JPH03230623A - Tracing method for rds radio receiver - Google Patents

Abstract

PURPOSE:To prevent a different program from being received in the case of tracing by applying mute in the manual tracing mode, discriminating up to the identity of a PI data during the muting state and releasing the mute after an AF station whose PI data is the same and reception electric field strength is excellent is tuned. CONSTITUTION:A processor 14a monitors the mode as to whether or not the manual tracing mode is set by the operation of a tracing mode switching key TMK of an operation section 15a. When the manual tracing mode is set, mute is applied and while mute is applied, a broadcast station with a maximum reception electric field strength is identified among broadcast stations in an AF (frequency) list larger than the reception electric field strength of an original reception station and sending the same PI data as the program identification data (PI data) of the original reception station and the frequency of the broadcast station is tuned and simultaneously the mute is released. Thus, no sense of displeasure given to the user is avoided as the reception of a program different from the original program in the case of the automatic tracing.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a tracking method for an RDS radio receiver, and particularly to a tracking method for an RDS radio receiver equipped with a manual tracking function.

<Prior art> In Europe, where the main radio broadcasting service is FM broadcasting, which has a relatively narrow service area, and where the proportion of broadcasting reception on car radios is high, RDS (Radio Data System)
has been put into practical use. This RDS is a method that superimposes various digital data on an FM radio broadcast signal, and the messages include (i) program (broadcast program) identification data (PI) (i) of the currently received FM broadcast;
i) Broadcasting station name data (PS data) (iii) Frequency list of broadcasting stations broadcasting the same program (AF list) (Han) Program content identification data (PTY) (V) Transmission status identification data (DI) (vi) Identification data (M/S data) for music or conversation (
Regret) Traffic information broadcasting station identification data (TP data) (th
) Identification data (TA data) during traffic information broadcasting, etc.

In this way, with RDS, messages (RDS data) regarding the FM broadcast being received are transmitted multiplexed, so that unprecedented tuning operations can be performed using the messages.

For example, if you turn on the auto tracking on/off key,
Demodulates the frequency list (AF list) of the same program broadcasting stations, sequentially tunes to stations with frequencies listed on the AF list (referred to as AF stations), checks their received field strength, and checks the reception of the receiving stations up to that point. It tunes to the frequency of the AF station with the highest received field strength (referred to as automatic tracking), which is larger than the field strength.

By the way, when checking the received field strength of the AF station during automatic tracking (referred to as AF search), the front end is tuned to the AF station frequency for about 10 m5ec at 2.5 second intervals to avoid discomfort, and muted during that time. This is done by multiplying . However, at 10m5ec, only the received field strength of the AF station can be checked. For this reason.

A determination as to whether the same PI data as the original broadcasting station is being transmitted from the AF station is made after moving to the maximum AF station.

If the PI data are not the same, the AF station with the next strongest received field strength is regarded as the maximum AF station, and the tuning is shifted to the maximum AF station.The identity of the PI data is then confirmed, and if they do not match, the same processing is performed. If they match, reception of the maximum AF station is continued, and automatic follow-up control is repeated after a predetermined period of time.

<Problem to be solved by the invention> If the same program as the original broadcast station is reliably broadcast from the broadcast station on the AF list and the PI data is the same,
There is no problem even if the identity of the PI data is confirmed after moving to the maximum AF station as in the conventional method, and in such a case, the identity of the PI data is more likely to be confirmed merely as a precaution.

However, in countries such as France and Italy, there are many stations using the same frequency, so the PI data often differs. Previously, the PI was broadcast after moving to the AF station.
Since the data identity is checked, if the PI data is different, the user may be tuned into the wrong station until the identity determination is completed, resulting in a different program being broadcast than the previous one. make you feel uncomfortable.

From the foregoing, it is an object of the present invention to provide a tracking method for an RDS radio receiver that can prevent different programs from being received during tracking.

<Means for Solving the Problems> In the present invention, the above problems are solved by providing a means for setting the manual tracking mode, a muting means, a means for muting during manual tracking, and an R including an AF list and PI data.
A means for demodulating DS data, a means for checking the received field strength of a broadcasting station (AF station) in the AF list, and a means for checking the received field strength of a broadcasting station (AF station) in the AF list, and a PI of a failed receiving station that is an AF station whose received field strength is higher than that of the original receiving station. This is achieved by means for identifying the AF station with the highest received field strength among the AF stations transmitting the same PI data as the data, and means for tuning to the frequency of the AF station.

<Effect> Mute when manual tracking is instructed.

While muting is applied, the broadcasting station (AF station) in the AF list whose received field strength is higher than that of the original receiving station, and which transmits the same PI data as the PI data of the dead receiving station. Among them, the AF station with the highest received field strength is identified, and the frequency of the AF station is tuned to be tuned and the mute is canceled.

