JP2923369B2 - Broadcast station name display method of RDS receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of displaying a broadcast station name of an RDS radio receiver, and more particularly to a method of displaying a broadcast station name when reception conditions are poor.

[0002]

2. Description of the Related Art In car radios, in addition to easy access to traffic information, there is a demand for a higher function of channel selection. This demand is particularly strong in Europe, where FM broadcasts with a relatively narrow service area are mainly used for radio broadcast services and the broadcast reception ratio on car radio is high. In order to meet this demand, the European Broadcasting Union
(Radio data system) has been proposed and is being put to practical use. This RDS is a system in which various digital data are superimposed on an FM radio broadcast signal, and a message (RDS
As data, (i) program (broadcast program) identification data (PI data) of the currently received FM broadcast (ii) broadcast station name data (PS data) (iii) broadcast station frequency list during the same program broadcast ( (Iv data) (iv) program content identification data (PTY data) (v) transmission state identification data (DI data) (vi) identification data of music or conversation (M / S data) and (vii) a traffic information broadcasting station Identification data (TP data) (viii) Identification data (TA data) during traffic information broadcasting. Note that (i) to (vi) are information related to the channel selection function, and (vii) to (viii) are traffic information.

[0003] As described above, in the RDS, the FM
Since a message (RDS data) related to broadcasting is transmitted in a multiplex manner, an exceptional tuning operation and display operation can be achieved by using the message. For example, the frequency list data (AF
(List data) is demodulated and sequentially tuned to each of the AF stations on the AF list to check the reception electric field strength thereof, and it is possible to tune to the frequency of the AF station having a large reception electric field strength. (Automatic tracking). Also, the broadcast station name data (PS data) included in the RDS data can be extracted and the name of the RDS broadcast station being received can be displayed on the display unit.

[0004]

The RDS data superimposed on the FM broadcast signal and transmitted is transmitted without interruption in a group of 104 bits. There are 16 types of groups, and the messages sent in one group differ depending on the type.

Although the program identification data (PI data) is always included in each group, a maximum of eight characters (one character /
Broadcast station name data (PS data) consisting of 8 bits) is 1
The group contains only 2 bytes each, and is included in the group only with a probability of about 30% (about 3 out of 10 groups).

For this reason, it is necessary to receive a considerable number of groups before all the data constituting the PS data for 8 characters (data for 64 bits) are prepared. There is a problem that all data constituting the PS data for characters are not prepared and cannot be displayed.

Accordingly, an object of the present invention is to provide a broadcast station name display method of an RDS radio receiver capable of displaying a broadcast station name even when reception conditions are poor.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided an RDS data transmitting apparatus which is superimposed on an FM broadcast signal and transmitted.
Demodulates the broadcasting station name data contained in the RDS data.
RDS label that displays broadcast station names based on data (PS data)
In the method of displaying a broadcast station name of a geo receiver, the PS data
Each time the data is demodulated in an identifiable manner,
Corresponding to the program identification data (PI data)
While registering the PS data in the first memory,
Have the same PI data registered in the first memory
Compare the PS data and extract the different partial data
Respectively, and extracts the partial data into the corresponding P of the first memory.
So that it can be associated with S data and registered in the second memory
In advance, all the received PS data is extracted within a predetermined time.
If not, the PS data extracted within the predetermined time
The partial data matching the partial data of the second memory
Search if it is registered in, and if it is registered,
P of the first memory associated with the partial data
This is achieved by reading the S data and displaying the broadcast station name based on the PS data.

[0009]

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

Reference numeral 1 denotes an antenna, and 2 denotes a front end, which generates an intermediate frequency signal (IF) in synchronization with a predetermined broadcasting station based on a voltage signal output from a PLL circuit described later. An intermediate frequency amplifier 3 amplifies the intermediate frequency signal converted by the front end 2 to a predetermined level. Reference numeral 4 denotes a stereo demodulation circuit (MPX), which demodulates the intermediate frequency signal input from the intermediate frequency amplifier 3 into a stereo signal. 5 is a mute circuit, 6 is an amplifier (AM
P) and 7 are speakers, which are driven by the amplifier 6 and output sound.

