JP2709588B2 - Digital data multiplexing system receiving method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an in-vehicle radio receiver for identifying program content based on a program content identification code PTY included in RDS (radio data system) transmission data. In particular, the present invention relates to an in-vehicle radio receiver that can receive a PTY station transmitting a specific PTY code during a search operation.

<Prior art> In a car radio, the driver usually operates the radio, and when the car moves long distances and leaves the service area of the receiving station, it is necessary to reselect the station every time. Advanced functions have been required. This requirement was particularly strong in Europe, where radio broadcasting services are mainly used for FM broadcasting, which has a relatively narrow service area, and the broadcast reception ratio on car radio is high. A digital data multiplexing system standardized by the European Broadcasting Corporation to meet this demand is the RDS (Radio Data System).

RDS is a system that multiplexes and transmits various digital data (data that can be used for automatic selection of the best receiving station, traffic information identification, display of broadcast station name, etc.) to FM radio broadcasting. There are AF code, PI code, PTY code, etc.

The AF code is called an alternative frequency code, and corresponds to a frequency code of a broadcasting station (AF station) broadcasting the same program in the same or adjacent reception area. All frequencies can be understood. The PI code is called a program identification code, and is a unique code given to a broadcast program (program). The PTY code is called a genre identification code and is a code for identifying a genre (program type) of a broadcast program. The PTY code has an individual code for each of 32 types of genres such as classical, rock, poppy, and news. It is defined as shown in FIG.

Table 1 No. PTY code Program type 0 00000 No type 1 00001 News 2 00010 Current events 3 00011 Magazine 4 00100 Sports 5 00101 Education 6 00110 Programs for children 7 00111 Programs for young people 8 01000 Religious programs 9 01001 Drama 10 01010 11 01011 Light music 12 01100 Classic 13 01101 Jazz 14 01110 Fork music 15 01111 Variety 16 ~ 30 Undefined 31 11111 Emergency broadcast When using these digital data, broadcast stations with the same broadcast content with good reception conditions are received one after another. Automatic tracking can be performed. For example, when performing automatic tracking of the same program, compare the signal strength (eg, electric field strength) of the currently receiving broadcast station with the signal strength of the broadcast station (AF station) broadcasting the same program obtained from the AF list. Then, the signal strength is automatically compared with that of the current receiving station, and the receiving station is automatically switched one after another to the AF station having the stronger signal strength than the current receiving station.

<Problems to be Solved by the Invention> In the case where the same program is automatically followed, a PI code is used as digital data to be used in addition to the above-described AF code. However, PI codes are not always completely unified in all European countries or even in the same country.For example, in the same program in West Germany, the transmitted PI code may be different if the broadcasting area is different even for the same program. As a result, if the user leaves the original broadcast area, the same PI code cannot be detected, and the automatic tracking ends. Therefore, while searching for a receivable RDS station and receiving it, the received station is not necessarily a station broadcasting the genre desired by the user. The user has received a desired genre station by operating an up / down channel selection key or the like. However, the above operation is very troublesome, and is very dangerous while traveling.

<Means for Solving the Problems> According to the present invention, in a receiving method of a digital data multiplexing system for multiplexing and transmitting various kinds of information including program information to a broadcast signal, reception is performed in correspondence with each preset key. The program contents having the priority are stored,
The signal level of the receiving station is monitored, and when the signal level falls below a predetermined value, the broadcasting station transmitting the program content identification code is searched, and the program content of the broadcast signal from the received broadcasting station is identified. The reception field strength of the broadcasting station is determined by the code, and the received broadcasting stations are stored in the order of the reception field strength in correspondence with the program contents of each preset key. This is achieved by identifying the broadcast station having the highest received electric field strength and having the highest program content, and receiving the broadcast from the identified broadcast station.

<Operation> A program content having a reception priority is stored in association with each preset key, a signal level of a receiving station is monitored, and a program content identification code is transmitted when the signal level falls below a predetermined value. Search for the broadcasting station that is performing, determine the program content of the broadcast signal from the received broadcasting station by the program content identification code, determine the reception electric field strength of the broadcasting station, and correspond to the program content of each preset key, The received broadcast stations are stored in the order of the received electric field strength, and after the search is completed, the broadcast station having the highest received electric field strength and the program contents having the highest priority than the stored contents is identified, and from the identified broadcast station, To receive the broadcast.

