98 + Interview Questions in Spread Spectrum Techniques in Digital Communications Page 1 InterviewSolution

1.	The segment of the key-stream of plaintext is obtained by _____of two sequences together.(a) ANDing(b) ORing(c) Addition(d) Modulo 2 additionThe question was asked by my school teacher while I was bunking the class.This key question is from Stream Encryption and Commercial Applications topic in chapter Spread Spectrum Techniques of Digital Communications
Answer» CORRECT option is (d) Modulo 2 addition The BEST explanation: The crypt-analyst PERFORMS modulo 2 addition of two sequences together to get the sequence of key-stream of PLAINTEXT.

Discussion

2.	Perfect secrecy can be achieved for(a) Finite number of messages(b) Infinite number of messages(c) Finite & Infinite number of messages(d) None of the mentionedI have been asked this question in an interview for internship.Origin of the question is Stream Encryption and Commercial Applications in portion Spread Spectrum Techniques of Digital Communications
Answer» Right choice is (B) Infinite number of messages Explanation: Perfect SECRECY can be achieved for infinite number of messages since each message would be ENCRYPTED with DIFFERENT portion of random KEY.

Discussion

3.	Cryptosystems are used for(a) Privacy(b) Authentication(c) Privacy & Authentication(d) None of the mentionedThis question was addressed to me in class test.The above asked question is from Cipher Systems and Secrecy of Cipher Systems in division Spread Spectrum Techniques of Digital Communications
Answer» Correct answer is (C) Privacy & Authentication The best explanation: Cryptosystems which INCLUDES the process of ENCRYPTION and decryption is USED for both privacy and authentication.

Discussion

4.	Which serves the soft hand-off process?(a) Base station(b) Mobile switching center(c) Mobile(d) None of the mentionedI had been asked this question by my school principal while I was bunking the class.The doubt is from Cellular Systems topic in chapter Spread Spectrum Techniques of Digital Communications
Answer» CORRECT ANSWER is (c) MOBILE The explanation is: Soft hand off PROCESS is served by the mobile. It scans for stronger pilot and requests HANDOFF to base station.

Discussion

5.	Which channel is more robust?(a) Forward channel(b) Reverse channel(c) Forward & Reverse channel(d) None of the mentionedI had been asked this question during an interview.My doubt stems from Cellular Systems topic in division Spread Spectrum Techniques of Digital Communications
Answer» The correct ANSWER is (a) FORWARD channel The explanation is: Forward channel is more robust than the REVERSE channel.

Discussion

6.	If the active users using a cell doubles, the required Eb/I0(a) Doubles(b) Halves(c) Remains the same(d) None of the mentionedThe question was asked in a national level competition.The question is from Cellular Systems topic in portion Spread Spectrum Techniques of Digital Communications
Answer» RIGHT option is (B) Halves To explain I would SAY: If the active USERS were to double, then the received Eb/I0 would ESSENTIALLY be halved.

Discussion

7.	How many channels are transmitted in the forward and reverse direction?(a) 1,64(b) 64,1(c) 2,32(d) 32,2I got this question by my college professor while I was bunking the class.This question is from Cellular Systems in section Spread Spectrum Techniques of Digital Communications
Answer»

Discussion

8.	In the case of direct CDMA, interference will occur if the PN codes are(a) Orthogonal to each other(b) Non orthogonal to each other(c) Orthogonal & Non orthogonal to each other(d) None of the mentionedThe question was asked during an online interview.The above asked question is from Cellular Systems topic in chapter Spread Spectrum Techniques of Digital Communications
Answer» Correct choice is (B) Non orthogonal to each other Explanation: If the PN codes are not purely orthogonal in direct CDMA INTERFERENCE will OCCUR.

Discussion

9.	The properties used for pseudorandom sequence are(a) Balance(b) Run(c) Correlation(d) All of the mentionedI got this question in examination.My question comes from Pseudo-Noise Sequence and Jamming topic in section Spread Spectrum Techniques of Digital Communications
Answer» The correct ANSWER is (d) All of the mentioned To explain: The THREE BASIC properties that can be applied for PSEUDORANDOM sequence are balance, run and correlation properties.

