JPH0275227A - Automatic preset method for radio receiver - Google Patents

Abstract

PURPOSE:To expand the identification enable range of an electric field intensity and to preset each channel with fidelity to the electric field intensity by attenuating a received electric field intensity at automatic preset by means of an attenuator and varying the station detection level in response to the attenuation of the attenuator. CONSTITUTION:The received electric field intensity E0 of an antenna ANT is attenuated by the attenuator 1 in the automatic preset and the station detection level of the attenuator 1 is varied in response to the attenuation. A system controller 2 compares the level of an intensity instruction signal E1 detected in this way with that at the automatic preset so as to preset a prescribed number of stations with a high intensity instruction signal E1 into a preset memory 2a automatically. Thus, the identification range of the received electric field intensity E0 is expanded and each station is preset with fidelity to the intensity of the electric field.

Description

[Detailed Description of the Invention] <Field of Application in Industry> The present invention relates to an auto-preset method for a radio receiver that automatically selects and stores broadcast stations according to the strength of the electric field, and in particular, The present invention relates to an automatic presetting method for a radio receiver that can expand the identification range of a radio receiver.

<Prior Art> FIG. 4 is a block diagram of the main parts of a conventional radio receiver.

In the figure, 11 is a local oscillator that outputs a local frequency. A mixer 12 mixes the received frequency and the local frequency and outputs an intermediate frequency. Reference numeral 13 denotes an intermediate frequency detection circuit that detects the intermediate frequency output from the mixer 12. 14 is a noise killer circuit that reduces noise components. 15 is a stereo demodulation circuit that separates left and right signals and outputs a stereo audio signal. A NT is an antenna.

Reference numeral 16 denotes an operation unit, which has an auto preset key 16a, a plurality of preset keys 16b, etc., and automatically selects a broadcasting station according to the strength of the electric field by operating the O1-preset key 1.6a. A 1-preset operation is performed in which the selected broadcasting station is stored in association with each preset key 16b.

Reference numeral 17 denotes a system controller composed of a microcomputer, which performs various processes including electronic tuning processing. For example, when auto preset is instructed, the oscillation frequency control signal FCD is output to the local oscillator 11 to perform tuning by electronic tuning, and a predetermined number of broadcast stations are automatically selected depending on the strength of the electric field. Stored in Priscella 1 to memory 1-7a.

] 8 is a level detector, which detects a level E according to the electric field strength of the receiving station input from the antenna ANT. , outputting an intensity indicating signal having . 19 is an A/D comparator and the level E of the intensity indication signal. The analog value of □ is converted into a digital value and output to the system controller 17. 2
0 is a station detection circuit, which detects the strength indication signal level E of the receiving station.
. , is greater than a predetermined value and the reception condition is good, a station detection signal BDS is output to notify that the receiving station is to be compared for O1-preset.

The operation shown in FIG. 4 will be explained below. When auto preset key 1-68 is operated to instruct auto preset key 1-68, system controller 1-roller]-7 controls the receive frequency of mixer 12. ) action is performed. Note that the scanning operation is performed by changing the local oscillation frequency of the local oscillator 11 using the oscillation frequency control signal FCD.

Due to the scanning operation, the station detection circuit 20 detects
When the station detection signal BDS is output from , the level E of the strength indication signal at that time. I is A / I) = + inverter 1
9 and converted into digital data and sent to system controller 1]
7 will be powered by humans. The system controllers 1 to 0-17 store the level of the intensity instruction signal up to a predetermined number of stations (for example, 6 stations) in the preset memory 17a together with the receiving frequency. Then, the reception frequency is gradually increased and the above scanning operation is repeated until the end of the reception band.

By the way, the preset memory 17a stores broadcast stations one after another according to the auto preseller 1.

When a new broadcasting station is detected after a predetermined number of stations (for example, 6 stations) have been stored, the system controller 17 compares the strength indication signal level of this broadcasting station with the strength indication signal level of the six already stored stations. , the broadcasting station with the lowest intensity indication signal 1/bell is deleted.

