| 摘要 |
PURPOSE:To decide whether or not a signal is a call signal to the own device by binary-coding a signal on a transmission line so as to compress the amount of information, sampling the binary-coded signal repetitively at a specific period and obtaining the accumulated value of the same phase of the sampling value of each sampling point. CONSTITUTION:When a power of a transmitter is applied, a microprocessor 102 goes to the standby mode after initial setting and awaits pulse input. Equation I is set as the sampling period in the initial setting, where T is a period of a call signal specific to a transmitter, N is a sampling point number per T, and the N is 8 and the I is selected from integral numbers such as 3, 5, 7. When the signal is the call signal of the own device, the pattern of the accumulated value of the sampling value of each sampling point is as shown in Fig. (a) ideally and if a slight frequency shift or noise exists, the pattern is as shown in Fig. (b). When the signal is the call signal of the own device in this way, the accumulated value is increased monotonously from a certain sampling point and when the value reaches a maximum value, the value is decreased monotonously. Whether or not the signal is the call signal to the own device is discriminated by recognizing the accumulated pattern with a simple method comparing sequentially the accumulated value of the adjacent sampling point. |
