JPH0637665A - Bs and cs receiver - Google Patents

Abstract

PURPOSE:To obtain a BS and CS receiver unnecessitating the setting of local oscillation frequency with a manual by selecting a corresponding frequency from the inside of the local oscillator inside of a tuner based on the local oscillation frequency of a decided first stage down converter and tuning it. CONSTITUTION:After detecting and A/D converting 25a high-frequency output from an input terminal 8 from the first stage down converter 1 by way of filters 20 to 23, a control part 15 detects the presence/absence of the output. The control part 15 checks the output of the respective filters while switching the output switch 24 of the filters. The filter 20 is LPF allowing not more than 1450MHz to pass, the filter 21 is BPF having the band 1450 to 1550MHz, the filter 22 is BPF having the band 1550 to 1760MHz and the filater 23 is HPF having the band allowing not less than 1760MHz to pass. The controller 15 executes tuning by detecting a high frequency level like this, selecting the corresponding local oscillation frequency and selecting the corresponding frequency from the inside of the local oscillator inside of the tuner based on the kind of the local oscillation frequency of the decided converter 1.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to BS and CS receivers.

[0002]

2. Description of the Related Art A system configuration of a conventional BS and CS receiver will be described with reference to the drawings. In FIG. 4, 31 is a parabolic antenna, 32 is a first stage down converter, and the weak 12 GHzt band radio wave received by the parabolic antenna is 1.4 G
It is a device that converts to the CS-IF frequency for broadcasting in the Hz band. 33
Is an indoor receiver, 34 is a second stage down converter, 35 is a manual switch for setting the frequency of the local oscillator of the second stage down converter, and 36 is a tuner. , 37 is an input terminal from the first stage down converter to the second stage down converter, the output of the second stage down converter is connected to the tuner input terminal 38, and 39 is the local oscillator of the second stage down converter. Input terminal with the manual switch
Connected to 35. Next, the operation of the conventional BS and CS receiver will be described with reference to the figures. There are four types of frequencies of the local oscillator of the first-stage down converter in FIG. Therefore, when adjusting the indoor receiver, the coordinator must check the frequency of the local oscillator of the outdoor first-stage down converter, and then the local oscillator of the second-stage down converter. The frequency had to be set by the manual switch 35, and adjustment was troublesome.

[0003]

As described above, in the conventional BS and CS receivers, the coordinator knows the frequency of the local oscillator of the outdoor first-stage down converter, and then adjusts the second frequency according to the frequency. The frequency of the local oscillator of the step-down converter needs to be set by the manual switch 35, which has a drawback that adjustment is troublesome.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is designed such that when the receiver is adjusted, the adjuster is first outdoors.
It is not necessary to know the frequency of the local oscillator of the second stage down converter, and it is not necessary to set the frequency of the local oscillator of the second stage down converter by a manual switch.
It is to provide an S, CS receiver.

[005]

With the above-mentioned structure, B according to the present invention
In the S and CS receivers, the high frequency level output of the first stage down converter is detected by the control unit inside the BS and CS receivers, and the corresponding local oscillation frequency is selected. Based on the type of the local oscillation frequency of the first stage down converter determined by the above method, the control unit selects a local oscillator having a corresponding frequency from the local oscillator inside the tuner, and performs a predetermined tuning. To

[0006]

Embodiments of the BS and CS receivers according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of a receiver according to the present invention, in which 1 is a second stage down converter,
2 is the input terminal from the parabolic antenna, 3 is the band pass filter, 4 is the mixer, 5 is the first stage local oscillator,
6 is an output terminal. 7 is the second stage down converter,
8 is an input signal from the first stage down converter, 9 is a bandpass filter, 10 is a mixer, 11 is a bandpass filter, 12 is an IF stage, and 13 is an output terminal. 14 is an input terminal of the control unit, 15 is a control unit, 16 is an output terminal of the control unit,
17 is a local oscillator of four different frequencies, 18 is a multiplexer, 19 is the output terminal of the multiplexer,
20 to 24 are four types of filters, and 14 is a switch for detecting the output of the filters. Reference numeral 23 is a portion for detecting and A / D converting the output of the filter. FIG. 2 is a system configuration diagram of a BS / CS receiver according to the present invention, in which 21 is a parabolic antenna, 22 is a first stage down converter, and 23 is a
Is a receiver, 24 is a second stage down converter, 25 is a control unit, 26 is a tuner, 27 is an input terminal from a parabolic antenna, 28 is an input terminal of the tuner, and 29 is an input terminal of the control unit. , 30 are input terminals of the local oscillator of the second stage down converter.