Discussion

10.	Pseudorandom signal ________ predicted.(a) Can be(b) Cannot be(c) maybe(d) None of the mentionedThe question was asked at a job interview.I'm obligated to ask this question of Pseudo-Noise Sequence and Jamming in division Spread Spectrum Techniques of Digital Communications
Answer» The correct choice is (a) Can be Easy explanation: RANDOM SIGNALS cannot be predicted whereas PSEUDORANDOM sequence can be predicted.

Discussion

11.	In DSSS the signal is recovered using(a) Low pass filter(b) High pass filter(c) Band pass filter(d) Band stop filterI got this question in an online interview.This question is from Spread Spectrum topic in chapter Spread Spectrum Techniques of Digital Communications
Answer»

Discussion

12.	The original bandwidth of the unspread signal in spread spectrum is ____ to data rate.(a) Proportional(b) Inversely proportional(c) Not related(d) None of the mentionedThis question was posed to me by my college director while I was bunking the class.My enquiry is from Spread Spectrum in section Spread Spectrum Techniques of Digital Communications
Answer» RIGHT CHOICE is (a) Proportional The EXPLANATION: In spread spectrum, the original bandwidth of the unspread signal is proportional to the DATA rate.

Discussion

13.	In CDMA the incoming signal is _____ with the spreading code.(a) Added(b) Multiplied(c) XOR-ed(d) None of the mentionedThis question was posed to me in an online interview.My question is taken from Spread Spectrum in division Spread Spectrum Techniques of Digital Communications
Answer»

Discussion

14.	The transmitter of frequency hopping system is fed with encoding scheme such as(a) Frequency shift keying(b) Binary phase shift keying(c) Frequency & Binary phase shift keying(d) None of the mentionedI got this question during an online interview.My doubt stems from Spread Spectrum topic in portion Spread Spectrum Techniques of Digital Communications
Answer» Right choice is (c) FREQUENCY & Binary PHASE SHIFT keying Explanation: For transmission, the binary data is FED into modulator using modulation scheme such as frequency shift keying or binary phase shift keying.

Discussion

15.	Which filter is used to get the final FHSS signal?(a) Low pass filter(b) High pass filter(c) Band pass filter(d) Band stop filterThe question was asked in an interview for internship.I want to ask this question from Spread Spectrum in chapter Spread Spectrum Techniques of Digital Communications
Answer» Right option is (C) Band pass FILTER The best explanation: Band pass filter is used to block DIFFERENCE frequency and allow the SUM frequency to yield final FHSS signal.

Discussion

16.	The width of each channel in frequency hopping spread spectrum corresponds to(a) Bandwidth of input signal(b) Pseudorandom sequence used(c) Carrier frequency(d) None of the mentionedThis question was addressed to me during an online exam.My query is from Spread Spectrum in chapter Spread Spectrum Techniques of Digital Communications
Answer» CORRECT option is (a) Bandwidth of input signal The BEST explanation: The WIDTH of the CHANNEL in frequency hopping spread spectrum corresponds to bandwidth of the input signal.

Discussion

17.	Spread spectrum can be used to transmit(a) Analog data(b) Digital data(c) Analog & Digital data(d) None of the mentionedI had been asked this question in examination.The question is from Spread Spectrum topic in section Spread Spectrum Techniques of Digital Communications
Answer» The correct choice is (C) Analog & Digital data Easiest explanation: SPREAD spectrum is used to transmit analog data and digital data using analog signal.

Discussion

18.	Spread spectrum has immunity from(a) Noise(b) Multi-path distortion(c) Noise & Multi-path distortion(d) None of the mentionedThis question was posed to me in an online quiz.This interesting question is from Spread Spectrum topic in division Spread Spectrum Techniques of Digital Communications
Answer» The correct ANSWER is (C) Noise & Multi-path distortion The BEST EXPLANATION: Spread spectrum has immunity to noise and multi-path distortion.

Discussion

19.	Spread spectrum makes ______ difficult.(a) Jamming(b) Interception(c) Jamming & Interception(d) None of the mentionedI had been asked this question during an interview for a job.Query is from Spread Spectrum in division Spread Spectrum Techniques of Digital Communications
Answer» Right CHOICE is (C) Jamming & INTERCEPTION The explanation is: SPREAD spectrum makes jamming and interception difficult and provides improved reception.