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

1 is an antenna, 2 is a front end, and P
Based on the voltage signal output from the LL circuit, an intermediate frequency signal (IF) is generated in tune with a predetermined broadcasting station. 3 is an intermediate frequency amplifier, which amplifies the intermediate frequency signal outputted 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.

5 is a mute circuit, 6 is an amplifier (AMP), and 7 is a speaker, which is driven by the amplifier 6 and outputs audio.

8 is a 57KHz band pass (B P F), R
A subcarrier of 57KH2 amplitude modulated based on DS data is passed. 9 is an RDS decoder and outputs an AF list from a bandpass filter.

Demodulates PI data etc. 10 is an error correction circuit, which collects the AF data demodulated by the RDS decoder 9, PI
Errors in RDS data such as data are detected while synchronizing each group, and the errors are corrected.

Reference numeral 11 denotes a signal meter, which monitors the received electric field strength using the intermediate frequency signal output from the intermediate frequency amplifier 3. Reference numeral 12 denotes a station detector, which determines that a receiving station is present when the frequency shift Δf (bandwidth) of the received signal is within the range and the signal strength is above a predetermined level.

Therefore, when the station detect signal SD is at a low level, even if the signal strength detected by the signal meter 11 is high, there is actually no broadcasting station at the tuning point, and the detected signal strength is the same as that of the neighboring station. Decide that you are affected. 13 is an RDS that detects whether the receiving station is an RDS station based on the presence or absence of the output of the bandpass filter 8;
This is a station detection circuit.

14 is a microcomputer-configured controller that performs automatic tracking and manual tracking processing (described later) based on RDS data, signal meter output, station detector output, etc., as well as digital tuning processing (electronic tuning processing); (ROM
) 14b, data memory (RAM) 14c, etc.

15 is an operation panel, 15a is an operation section, 15b is a display section,
16 is reception frequency data F input from the controller
This is a PLL circuit that inputs a voltage signal corresponding to DT to the front end 2 and tunes it to a predetermined broadcast station.

The operation unit 15a is provided with a follow-up mode switching key TMK, and when it is pressed for 1.7 seconds or more, it switches alternately between automatic follow-up mode and non-follow-up mode (referred to as fixed station mode) each time. Push too 1
．． When the button is pressed (for 7 seconds or less), it switches to manual follow-up mode, and after one manual follow-up operation, it switches back to the original mode. Furthermore, mode data M indicating whether the current mode is automatic tracking mode or fixed station mode is
D is stored in the memory 14c.

The follow-up process of the present invention will be explained below according to the flowcharts shown in FIGS. 2 to 4.

Overall error (2) The processor 14a monitors whether the manual tracking mode has been entered by operating the tracking mode switching key TMK (step 101), and when manual tracking is requested, the manual tracking process shown in the flowchart of Fig. 3 is performed. The routine is executed (step 102).

If the manual tracking mode is not set, or if the manual tracking processing routine is executed, the mode data MD stored in the memory 14c is referred to, and whether the mode before the manual tracking mode is the automatic tracking mode or the fixed station mode is determined. Check whether there is one (step 103).

If the station is in the fixed station mode, no follow-up operation is performed and the current receiving station is fixed (step 104); if it is the one-way dynamic follow-up mode, the automatic follow-up processing routine shown in FIG. 4 is executed (step 105).

After that, check to see if the tracking mode switching key TMK has been pressed for 1.7 seconds or more, and if it has been pressed, change the mode data MD from automatic tracking mode to fixed station mode or vice versa and return to the beginning. (Steps 106, 107)
.

In addition, in cases such as France and Italy, where there is a risk of receiving another program due to automatic tracking operation (risk of malfunction), if you operate the tracking mode switch key TMK to switch to manual mode, mute will be disabled as described later. During this time, the user searches for the best station with the same program, tunes to that station, and then unmutes the program without broadcasting another program.

Manual' processing (see Figure 3) In the manual follow-up process, the controller 14 first displays the characters rA F S E E KJ on the display section 15b, indicating that the manual follow-up process is in progress (
Step 201).

Next, the RDS data superimposed on the FM broadcast of the current receiving station is received via the bandpass filter 8, RDS decoder 9, and error correction circuit 10.
Step 202), mute command MUT is muted N times
5 to mute the audio.

After that, the controller 14 determines the i-th AF station frequency from the AF list included in the RDS data (the initial value of i is 1), instructs the PLL circuit 16 to receive the i-th AF station, and sends a command to the front end. 2 to tune to the frequency of the AF station (step 204).

In the state tuned to the i-th AF station, check whether the output signal SD of the station detector 12 is at a high level (step 205). If it is at a high level, there is a receiving station, so the received electric field is output from the 5-signal meter 11. The received field strengths of the AF stations that have been imported so far are sorted in ascending order (step 206).

