JPH0736529B2 - Radio receiver station name display method - Google Patents

Description

The present invention relates to a broadcasting station name display method for a radio receiver, and more particularly to a method for displaying the name of an RDS (radio data system) broadcasting station in a short time.

<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. 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 is strong. Therefore, in order to meet this demand, RDS (Radio Data System) has been proposed and put into practical use by the European Broadcasting Union. This RDS is FM
This is a method of superimposing various digital data on a radio broadcast signal. As a message (RDS data), currently received FM broadcast (i) program (broadcast program) identification data (PI) (ii) broadcast station name data (PS) (iii) Broadcasting station frequency list (AF) during the same program broadcasting (iv) Program content identification data (PTY) (v) Transmission status identification data (DI) (vi) Music or conversation identification data (M / S data) and (vii) identification data of traffic information broadcasting stations (TP data) (viii) identification data during traffic information broadcasting (TA data). The above (i) to (vi) are information related to the channel selection function, and (vii) to (viii) are traffic information.

In this way, since the message (RDS data) related to the received FM broadcast is transmitted in multiplex in the RDS, it is possible to use the message to perform a special tuning operation and display operation that have never been seen.

For example, the frequency data (AF list) of the same program broadcasting station is demodulated every predetermined time, and the received electric field strength is checked by sequentially tuning to each AF station on the AF list, and the AF having a large received electric field strength is detected. Can be tuned to the frequency of the station (automatic tracking). Also, the broadcasting station name (P
S data) can be extracted and the name of the RDS broadcasting station being received can be displayed on the display unit.

<Problems to be solved by the invention> RDS data transmitted by being superimposed on an FM broadcast signal is 1
It is sent seamlessly in units of 04 bits. There are 16 types of groups, and the messages sent by one group differ depending on the type.

Program identification data (PI data) is always included in each group, but broadcasting station name data (PS data) consisting of a maximum of 8 characters (1 character / 8 bits) contains only 2 bytes per group, and 30 It is included in the group only when the probability is about 10% (about 3 out of 10 groups).

Therefore, 8 characters of PS data (64 bits of data)
It takes a considerable amount of time to receive a considerable number of groups before they are aligned. Since the broadcasting station name is displayed after confirming that the same PS data has been received several times in succession, it takes 2 to 10 seconds to display the broadcasting station name. is there.

From the above, it is an object of the present invention to provide a broadcasting station name display method for a radio receiver, which can display the broadcasting station name in a short time.

<Means for Solving the Problems> In the present invention, the above-mentioned problems are related to PI data by PS.
Memory for storing data, means for extracting program identification data (PI data) included in RDS data, means for determining whether PS data is registered in the memory corresponding to the extracted PI data, and PS data This is achieved by means of displaying on the display unit and means of registering the correspondence between the transmitted PI data and PS data in the memory.

<Operation> When the RDS broadcast is received, the program identification data (PI data) included in the RDS data is extracted, and it is determined whether the PS data is registered in the memory corresponding to the PI data, (1)
If not registered, PS data is extracted from the RDS data and displayed, and the correspondence between the extracted PI data and PS data is registered in the memory. (2) If registered, the PI data is registered. The PS data registered corresponding to the data is immediately displayed, and when the PS data is subsequently extracted from the PDS data, the PS displaying the extracted PS data is displayed.
If it is different from the data, the extracted PS data is displayed instead, and the PS data registered corresponding to the PI data is updated with the extracted PS data.

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

1 is an antenna, 2 is a front end, and PL described later
An intermediate frequency signal (IF) 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 to a predetermined level. 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. An RDS decoder 9 demodulates AF data, PI data, PS data and the like from the output of the bandpass filter. 1
0 is an error correction circuit, which is an RDS decoder demodulated by the RDS decoder 9 (AF data, PI data, PS data, etc.)
Error is detected in synchronization with each group and the error is corrected.