Next, the operation of the BS, CS receiver according to the present invention will be described with reference to FIG. 1. In FIG. 1, the high frequency level output of the first stage down converter at the input terminal 8 is changed to BS, CS.
After detection and A / D conversion through the filter inside the receiver, the control unit detects the presence or absence of output. The controller checks the output of each filter while switching the output switch 24 of the filter. Filter 20 is a low-pass filter that passes below 1450MHz, filter 21 is from 1450MHz to 1550MH.
Bandpass filter with band up to z, filter 22
Is a bandpass filter having a band from 1550MHz to 1760MHz, and the filter 23 is a highpass filter having a pass of 1760MHz or more. FIG. 3 is a flow chart of the operation, the contents of which will be described below. Of the signals that have been detected and A / D converted through the filter, the contact of the switch 14 in FIG. 1 is switched to the filter 20 side at 60 to detect the output of the filter, and the signal level is detected at step 61. If so, the local frequency of the 1st stage down converter is 1
Assuming that the frequency is 1.3 GHz, the process 70 is performed and the end process 69 is performed.
Go to If the signal level is not detected in processing 61, 62
Switch the contact of the switch 14 in Fig. 1 to the filter 21 side. If the signal level is detected in process 63, it is assumed that the local oscillation frequency of the first stage down converter is 11.2 GHz, and the process 71 is passed. , Go to end processing 69. If the signal level is not detected in process 63, the switch in Fig. 1 is switched in 64.
Switch the contact of 14 to the side of the filter 22, and if the signal level is detected in the process 65, it is determined that the local oscillation frequency of the first stage down converter is 10.992GHz, and the process goes to the end process 69 via the process 72. . If the signal level is not detected in step 65, the contact of the switch 14 in FIG. 1 is switched to the filter 23 side in 66. If the signal level is detected at 67, the local oscillation frequency of the first stage down converter is 10.7873GH.
Going to the end process 69 via the process 68 assuming that it is z.
If no output is detected in any of the above filters, it is determined that an error has occurred, and the failure diagnosis is performed via the process 73. Based on the local oscillation frequency of the first-stage down-converter determined as described above, the control unit selects the one having the corresponding frequency from the local oscillators inside the tuner, sends it to the IF stage with predetermined tuning.

As described above, instead of the method of detecting the presence or absence of the output of the filter inside the receiver, after the high frequency output of the first stage down converter is directly read by the frequency counter, the control unit controls the internal oscillator of the tuner. There is also a method of selecting the one of the corresponding frequency from the above and performing a predetermined tuning and sending it to the IF stage.

[0009]

As described above, B according to the present invention
According to the S, CS receiver, the output signal frequency of the first stage down converter is detected by the control unit without knowing the local oscillation frequency of the first stage down converter, and the second stage down converter that matches the frequency is detected. Since the tuning of can be automatically set, the manual setting of the local oscillation frequency is unnecessary, which is extremely convenient.

[Brief description of drawings]

FIG. 1 is a block diagram of a receiver according to the present invention.

FIG. 2 is a system configuration diagram of a BS and CS receiver according to the present invention.

FIG. 3 is a flow chart of the operation of the system of BS and CS receiver according to the present invention.

FIG. 4 is a system configuration diagram of a conventional BS and CS receiver.

[Explanation of symbols]

 1 1st stage down converter 2 Input terminal from parabolic antenna 3 Bandpass filter 4 Mixer 5 1st stage local oscillator 6 Output terminal 7 2nd stage downconverter 8 Input signal from 1st stage downconverter 9 Bandpass filter 10 Mixer 11 Band pass filter 12 IF stage 13 Output terminal 14 Control section input terminal 15 Control section

Claims (2)

[Claims] 1. In a BS or CS receiver in which it is necessary to determine the frequency of the local oscillator of the second stage down converter in accordance with the frequency of the local oscillator of the first stage down converter, the high frequency of the first stage down converter is used. Based on the means for detecting the frequency of the output, the means for selecting the corresponding local frequency from the detected frequency, and the determined type of the local frequency for the first-stage down converter, the tuner internal BS and CS receiver, characterized in that it is provided with means for selecting a corresponding frequency from among the local oscillators. 2. The BS, CS receiver according to claim 1, wherein a filter circuit is used for frequency detection of the high frequency output of the first stage down converter.