After that, or if the signal SD is at a low level in step 205, check whether the AF search has been completed for the AF stations in the entire AF list (step 207).
- If not completed, increment i by i+1→i (step 208) and repeat the processing from step 204 onwards. Note that it takes about 6 a+sec to tune to one station, take in its received electric field strength, and rearrange it in order of strength.

When the AF search process is completed for all AF stations as described above, the received field strength level La of the current receiving station and the maximum received field strength level Lm of the AF station are compared (step 209).
, if La≧L+a, there is no need to change the receiving station, in other words, there is no AF station to change to, so rNo A
The character "FJ" is displayed (step 210), and after 2 seconds it is tuned to the original receiving station (step 211), and after "L", the mute is canceled (step 212) and the manual follow-up processing routine is ended.

On the other hand, in step 209, if La(Lm,
The controller 14 instructs the PLL circuit 16 to receive the AF station showing the maximum received field strength, and causes the front end 2 to tune to the broadcast frequency of the AF station (step 213).
).

Next, check whether the receiving station is an RDS station based on the output of the RDS detection circuit 13 (step 214), and the RD
If it is an S station, RDS is sent superimposed on the FM signal.
Extract the PI data included in the data and check whether the PI data matches the PI data indicating the name of the broadcast program broadcasted by the original receiving station (Step 215). If it matches, the process jumps to Step 212 and mutes. It is released and the manual follow-up processing routine ends.

However, if the maximum AF station is not an RDS station or P
If the I data do not match, select the corresponding maximum A from the AF list.
Delete station F (step 216).

Check whether there is an AF station with the next highest received field strength (Step 217); if it does not exist, there is no AF station to move to, so perform the processing from Step 210 onwards, and select rNo.
The characters AFJ are displayed, and after 2 seconds, the device is tuned to the original receiving station, and then the mute is canceled and the manual follow-up processing routine is ended.

On the other hand, if there is an AF station with the next highest received field strength,
Set the AF station as the AF station with the maximum received field strength Step 2
18), repeat the processing from step 209 onwards.

Note that by the time the PI data is extracted from the AF station with the maximum received field strength and the determination of identity is completed, the AF station must use RDS.
400 if it is not a station. If it is an RDS station, it will take 800 m5ec. Therefore, assuming that there are about 10 AF stations, the reception field strength check time, PI
Considering the data identity determination time, the manual follow-up process takes about 4 to 10 seconds, and during this time mute continues and audio output is prohibited.

1 Supervised moxibustion A-o (See Figure 4) In the automatic tracking process, the controller 14 first processes the RDS data sent superimposed on the FM broadcast of the current receiving station, passes it through the bandpass filter 8, the RDS decoder 9, and performs error correction. It is received via the circuit 10 (step 301).

Next, the controller 14 reads A included in the RDS data.
Find the i-th AF station frequency from the F list (the initial value of i is 1), and calculate 10+m5ec for the i-th AF station.
AF station search processing is executed. That is, the mute command MUT is output to the mute circuit 5 to mute the audio, and the PLL circuit 16 is commanded to receive the i-th AF station, and the front end 2 is tuned to the frequency of the AF station (step 3o2).

When tuned to the i-th AF station, check whether the output signal SD of the station detector 12 is at a high level (step 303). If it is at a high level, a receiving station exists, so the received electric field output from the signal meter 11 The received field strengths of the AF stations that have been imported so far are sorted in descending order of strength (step 304).

After that, or if the signal SD is at a low level in step 303, check whether the AF search has been completed for the AF stations in the entire AF list (step 305).
, if not, increments i by i+1→i (step 306), cancels muting and returns the receiving station to the original receiving station, and ends the search for the i-th AF station (step 307). .

Thereafter, check whether the AF station search period (for example, 2.5 seconds) has elapsed (step 308); if it has elapsed, the process jumps to step 302 and returns.

When the AF search process is completed for all AF stations, the received field strength level La of the original receiving station is compared with the maximum received field strength level Lm of the AF station (step 309).
If La≧Lm, there is no need to change the receiving station, and the receiving station is returned to the original receiving station (step 309'). The automatic tracking process is ended.

However, if La<Lm, the controller instructs the PLL circuit 16 to receive the AF station exhibiting the maximum received field strength, and causes the front end 2 to tune to the broadcast frequency of the AF station (step 310).

Next, check whether the receiving station is an RDS station based on the output of the RDS detection circuit 13 (step 214), R
If it is a DS station, the RD sent superimposed on the FM signal
Step 312), -fi
Then, reception from the current receiving station (maximum AF station) is continued and the automatic follow-up process is repeated to complete the loop routine.