Reference numeral 11 is an RDS station detection circuit that outputs a signal SDT indicating whether the current reception station is an RDS station based on the output signal of the bandpass filter 8, 12 is a signal meter, and the intermediate frequency amplifier 3
The level (reception electric field strength) of the receiving state of the receiving station is detected by monitoring the signal strength of the intermediate frequency signal output from the. Reference numeral 13 denotes a station detector, which determines that a receiving station exists when the received signal is within a frequency variation Δf (bandwidth) of the received signal and the signal strength is equal to or higher than a predetermined level. For example, a Toshiba integrated circuit. It is commercialized as TA91210Z.

14 is a controller that performs automatic tracking processing based on RDS data, received electric field strength, station detect signal SD, RDS station detection signal SDT, etc., and controls display of a broadcasting station name, which will be described later, processor (CPU) 14a, It has a program memory (ROM) 14b, a data storage memory (RAM) 14c, and the like.

PS data is registered in the memory 14c in association with PI data. That is, the processor 14a
When the PS data (broadcasting station name) of maximum 8 characters is identified from the data, the identified PS data is registered in the memory 14c in association with the PI data at that time.
By storing the correspondence between the latest received PI data and PS data in this way, when PI data (included in each group) is detected from RDS data, the PS corresponding to the PI data is detected. The data (broadcast station name) can be read from the memory and immediately displayed on the display unit. In addition, the reason why the broadcasting station name can be displayed based on the PI-PS correspondence is that "in general, RDS stations that transmit the same PI data transmit the same PS data (broadcasting station name)." This is because it can be considered, and the time required to display the broadcasting station name can be shortened. However, if the true PS data (broadcast station name) is identified from the RDS data and the broadcast station name display is incorrect, the correct broadcast station name identified at that time is displayed.

Reference numeral 15 denotes an operation panel, which has a display unit 15a and an operation unit 15b. The display unit 15a displays the name of the broadcasting station being received and the like, and the operation unit 15b is provided with a tuning switch and a seek key.

16 is the 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.

The broadcast station name display process of the radio receiver of FIG. 1 will be described below with reference to the flowchart of FIG.

When the reception frequency is changed by operating a tuning switch or a seek key (not shown) of the operation unit 15b, the controller 14 determines that the current reception station is R based on the output of the RDS station detection circuit 11.
If it is a DS station (step 101), if it is not an RDS station, another processing is performed, and if it is an RDS station, the group of RDS data sent superimposed on the FM broadcast is sent to the bandpass filter 8 and the RDS decoder. 9. Received via the error correction circuit 10 (step 102).

Then, the PI data included in the RDS data is extracted (it is immediately extracted because it is included in all the groups), and it is determined whether the extracted PI data is registered in the memory 14c (steps 103 and 104).

If the extracted PI data is not registered in the memory 14c, that is, if a program (program) having the extracted PI data has not been received until now, one group of RDS data includes 2 bytes of PS data. It is determined (step 105) whether it is not included or not, the broadcasting station name display up to that point is continued (step 106), and thereafter, the processing from step 102 onward is repeated for the RDS data of the next group.

If 2-byte PS data is included, it is stored in the memory (step 107), then it is judged whether PS data of 8 characters (64 bits) is complete (step 108). The name display continues and the RD of the next group
The processing from step 102 onward is repeated for the S data.

On the other hand, in step 108, 8 characters of PS data (PS
When n) are complete, the flag F is set to "1" and the P
The S data (PSn) is displayed on the display unit 15a as the broadcasting station name (steps 109 and 110). The flag F indicates that the PS data for 8 characters is complete.

Then, the identified PS data (PSn) is compared with the previously identified PS data (PSn ′), and if they match, n (initial value is zero) is incremented, and then n = N (2 (Set value of 4 to 4) (step 111), and if n <N, the processing from step 102 onward is repeated for the RDS data of the next group.

