In high speed TDM, the channels are separated in the receiver employing
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ECE · all questionsDigital Communication
Digital Communication
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Delta modulation and pulse code modulation have a threshold Pe, (Considering the impact of errors in various digits).
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The bit rate of 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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Five channels each with 100 kHz bandwidth are to be multiplexed together. What is the minimum bandwidth of the link, if three is a need of a guard band is a need of a guard band of 10 kHz between the channels to prevent interference?
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Minimum Bandwidth required for Minimum Shift Keying (MSK)? Where fb is maximum frequency of baseband signal.
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The criterion used for pulse shaping to avoid ISI is
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Which signaling scheme is most affected by noise?
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The received signal level for a particular digital system is -151 dBW and the effective noise temperature of the receiver system is 1500 K. The value of required for a link transmitting 2400 bps is:
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PAM signals are constructed by using a low pass filter of pass band slightly greater than base band to avoid aliasing. This avoids distortion
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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 The value of p(t) at is
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As practical signals are time limited, they have infinite frequency bandwidth. Sampling of such signals lead to aliasing. To avoid aliasing, an anti-aliasing filter is used
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In a PCM system, if we increase the quantization levels from 2 to 8, how do the relative bandwidth requirements vary?
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Four signals g1(t), g2(t), g3(t) and g4(t) are to be multiplexed and transmitted g1(t) and g4(t) have a bandwidth of 4 kHz, and the remaining two signals have bandwidth of 8 kHz. Each sample requires 8 bit for encoding. What is the minimum transmission bit rate of the system?
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Consider a Binary Symmetric Channel (BBC) 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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In a uniform quantizer, the quantization noise is
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Obtain the phase states of the carrier when the bit stream 1001101100 is applied to a QPSK modulator
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Which of the following modulation scheme requires minimum power for transmission?
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The line code that has zero dc component for pulse transmission of random binary data is
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In MSK, the difference between the higher and lower frequency is
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Q100
Open questionAmplitude shift keying is not widely used, because
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