However, if the maximum AF station is not an RDS station or P
If the I data do not match, the receiving frequency is returned to the broadcast frequency of the original receiving station (step 313), and the maximum AF station is deleted from the AF list (step 314). Then,
Check whether there is an AF station with the next highest received field strength (step 315); if not, there is no AF station to move to, and the automatic tracking process ends.

On the other hand, if there is an AF station with the next highest received field strength,
This AF station is regarded as the AF station with the maximum received field strength, and the processes from step 309 onwards are repeated (step 316).

The above is a case of switching to manual tracking mode by operating the tracking mode switch key TMK, but if there is a malfunction (reception of another program) more than a predetermined number of times during automatic tracking, it will automatically switch to manual tracking mode. It can also be done. However, in this case.

It is necessary to insert the following steps 411 to 413 between step 312 and step 313 in FIG. 4 (see the dotted line in FIG. 5).

That is, in step 312, if the PI data do not match, m (initial value is 0) indicating the number of malfunctions is incremented by 1 (step 411), and then m is increased to a preset number M, for example 3. Step 412) to check whether it has changed, and if m - 3, return the reception frequency to the broadcast frequency of the original receiving station (step 313), and execute the subsequent steps. However, if m = 3 in step 412, it is assumed that the vehicle is currently located in an area where the network is inadequate, and the mode is automatically set to manual tracking mode (step 413), and the automatic tracking process is terminated. After the automatic follow-up process is completed, in step 101 of FIG. 2, rYEsJ is established, so in step 102, the above-mentioned manual follow-up process is executed.

If m is configured to be cleared to 0 before the automatic tracking process ends, manual tracking mode will be activated when stations with different M@PI data are received (malfunction) consecutively in one automatic tracking cycle. If it is not cleared, the manual tracking mode will be activated when a total of M malfunctions occur after radio reception.

<Effects of the Invention> As described above, according to the present invention, a manual tracking mode is provided, muting is applied during the manual mode, and even the identity of PI data is determined during the manual tracking mode. Since the system is configured to cancel muting after tuning to a station, there is no possibility of receiving a program different from the original program and causing discomfort to the user, unlike automatic tracking. Note that manual tracking requires muting for a long time of 4 to 10 seconds, so manual tracking is effective in areas where another program is received by mistake during automatic tracking, and automatic tracking is sufficient in areas where no malfunction occurs.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the RDS radio receiver according to the present invention, Fig. 2 is an overall flowchart of tracking processing, Fig. 3 is a flowchart of manual tracking processing, Fig. 4 is a flowchart of automatic tracking processing, and Fig. 5 is a flowchart of another automatic tracking process of the present invention. 2...FM front end 5...Mute circuit 9...RDS decoder 11...Signal meter 14...Controller 15...Operation panel. 15a...Following mode switching key 16...PLL circuit

Claims (2)

[Claims] (1) Based on the AF list included in the RDS data sent superimposed on the FM broadcast signal, the received field strength of the same program broadcasting station is checked by muting it at predetermined intervals, and the receiving station In a tracking method for an RDS radio receiver equipped with an automatic tracking function that tunes to the frequency of the same program broadcasting station with the highest received field strength, which is a broadcasting station with a received field strength greater than , When manual tracking is instructed by the means, muting is applied, and while the muting is being applied, a broadcasting station in the AF list whose received field strength is greater than the received field strength of the original receiving station, and the program identification of the original receiving station is An RDS radio characterized by identifying the broadcasting station with the highest received field strength among the broadcasting stations transmitting the same PI data (PI data), tuning to the frequency of the broadcasting station, and canceling muting. Receiver tracking method. (2) Based on the AF list included in the RDS data sent superimposed on the FM broadcast signal, the received field strength of the same program broadcasting station is checked by muting it at predetermined intervals, and the receiving station receiving a broadcast from a broadcasting station with a maximum received field strength, which is larger than the received field strength of the broadcasting station, and then determining whether the PI data of the broadcast station matches the PI data of the original broadcast station; If they match, reception from the broadcast station continues; if they do not match, the broadcast from the next broadcast station with the highest reception field strength is received, and the PI of the original receiving station is changed.
Find a broadcast station that transmits PI data that matches the data,
R equipped with an automatic tracking function to receive broadcasts from the broadcast station.
In the tracking method of the DS radio receiver, when in automatic tracking mode, it monitors whether broadcasting stations with different PI data are received more than a predetermined number of times, and if it receives broadcasting stations with different PI data more than a predetermined number of times, it switches to manual tracking mode. At the same time, mute the station, and while muting, transmit PI data that is the same as the PI data of the original receiving station that is a broadcasting station in the AF list that has a higher received field strength than the original receiving station. An RD characterized by identifying the broadcasting station with the highest received field strength among the broadcasting stations, tuning to the frequency of the broadcasting station, canceling mute, and then returning to automatic tracking mode.
S radio receiver tracking method.