KR920014304A - CCT Receiving Method Using Digital Signal Processor - Google Patents

Abstract

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Description

CCT Receiving Method Using Digital Signal Processor

Since this is an open matter, no full text was included.

2 is a block diagram of a CCT signal receiving function configuration of the present invention, and FIG. 3 is a flowchart of a CCT receiving program in a digital signal processor to which the present invention is applied.

Claims (3)

Digital signal processor 5, EP ROMs 3 and 4 connected to the digital signal processor 5, channel multiplexing circuit 6, input / output memory 2, monitor 7, reset circuit 9 and local oscillator (8), a CCT signal receiving device having a microcontroller (1) connected to the input / output memory (2) and a monitor (7), the channel multiplexing circuit (6) and a timing control circuit connected to a monitor, wherein the digital signal The first step of initializing (17) various data contents necessary for the CCT receiving program to be executed in the processor 5, and continuously checking whether the PCM data has been input into the digital signal processor 5 after the first step. (18) a second step of determining whether the number of the input PCM data is 133 if the PCM data is input; system By converting the linear data into linear data (20), multiplying the window function (21), and obtaining a power spectrum by full calculation for each frequency component of 1,780 [Hz] and 2,000 [Hz] by the DFT method. CCT signal receiving method characterized in that. According to claim 1, If the number of the PCM data input from the second terminal is 133 first, the power for each frequency is obtained by the zero calculation for each frequency component by the DET method, and then the total reception of the sum of the calculated power for each frequency component Obtaining power, checking whether the received standard, such as total reception power and signal-to-noise ratio, are satisfied, detecting one frequency (23), converting the detected frequency into signal code information (24), and performing the same signal code twice in succession. If it is detected (25) and the information is detected with the same signal code twice in succession, it is determined as signal code information having an effective frequency that satisfies the reception standard and outputted out of the digital signal processor 5 to output the input / output memory ( 2), but if the same signal code information has not been detected twice in a row as a result of the test, it continues to set the relevant initial value for CCT signal detection. And (27), wherein the method CCT received signal, characterized in that further comprising repeated from step 2. The method of claim 1, wherein in the third step, in order to efficiently detect the CCT signal frequency, the reception power for each frequency calculated by DET is used, and the reception power of 1,780 [Hz] and 2,000 [Hz] is respectively P1. And P2, and the total power of the sum of P1 and P2 is Pt, and when the reception determination threshold level determined by the experiment as the intermediate value between the minimum operating level and the maximum non-operating level is Th, P1> Th first, P1 Only when all the conditions of> Pt / M and P2 <Th are satisfied, the signal is judged as 1,780 [Hz]. Alternatively, only when all of the conditions of P2> Th, P2> Pt / M and P1 <Th are satisfied. The signal is determined as a 2,000 [Hz] signal, where M is a permissible factor of the noise power level excluding the signal. ※ Note: The disclosure is based on the initial application.