JPH06268483A - Receiver for rds - Google Patents

Abstract

PURPOSE:To receive a same program at all times by selecting a broadcasting station group based on identification PI data from a station frequency list when a reception electric field intensity becomes equal to or less than a prescribed level and automatically following up a broadcasting station broadcasting the same program. CONSTITUTION:When the local station selecting key 12c of an operation part 12 is turned ON, RDS data such as frequency AF data and the PI data, etc., sent by being superimposed on the FM broadcasting of a present reception station are received through an RDS decoder circuit 7 and an error detection and correction circuit 8. When reception is performed, the data are read and stored in a storage part 11. The signal intensity of the reception station is monitored by a signal meter circuit 9. When the signal intensity becomes equal to or less than a prescribed level, a control part 13 obtains AF station frequencies in an ascending order from an AF list, a frequency control signal for the AF station is outputted to a PLL 1 and the AF station in the ascending order 15 received-Also, by pushing the key 12c, AF search for local stations is executed and the local station with strong signal intensity can be received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RDS receiver using an RDS (radio data system), and more particularly to an RDS receiver capable of receiving the same program broadcasting station by automatic tracking.

[0002]

2. Description of the Related Art In a car radio, it is usually the driver who operates it, and when the car travels a long distance and goes out of the service area of the receiving station, it is necessary to re-tune each time. , The sophistication of the tuning function has been demanded. Especially in Europe, where FM broadcasting, which has a relatively small service area, is the main body of radio broadcasting services and the ratio of car radio reception is high, this requirement was strong. A digital data multiplexing system standardized by the European Broadcasting Union to meet this demand is RDS (Radio Data System).

FIG. 2 is a data structure diagram of type 0A showing an example of a transmission format of RDS data. Referring to FIG. 2, a block 1 includes program identification data (PI data) of 16 bits including a country identification code, a cover area code, and a broadcasting station code, and a block 2 includes a group type code, a version code (Bo), and traffic. Various codes such as information identification code (TP code) and program content identification code (PTY code), station frequency data (AF data) of a network station broadcasting the same program in block 3, and broadcast station name in block 4. Data (PS data) is arranged respectively.

AF data is also called alternative frequency data, and is a frequency list (AF list) of broadcasting stations (referred to as AF stations) broadcasting the same program in the same or adjacent receiving areas.
Therefore, all the frequencies of the same program broadcasting station can be known by referring to the AF list. The PI data is 16-bit data given to the same broadcast program (program), and includes a country identification code (4 bits) for identifying a country and an area covered by the broadcast of the broadcasting station (broadcast reception is possible). It consists of a cover area code (4 bits) indicating a region and a broadcasting station code (8 bits).

Therefore, when receiving, the above-mentioned AF data and PI data obtained by demodulation are fetched and stored at the time of reception, and the reception sensitivity of the currently receiving broadcasting station is lowered due to disturbance such as multipath interference. , The received field strength of each AF station on the AF list is checked every predetermined time (referred to as AF search), and from the AF station whose received field strength is higher than the received field strength of the receiving station up to that point, Received the broadcast, and then the maximum AF
When the PI data of the station is detected, it is determined whether the PI data matches the PI data of the original receiving station, and when the detected PI data matches the PI data of the original receiving station, the maximum AF station is detected. To continue receiving.

However, if PI data is not detected,
Alternatively, if the detected PI data does not match the PI data of the original receiving station, the AF station with the next largest received electric field strength is regarded as the maximum AF station, and tuning is moved to the maximum AF station. If the two do not match, the same processing is continued, and if the two match, the maximum AF station is received, and the same program can always be listened to in a good reception state without being affected by disturbance.

[0007]

However, when receiving a local station (local broadcasting station) with a conventional RDS receiver, a local station group that always broadcasts the same broadcast program even on the same network. Since there is a local station group that occasionally broadcasts a so-called local program that is unique to that region, when receiving from a local station that is receiving to another local station on the same network by automatic tracking, which is the main function of RDS, There was a feeling of strangeness that I followed a local station broadcasting a local program and received another broadcasting station, although it was automatically following a station broadcasting the same broadcast program. .

Therefore, an object of the present invention is to provide the same broadcast program as the broadcast program of the local station being received when the received electric field strength of the local station being received becomes below a predetermined level and automatically follows other local stations. An RDS receiver capable of receiving a local station that constantly broadcasts.

[0009]

SUMMARY OF THE INVENTION In the present invention, the above-mentioned problems are automatically tracked by using AF data of a predetermined channel selection format sent superposed on an FM broadcast signal and RDS data such as PI data. In the receiver for RDS, the A of the national broadcasting station group and the local broadcasting station group consisting of the AF data is used.
A storage unit for storing the R list data such as the F list and PI data, and a predetermined local broadcast in the local broadcast station group among the national broadcast station group and the local broadcast station group of the AF list stored in the storage unit. Local station selection key to select the station,
When the received electric field strength of the local broadcasting station being received falls below a predetermined level, a local broadcasting station group is selected from the AF list based on PI data in response to a local broadcasting station selection command from the local station selection key. This is achieved by a control unit that discriminates a local broadcasting station that is always broadcasting the same program as the local broadcasting station that is being received based on a predetermined channel selection format of the AF data, and automatically follows the local broadcasting station.

