JPH0879016A - Network follow processing method and rds receiver executing it - Google Patents

Abstract

PURPOSE: To reduce the time required for network follow processing. CONSTITUTION: The network follow processing reads substitute frequency data corresponding to a setting network from a memory and makes channel selection based on the read substitute frequency data. The method has a channel selection control process S 12 making channel selection control at a reception frequency corresponding to substitute frequency data read from the memory, a, reception data fetch process S 15 fetching one block of RDS data from a broadcast wave selected and received by the channel selection control process, and a block comparison process S 17 comparing the RDS data of one block received by the reception data fetch process with block data including network identification data to identify the setting network and when the block comparison process discriminates that they are coincident with each other, the reception of a broadcast wave sent from a broadcast station belonging to the setting network is recognized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio data system (hereinafter referred to as "RDS") which receives a broadcast wave received from a broadcasting station when the reception condition of the broadcast wave deteriorates. Based on the PI (Programme Identification) code in the RDS data that is multiplexed on the reception frequency, the reception frequency is automatically received from another broadcasting station that belongs to the same broadcasting network as the broadcasting station and has a good reception state. The present invention relates to a network follow process that performs switching control of the above, and also relates to an RDS receiver that executes such a process.

[0002]

2. Description of the Related Art Data such as information on broadcast program contents, traffic information broadcast station identification information, and frequency information of broadcast waves transmitted from broadcast stations belonging to a broadcast network broadcasting the same program as the broadcast. Frequency-multiplexing the RDS signal containing the RDS signal with the FM stereo audio signal, which is the main information signal (broadcast signal), and transmitting the RDS broadcast wave.
There is an RDS system in which the RDS signal is demodulated on the receiving side and various functions other than the reproduction of the main information are provided based on the respective information.

The RDS signal has a bit rate of 1187.
Two-phase DPSK (Differentially Encoded P) of 5 bps
The SK) signal, which is a 57 KHz subcarrier that is the third harmonic of the stereo pilot signal having a frequency of 19 KHz, is frequency-multiplexed outside the frequency band of the audio FM modulated wave by performing carrier suppression type amplitude modulation. As shown in FIG. 1, the data structure of the base band of the RDS signal is composed of 4 blocks with 104 bits as one group, and each block is composed of a 16-bit information word, a 10-bit check word and an offset word. It consists of bits. The content of each information word is defined by the group type code.

Block 1 of the information words of each block
The information word is always a 16-bit program identification code (hereinafter referred to as PI code), and includes information such as country, region, and network. The information word of block 2 includes a 4-bit group type code and a 1-bit traffic information station (TP).
n) Code, 5-bit program type (PTY: Programme)
Type) code and other information is included. Block 3
And the information word of block 4 is defined by the group type determined by the group type code of block 2. If the group type is 0A, block 3
Is an alternative frequency of the current reception frequency, that is, an AF (Alternative Frequenc) with an 8-bit frequency of a broadcast wave transmitted from another broadcasting station belonging to the same network as the current reception station.
ies) data, broadcasting station name data for displaying the station name of the receiving station on the display in block 4 is defined as 16-bit PS (Programme Service name) data.

One of the methods of using such an RDS signal is the network follow function. This function is
PI code and A multiplexed in the received broadcast wave
F data is demodulated and fetched, and the AF data is stored as an AF list in a predetermined area in the memory for each PI code, that is, for each broadcast network. When the reception status of the broadcast wave from the receiving broadcast station deteriorates while moving, for example, in a car, the same PI code (set PI code) as the broadcast wave received up to now from the AF list. Each of the AF data corresponding to the PI code of 1 is sequentially read, and another broadcasting station that belongs to the same broadcasting network and can be well received is automatically tuned to always listen to the same broadcasting program with clear sound. It is something to do.

In such network follow,
In order to obtain the reception frequency of the same network, basically, the RD received by the newly set reception frequency
A PI code is detected from the S signal, the detected PI code is compared with a desired PI code (PI code for identifying a network to be tuned), and if they match, the new reception frequency is fixed, and thereafter. Broadcast waves are received and audio is output at this fixed reception frequency.

