Constellation diagram
The constellation diagram is used to represent a signal that belongs to a digital modulation scheme, such as quadrature amplitude modulation (QAM), quadrature phase shift keying ( QPSK) or phase shift keying (PSK).
By displaying a transmitted symbol as a complex number and modulating a cosine and sine carrier signal with the real or the imaginary part of the symbol, the symbol can be transmitted using two carriers on the same frequency. With a pure phase modulation, the phase of the carrier signal corresponds to the phase of the transmitted symbol in the constellation diagram.
Since the symbols represent complex numbers, they can be represented as points in the complex plane. The constellation diagrams of the two images assign a symbol to phase and / or amplitude information.
literature
- Sanjay Kumar: Wireless Communication - The fundamental and advanced concepts . River Publishers, 2015, ISBN 978-87-93102-80-4 , Chapter 9.8: Vector Representation of Signals.