[0010]

When the received electric field strength of the local broadcasting station being received falls below a predetermined level, national broadcasting in the AF list stored in the storage unit according to the local broadcasting station selection command of the local station selection key is received. The local broadcasting station group is selected from the station group and the local broadcasting station group based on the PI data, and the local broadcasting station that always broadcasts the same program as the local broadcasting station that is receiving is selected based on the predetermined selection format of the AF data. It is determined and the local broadcasting station is automatically followed. Therefore, when the receiving local broadcast station receives another local broadcast station of the same network by automatic tracking,
It does not receive programs with different broadcast contents.

[0011]

1 is a block diagram of an essential part of an RDS receiver according to the present invention. Reference numeral 1 denotes a PLL circuit, which outputs a predetermined voltage signal corresponding to a station to be received to the FM front end 2. The FM front end 2 receives the broadcasting station input from the antenna ANT based on the voltage signal, and generates a predetermined intermediate frequency signal (IF). An intermediate frequency detection amplifier 3 amplifies the intermediate number frequency signal converted by the FM front end 2 to a predetermined level and detects it.

Reference numeral 4 denotes an MPX, which is an intermediate frequency amplification detector 3
The detected signal input from is demodulated into a stereo signal. 5
Is an amplifier (AMP), which amplifies a stereo signal according to a volume setting value (not shown). Reference numeral 6 is a speaker, which is driven by the amplifier 5 and outputs an audio signal.
An RDS decoder circuit 7 demodulates AF data, PI data, etc. sent at a predetermined transmission timing.
Reference numeral 8 denotes an error detection / correction circuit, which is an RDS decoder circuit 7
The error in the RDS data such as the AF data and the PI data demodulated by is detected in synchronization with each group,
Correct the error.

A signal meter circuit 9 detects the level of the reception state of the receiving station by monitoring the signal strength (for example, electric field strength) of the intermediate frequency signal output from the intermediate frequency amplification detector 3. Reference numeral 10 is a display unit for displaying the frequency of the broadcasting station being received, and 11 is a storage unit for storing an AF list including AF data and PI data.

Here, the PI data will be described. The PI data is a country identification code, a cover area code,
It consists of broadcasting station codes, the country identification code is a code given to each country, and the broadcasting station code is a reference number given to each broadcasting station. Now, the cover area code will be described in detail. National network stations and local stations are roughly classified by the cover area code as follows.
That is, as a nationwide network station, (1) I (International) International Broadcasting: A program transmitted to other countries. (2) N (National) National Broadcasting: A program transmitted all over the country. (3) S (Super-regional) local broadcasting:
A program that is sent to most of the country. In addition, as local stations, (1) R1 to R12 (Regional) local broadcasting: a program transmitted only to one place and one region. (2) L (Local) Local Broadcasting: A program transmitted only from one broadcasting station. There is.

Reference numeral 12 denotes an operation unit, as described above, preset keys 12a having numbers 1 to 3 capable of presetting national network stations, and number 4 capable of presetting local stations.
6 preset keys 12b, a local station selection key 12c for selecting a local station among the broadcasting stations in the AF list stored in the storage unit 11, and an up / down selection of a frequency of a desired receiving broadcasting station. It has an auto memory key 12e for operating the key 12d and the up / down key 12d, and automatically storing the frequency in each of the six preset keys 12a and 12b of the operation unit 12.

Reference numeral 13 is a control unit for controlling the overall operation of the RDS receiver, for example, a microcomputer, which is a local station selection key when the received electric field strength of the local broadcasting station being received falls below a predetermined level. In response to the local station selection command, the local broadcasting station group is selected from the nationwide network station group and the local station group in the AF list based on the PI code, and is being received from Method B, which will be described later, which is the AF data transmission format. A local station that always broadcasts the same program as the local broadcasting station is discriminated and the local broadcasting station is received.

Further, the control unit 13 pushes the auto memory key 12e of the operation unit 12 and then the up / down key 1
If you press either 2d, the preset keys 12a, 12
Start the seek operation to make b automatically memory,
Based on the PI data, the preset keys 12a from No. 1 to No. 3 are preset to nationwide network stations in the order of strong received electric field strength, and the preset keys 12b from No. 4 to No. 6 are set to local stations in the order of strong received electric field strength. It can also be preset.

