What is QPSK modulation primarily used for in communication systems?

QPSK (Quadrature Phase Shift Keying) modulation is primarily used for enabling efficient signal transmission in communication systems. This modulation technique utilizes four distinct phase shifts to encode data, allowing it to transmit two bits of information per symbol, which effectively doubles the data rate compared to traditional BPSK (Binary Phase Shift Keying). By using the available bandwidth more effectively, QPSK can accommodate higher data rates without requiring additional bandwidth.

While other factors such as bandwidth enhancement or improved data transfer rates are indirectly influenced by QPSK, the key aspect is its ability to transmit signals efficiently within the existing bandwidth. This efficiency is crucial for optimizing the use of available resources in communication networks, particularly in scenarios where bandwidth is limited.