If coherence bandwidth is smaller than the bandwidth of the signal, _____ fading occurs.(a) Flat(b) Frequency selective(c) Fast fading(d) Time selectiveI have been asked this question during an interview.This key question is from Signal Time Spreading in portion Fading Channels of Digital Communications
Answer» Correct answer is (b) Frequency selective To elaborate: Frequency selective fading OCCURS when coherence BANDWIDTH is smaller than the bandwidth of the TRANSMITTED SIGNAL.

Discussion

38.	Block fading occurs in(a) Frequency domain(b) Time domain(c) Frequency & Time domain(d) None of the mentionedThis question was posed to me in an interview.The origin of the question is Signal Time Spreading topic in chapter Fading Channels of Digital Communications
Answer» The correct answer is (C) Frequency & Time DOMAIN The best explanation: BLOCK fading can OCCUR in both frequency domain and time domain. This is called as doubly block fading.

Discussion

39.	When a user’s moving, the user’s velocity causes shift in frequency. This is called as(a) Doppler shift(b) Frequency shift(c) Velocity shift(d) None of the mentionedI got this question during an interview for a job.I'm obligated to ask this question of Signal Time Spreading topic in division Fading Channels of Digital Communications
Answer»

Discussion

40.	Minimum time required for magnitude change or phase change is called as(a) Shift time(b) Coherence time(c) Delay time(d) None of the mentionedThe question was asked in an interview.The above asked question is from Signal Time Spreading in division Fading Channels of Digital Communications
Answer» Correct option is (b) Coherence time The best I can explain: Coherence time is the minimum time required for MAGNITUDE or PHASE CHANGE of the channel to BECOME uncorrelated from the previous value.

Discussion

41.	Coherence time is _______ to Doppler spread.(a) Directly proportional(b) Inversely proportional(c) Not dependent(d) None of the mentionedThe question was posed to me by my school teacher while I was bunking the class.The query is from Signal Time Spreading topic in division Fading Channels of Digital Communications
Answer»

Discussion

42.	When channel coherence time is less than the time duration of a transmission symbol, then ______ fading occurs.(a) Fast(b) Slow(c) Time selective(d) None of the mentionedThis question was posed to me during an online interview.This interesting question is from Signal Time Spreading in section Fading Channels of Digital Communications
Answer» The correct choice is (a) Fast Best EXPLANATION: Fast fading OCCURS when the channel coherence time is less than the time duration of a transmission SYMBOL.

Discussion

43.	Channel’s time spreading properties are(a) Coherence bandwidth(b) Signal dispersion(c) Coherence bandwidth & Signal dispersion(d) None of the mentionedI got this question during an online exam.My question is taken from Signal Time Spreading topic in chapter Fading Channels of Digital Communications
Answer» The correct CHOICE is (c) COHERENCE bandwidth & Signal dispersion The best EXPLANATION: Signal dispersion and coherence bandwidth characterizes the CHANNEL’s time spreading properties in a local AREA.

Discussion

44.	If delay time is greater than symbol time, _______ fading occurs.(a) Frequency selective(b) Time selective(c) Frequency non selective(d) None of the mentionedThe question was posed to me during an interview.My question is taken from Signal Time Spreading in chapter Fading Channels of Digital Communications
Answer» Correct OPTION is (a) Frequency selective Easy explanation: When delay TIME is GREATER than symbol time, frequency selective FADING occurs.

Discussion

45.	If delay time is lesser than symbol time, ______ fading occurs.(a) Frequency non selective(b) Flat(c) Frequency non selective & Flat(d) None of the mentionedThe question was posed to me in class test.My question is based upon Signal Time Spreading in division Fading Channels of Digital Communications
Answer» CORRECT option is (c) Frequency NON SELECTIVE & FLAT Easiest explanation: If delay time is lesser than the symbol time, frequency non selective or flat fading occurs.

Discussion

46.	When channel coherence bandwidth is greater than the transmitted signal bandwidth ______ occurs.(a) Time selective(b) Frequency selective(c) Frequency non selective(d) None of the mentionedThis question was addressed to me in an online interview.This key question is from Signal Time Spreading topic in section Fading Channels of Digital Communications
Answer» The correct answer is (c) Frequency non SELECTIVE For explanation I WOULD say: Frequency non selective or flat FADING occurs if CHANNEL coherence bandwidth is GREATER than the transmitted signal bandwidth.

Discussion

47.	Small scale refers to changes in(a) Amplitude(b) Phase(c) Amplitude & Phase(d) None of the mentionedThis question was addressed to me during an online interview.Origin of the question is Mobile Radio Propagation topic in portion Fading Channels of Digital Communications
Answer» Right OPTION is (C) Amplitude & Phase Explanation: Small scale fading refers to changes in amplitude and phase as a result of small changes in spatial POSITIONING between transmitter and RECEIVER.

Discussion

48.	Multiple isolated peaks in multipath components is called as(a) Fingers(b) Returns(c) Fingers & Returns(d) None of the mentionedThis question was posed to me by my school teacher while I was bunking the class.I'd like to ask this question from Signal Time Spreading topic in portion Fading Channels of Digital Communications
Answer» RIGHT OPTION is (c) Fingers & Returns For explanation: The RECEIVED signal usually consists of SEVERAL discrete multipath components causing multipath intensity profile to EXHIBIT multiple isolated peaks also called as fingers or returns.

Discussion

49.	The parameters used to describe large scale fading are(a) Reference distance(b) Path loss exponent(c) Standard deviation of random variable(d) All of the mentionedThis question was addressed to me in a national level competition.I want to ask this question from Mobile Radio Propagation in chapter Fading Channels of Digital Communications
Answer» Correct option is (d) All of the mentioned Explanation: The parameters used to statistically DESCRIBE path loss due to large scale fading are reference DISTANCE, path loss exponent and standard DEVIATION of random variable.

