| 摘要 |
PURPOSE: To reduce the distribution of each point of an original constellation chart to its cloud by deciding approximate advanced distorting data based on the part of the 2M bits (M<N) of 2N bit fields, and correcting the data by the residual part of 2(N-M) bit fields. CONSTITUTION: 2M bit fields address a memory 112 which stores approximate advanced distorting values (FI0 , FQ0 ). Also, 2(N-M) bit fields are inputted to an interpolating circuit 111. In this case, the two (N-M) bit fields express values Δx and Δy for each channel, and the two M bit fields express values (x) and (y) for each channel. Then, the interpolating circuit 111 calculates corrected data (FI, FQ) with the help of the values Δx and Δy based on the approximate data FI0 , FQ0 and the address fields. Thus, the distribution of each point of the original constellation chart to its cloud can be reduced. |
