Digital Modulation MCQ || Introduction To Digital Modulation Questions and Answers

Answer.1. k/n

Explanation:-

The code rate (or information rate) is a fractional number that expresses what part of the redundant message is actually meaningful. The code rate is k/n. Block code: k message bits encoded to n code bits i.e., each of 2k messages encoded into a unique n-bit codeword via a linear transformation. Key property: The sum of any two codewords is also a codeword → necessary and sufficient for code to be linear. (n,k) code has rate k/n.

Answer.3. Pulse code modulator

Explanation:-

A signal in pulse code modulation is pulse code modulated to convert its analog information into a binary sequence. This is the reason why we call PCM a modulation technique. In electronics and telecommunications, pulse shaping is the process of changing the waveform of transmitted pulses. Pulse code modulator is used for pulse shaping.

Answer.3. All of the mentioned

Explanation:-

In telecommunication, equalization is the reversal of distortion incurred by a signal transmitted through a channel. Equalizers are used to render the frequency response—for instance of a telephone line—flat from end-to-end.

Answer.4. All of the mentioned

Explanation:-

The Source encoder ( or Source coder) converts the input i.e. symbol sequence into a binary sequence of 0’s and 1’s by assigning code words to the symbols in the input sequence. … At the receiver, the source decoder converts the binary output of the channel decoder into a symbol sequence. Source encoding does all these processes-compression, digitizing the signal, and performs analog to digital conversion.

Answer.1. Coherent

Explanation:-

Coherent signals are signals having the same phase and frequency. … Coherent systems mean that the receiver needs the phase information of the transmitter (the carrier phase) to recover the transmitted data at the receiver side. Coherent measurement considers phase as an important parameter.