Discussion

20.	Direct system allows detection of signals whose psd level is(a) Below noise level(b) Above noise level(c) All of the mentioned(d) None of the mentionedI got this question during an interview for a job.My query is from Stream Encryption and Commercial Applications in division Spread Spectrum Techniques of Digital Communications
Answer» The correct option is (a) Below NOISE level Explanation: Direct sequence SPREAD spectrum techniques ALLOW for the detection of signals WHOSE psd is below noise level.

Discussion

21.	Spread spectrum is a ______ technique.(a) Encoding(b) Decoding(c) Encoding & Decoding(d) None of the mentionedI had been asked this question in an interview for job.Enquiry is from Spread Spectrum topic in portion Spread Spectrum Techniques of Digital Communications
Answer» Correct CHOICE is (a) ENCODING Explanation: Spread SPECTRUM is an important encoding technique for a wireless communication system.

Discussion

22.	Spread spectrum multiple access techniques allows the multiple signal to be transmitted(a) One after the other(b) Simultaneously(c) All of the mentioned(d) None of the mentionedThis question was addressed to me in an interview.I need to ask this question from Stream Encryption and Commercial Applications topic in section Spread Spectrum Techniques of Digital Communications
Answer» Correct option is (b) SIMULTANEOUSLY Easy explanation: Spread SPECTRUM MULTIPLE ACCESS technique allows multiple signals OCCUPYING the same RF bandwidth to be transmitted simultaneously without interfering with one and another.

Discussion

23.	For hybrid systems the minimum required processing gain is(a) 5db(b) 10db(c) 17db(d) 25dbI had been asked this question in an international level competition.Enquiry is from Stream Encryption and Commercial Applications in chapter Spread Spectrum Techniques of Digital Communications
Answer» The CORRECT option is (c) 17db Best explanation: For hybrid SYSTEMS employing both direct SEQUENCE and frequency hopping, the minimum required processing gain is 17db.

Discussion

24.	Multi paths may be because of(a) Reflections from buildings(b) Refraction(c) Atmospheric reflections(d) All of the mentionedThis question was addressed to me in exam.Query is from Stream Encryption and Commercial Applications in division Spread Spectrum Techniques of Digital Communications
Answer» The correct choice is (d) All of the mentioned The best EXPLANATION: MULTI paths may be caused by atmospheric reflections, refraction, reflections from buildings or other objects and may RESULT in FLUCTUATION in the received signal level.

Discussion

25.	In CDMA, the users share the bandwidth(a) Synchronously(b) Asynchronously(c) Synchronously & Asynchronously(d) None of the mentionedI had been asked this question during an interview for a job.The doubt is from Stream Encryption and Commercial Applications in chapter Spread Spectrum Techniques of Digital Communications
Answer» Correct OPTION is (b) ASYNCHRONOUSLY The EXPLANATION: In CDMA system, all participants can share the ENTIRE bandwidth asynchronously.

Discussion

26.	Frequency hopping system can provide reliable mitigation only if(a) Hopping rate is greater than the symbol rate(b) Hopping bandwidth is large(c) Hopping rate is greater than the symbol rate & its bandwidth is large(d) None of the mentionedI got this question in exam.My question is from Stream Encryption and Commercial Applications in chapter Spread Spectrum Techniques of Digital Communications
Answer» The correct OPTION is (c) Hopping rate is GREATER than the symbol rate & its BANDWIDTH is large Easiest explanation: The frequency hopping SYSTEM can provide reliable mitigation only if its hopping rate is faster than the symbol rate and the hopping bandwidth is large.

Discussion

27.	For direct sequence systems what is the minimum required processing gain?(a) 3db(b) 10db(c) 12db(d) 20dbThis question was addressed to me in exam.This interesting question is from Stream Encryption and Commercial Applications in chapter Spread Spectrum Techniques of Digital Communications
Answer» The correct ANSWER is (b) 10DB To explain I WOULD say: For a direct sequence SYSTEMS, the minimum required PROCESSING gain is 10db.

