| 摘要 |
PROBLEM TO BE SOLVED: To expand a linear area in a section for detecting a frequency error and to quickly correct frequency by applying a delay element, a multiplier, an adder/subtractor, a divider and a reverse sine device to the in-phase compo nent and the quadrature component in an input signal. SOLUTION: The in-phase component of a received signal is inputted to a terminal and the quadrature component is inputted to a terminal 2. Outputs from respective terminals 1, 2 are delayed by respective delay elements 3, 4, the output of the terminal 1 and the output of the element 4 are mutually multiplied by a multiplier 5, the output of the terminal 2 and the output of the element 3 are mutually multiplied by a multiplier 6 and outputs from the multipliers 5, 6 are inputted to a subtractor 9. The output of the terminal 1 and the output of the element 3 are mutually multiplied by a multiplier 7, the output of the terminal 2 and the output of the element 4 are mutually multiplied by a multiplier 8 and these multiplied outputs are inputted to an adder 10. A divider 11 divides the output of the subtractor 9 by the output of the adder 10. The inverse tangent device 12 finds out the inverse tangent of an output from the divider 11 and the inverse tangent is outputted from a terminal 13. A frequency error is found out from the output of the terminal 13. |
