Mobile Communication Test Questions Set 3

1)   Probability of outage refers to

a. Noise developed at the receiver
b. Number of bit errors during transmission
c. Signal to noise ratio
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Number of bit errors during transmission

Explanation:
No explanation is available for this question!


2)   The digital modulation technique used in frequency selective channels is

a. FSK
b. ASK
c. BPSK
d. QPSK
Answer  Explanation  Related Ques

ANSWER: BPSK

Explanation:
No explanation is available for this question!


3)   Working of Adaptive Equalizers include

a. Training
b. Tracking
c. Modulation
d. Both a and b
e. All a, b and c are correct
Answer  Explanation  Related Ques

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


4)   The time span for which the equalizer converges depends upon

1. Equalizer algorithm
2. Equalizer structure
3. Rate of change of multipath radio channel
4. Amplitude of signal


a. 1 and 2 are correct
b. 1, 2 and 3 are correct
c. 2 and 3 are correct
d. All the four are correct
Answer  Explanation  Related Ques

ANSWER: 1, 2 and 3 are correct

Explanation:
No explanation is available for this question!


5)   The Linear Equalizer may be implemented as

a. FIR filter
b. Lattice filter
c. Low pass filter
d. Both a and b
e. Both a and c
Answer  Explanation  Related Ques

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


6)   Linear equalizer is also known as

a. Transversal filter
b. Lattice filter
c. Low pass filter
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Transversal filter

Explanation:
No explanation is available for this question!


7)   The methods used for non linear equalization are

a. Decision Feedback Equalization
b. Maximum Likelihood Symbol Detection
c. Maximum Likelihood Sequence Estimation


a. 1 and 2 are correct
b. 1, 2 and 3 are correct
c. 2 and 3 are correct
d. None of the above
Answer  Explanation  Related Ques

ANSWER: 1, 2 and 3 are correct

Explanation:
No explanation is available for this question!


8)   The performance of algorithms for Adaptive Equalization are given by

1. Rate of convergence
2. Computational complexity
3. Numerical properties
4. Frequency change


a. 1 and 2 are correct
b. 1, 2 and 3 are correct
c. 2 and 3 are correct
d. All are correct
Answer  Explanation  Related Ques

ANSWER: 1, 2 and 3 are correct

Explanation:
No explanation is available for this question!


9)   Computational complexity of an algorithm refers to the

a. Number of operations for one iteration of algorithm
b. Inaccuracies in the mathematical analysis
c. Noise produced during one complete iteration of algorithm
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Number of operations for one iteration of algorithm

Explanation:
No explanation is available for this question!


10)   The algorithms acquired for adaptive equalization are

1. Zero forcing algorithm
2. Least mean squares algorithm
3. Recursive least squares algorithm


a. 1 and 2 are correct
b. 1, 2 and 3 are correct
c. 2 and 3 are correct
d. None of the above
Answer  Explanation  Related Ques

ANSWER: 1, 2 and 3 are correct

Explanation:
No explanation is available for this question!


11)   Fractionally spaced equalizer acts as

a. Matched filter
b. Equalizer
c. Demodulator
d. Both a and b
e. All a, b and c are correct
Answer  Explanation  Related Ques

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


12)   Diversity employs the decision making at

a. Transmitter
b. Receiver
c. Transmitter and receiver
d. Communication channel
Answer  Explanation  Related Ques

ANSWER: Receiver

Explanation:
No explanation is available for this question!


13)   The diversity schemes are based on

1. Time diversity
2. Frequency diversity
3. Space diversity
4. Polarization diversity


a. 1 and 2 are correct
b. 1, 2 and 3 are correct
c. 2 and 3 are correct
d. All the four are correct
Answer  Explanation  Related Ques

ANSWER: All the four are correct

Explanation:
No explanation is available for this question!


14)   In time diversity

a. Multiple versions of signals are transmitted at different time instants
b. The signal is transmitted using multiple channels
c. Signal is transmitted with different polarization
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Multiple versions of signals are transmitted at different time instants

Explanation:
No explanation is available for this question!


