JPH0738570B2 - Radio receiver auto memory method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auto memory method for a radio receiver, and more particularly to an auto memory method capable of shortening the time required for the auto memory.

<Prior Art> In a car radio, in addition to being able to easily obtain traffic information, it is required to have an advanced tuning function. For this reason,
RDS (Radio Data System) has been proposed and put into practical use by the European Broadcasting Union. This RDS is a method of superimposing various digital data on an FM radio broadcast signal. As a message, (i) program identification code (PI code) of the currently received FM broadcast (ii) broadcast station name (PS) (Iii) Broadcasting station frequency list (AF) during the same program broadcasting (iv) Program content identification code (PTY) (v) Transmission status identification code (DI) (vi) Music or conversation identification code (M / S code) ) And (vii) Identification code (TP) of the traffic information broadcasting station (viii) Identification code (TA) in the traffic information broadcasting.

In this way, since the RDS message and the traffic information relating to the received FM broadcast are transmitted in multiples, it is possible to use the message to perform a special tuning operation or traffic information operation that has never been done.

The RDS compatible radio receiver has an auto memory function (preset function). According to this auto memory function, if there are 6 preset keys, the reception frequency is scanned, 6 RDS stations are obtained in the order of the received electric field strength, and these RDS stations are automatically stored in the memory in correspondence with the preset keys. it can. Then, if you press the predetermined preset key when tuning, the RDS corresponding to the preset key with good reception
Can receive stations.

To describe this auto memory operation in a little more detail, it searches for a station with a good reception state by seeking, determines if it is an RDS station when a good station is searched, and if it is an RDS station, sorts it in the order of received field strength, Finally, the 6
RDS stations are sought, and these are stored in the preset memory in correspondence with the preset keys.

<Problems to be solved by the invention> However, about 50 stations per station are required for the conventional auto memory operation.
It takes about 0 msec, and there are 50 to 60 auto memory stations. Therefore, there is a problem that a long time of about 30 seconds to 1 minute is conventionally required until the auto memory operation is completed.

From the above, it is an object of the present invention to provide an automatic memory method for a radio receiver, which can reduce the time required for the automatic memory operation.

<Means for Solving the Problem> In the present invention, the above-described problem is a means for scanning the reception frequency by the seek operation to detect the reception electric field strength when there is an auto memory command, and the reception electric field strength after the seek is completed. Means for tuning in order of strong broadcasting station, means for checking whether the tuning broadcasting station is a data multiplex broadcasting station, and if it is a data multiplex broadcasting station, a preset memory for storing the broadcasting station in association with a preset key, This is achieved by means for completing the auto memory operation when the broadcasting station is stored in correspondence with all preset keys.

<Operation> When an auto-memory command is issued, the receiving frequency is scanned by the seek operation to detect the received electric field strength, and after the seek is completed, tuning is performed in the order of the strongest received electric field strength broadcasting station, and the tuning broadcasting station performs data multiplexing. It is checked whether it is a broadcasting station, and if it is a data multiplex broadcasting station, the broadcasting station is stored in association with a preset key, and the automatic memory operation is completed when the broadcasting station is stored in association with all preset keys. Further, when the PI data is also stored in association with the preset key, the broadcasting station having the same PI data as the already stored PI data is not stored. In this way, the signals are arranged in the order of the received electric field strength, and then, in the order of the received electric field, whether or not the data multiplexed broadcasting station is found, and if the data multiplexed broadcasting stations are found by the number of preset keys, the auto memory operation can be ended at that time, that is, all stations. About the existence of data multiplex broadcasting station,
Since it is not necessary to check the presence / absence of PI data, the time required for auto memory operation can be shortened. It takes about 10 msec for one station to detect the received electric field strength and rearrange it in the order of the received electric field strength.

<Embodiment> FIG. 1 is a block diagram of an essential part of an RDS receiver that realizes an automatic memory according to the present invention.

1 is an antenna, 2 is a front end, and PL described later
An intermediate frequency signal is generated by tuning to a predetermined broadcasting station based on the voltage signal output from the L circuit. An intermediate frequency amplifier 3 amplifies the intermediate frequency signal converted by the front end 2. A stereo demodulation circuit (MPX) 4 demodulates the intermediate frequency signal input from the intermediate frequency amplifier 3 into a stereo signal. Reference numeral 5 is a mute circuit, 6 is an amplifier (AMP), and 7 is a speaker, which is driven by the amplifier 6 and outputs sound.

Reference numeral 8 is a 57 KHz band pass filter (BPF) that passes a 57 KHz subcarrier whose amplitude is modulated based on RDS data. 9 is an RDS decoder / clock recovery circuit,
It demodulates the RDS data from the bandpass filter output and regenerates the clock. 10 is group synchronization / error detection /
This is a correction circuit and detects an error in the RDS data demodulated by the RDS decoder / clock recovery circuit 9 while synchronizing each group and corrects the error.

