amplituudklahvlülitus

Amplituudklahvlülitus, also known as amplitude shift keying (ASK), is a form of amplitude modulation used in digital communication. It transmits digital data by varying the amplitude of a carrier wave. In its simplest form, known as binary amplitude shift keying (BASK), there are two distinct amplitude levels representing the binary digits 0 and 1. A higher amplitude typically signifies a '1' and a lower or zero amplitude signifies a '0'.

The basic principle involves a carrier wave that is either present at a certain amplitude or absent, or present at two different amplitudes, corresponding to the digital signal's bits. When the input bit is a '1', the transmitter sends a carrier wave of a specific amplitude. When the input bit is a '0', the transmitter either sends a carrier wave of a different, usually lower, amplitude or turns the carrier wave off completely (this latter variation is sometimes called on-off keying or OOK). At the receiver, the amplitude of the incoming signal is measured and compared to predefined thresholds to determine whether a '0' or a '1' was transmitted.

ASK is relatively simple to implement and requires less power for transmission compared to some other modulation schemes, especially OOK. However, it is susceptible to noise and interference, which can cause amplitude variations that might be misinterpreted as data bits, leading to a higher bit error rate. Its bandwidth efficiency is not as high as some other digital modulation techniques. Due to its simplicity and low cost, ASK is often used in short-range, low-data-rate applications such as remote controls, RFID systems, and some infrared remote controls.