Q141
Open questionTime division multiplexing (TDM) is possible with
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Q142
Open questionThe PSD of the Manchester line code
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Q143
Open questionWhat is the required bandwidth of a PCM system for 256 quantization levels when 48 telephone channels, each band limited to 4 kHz, are to be time-division multiplexed by this PCM?
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Q144
Open questionThe temperature at a particular place varies between 14°C and 34°C. For the purpose of transmitting the temperature record of that place using PCM, the record is sampled at an appropriate sampling rate and the samples are quantized. If the error in representation of the samples due to quantization is not to exceed ±1% of the dynamic range, what is the minimum number of quantization levels that can be used?
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Q145
Open question24 voice signals are sampled uniformly at 8 kHz and then sent using TDM scheme. The sampling process uses flat-top samples with 1 µs duration. An extra pulse of duration 1 µs is added for the purpose of synchronization. The spacing between two consecutive pulses is-
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Q146
Open questionThe quantization of a PCM system depends on
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Q147
Open questionIn asynchronous TDM, for n signal sources, each frame contains m slots, where m is usually
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Q148
Open questionIn a PCM system, if the code word length is increases form 6 to 8 bits, the signal to quantization noise ratio improves by the factor
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Q149
Open questionA source emits bit 0 with probability and bit 1 with probability The emitted bits are communicated to the receiver. The receiver decides for either 0 or 1 based on the received value R. It is given that the conditional density functions of R as
\begin{array}{l} {f_{R/0}}\left( r \right) = \left\{ {\begin{array}{*{20}{c}} {\frac{1}{4},}&{ - 3 \le r \le 1}\\ {0,}&{{\rm{otherwise}}} \end{array}} \right.\,{\rm{and}}\\ {f_{R/1}}\left( r \right) = \left\{ {\begin{array}{*{20}{c}} {\frac{1}{6},}&{ - 1 \le r \le 5}\\ {0,}&{{\rm{otherwise}}} \end{array}} \right. \end{array}
The minimum decision error probability is
\begin{array}{l} {f_{R/0}}\left( r \right) = \left\{ {\begin{array}{*{20}{c}} {\frac{1}{4},}&{ - 3 \le r \le 1}\\ {0,}&{{\rm{otherwise}}} \end{array}} \right.\,{\rm{and}}\\ {f_{R/1}}\left( r \right) = \left\{ {\begin{array}{*{20}{c}} {\frac{1}{6},}&{ - 1 \le r \le 5}\\ {0,}&{{\rm{otherwise}}} \end{array}} \right. \end{array}
The minimum decision error probability is
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Q150
Open questionDiscrete samples of an analog signal are uniformly quantized to PCM. If the maximum value of analog sample is to be represented within 0.1% accuracy, then the minimum number of binary digits required per sample is
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Q151
Open questionTo reduce the distortion, which one of the following can be used?
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Q152
Open questionConsider minimum shift keying (MSK) also known as fast with frequency spacing 2fd between the state frequencies. rb is the data rate. Which one of the following correctly relates rb and fd?
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Q153
Open questionIn delta modulation, the quantizer is a
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Q154
Open question. . . . . . . . step is NOT involved in pulse code modulation system.
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Q155
Open questionFigure shows a block diagram of a system to recover a sampled signal shown as input.
Blocks A and B can be respectively
Blocks A and B can be respectively
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Q156
Open questionRoll - off factor is defined as
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Q157
Open questionA ramp signal m(t) = at is applied to a delta modulator with sampling period TS and step size d. Slope overload distortion would occur if
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Q158
Open questionAt a given probability of error, binary coherent FSK is inferior to binary coherent PSK by
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Q159
Open questionA continuous signal has voltage range of -4 V to +2 V. If this is quantized to 8 bits, then the step size of the quantizer will be:
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Q160
Open questionFour voice signals, each limited to 4 kHz and sampled at Nyquist rate, are converted into binary PCM signal using 256 quantization levels. The bit transmission rate for the timedivision multiplexed signal will be
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