Discussion

28.	In which method cipher feedback is used?(a) Synchronous encryption method(b) Self synchronous encryption method(c) All of the mentioned(d) None of the mentionedI got this question in homework.This intriguing question comes from Stream Encryption and Commercial Applications topic in chapter Spread Spectrum Techniques of Digital Communications
Answer» Correct choice is (b) Self synchronous encryption method The BEST explanation: In self synchronous encryption technique, CIPHER feedback is USED and the key-stream is RELATED to the MESSAGES.

Discussion

29.	In which method the key-stream is generated independently of the message?(a) Synchronous encryption method(b) Self synchronous encryption method(c) All of the mentioned(d) None of the mentionedThis question was addressed to me by my college director while I was bunking the class.This is a very interesting question from Stream Encryption and Commercial Applications topic in chapter Spread Spectrum Techniques of Digital Communications
Answer» The CORRECT choice is (a) Synchronous encryption method Explanation: In Synchronous encryption method, the key-stream is generated INDEPENDENTLY of MESSAGE.

Discussion

30.	One-time pad has(a) Random key(b) Unconditional security(c) Can be used only once(d) All of the mentionedThe question was posed to me in my homework.The above asked question is from Stream Encryption and Commercial Applications topic in portion Spread Spectrum Techniques of Digital Communications
Answer»

Discussion

31.	The 64 bit block input key has _____ number of parity bits.(a) 4(b) 6(c) 8(d) 16I have been asked this question by my college professor while I was bunking the class.My doubt stems from Stream Encryption and Commercial Applications in section Spread Spectrum Techniques of Digital Communications
Answer» Correct option is (c) 8 Easy explanation: The 64 BIT INPUT KEY has 8 parity bits placed in 8,16…..64 bit POSITIONS.

Discussion

32.	The standard building block uses _______of a key to transform 64-bit input into 64-bit output.(a) 32 bit(b) 48 bit(c) 64 bit(d) 128 bitI had been asked this question in exam.My enquiry is from Stream Encryption and Commercial Applications topic in portion Spread Spectrum Techniques of Digital Communications
Answer» CORRECT ANSWER is (b) 48 bit For explanation: The standard building block USES 48 bit KEYS to transform 64 bit input data into 64 bit output.

Discussion

33.	In substitution technique encryption protection is more.(a) True(b) FalseI had been asked this question in semester exam.My question is from Stream Encryption and Commercial Applications in division Spread Spectrum Techniques of Digital Communications
Answer» The CORRECT option is (B) False To explain I would say: The substitution TECHNIQUES have less encryption PROTECTION.

Discussion

34.	Which are called as substitution encryption techniques?(a) Caesar cipher(b) Trithemius cipher(c) Caesar & Trithemius cipher(d) None of the mentionedI had been asked this question in examination.The above asked question is from Stream Encryption and Commercial Applications in chapter Spread Spectrum Techniques of Digital Communications
Answer» Right answer is (C) Caesar & Trithemius cipher The EXPLANATION: Examples of substitution ENCRYPTION techniques are Caesar cipher and Trithemius cipher.

Discussion

35.	When a system is called as unbreakable?(a) When unique solution is available(b) When unique solution is not available(c) All of the mentioned(d) None of the mentionedI got this question during an online exam.My query is from Cipher Systems and Secrecy of Cipher Systems in chapter Spread Spectrum Techniques of Digital Communications
Answer» The correct CHOICE is (B) When unique SOLUTION is not available For explanation: A system is said to be unbreakable when unique solution is not available because of the number of equations being smaller than the number of UNKNOWN KEY bits.

Discussion

36.	When the key size is finite, equivocation approaches(a) Unity(b) Zero(c) Infinity(d) None of the mentionedThe question was asked during a job interview.The origin of the question is Cipher Systems and Secrecy of Cipher Systems topic in portion Spread Spectrum Techniques of Digital Communications
Answer» The CORRECT option is (B) ZERO Explanation: With a finite key size, equivocation APPROACHES zero.

Discussion

37.	The maximum number of message bits contained in each character is called as(a) True rate(b) Absolute rate(c) Optimum rate(d) None of the mentionedI had been asked this question in an interview for job.The origin of the question is Cipher Systems and Secrecy of Cipher Systems topic in chapter Spread Spectrum Techniques of Digital Communications
Answer» The correct ANSWER is (B) Absolute rate To EXPLAIN: Absolute rate is the MAXIMUM number of MESSAGE bits contained in each character.