However, if the PS data match several times in succession (if n = N), it is judged again whether the extracted PI data is registered in the memory 14c (step 112). If not, the PI data is registered. The correspondence of the PS data (PSn) identified as is newly registered in the memory 14c (step 113), the flag F is set to "0" (step 114), and the process is terminated.

The above is the case where the extracted PI data is not registered in the memory, but if it is registered, step 104
Is "YES".

Then, the processor 14a determines whether the flag F (initially "0") is "0" (step 115), and if F = "0", it is registered from the memory 14c corresponding to the extracted PI data. The PS data (PSo) is read out and displayed on the display unit 15a (step 116), after which the processing from step 105 onward is repeated. As a result, the registered PS data (PSo) continues to be displayed until the PS data for eight characters are available.

Then, when the PS data (PSn) for eight characters are complete, the result is "YES" in step 108, so the flag F is set to "1" and the PS data (PSn) is used as the broadcasting station name in the display unit 15a. (Steps 109 and 110). As a result, the PS data (PSn) extracted from the RDS data is displayed on the display.
If it is different from the PS data PSo (PS data registered in the memory) displayed on 15a, PSn is displayed on the display unit 15a instead, and if the same, the display does not change.

Then, it is judged whether or not the identified PS data (PSn) match several times in succession (step 111). If they do not match, the identified broadcast station name display is continued, and thereafter the next group
The processing from step 102 onward is repeated for the RDS data.
It should be noted that F = "1" until "YES" in step 111.
Therefore, in step 115, the result is “NO”, and the identified PS data (PSn) is displayed thereafter.

Then, if the PS data (PSn) match several times in a row,
It is determined whether the PI data extracted in step 103 is registered in the memory 14c (step 112).

If the extracted PI data is registered in the memory, it is determined whether the PS data (PSn) that matches several times in a row matches the PS data (PSo) stored corresponding to the extracted PI data. (Step 117), if they match, do nothing, and if they do not match, replace the PS data (PSo) corresponding to the extracted PI data with the identified PS data (PSn), and PI-PS
The correspondence relationship of is updated (step 118).

<Effects of the Invention> According to the present invention, the PI data (included in each group) is detected from the transmission data by storing or updating the correspondence between the latest received PI data and PS data. At this time, the PS data (broadcast station name) corresponding to the PI data can be immediately read from the memory and displayed, and the time required to display the broadcast station name can be shortened. Generally, since multiple stations transmitting the same PI data can be regarded as transmitting the same PS data (broadcast station name), there are few errors in the broadcast station display.

Further, according to the present invention, when the true PS data (broadcasting station name) is identified from the transmission data, even if the broadcasting station name display based on the PI-PS correspondence is wrong, the correct broadcasting at that time is obtained. The station name can be displayed.

[Brief description of drawings]

FIG. 1 is a block diagram of an RDS radio receiver according to the present invention, and FIG. 2 is a flow chart of a broadcast station name display processing of the present invention. 2 …… FM front end 9 …… RDS decoder 11 …… RDS station detection circuit 14 …… Controller 14c …… Data storage memory 15a …… Display section

Claims (1)

[Claims] 1. A demodulation of transmission data sent superimposed on an FM broadcast signal, and a broadcasting station name (PS) included in the transmission data.
In the broadcasting station name display method of the radio receiver that displays the code) on the display unit, when multiplex broadcasting is received, the program identification data (PI data) included in the transmission data is extracted and made to correspond to the extracted PI data. If the PS data is not registered, the PS data is extracted and displayed from the transmission data, and the correspondence between the extracted PI data and PS data is registered and registered. When the PS data registered corresponding to the extracted PI data is displayed, and then PS data is extracted from the transmission data, the PS data displaying the extracted PS data is displayed. PS that is displayed instead and is registered in correspondence with the PI data
A method of displaying a broadcasting station name of a radio receiver, characterized by updating the data with the extracted PS data.