In this way, a predetermined number of broadcast stations having a high intensity instruction signal level are pre-selected.

<Problems to be Solved by the Invention> By the way, the level E of the strength indication signal. 1 depends on the electric field strength discrimination ability of the level detector 18, and there is a problem that the electric field strength E sat is saturated at a predetermined electric field strength E sat or higher. Therefore, even if a broadcasting station with a stronger electric field strength than these stations is selected after a predetermined number or more of stations with received field strengths equal to or higher than Esat are stored, the strength indication signal level will be the same as the strength of the stored station. There is a problem that since the signal level is not north of the instruction signal level, this broadcasting station is not stored, and therefore only the broadcasting stations on the low frequency side of the reception hunt where the scanning operation is started are pre-selected.

From the above, it is an object of the present invention to attenuate the received electric field strength when presetting to O1 using an attenuator, and to vary the station detection level according to the amount of attenuation of the attenuator, thereby widening the discernible range of electric field strength. It is an object of the present invention to provide an auto-presetting method for a radio receiver that can perform presetting that faithfully follows the strength of the electric field.

<Means for Solving the Problems> FIG. 1 is a block diagram of the main parts of a radio receiver that can realize the present invention.

1 is an attenuator, 2 is a system controller, 2a is a preset memory, 18 is a level detector, 20 is a station detection circuit, E is a received electric field strength, and El is an intensity instruction signal.

<Function> Antenna received electric field strength E during auto preset. is attenuated by the attenuator 1 to generate the intensity instruction signal E, and the station detection level in the station detection circuit 20 is varied according to the amount of attenuation of the attenuator 1, and based on the level of the intensity instruction signal E1 at this time. Compare the electric field strength of the receiving station and find the received electric field strength E. A predetermined number of strong stations are automatically preset in the preset 1-memory 2a.

<Embodiment> FIG. 1 is a block diagram of main parts of a radio receiver that can realize the present invention, and the same reference numerals as in FIG. 4 indicate the same or corresponding parts.

1 is an attenuator, which is the received electric field strength E of the antenna A N T during auto presetting. For example, 15dBμ
Attenuation causes level detector 18 to generate an intensity indication signal E.

Reference numeral 2 denotes a system controller 1-roller having a microcomputer configuration, which compares the electric field strength of the receiving station based on the level of the strength instruction signal E at the time of Ohmil presetting, and determines the received electric field strength E. A predetermined number of strong stations are automatically stored in the preset memory 2a.
to. In addition, at the time of auto preset, the station detection circuit 20
The station detection level at is set low according to the attenuation amount of the attenuator 1.

The above operation will be explained with reference to FIG.

FIG. 2 is an output characteristic diagram of the strength indication signal, where the vertical axis represents the strength indication signal level and the horizontal axis represents the antenna received electric field strength E. shows. Note that the solid line is a characteristic curve when normal reception is performed with zero attenuation, and the dotted line is a characteristic curve when attenuation is performed by 15 dB during auto preset.

The strength instruction signal E shown by the solid line is the received electric field strength E during normal reception. The level detector 18 has a level corresponding to
Depending on the performance, for example, the received electric field strength E. is 60dBμ
(Point 1-A) or higher, saturation occurs (saturation level SD).Therefore, in the present invention, when performing auto-printing, the received electric field strength E is adjusted by the attenuator l. For example λ
It is attenuated by 15 dBμ. As a result, the bell detector 1
The characteristic curve 8 changes from a solid line to a dotted line, and the received electric field strength E is in the range shown in a in the figure. becomes newly distinguishable. That is, the intensity indication signal E at the saturation point A before attenuation
1 is Ec below the saturation level SD.

