RADIO DEVICE, CONTROL METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To suppress click noise during an analog FM communication period in a radio device 10 which executes detection using the tan-1detection method. SOLUTION: A buffer 43 receives tan-1(X(k)/Y(k)) based on I and Q components of an FM reception signal as an original phase and stores original phases at a plurality of most recent continuous sample times. A maximum value storing device 44 and a minimum value storing device 45 store the maximum value and the minimum value out of the plurality of stored original phases, together with indexes (corresponding to the sample times), respectively. A threshold decision device 47 and a code decision device 53 determine whether a positive or negative impulse, which causes click noise, has occurred in the original phases, based on a difference and a temporal relationship between the maximum value and the minimum value. When the positive or negative impulse is detected, a multiplier 49 outputs a unit impulse with a code, and then the unit impulse is integrated in an adder 56 and a delay device 57. An inverted value of the integrated value is added to the original phases in the adder 60, and the added value is supplied to a differential circuit for calculating a frequency shift. COPYRIGHT: (C)2009,JPO&INPIT