Modulation Statements Analysis

This solution analyzes the correctness of three statements regarding modulation techniques, focusing on bandwidth, noise handling, and multiplexing.

Statement 1 Analysis: Bandwidth Comparison

Statement 1 claims that analog modulation requires lower bandwidth than digital modulation methods. This statement can be considered correct in certain contexts, particularly when comparing basic analog modulation schemes (like AM or FM) with digital schemes designed for very high data rates or complex error correction. While digital modulation can achieve high spectral efficiency, the fundamental nature or simpler implementations of analog modulation might occupy less bandwidth for transmitting basic information.

Statement 2 Analysis: Noise Separation and Repeaters

Statement 2 asserts that signal separation from noise is impossible in analog modulation, leading to the use of repeaters. This statement is incorrect. While separating noise from an analog signal is challenging and degrades over distance, it is not entirely impossible using filters. Furthermore, analog repeaters (amplifiers) amplify both the signal and the noise, unlike digital repeaters which regenerate the signal, effectively removing noise. The premise and conclusion of this statement are flawed.

Statement 3 Analysis: FDM in Analog Modulation

Statement 3 states that Frequency Division Multiplexing (FDM) is used for multiplexing in analog modulation. This is correct. FDM is a standard technique used in analog communication systems to combine multiple independent signals into a single communication channel by allocating distinct frequency bands to each signal.

Conclusion on Correct Statements

Based on the analysis:

• Statement 1 is considered correct in specific comparison contexts.
• Statement 2 is incorrect.
• Statement 3 is correct.

Therefore, the correct statements are 1 and 3.