Reference numeral 8 denotes a 57 KHz band-pass filter (BP)
F), and 5 which is amplitude-modulated based on the RDS data.
Pass a 7KHz sub-carrier. Reference numeral 9 denotes RDS data, which demodulates AF data, PI data, PS data and the like from the band pass filter output. An error correction circuit 10 detects an error of the RDS data (AF data, PI data, PS data, etc.) demodulated by the RDS decoder 9 while synchronizing each group, and corrects the error.

Reference numeral 11 denotes a signal SDT indicating whether the current receiving station is an RDS station based on the output signal of the band-pass filter 8.
Is a signal meter, and detects the level (reception electric field strength) of the reception state of the receiving station by monitoring the signal strength of the intermediate frequency signal output from the intermediate frequency amplifier 3. Reference numeral 13 denotes a station detector, which determines that a receiving station is present 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 predetermined level. It is commercialized as a circuit TA912102.

Reference numeral 14 denotes RDS data, received electric field strength, station detect signal SD, and RDS station detection signal SDT.
A controller that performs automatic follow-up processing based on, for example, and controls display of a broadcast station name, which will be described later.
b, data storage memory (RAM) 14c, timer means 14d, and the like.

In the data storage memory 14c, PS data is registered in correspondence with PI data. That is, when the processor 14a identifies PS data (broadcasting station name) of up to eight characters from the RDS data,
The identified PS data is registered in the main area 15a of the data storage memory 14c in correspondence with the PI data at that time, and the registered PS data is compared with the registered PS data. And
The difference between the data is registered in a memory area (sub area 15b) different from the memory area in which the PS data is registered. In the sub area 15b, PS
In addition to the data difference data, the reception frequency of the broadcast station indicated by the PS data is stored based on the reception frequency data FDT output from the controller 14.

[0015]

[Table 1]

Table 1 shows a specific example of the data storage memory 14c. The PS data is registered in the main area 15a, and the difference between the PS data and the reception frequency are registered in the sub area 15b. According to the figure, PI
It can be understood that there are four broadcasting stations with code 1, and the station with the highest receiving frequency among them is the broadcasting station of "BBC1GE".
In general, if the RDS station is a station having the same PI, the RDS station may be regarded as a station of the same network, for example, a BBC1 affiliated station. There is only a difference of 2 bytes of data such as "GE (Germany)". Therefore, the 2-byte data is stored in the sub-area 15b.

The processor 14a has a PS of up to eight characters.
When data cannot be identified, that is, the timer means 1
If the PS data cannot be completely identified within a predetermined time after the start of counting by 4d, it is searched whether or not there is data corresponding to the sub-area 15b among the already identified data. If there is, PS data corresponding to the data is read out from the main area and displayed. When there is no corresponding data in the sub area 15b, the PS data of the station having the highest reception frequency is displayed.

An operation panel 16 has a display section 16a and an operation section 16b. The display section 16a displays the name and the like of the broadcasting station being received, and the operation section 16b is provided with a tuning switch, a seek key, and the like.

Reference numeral 17 denotes a front end 2 which outputs a voltage signal corresponding to the reception frequency data FDT input from the controller.
To tune to a predetermined broadcast station. Hereinafter, the broadcast station name display processing of the radio receiver of FIG. 1 will be described with reference to the flowchart of FIG. When the controller 14 changes the reception frequency by operating a tuning switch or a seek key (not shown) of the operation unit 16b, the controller 14 determines whether the current reception station is an RDS station based on the output of the RDS station detection circuit 11 (step 101). If it is not an RDS station, another process is performed, and if it is an RDS station, it is superimposed on the FM broadcast and sent. One group of RDS data is received via the band pass filter 8, the RDS decoder 9, and the error correction circuit 10 (step 102).

Thereafter, PI data included in the RDS data is extracted (it is immediately extracted because it is included in all groups) (step 103), and RDS of one group is extracted.
It is determined whether or not the data includes 2-byte PS data (step 104). If not, the display of the broadcast station name is continued (step 105). The processing after 102 is repeated.

On the other hand, if it is determined in step 104 that PS data of 2 bytes is included, the PS data is stored in a memory (step 106), and
The timer means 14 after receiving the RDS data at
It is determined whether a predetermined time (N seconds) measured by d has elapsed (step 107). If not, it is determined whether all PS data (2 byte data) for 8 characters (64 bits) have been collected. (Step 108), and if not, the display of the broadcast station name up to that point is continued (step 10).
5) Thereafter, the processing from step 102 onward is repeated for the RDS data of the next group.