Discussion

38.	The _____ the uncertainty, the ______ is the information content.(a) Lesser, greater(b) Greater, lesser(c) Lesser, lesser(d) Greater, greaterI had been asked this question in examination.This interesting question is from Cipher Systems and Secrecy of Cipher Systems topic in portion Spread Spectrum Techniques of Digital Communications
Answer» RIGHT option is (d) Greater, greater The best I can explain: The more uncertainty there is in predicting the OCCURRENCE of a MESSAGE, the greater the INFORMATION CONTENT.

Discussion

39.	Equivocation is the(a) Joint probability of X and Y(b) Conditional probability of X given Y(c) Conditional probability of Y given X(d) None of the mentionedThe question was asked in quiz.This intriguing question comes from Cipher Systems and Secrecy of Cipher Systems topic in section Spread Spectrum Techniques of Digital Communications
Answer» The correct option is (B) Conditional probability of X GIVEN Y For explanation I WOULD say: Equivocation is DEFINED as the conditional probability of X given Y.

Discussion

40.	In Vigenere method ______ is provided.(a) Priming key(b) Feedback(c) Priming key & Feedback(d) None of the mentionedThis question was addressed to me during an internship interview.My question is taken from Cipher Systems and Secrecy of Cipher Systems in portion Spread Spectrum Techniques of Digital Communications
Answer» The correct answer is (c) Priming KEY & Feedback The EXPLANATION is: VIGENERE METHOD which is also called as vigenere auto method priming key and feedback are used.

Discussion

41.	The conditions for perfect secrecy are(a) Only one key transforming message should exist(b) All keys should be equally likely(c) One key transforming message to each cipher text & all keys should be equally likely(d) None of the mentionedThe question was asked in an online quiz.I'm obligated to ask this question of Cipher Systems and Secrecy of Cipher Systems in portion Spread Spectrum Techniques of Digital Communications
Answer» Correct ANSWER is (c) ONE key transforming MESSAGE to each cipher text & all KEYS should be equally likely Easy explanation: The conditions for perfect SECRECY are, there is only one key transforming message to each cipher text and all keys should be equally likely.

Discussion

42.	In auto key method(a) Feedback is necessary(b) Feedback is not necessary(c) Can be either necessary or not(d) None of the mentionedThe question was asked in a job interview.This question is from Cipher Systems and Secrecy of Cipher Systems in portion Spread Spectrum Techniques of Digital Communications
Answer» Correct answer is (a) Feedback is necessary To explain I would SAY: In AUTO key METHOD feedback is necessary for the ENCRYPTION PROCESS.

Discussion

43.	The trithemius cipher is a mono alphabetical cipher.(a) True(b) FalseI have been asked this question during an online exam.My question comes from Cipher Systems and Secrecy of Cipher Systems in portion Spread Spectrum Techniques of Digital Communications
Answer»

Discussion

44.	In Caesar cipher, each plain text is replaced by(a) Alphabet shift(b) Numerals(c) Symbols(d) None of the mentionedThis question was addressed to me in class test.My doubt stems from Cipher Systems and Secrecy of Cipher Systems topic in division Spread Spectrum Techniques of Digital Communications
Answer» The correct CHOICE is (a) Alphabet shift To EXPLAIN: In CAESAR cipher each PLAIN text is replaced with a new letter OBTAINED by an alphabetic shift.

Discussion

45.	Caesar cipher was a mono alphabetic cipher.(a) True(b) FalseThe question was posed to me during a job interview.The origin of the question is Cipher Systems and Secrecy of Cipher Systems in chapter Spread Spectrum Techniques of Digital Communications
Answer» Correct OPTION is (a) True For EXPLANATION: An EARLIEST example of a mono alphabetic CIPHER was the Caesar cipher.

Discussion

46.	The system which has insufficient information available to crypt-analyst is(a) One-time pad(b) Unconditionally secure(c) One-time pad & Unconditionally secure(d) None of the mentionedI got this question in semester exam.I'm obligated to ask this question of Cipher Systems and Secrecy of Cipher Systems in division Spread Spectrum Techniques of Digital Communications
Answer» Right answer is (C) ONE-time PAD & Unconditionally secure To elaborate: Unconditionally secure system is the one which has insufficient information AVAILABLE to crypt-analyst. One such system is one-time pad.

