What is QAM and QPSK?

Quadrature Amplitude Modulation (QAM) is a modulation technique that combines both amplitude modulation and phase modulation to transmit data by varying the amplitude of two carrier waves, thus allowing multiple bits of data to be sent simultaneously. Quadrature Phase Shift Keying (QPSK) is a specific type of phase modulation that encodes data by changing the phase of the carrier signal, allowing for four distinct phase shifts, each representing two bits of information. Both techniques are widely used in digital communication systems, but QAM can transmit more bits per symbol compared to QPSK, making it more efficient in bandwidth utilization.