PSKdemodulaattori

A PSKdemodulator is a circuit or algorithm used in telecommunications to recover the original digital data transmitted using Phase-Shift Keying (PSK) modulation. PSK is a digital modulation technique where the phase of a carrier wave is varied to represent binary data. For example, in Binary Phase-Shift Keying (BPSK), one phase might represent a '0' and another phase, typically 180 degrees shifted, represents a '1'.

The PSKdemodulator's primary function is to detect these phase shifts and convert them back into a stream of binary bits. It typically operates by comparing the incoming modulated signal's phase with a reference phase. This reference can be derived from the incoming signal itself through a phase-locked loop (PLL) or from a separate clock signal.

Different types of PSKdemodulators exist, tailored to specific PSK schemes such as BPSK, Quadrature Phase-Shift Keying (QPSK), or M-ary PSK (M-PSK), where M represents the number of possible phase states. The complexity of the demodulator increases with the number of phase states. For instance, a QPSKdemodulator needs to distinguish between four different phase shifts.

The process often involves correlating the received signal with known phase states or using a matched filter. The output of this correlation or filtering process is then sampled and quantized to determine which phase state was transmitted. This recovered data stream is then passed on for further processing or decoding. The performance of a PSKdemodulator is often measured by its bit error rate (BER), which is influenced by factors like signal-to-noise ratio (SNR) and the accuracy of its phase detection circuitry.