15)   RAKE receiver is

1. Several sub receivers
2. Several correlators
3. Fingers
4. Equalization based


a. 1 and 2 are correct
b. 1, 2 and 3 are correct
c. 2 and 3 are correct
d. All the four are correct
Answer  Explanation  Related Ques

ANSWER: 1, 2 and 3 are correct

Explanation:
No explanation is available for this question!


16)   The RAKE receiver involves the steps

a. Correlator, estimation of transmitted signal, demodulation, bit decision
b. Estimation of transmitted signal, correlator, demodulation, bit decision
c. Estimation of transmitted signal, demodulation, correlator, bit decision
d. Estimation of transmitted signal, demodulation, bit decision, correlator
Answer  Explanation  Related Ques

ANSWER: Correlator, estimation of transmitted signal, demodulation, bit decision

Explanation:
No explanation is available for this question!


17)   Search window of a RAKE receiver is

a. Frequency band of the channel
b. Range of the time delays
c. Range of noise
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Range of the time delays

Explanation:
No explanation is available for this question!


18)   Speech Coders are categorized on the basis of

a. Signal compression techniques
b. Frequency of signal
c. Bandwidth of the signal
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Signal compression techniques

Explanation:
No explanation is available for this question!


19)   Waveform coders and Vocoders are the types of

a. Speech coders
b. Modulation technique
c. Frequency translation methods
d. Channel allocation for transmission
Answer  Explanation  Related Ques

ANSWER: Speech coders

Explanation:
No explanation is available for this question!


20)   PCM, DPCM, DM, ADPCM are the types of

a. Vocoders
b. Waveform coders
c. Channel allocation for transmission
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Waveform coders

Explanation:
No explanation is available for this question!


21)   Speech coding technique that is independent of the source is

a. Vocoders
b. Waveform coders
c. Both a & b
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Waveform coders

Explanation:
No explanation is available for this question!


22)   Advantage of using waveform coders is

1. Independent of the signal source
2. Less complexity
3. Suitable for noisy environments


a. 1 and 2 are correct
b. 1 and 3 are correct
c. 2 and 3 are correct
d. All the three are correct
Answer  Explanation  Related Ques

ANSWER: All the three are correct

Explanation:
No explanation is available for this question!


23)   The type of frequency domain coding that divides the speech signal into sub bands is

a. Waveform coding
b. Vocoders
c. Block transform coding
d. Sub-band coding
Answer  Explanation  Related Ques

ANSWER: Sub-band coding

Explanation:
No explanation is available for this question!


24)   The speech coding technique that is dependent on the prior knowledge of the signal is

a. Waveform coders
b. Vocoders
c. Sub band coding
d. Block transform coding
Answer  Explanation  Related Ques

ANSWER: Vocoders

Explanation:
No explanation is available for this question!


25)   The steps involved in Channel vocoders for speech transmission are

a. Envelope detection, sampling, encoding, multiplexing
b. Sampling, Envelope detection, encoding, multiplexing
c. Envelope detection, encoding, sampling, multiplexing
d. Sampling, Envelope detection, multiplexing, encoding
Answer  Explanation  Related Ques

ANSWER: Envelope detection, sampling, encoding, multiplexing

Explanation:
No explanation is available for this question!


26)   Vocal tract cepstral coefficients and excitation coefficients are separated by

a. Samplers
b. Linear filters
c. Encoders
d. Multiplexers
Answer  Explanation  Related Ques

ANSWER: Linear filters

Explanation:
No explanation is available for this question!


27)   In voice excited vocoders, PCM transmission helps in transmission of

a. High frequency bands of speech
b. Low frequency bands of speech
c. Multiplexed signals
d. Modulated signals
Answer  Explanation  Related Ques

ANSWER: Low frequency bands of speech

Explanation:
No explanation is available for this question!


28)   Linear predictive coders are based on the principle that

1. Current signal sample is obtained from linear combination of past samples
2. Current signal sample is independent of past samples
3. These are time domain vocoders
4. They are among low bit rate vocoders


a. 1, 3 and 4 are correct
b. 2, 3 and 4 are correct
c. 1 and 4 are correct
d. All the four are correct
Answer  Explanation  Related Ques

ANSWER: 1, 3 and 4 are correct

Explanation:
No explanation is available for this question!