<Embodiment> FIG. 1 is a block diagram of an on-vehicle radio receiver showing an embodiment of 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 front end 2. The front end 2 receives a broadcast station input from an antenna (ANT) based on a voltage signal, and generates a predetermined intermediate frequency signal (IF). Reference numeral 3 denotes an intermediate frequency amplifier, which amplifies the intermediate frequency signal. Reference numeral 4 denotes an IF detector, which detects an intermediate frequency signal converted by the front end 2 and amplified by the intermediate frequency amplifier circuit. Reference numeral 5 denotes an FM demodulation circuit, which demodulates the detection output of the IF detector 4 into a stereo signal. Reference numeral 6 denotes an amplifier, which amplifies a stereo signal. Reference numeral 7 denotes a speaker which is driven by the amplifier 6 and outputs an audio signal corresponding to the stereo signal.

Reference numeral 8 denotes an RDS decoder for demodulating a PTY code or the like transmitted at a predetermined transmission timing. An error correction circuit 9 detects an error of RDS data such as a PTY code demodulated by the RDS decoder 8 while synchronizing each group, and corrects the error.

Reference numeral 10 denotes a signal meter, which detects the level of the reception state of the receiving station (including the PTY station) by monitoring the signal strength (for example, electric field strength) of the intermediate frequency signal output from the intermediate frequency amplifier 3.

Reference numeral 11 denotes a control unit having a microcomputer configuration, a discriminating means 12 for discriminating which genre is the PTY code demodulated by the RDS decoder 8, and a program-specific frequency data corresponding to the PTY code and a reception electric field strength thereof. A preset memory 13 for storing the received signals, a signal corresponding to the reception electric field strength of the frequency data for each genre already stored in the preset memory 13 and a reception electric field strength of a newly received PTY station. And comparing means 14 for comparing the received signals. The control unit 11 performs a search operation and controls and processes when storing the selected broadcasting station in the preset memory 13.

Reference numeral 15 denotes an operation / display unit, which has a display 16 for displaying a frequency and a genre, an up / down key 17 for increasing or decreasing a reception frequency, an automatic tuning key 18 for automatically selecting a broadcasting station, and the like. ing.

Reference numeral 19 denotes a genre selection key (S) for calling genres such as classical, rock poppy, and news for each push, and displaying them on the display 16. Note that these genres follow the RDS PTY signal. Reference numeral 20 denotes a tuning key (TUNE), which is used to register a genre (PTY code) in the preset memory 13.

Reference numeral 21 denotes preset memory keys ［[1] ▼ to ▼ [6] ▼, which have a function of storing frequency data of a selected broadcasting station in the preset memory 13 and calling it to set a reception state. In this embodiment, as will be described later, the preset memory key 21 is also used as an operation key for setting a priority to the genre in addition to the preset of the frequency data. For example, the key of ▲ [1] ▼ is Pops, ▲ [2]
The key of ▼ is set as a lock. In the following, referring to FIG. 2, the preset memory key 21 ▲ [1]
An operation method of the operation / display unit 15 when setting the relation with the genre in ▼ to ▲ [6] ▼ will be described.

Pressing the tuning key 20 (step 100)
The control section 11 sets PTY code number (N) = 0 (step 101), and the display section 16 displays a genre of N = 0, ie, "no type" (step 102). Therefore, if the displayed genre is not satisfactory, the user presses the genre selection key 19 (step 103). Control unit 11
Adds 1 to the code number of N = 0 (step 10
4) The genre of N = 1, that is, "NEWS" is displayed on the display unit (step 102). If the displayed genre is acceptable, the preset memory key ▲ [1] ▼ ～ ▲
[6] Press the preset memory key corresponding to the desired priority among the keys of [▼]. Specifically,
If you want to give top priority to news genre ▲
If you want the [1] ▼ key to be in the sixth position, ▲
The key number of the preset memory key 21 such as [6] ▼ is set as the priority number of the preset memory key 21, and the preset memory key 21 may be pressed (step 105). ). The control unit 11 stores an N = 1 genre code (00001) in a memory area of the preset memory 13 corresponding to the number of the preset memory key pressed by the user.
Is written (step 106). As shown in Table 1 above, the PTY code number (N) is composed of 5-bit binary data. If N = 2, 00010, if N = 3, 0.
The configuration is as follows. By repeating the operation from step 103 to step 106 as described above, the genre can be set to each of [1] to [6] of the preset memory key 21. If the user wants to end the presetting of the genre, the user can press the tuning key 20 (step 107). When the tuning key 20 is depressed in step 107, the control section 11 causes the display section 16 to blink "OK" (step 108). In this case, when it is desired to further modify the preset contents, the process after the angle step 101 can be repeated by pressing the genre selection key 19 (step 109). In step 109, select the genre selection key 19
If "OK" is not pressed, the "OK" display is flashed for a predetermined time (step 110), and then the priority setting-based genre setting operation ends.

