QPSK

Introduction to QPSK

Quadrature Phase-Shift Keying (QPSK) is a widely used modulation technique in modern digital communication systems, known for its efficient spectral utilization and interference resistance. QPSK transmits data by changing the phase of the carrier signal, where each symbol represents two bits, corresponding to four possible phase states (0, 90, 180, 270 degrees).

Material Source

This course primarily references GNU Radio Tutorials: QPSK Mod and Demod, which involves various digital communication technologies, such as Raised Cosine Filter, Inter-Symbol Interference (ISI), pulse shaping, differential encoding, multipath effects, Additive White Gaussian Noise (AWGN), frequency offset and time offset, equalizers, phase-locked loop, etc.

The purpose of this textbook is to provide students with a deeper understanding and appreciation of the entire digital communication system. During the learning process, there may be many areas that are not understood, but there is no need to worry too much, as each unit provides a system architecture file that can be downloaded and executed directly. For the theoretical part, in addition to referring to the textbook content, you can also consult the original text and the many references provided therein. This will naturally lead to a more profound understanding of the material learned.