What is the primary purpose of synchronous detection in signal processing?

The primary purpose of synchronous detection in signal processing is to extract relevant information from modulated signals. This technique is particularly useful in demodulating amplitude-modulated (AM) signals and similar applications. By using a reference signal that is synchronized in phase and frequency with the carrier wave, synchronous detection effectively recovers the original information signal from the modulated carrier.

This method improves the quality of the signal detection by enhancing the desired signal while concurrently minimizing the effects of noise and interference. The synchronization ensures that the demodulation process accurately tracks the signal variations, allowing for a more precise recovery of the transmitted information.

In contrast, the other choices involve functions that are not the primary role of synchronous detection. While amplification, noise reduction, and further modulation can be related to signal processing, they do not specifically address the core function of synchronous detection, which is focused on demodulation and information extraction.