FIG. 3 is a flow chart according to the present invention. The automatic tracking process of the RDS receiver shown in FIG. 1 will be described below with reference to this flow chart. In FIG. 3, the control unit 13 first receives the FM broadcast of the current receiving station (local station) while the RDS receiver receives the broadcast program of the local station and the local station selection key 12c of the operation unit 12 is turned on. AF data, PI data, and other RDSs superimposed and sent to
RDS decoder circuit 7, error detection and correction circuit 8 for data
When the data is received via (step 101), the data is read (step 102) and stored in the storage unit 11 (step 103).

As a method of transmitting AF data, method A (M
ETHOD-A) and method B (METHOD-B), and method B is used in the present invention. FIG. 4 is an explanatory diagram for explaining method B. In Method B, the receiving station and the AF station are always paired, for example, 90.
There are five local stations of 0, 92.8, 94.2, 98.1, and 99.5 MHz, the five local stations are the same network, 98.1 MHz is a receiving station, and the rest are AF stations. To do.

Here, referring to FIG. 4, a pair with a higher frequency is called "ascending order", which indicates that the broadcast programs of the receiving station and the AF station are always the same, and a pair with a lower frequency is It is called "descending order", and sometimes indicates that different broadcast programs are also broadcast. That is, 94.2MHz
And the pair of 98.1MHz indicate ascending order, and 98.1
MHz and 90.0MHz pairs are in descending order, 99.5MHz
And 98.1MHz pairs in descending order, 98.1MHz and 9
The 2.8 MHz pair indicates descending order.

Here, the signal strength of the current receiving station is monitored by the signal meter circuit 9 for the purpose of maintaining a good receiving state of the signal strength level of the current receiving station (step 10).
4) When the signal strength falls below a predetermined level (step 1
05), the control unit 13 obtains the AF station frequencies in ascending order from the AF list, and PLLs the frequency control signals for the AF stations.
The signals are output to the circuit 1 and the ascending AF stations are received (step 106). On the other hand, in the processing of step 105, if the signal strength of the receiving station is not below the predetermined level, step 104
Return to and repeat the same process.

Further, when it is desired to receive the local stations in descending order, for example, when the local station having the preset number 5 is being received, the key is pressed again. If the local station is not preset, the local station selection key 12c is pressed. By pushing the button, an AF search for the local station is executed, and the local station having a strong signal strength can be received.

[0023]

As described above, according to the present invention, when the received electric field strength of the local broadcasting station being received falls below a predetermined level, it is stored in the storage unit according to the local broadcasting station selection command of the local station selection key. Select the local broadcasting station group based on PI data from the national broadcasting station group and the local broadcasting station group in the AF list,
The local broadcasting station that always broadcasts the same program as the local broadcasting station that is receiving is determined based on the predetermined channel selection format of the AF data,
Since the local broadcasting station can be automatically followed, the local station broadcasting a different broadcast program will not be received when the local broadcasting station is automatically followed.

[Brief description of drawings]

FIG. 1 is a block diagram of an essential part of an RDS receiver according to the present invention.

FIG. 2 is a data configuration diagram of type 0A showing an example of a transmission format of RDS data.

FIG. 3 is a flow chart according to the present invention.

[Explanation of symbols]

 1 PLL circuit 2 FM front end 3 Intermediate frequency amplification detector 7 RDS decoder circuit 8 Error detection / correction circuit 9 Signal meter circuit 11 Storage section 12 Operation section 12c Local station selection key 13 Control section

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[Procedure amendment]

[Submission date] February 8, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a block diagram of an essential part of an RDS receiver according to the present invention.

FIG. 2 is a data configuration diagram of type OA showing an example of a transmission format of RDS data.

FIG. 3 is a flow chart according to the present invention.

FIG. 4 is an explanatory diagram for explaining a method B.

[Explanation of reference symbols] 1 PLL circuit 2 FM front end 3 Intermediate frequency amplification detector 7 RDS decoder circuit 8 Error detection / correction circuit 9 Signal meter circuit 11 Storage section 12 Operation section 12c Local station selection key 13 Control section

Claims (1)

[Claims] 1. An R data such as AF data and PI data in a predetermined channel selection format, which is superposed on an FM broadcast signal and transmitted.
In an RDS receiver that automatically follows using DS data, a storage unit that stores the AF list of the national broadcasting station group and the local broadcasting station group including the AF data, and RDS data such as PI data, and the storage unit A local station selection key for selecting a predetermined local broadcast station from the local broadcast station group among the national broadcast station group and the local broadcast station group stored in the AF list, and reception of the local broadcast station being received. When the electric field strength falls below a predetermined level, a local broadcasting station group is selected from the AF list based on PI data in response to a local broadcasting station selection command of the local station selection key, and a predetermined selection of AF data is performed. A receiver for RDS, characterized by comprising: a control unit that discriminates a local broadcasting station that is always broadcasting the same program as the local broadcasting station currently receiving based on the format and automatically follows the local broadcasting station. .