Discussion

47.	The key also contains a(a) Plaintext(b) Ciphertext(c) Plaintext & Ciphertext(d) None of the mentionedI have been asked this question in an interview for job.I need to ask this question from Cipher Systems and Secrecy of Cipher Systems topic in division Spread Spectrum Techniques of Digital Communications
Answer» The correct ANSWER is (c) Plaintext & Ciphertext The EXPLANATION: The KEY is supplied along with a plaintext message for ENCRYPTION and cipher text message for decryption.

Discussion

48.	Which serves the hard hand-off process?(a) Base station(b) Mobile switching center(c) Mobile(d) None of the mentionedI had been asked this question in an online interview.My doubt is from Cellular Systems topic in portion Spread Spectrum Techniques of Digital Communications
Answer» Correct choice is (b) Mobile switching center To elaborate: Mobile unit continuously SCANS for STRONGER PILOT and PROVIDES and serves HAND off process.

Discussion

49.	Short code is configured using ______ shift register.(a) 4-stage(b) 2-stage(c) 12-stage(d) 15-stageThe question was asked in an online interview.I'm obligated to ask this question of Cellular Systems topic in division Spread Spectrum Techniques of Digital Communications
Answer» CORRECT choice is (d) 15-stage To elaborate: The CODE in the FORWARD direction, short code is designed using 15 stage shift REGISTER.

Discussion

50.	Walsh cover technique is used for(a) Channelization(b) Spreading(c) Channelization & Spreading(d) None of the mentionedThe question was posed to me during an internship interview.This key question is from Cellular Systems topic in division Spread Spectrum Techniques of Digital Communications
Answer» Right OPTION is (C) Channelization & Spreading Easy EXPLANATION: Walsh cover is used for channelization PLUS spreading.

Discussion

Explore topic-wise InterviewSolutions in .

Cryptosystems are used for(a) Privacy(b) Authentication(c) Privacy & Authentication(d) None of the mentionedThis question was addressed to me in class test.The above asked question is from Cipher Systems and Secrecy of Cipher Systems in division Spread Spectrum Techniques of Digital Communications

Which channel is more robust?(a) Forward channel(b) Reverse channel(c) Forward & Reverse channel(d) None of the mentionedI had been asked this question during an interview.My doubt stems from Cellular Systems topic in division Spread Spectrum Techniques of Digital Communications

If the active users using a cell doubles, the required Eb/I0(a) Doubles(b) Halves(c) Remains the same(d) None of the mentionedThe question was asked in a national level competition.The question is from Cellular Systems topic in portion Spread Spectrum Techniques of Digital Communications

How many channels are transmitted in the forward and reverse direction?(a) 1,64(b) 64,1(c) 2,32(d) 32,2I got this question by my college professor while I was bunking the class.This question is from Cellular Systems in section Spread Spectrum Techniques of Digital Communications

The properties used for pseudorandom sequence are(a) Balance(b) Run(c) Correlation(d) All of the mentionedI got this question in examination.My question comes from Pseudo-Noise Sequence and Jamming topic in section Spread Spectrum Techniques of Digital Communications

Pseudorandom signal ________ predicted.(a) Can be(b) Cannot be(c) maybe(d) None of the mentionedThe question was asked at a job interview.I'm obligated to ask this question of Pseudo-Noise Sequence and Jamming in division Spread Spectrum Techniques of Digital Communications

In DSSS the signal is recovered using(a) Low pass filter(b) High pass filter(c) Band pass filter(d) Band stop filterI got this question in an online interview.This question is from Spread Spectrum topic in chapter Spread Spectrum Techniques of Digital Communications

In CDMA the incoming signal is _____ with the spreading code.(a) Added(b) Multiplied(c) XOR-ed(d) None of the mentionedThis question was posed to me in an online interview.My question is taken from Spread Spectrum in division Spread Spectrum Techniques of Digital Communications

Which filter is used to get the final FHSS signal?(a) Low pass filter(b) High pass filter(c) Band pass filter(d) Band stop filterThe question was asked in an interview for internship.I want to ask this question from Spread Spectrum in chapter Spread Spectrum Techniques of Digital Communications