FIG. 3 is a flowchart of a search operation process of the PTY station of the present invention,
FIG. 4 is a diagram showing a specific example of frequency data stored in the preset memory 13. Hereinafter, the search operation of the PTY station according to the present invention will be described with reference to FIG. 3 and FIG.

If the reception area changes during automatic tracking of the same program, the same PI code cannot be detected, and the automatic tracking ends, the control unit 11 searches for a predetermined frequency band (step). 200), when a station whose electric field strength obtained from the signal meter 10 is higher than a predetermined level is found (step 201), an RDS code such as a PTY code is superimposed on the received broadcast wave via the RDS decoder 8 and the error correction circuit 9. Check if it is (Step 202). If the receiving station is an RDS station, the superimposed PTY code,
For example, the determination unit 12 determines whether or not the code number 00001 is stored in the preset memory 13.If the code number 00001 is stored, the frequency information of the station on which the PTY code is superimposed, for example, 92.3 MHz, is stored in the preset memory. The memory is stored in a predetermined area (see (a)) indicating 13 PTY codes 00001. The signal corresponding to the received electric field strength obtained from the signal meter 10 is also stored in a predetermined area together with the frequency data (step 203). At this time, if at least one station has been stored, the comparing means 14 performs a signal corresponding to the reception electric field intensity of the currently receiving PTY station based on the detection result of the signal meter 10 and the stored station. Compare the signal corresponding to the received electric field strength of the frequency data (step 20).
4) Reorder the frequency information data in the order of the signal strength (Step 205). When the above process is continued until the search of the predetermined frequency band is completed (step 206),
The frequency data as shown in (a) to (f) is stored in the preset memory 13, and reception is started at the station of the highest priority genre, in this example, 92.3 MHz (see (a)) ( Step 207). If there is no station stored in (a), reception starts at 98.56 MHz (see (b)) as the second highest-rank station, and the priority shown in (c) to (f) below. Reception is possible in order.

Note that the memory contents of the preset memory 13 shown in (a) to (f) can also be called by the preset memory key 21. In this case, the frequency information is called for each push, and when all the calls are completed, In this case, a cyclic configuration is used in which the frequency called first is called again.
Further, the frequency information stored in the preset memory 13 is four at maximum in the embodiment, but is not limited to this number.

When each genre is set to the preset memory key, what genre is set to each preset memory key may be displayed on the display.

<Effects of the Invention> According to the present invention, in a receiving method of a digital data multiplexing system for multiplexing and transmitting various information including program information to a broadcast signal, a program having a reception priority in correspondence with each preset key The content is stored, the signal level of the receiving station is monitored, and when the signal level falls below a predetermined value, the broadcasting station transmitting the program content identification code is searched, and the broadcasting signal from the receiving broadcasting station is searched. Of the broadcast station is determined by the program content identification code, the received electric field strength of the broadcast station is obtained, and the received broadcast stations are stored in the order of the received electric field strength in correspondence with the program contents of each preset key. Since the broadcast station that has the highest received electric field strength and is the highest priority program content than the stored content is identified and receives the broadcast from the identified broadcast station,
The user simply stores the desired genre in advance in the reception priority order in association with each preset key,
When the reception electric field strength of the currently receiving broadcasting station becomes weak and it becomes difficult to listen, the broadcasting station having the strong reception electric field strength of the genre of the highest priority desired by oneself can be automatically received, and the desired This eliminates the need to perform a cumbersome operation for receiving a genre of broadcast stations, greatly improving the operability of the device, and has the effect of always receiving a broadcast station of a genre that is optimal for listening in accordance with the priority order desired by the user. .

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a block diagram, FIG. 2 is a flowchart of a method of registering a PTY code in a preset memory, and FIG. FIG. 4 is a diagram showing a specific example of the memory contents of the preset memory. 8 RDS decoder, 9 Error correction circuit, 10 Signal meter, 11 Control unit, 12 Discriminating means, 13
Preset memory, 14... Comparison means, 15... Operation / display section, 19... Genre selection key, 21... Preset memory key.

Claims (1)

(57) [Claims] 1. A receiving method for a digital data multiplexing system for multiplexing and transmitting various information including program information on a broadcast signal, wherein program contents having a receiving priority are stored in association with each preset key, The signal level of the receiving station is monitored, and when the signal level falls below a predetermined value, the broadcasting station transmitting the program content identification code is searched, and the program content of the broadcast signal from the received broadcasting station is identified. The received electric field strength of the broadcast station is determined in accordance with the code, and the received broadcast stations are stored in the order of the received electric field strength corresponding to the program contents of each preset key. After the search is completed, the highest priority is given to the stored contents. A digital data multiplexing system characterized by identifying a broadcasting station having high reception electric field strength and having high program contents, and receiving a broadcast from the identified broadcasting station. The method of receiving beam.