On the other hand, in step 108, if all the PS data (two-byte data) for eight characters have been prepared, the PI code extracted in step 103 and the sub-area 15b of the data storage memory 14c are stored. The past receiving experience is checked from the relationship of the receiving frequency data FDT indicating the receiving frequency (step 109), and if there is the past receiving experience, that is, if the station is registered in the data storing memory 14c, the data storing memory is checked. Register reception frequency in memory indicating reception frequency of sub-area 14c (+1)
Then, the display unit 1 uses the PS data for eight characters as a broadcast station name.
6a (step 110). In step 109, if the station has no reception experience, the correspondence between the PI data and the identified PS data is newly registered in the data storage memory 14c (step 111), and then the broadcast station name is displayed (step 111). 110) End the process.

The above is a case where the PS data has been collected within a predetermined time (N seconds) after receiving the RDS data. However, the reception state is poor and all the PS data (2 byte data) has been collected in the predetermined time. If not, in step 107, "Y
ES ”.

In this case, the processor 14a searches the sub area 15b of the data storage memory 14c based on the PS data and the PI code received within a predetermined time (step 112). For example, if the PI code is 1 and the received PS data is only “BB, GE”, a sub area search corresponding to PI code 1 is executed for each of the data.

When there is PS data corresponding to the sub-area 15b (step 113), the processor 14a reads the PS data corresponding to the sub-area from the main area and displays it on the display unit 16a as a broadcast station name (step 114). Referring to Table 1, “BB” is not stored in the sub area corresponding to PI code 1,
“GE” is stored. Therefore, the processor 14
“a” reads the PS data corresponding to “GE” from the main area, and displays “BBC1GE” on the display unit 16a here.

On the other hand, if the corresponding data does not exist in step 113, the processor 14a refers to the sub area 15b and displays the name of the broadcast station having the highest reception frequency (step 115).

[0027]

As described above, according to the present invention, it is possible to superimpose FM broadcast signals.
Demodulates the transmitted RDS data,
Based on broadcast station name data (PS data) included in the data
Table of RDS radio receivers that display the names of broadcast stations
Displaying the PS data in an identifiable state.
Program identification data that is demodulated simultaneously with each adjustment
Data (PI data) corresponding to the PS data
Registered in the memory and registered in the first memory
PS data with the same PI data
Different partial data, respectively,
Data associated with the PS data in the corresponding first memory.
And register it in the second memory.
If all data is not extracted within a predetermined time,
Matches the partial data in the PS data extracted in the interval
Check whether the partial data is registered in the second memory
And if it is registered, associate it with the partial data
The PS data stored in the first memory is read out, and
The name of the broadcasting station is displayed based on the PS data.
So, for example, even if the reception condition is poor,
This has the effect of displaying the correct broadcaster name.
I do.

[Brief description of the drawings]

FIG. 1 is a main block diagram of an RDS receiver.

FIG. 2 is a diagram illustrating a broadcast station name display process of a radio receiver.

[Explanation of symbols]

 2 FM front end 9 RDS decoder 11 RDS station detection circuit 14 Controller 14c Data storage memory 14a Processor 16a Display unit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04B 1/16 H04H 1/00 H03J 5/02

Claims (1)

(57) [Claims] 1. An FM broadcast signal superimposed and sent
Demodulates RDS data and broadcasts included in the RDS data
Display broadcast station name based on station name data (PS data)
In a method of displaying a broadcast station name of an RDS radio receiver,Each time the PS data is demodulated in an identifiable state,
Simultaneously demodulated program identification data (PI data)
Register the PS data in the first memory in correspondence with
And the same PI registered in the first memory
The parts that differ from each other by comparing PS data with data
Extract the data respectively, and
Registered in the second memory in association with the PS data in the memory
So that If all the received PS data is not extracted within a predetermined time
The partial data in the PS data extracted within the predetermined time.
The partial data that matches the data is registered in the second memory.
Search if it is registered, and if it is registered,
PS data of the first memory associated with the data
And read the Display broadcast station name based on PS data
Characteristic display method of broadcasting station name of RDS radio receiver
Law.