Discussion

50.	What are the types of small scale fading that occurs due to Doppler shift?(a) Slow fading(b) Fast fading(c) Slow & Fast fading(d) None of the mentionedThis question was posed to me in my homework.The question is from Mobile Radio Propagation topic in section Fading Channels of Digital Communications
Answer» Right answer is (c) Slow & Fast fading Easiest explanation: Slow fading and fast fading occurs DUE to DOPPLER or frequency shift.

Discussion

Explore topic-wise InterviewSolutions in .

Fading channel has memory.(a) True(b) FalseI had been asked this question in an online quiz.This question is from Effects of Fading and Decision Theory topic in portion Fading Channels of Digital Communications

What are the parameters calculated for an estimator?(a) Error(b) Mean square error(c) Variance(d) All of the mentionedI have been asked this question during an online exam.My query is from Effects of Fading and Decision Theory in section Fading Channels of Digital Communications

Which signal sets are called as equivalent signal sets?(a) Simplex(b) Bi-orthogonal(c) Simplex & Bi-orthogonal(d) None of the mentionedThe question was asked in my homework.This question is from Effects of Fading and Decision Theory topic in chapter Fading Channels of Digital Communications

Symbol error probability can also be determined using upper bound.(a) True(b) FalseThis question was posed to me in an online quiz.My doubt is from Effects of Fading and Decision Theory topic in section Fading Channels of Digital Communications

Which has higher transmission rate?(a) BPSK(b) 16-QAM(c) BPSK & 16-QAM(d) None of the mentionedI had been asked this question in an online interview.This question is from Effects of Fading and Decision Theory topic in section Fading Channels of Digital Communications

Which needs more signal power?(a) BPSK(b) 16-QAM(c) BPSK & 16-QAM(d) None of the mentionedI got this question by my college professor while I was bunking the class.The query is from Effects of Fading and Decision Theory in chapter Fading Channels of Digital Communications

The inter-leaver is more effective if the vehicle is(a) Fast(b) Slow(c) Fast & Slow(d) None of the mentionedThe question was posed to me during an interview for a job.The question is from Effects of Fading and Decision Theory topic in portion Fading Channels of Digital Communications

Channel noise is(a) Additive(b) White and stationary(c) Has infinite bandwidth(d) All of the mentionedI have been asked this question in an interview for internship.The origin of the question is Effects of Fading and Decision Theory in division Fading Channels of Digital Communications

Decision making needs(a) Priors(b) Likelihoods(c) Priors & Likelihoods(d) None of the mentionedThis question was addressed to me in exam.Asked question is from Effects of Fading and Decision Theory in portion Fading Channels of Digital Communications

Rake receivers are used in(a) Radio astronomy(b) CDMA(c) W-CDMA(d) All of the mentionedThe question was posed to me in an online quiz.I would like to ask this question from Diversity Technique and Rake Receivers topic in portion Fading Channels of Digital Communications

A rake receiver uses multiple(a) Delay circuits(b) Correlators(c) Detectors(d) None of the mentionedThe question was posed to me in an internship interview.This intriguing question originated from Diversity Technique and Rake Receivers topic in portion Fading Channels of Digital Communications

Uncorrelated fading occurs when(a) Time span is small(b) Time span is large(c) Does not depend on time span(d) None of the mentionedI had been asked this question in a job interview.My doubt is from Diversity Technique and Rake Receivers topic in section Fading Channels of Digital Communications

Diversity technique(a) Provides significant link improvement(b) Needs training overhead(c) All of the mentioned(d) None of the mentionedThis question was posed to me in homework.This question is from Diversity Technique and Rake Receivers in chapter Fading Channels of Digital Communications

Diversity technique is used for combating(a) Fading(b) Error bursts(c) Co-channel interference(d) All of the mentionedThe question was posed to me in an interview for job.The above asked question is from Diversity Technique and Rake Receivers in portion Fading Channels of Digital Communications

Diversity technique is applied at(a) Base station(b) Mobile receiver(c) Base station & Mobile receiver(d) None of the mentionedThe question was asked in a job interview.My question comes from Diversity Technique and Rake Receivers in section Fading Channels of Digital Communications

The technique for combining diversity signals are(a) Feedback(b) Maximal ratio(c) Equal gain(d) All of the mentionedThis question was posed to me during an internship interview.The query is from Diversity Technique and Rake Receivers in portion Fading Channels of Digital Communications

Frequency tracking loop can minimize irreducible error rate by using(a) GMSK(b) DMSK(c) MSK(d) QAMThis question was addressed to me in homework.This intriguing question originated from Signal Time Spreading topic in division Fading Channels of Digital Communications

Flat fading can be avoided or stopped by(a) Error coding(b) Equalization(c) Adaptive bit loading(d) All of the mentionedI have been asked this question in unit test.My question comes from Signal Time Spreading topic in division Fading Channels of Digital Communications

Block fading occurs in(a) Frequency domain(b) Time domain(c) Frequency & Time domain(d) None of the mentionedThis question was posed to me in an interview.The origin of the question is Signal Time Spreading topic in chapter Fading Channels of Digital Communications

Minimum time required for magnitude change or phase change is called as(a) Shift time(b) Coherence time(c) Delay time(d) None of the mentionedThe question was asked in an interview.The above asked question is from Signal Time Spreading in division Fading Channels of Digital Communications

Small scale refers to changes in(a) Amplitude(b) Phase(c) Amplitude & Phase(d) None of the mentionedThis question was addressed to me during an online interview.Origin of the question is Mobile Radio Propagation topic in portion Fading Channels of Digital Communications