29)   Multi pulse excited LPC includes

1. Multiple pulses per period
2. Minimization of weighted mean square error
3. Better speech quality
4. Pitch detection is not required


a. 1 and 4 are correct
b. 1 and 3 are correct
c. 2 and 4 are correct
d. All four are correct
Answer  Explanation  Related Ques

ANSWER: All four are correct

Explanation:
No explanation is available for this question!


30)   In residual excited LPC,

a. The residue of subtraction of generated and original signal is quantized at the transmitter
b. Pitch detection is not required
c. Multiple pulses per period
d. Coder and decoders have predetermined set of codes
Answer  Explanation  Related Ques

ANSWER: The residue of subtraction of generated and original signal is quantized at the transmitter

Explanation:
No explanation is available for this question!


31)   The speech sequence in GSM Codec consists of

a. Pre emphasis, segmentation, windowing, filtering
b. Windowing, Pre emphasis, segmentation, filtering
c. Pre emphasis, windowing, segmentation, filtering
d. Pre emphasis, segmentation, filtering, windowing
Answer  Explanation  Related Ques

ANSWER: Pre emphasis, segmentation, windowing, filtering

Explanation:
No explanation is available for this question!


32)   The windowing technique used for speech coding in GSM Codec is

a. Blackman window
b. Welch window
c. Cosine window
d. Hamming window
Answer  Explanation  Related Ques

ANSWER: Hamming window

Explanation:
No explanation is available for this question!


33)   The received signal at the GSM speech decoder is passed through

a. STP filter
b. LTP filter
c. Quantizer
d. PLL
Answer  Explanation  Related Ques

ANSWER: LTP filter

Explanation:
No explanation is available for this question!


34)   In GSM Codec, the bits encoded for forward error correction are

a. Ia bits
b. Ib bits
c. II bits
d. Both a and b
e. Both a and c
Answer  Explanation  Related Ques

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


35)   The speech coders are selected on the basis of

1. Robustness to transmission errors
2. Cell size
3. Type of modulation technique used
4. Distance between the transmitter and receiver


a. 1 and 4 are correct
b. 1, 2 and 3 are correct
c. 2 and 4 are correct
d. All four are correct
Answer  Explanation  Related Ques

ANSWER: 1, 2 and 3 are correct

Explanation:
No explanation is available for this question!


36)   FDMA is the division of

a. Time
b. Phase
c. Spectrum
d. Amplitude
Answer  Explanation  Related Ques

ANSWER: Spectrum

Explanation:
No explanation is available for this question!


37)   Guard band is

a. The small unused bandwidth between the frequency channels to avoid interference
b. The bandwidth allotted to the signal
c. The channel spectrum
d. The spectrum acquired by the noise between the signal
Answer  Explanation  Related Ques

ANSWER: The small unused bandwidth between the frequency channels to avoid interference

Explanation:
No explanation is available for this question!


38)   Cable television is an example of

a. TDMA
b. FDMA
c. CDMA
d. SDMA
Answer  Explanation  Related Ques

ANSWER: FDMA

Explanation:
No explanation is available for this question!


39)   In FDMA,

1. Each user is assigned unique frequency slots
2. Demand assignment is possible
3. Fixed assignment is possible
4. It is vulnerable to timing problems


a. 1 and 2 are correct
b. 2 and 4 are correct
c. 1, 2 and 3 are correct
d. All four are correct
Answer  Explanation  Related Ques

ANSWER: 1, 2 and 3 are correct

Explanation:
No explanation is available for this question!


40)   FDMA demand assignment uses

1. Single channel per carrier
2. Multi channel per carrier
3. Single transmission in one time slot
4. Multi transmission in one time slot


a. 1 and 2 are correct
b. 2, 3 and 4 are correct
c. 1, 2 and 3 are correct
d. All four are correct
Answer  Explanation  Related Ques

ANSWER: 1 and 2 are correct

Explanation:
No explanation is available for this question!