Method and apparatus for constant envelope quadrature amplitude modulation

摘要

A constant envelope quadrature amplitude modulation system is provided for solving the bandwidth efficiency problem resulting from a lack of frequency resources by implementing the constant envelope characteristic for a non-linear communication system, based on a 16-QAM (Quadrature Amplitude Modulation) system. The system limits the data, which will be modulated and transmitted, to 3-bit data and adds a parity bit to make the data have a constant envelope within the 16-QAM system, which modulates data to be transmitted in the unit of 4-bit. The data value of the parity bit is selected to satisfy the condition of a constant envelope in accordance with the QAM signals.