| 摘要 |
PROBLEM TO BE SOLVED: To properly perform phase comparison without excessively narrowing a distance from the border line of an error discrimination area in spite of where a symbol point is positioned. SOLUTION: At the time of carrier wave reproduction when demodulating a received quadrature amplitude modulated signal, points, where the C/N of each signal is made logically best, on an I-Q plane are defined as symbol points 1-16. Then, error discrimination areas 21-36 are respectively set to the symbol points 1-16 one by one, the point of the received quadrature amplitude modulated signal on the I-Q plane is defined as a signal point and a phase error signal is outputting for showing the position of this signal point has prescribed relation with the position of the symbol point inside the error discrimination area to which this signal point belongs. In this case, the border lines of the error discrimination areas 21-36 are deformed so that the distance between these border lines and the symbol points 1-16 can be extended. |
