| 摘要 |
PROBLEM TO BE SOLVED: To provide a TDD (Time Division Duplex) switching signal creation circuit which can output a TDD switching signal with accurate time duration width even if property changes on installing conditions because properties of the composing elements are bad. SOLUTION: The TDD switching signal sent from an IDU (In Door Unit) 10 of a 1st unit is demodulated by an ASK (Amplitude Shift Keying) detection circuit 31 of an ODU (Out Door Unit) 20 of a 2nd unit. Logical circuits of shift registers 32, 33, a NOT circuit 34, and a NAND circuit 35, detect completion of rise of the demodulated TDD switching signal. A counter 36 counts clocks of a standard oscillator 38 from time of detecting completion of the rise. A count value comparator 37 makes the time detecting the completion of the rise as a switching point to an operation mode, and makes a time the count value of the counter reaches a number of counts given beforehand as a switching point to another operation mode. COPYRIGHT: (C)2004,JPO
|