Spread spectrum can be used to transmit(a) Analog data(b) Digital data(c) Analog & Digital data(d) None of the mentionedI had been asked this question in examination.The question is from Spread Spectrum topic in section Spread Spectrum Techniques of Digital Communications

Spread spectrum has immunity from(a) Noise(b) Multi-path distortion(c) Noise & Multi-path distortion(d) None of the mentionedThis question was posed to me in an online quiz.This interesting question is from Spread Spectrum topic in division Spread Spectrum Techniques of Digital Communications

Spread spectrum makes ______ difficult.(a) Jamming(b) Interception(c) Jamming & Interception(d) None of the mentionedI had been asked this question during an interview for a job.Query is from Spread Spectrum in division Spread Spectrum Techniques of Digital Communications

Spread spectrum is a ______ technique.(a) Encoding(b) Decoding(c) Encoding & Decoding(d) None of the mentionedI had been asked this question in an interview for job.Enquiry is from Spread Spectrum topic in portion Spread Spectrum Techniques of Digital Communications

For hybrid systems the minimum required processing gain is(a) 5db(b) 10db(c) 17db(d) 25dbI had been asked this question in an international level competition.Enquiry is from Stream Encryption and Commercial Applications in chapter Spread Spectrum Techniques of Digital Communications

Multi paths may be because of(a) Reflections from buildings(b) Refraction(c) Atmospheric reflections(d) All of the mentionedThis question was addressed to me in exam.Query is from Stream Encryption and Commercial Applications in division Spread Spectrum Techniques of Digital Communications

For direct sequence systems what is the minimum required processing gain?(a) 3db(b) 10db(c) 12db(d) 20dbThis question was addressed to me in exam.This interesting question is from Stream Encryption and Commercial Applications in chapter Spread Spectrum Techniques of Digital Communications

One-time pad has(a) Random key(b) Unconditional security(c) Can be used only once(d) All of the mentionedThe question was posed to me in my homework.The above asked question is from Stream Encryption and Commercial Applications topic in portion Spread Spectrum Techniques of Digital Communications

The 64 bit block input key has _____ number of parity bits.(a) 4(b) 6(c) 8(d) 16I have been asked this question by my college professor while I was bunking the class.My doubt stems from Stream Encryption and Commercial Applications in section Spread Spectrum Techniques of Digital Communications

In substitution technique encryption protection is more.(a) True(b) FalseI had been asked this question in semester exam.My question is from Stream Encryption and Commercial Applications in division Spread Spectrum Techniques of Digital Communications

When the key size is finite, equivocation approaches(a) Unity(b) Zero(c) Infinity(d) None of the mentionedThe question was asked during a job interview.The origin of the question is Cipher Systems and Secrecy of Cipher Systems topic in portion Spread Spectrum Techniques of Digital Communications

The trithemius cipher is a mono alphabetical cipher.(a) True(b) FalseI have been asked this question during an online exam.My question comes from Cipher Systems and Secrecy of Cipher Systems in portion Spread Spectrum Techniques of Digital Communications

In Caesar cipher, each plain text is replaced by(a) Alphabet shift(b) Numerals(c) Symbols(d) None of the mentionedThis question was addressed to me in class test.My doubt stems from Cipher Systems and Secrecy of Cipher Systems topic in division Spread Spectrum Techniques of Digital Communications

Caesar cipher was a mono alphabetic cipher.(a) True(b) FalseThe question was posed to me during a job interview.The origin of the question is Cipher Systems and Secrecy of Cipher Systems in chapter Spread Spectrum Techniques of Digital Communications

Which serves the hard hand-off process?(a) Base station(b) Mobile switching center(c) Mobile(d) None of the mentionedI had been asked this question in an online interview.My doubt is from Cellular Systems topic in portion Spread Spectrum Techniques of Digital Communications

Short code is configured using ______ shift register.(a) 4-stage(b) 2-stage(c) 12-stage(d) 15-stageThe question was asked in an online interview.I'm obligated to ask this question of Cellular Systems topic in division Spread Spectrum Techniques of Digital Communications

Walsh cover technique is used for(a) Channelization(b) Spreading(c) Channelization & Spreading(d) None of the mentionedThe question was posed to me during an internship interview.This key question is from Cellular Systems topic in division Spread Spectrum Techniques of Digital Communications