A signal meter 11 detects the reception level (reception electric field strength) of the reception station by monitoring the signal strength of the intermediate frequency signal output from the intermediate frequency amplifier 3. Reference numeral 12 is a station detector, which determines that a receiving station exists (station exists) when the received signal is within the frequency deviation Δf (bandwidth) of the received signal and the signal strength is equal to or higher than a set level. is there.

13 is a controller of a microcomputer configuration that performs automatic tracking processing and auto memory processing described later based on RDS data, received electric field strength SM, station detect signal SD, etc., 14 is an operation unit, 15 is reception frequency data FDT input from the controller Is a PLL circuit that inputs a voltage signal according to the above into the front end 2 and tunes to a predetermined broadcasting station.

In addition, in the controller 13, 13a is in auto memory,
A field strength memory 13b for storing broadcast stations arranged in order of received field strength, and a preset memory 13b for storing a broadcast station and PI data (program identification data) of the broadcast station in association with a preset key. In the operation unit 14,
14a is an auto memory key to switch to auto memory mode, 14b
Is a preset key, and six keys are provided.

The auto memory operation of the RDS receiver of FIG. 1 will be described below with reference to the flowchart of FIG.

When the auto memory key 14a on the operation panel 14 is pressed, the auto memory mode is set. When in the auto memory mode, the controller 13 sets the mute signal MUT to the high level to cause the mute circuit 5 to prohibit the audio output, and executes the seek operation to detect the broadcasting station whose received electric field strength is equal to or higher than a predetermined level (step). 101).

The reception frequency is scanned in a predetermined width, and a broadcasting station whose reception electric field strength (output level SM of the signal meter 11) is equal to or higher than a predetermined level is searched (step 102), and the searched broadcasting stations are sorted in order of magnitude of the reception electric field strength. The data is rearranged and stored in the built-in electric field strength memory 13a (step 103). Then, such an operation is executed over the receivable frequency range (step 104).

When the seek operation is completed, 1 → i is set (step 10
5) The broadcasting station having the i-th largest received electric field strength is obtained from the electric field strength memory 13a and tuned to the frequency of the broadcasting station (step 106).

Then, it is judged whether the broadcasting station is an RDS station or not by detecting RDS data (step 107), and if it is not an RDS station, i is incremented (step 108) and thereafter the processing of step 106 is repeated. .

On the other hand, if it is an RDS station, PI data (program identification data) is extracted and it is checked whether the same PI data as the PI data is already stored in the preset memory 13b together with the broadcasting station (step 109). If the same PI data is stored, the broadcast content is the same, so the RDS station does not store it in the preset memory and repeats the processing from step 108.

If the same PI data is not stored, the broadcasting station having the i-th received electric field strength and its PI data are stored in the preset memory 13b in association with the unregistered preset key (step 110).

Then, it is checked whether the broadcasting station and the PI data are stored corresponding to all the preset keys, that is, whether there is an unregistered preset key (step 111). If there is an unregistered preset key, step 108 is performed. Step through i and repeat the processing from step 106. If there is no unregistered preset key, unmute at this point,
End the auto memory operation.

In the above, the PI data is stored in association with the preset key, but the PI data may not be stored and only the RDS station may be stored.

It should be noted that about 10 msec is required for one station to detect the received electric field strength and rearrange it in the order of the received electric field strength. Therefore, if the number of stations is 60, it takes less than 1 second to arrange them in the order of received electric field strength.
It takes about 7-8 seconds to find 6 RDS stations, and the auto memory operation is completed within 10 seconds in total.

<Effects of the Invention> According to the present invention, the stations in the band are arranged in the order of the reception electric field strength, and then the order of the reception electric fields is checked to see if the stations are data-multiplex broadcasting stations. At that point, the auto memory operation can be completed, that is, whether all stations have data multiplex broadcasting stations, PI
Since it is not necessary to check the presence / absence of data, the time required for the automatic memory operation can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram of an RDS receiver having an auto memory function according to the present invention, and FIG. 2 is a flow chart of processing of an auto memory operation of the present invention. 9 …… RDS decoder / clock recovery circuit 10 …… Group synchronization / error detection / correction circuit 13 …… Controller 13a …… Electrolytic strength memory 13b …… Preset memory 14a …… Auto memory key 14b …… Preset key

Claims (2)

[Claims] Claim: What is claimed is: 1. An auto memory method for a radio receiver, which demodulates transmission data superposed on an FM broadcast signal and is sent to perform a predetermined operation. When an auto memory command is issued, the reception frequency is changed by a seek operation. After scanning, the reception electric field strength of the broadcasting station is detected. After the seek is completed, the broadcasting station is tuned in order of the reception electric field strength and it is checked whether the broadcasting station is a data multiplex broadcasting station. An auto memory method for a radio receiver, characterized in that a broadcasting station is stored in correspondence with a preset key, and the auto memory operation is completed when the broadcasting station is recorded in correspondence with all the preset keys. 2. Program identification data (PI data) is stored in association with a preset key, and the stored PI is stored.
The automatic memory method for a radio receiver according to claim (1), wherein a broadcasting station having the same PI data as the data is not stored.