On the other hand, the strength indication signal E during normal reception. The level of □ is EM
(Point B) The station detection circuit 20, which outputs the station detection signal BDS by assuming that the reception condition is good when the condition is above, changes the station detection level during auto presetting from EQ to EQ according to the amount of attenuation of attenuator 1. (b in the figure), the level of the strength indication signal E□ or EQ is output, and if the level is lower than 2, the station detection signal BDS is output. Therefore, the received field strength E when the station is detected. The lowest input level does not change, and the station at point B, which was originally detected due to attenuator attenuation, will not be cut off as a weak current movement.

As mentioned above, the received electric field strength E. By attenuating the signal and varying the station detection level of the attenuator 1 according to the amount of attenuation, the range (dynamic range) of the distinguishable received field strength E 11 is expanded from C to d.

The system controller 2 compares the levels of the intensity instruction signals E detected as described above at the time of auto-presetting, and automatically presets a predetermined number of stations with strong intensity instruction signals E into the presellers 1 to 2a.

The operation shown in FIG. 1 will be explained below with reference to the flowchart shown in FIG.

First, in step 101), waiting for auto preset to be instructed by the auto preset key 16a, and when O1 to preset 1- is instructed, the received electric field strength E is set by the attenuator 1. is attenuated by 15 dBμ and (
Step 102), the station detection level is increased according to the amount of attenuation of the attenuator 1 (Step 103), and after that, the system controller 2 starts a scanning operation by changing the oscillation frequency control signal FCD in predetermined steps. (Step 104).

Next, wait for the station detection signal 13DS to be output from the station detection circuit 20 (Step 105), and when it is output, read the reception frequency and the level of the intensity indication signal E1 at that time (Step 106). The level and frequency of the stiff intensity instruction signal are automatically stored in the preset memory 2a until a predetermined number of stations are stored in the preset memory 2a, and if the predetermined number of stations are already stored, the intensity instruction signal is E.

is stored and compared with the level of a certain station (step 107) to determine the received field strength E. Priscilla 1~
It is preset in the memory 2a (step 108).

Thereafter, it is determined whether the scanning operation has been performed for the entire band (step 109), and if it is still in progress, the process returns to step 104, and if the entire band has been scanned, the process ends.

The received electric field strength E is determined by the above. If a strong broadcasting station is preset, press the preset key 16b on the operation panel
By operating the preset key 16b, the broadcasting station corresponding to the preset key 16b is selected with one touch.

Note that the attenuation amount of the attenuator 1 may be switched in steps from 0 to n (n is an integer).

<Effects of the Invention> According to the present invention, the antenna reception electric field strength during auto-presetting is attenuated by an attenuator, and the station detection level is varied according to the attenuation amount of the attenuator, and the level of the strength indication signal at this time is The field strength of the receiving stations is compared based on the field strength, and a predetermined number of stations with strong received field strength are automatically preset in the preset memory, so the identification range of received field strength can be expanded, and the field strength can be preset faithfully to the strength of the

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the main parts of a radio receiver that can realize the present invention, Fig. 2 is a diagram of the output characteristics of the intensity indication signal, Fig. 3 is a process flowchart explaining the operation of Fig. 1, and Fig. 4 is FIG. 1 is a block diagram of main parts of a conventional radio receiver. ■...Attenuator, 2...System controller, 2a...Preset memory. 18...Level detector. 20... Station detection circuit, E,... Received electric field strength, E□... Strength instruction signal,

Claims (1)

[Claims] A strength indication signal having a level corresponding to the received field strength of the antenna is generated, and when the level of the strength indication signal is equal to or higher than a predetermined station detection level, the levels are compared to detect a predetermined number of stations with strong received field strength. In an auto-preset method for a radio receiver that automatically presets a preset memory, the antenna reception electric field strength during auto-preset is attenuated by an attenuator, and the station detection level is varied according to the amount of attenuation of the attenuator. An auto-preset method for a radio receiver that compares the electric field strengths of receiving stations based on the level of a strength indication signal and automatically presets a predetermined number of stations with strong received electric field strengths in a preset memory.