As a pre-process for detecting the PI code, group synchronization with the RDS signal is performed after confirming the presence of a broadcast wave tuned at a set reception frequency and determined by the reception electric field strength and the detection output. In the group synchronization, the offset word of the received RDS signal is calculated, and it is confirmed that the obtained offset words are present in the order of A, B, C, D and at 26 bit intervals.
The offset word is a 1-bit rate clock (840
It is obtained by dividing the 26-bit data by the generator polynomial during (μsec).

The condition for determining whether or not synchronization has been established is that there is a possibility that incorrect synchronization may occur due to a data error due to noise, multipath distortion, or the like, or a false offset word accidentally included in the RDS signal itself. Will be taken into consideration. The process until synchronization is achieved, that is, the introduction of synchronization is performed as follows, for example. First, a division by a generator polynomial is performed for each bit of the received RDS signal.
F Repeat until either offset word matches. When the offset word can be detected, the result of division every 26 bits is extracted starting from that point, and it is confirmed whether it is the correct offset word and the correct order. For example, when the correct result is detected 5 times before the erroneous result is detected 8 times, it is determined that the synchronization can be detected. If 8 detections of false results are faster than 5 detections of correct results, the introduction process is repeated from the beginning.

Once group synchronization is achieved, the receiver
The error detection / correction of each block data is performed while predicting the next offset word. If the offset word predicted for 5 blocks or more in succession cannot be identified, it is determined that the synchronization is lost, and the synchronization introduction mode is entered again. When the group synchronization is established and the error detection / correction is completed, the PI code is fetched from the data of the first block in the received / corrected received RDS data. Thus, PI code detection from the RDS signal received by the newly set reception frequency is achieved.

As described above, in the conventional network follow, group synchronization is performed every time the tuning at the reception frequency set sequentially and the presence of the broadcast wave are confirmed, and comparison is made from the RDS data after error correction. For P
The I code is detected. Therefore, the receiver performing the network follow based on the PI code is
The longer the time taken for such group synchronization and error correction, the longer the time spent for network follow-up. It will take time.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a method capable of reducing the time spent for network follow and an RDS for executing the method. To provide a receiver.

[0012]

A network follow processing method according to the present invention provides a broadcast signal, network identification data for identifying a network to which the broadcast signal belongs, and a frequency of a broadcast signal transmitted from a broadcasting station belonging to the network. Receiving an RDS broadcast wave multiplexed with RDS data including alternative frequency data represented, demodulating the network identification data and the alternative frequency data in advance, and storing the alternative frequency data in a memory for each network, When the network follow activation command is issued while the network to be tuned is set, the alternative frequency data corresponding to the set network is read from the memory, and the tuning process is performed based on the read alternative frequency data. Network follow processing method, A channel selection control process for performing channel selection control at a reception frequency corresponding to the alternative frequency data read from the memory, and one block of the RDS data from the broadcast wave received by the channel selection control process. And a block comparison process for performing coincidence comparison between the RDS data for one block captured by the reception data capturing process and the block data including network identification data for identifying the set network. And it is recognized that the broadcast wave transmitted from the broadcast station belonging to the setting network is received when it is determined that they match each other in the block comparison process.

[0013]

According to the network follow processing method of the present invention, one block of RDS data is fetched from the broadcast wave selected and received, and the set network to which the fetched RDS data and the broadcast station to be selected belong. Matching comparison is performed with block data including network identification data for identifying, and if they match each other, it is recognized that a broadcast wave transmitted from a broadcasting station belonging to the setting network has been received.

[0014]

The present invention will be described in detail below with reference to the drawings. FIG. 2 is a schematic block diagram showing the basic configuration of the RDS receiver according to the embodiment of the present invention. In the figure,
F multiplexed with the RDS signal received by antenna 1
For the M broadcast wave, the radio wave of the desired broadcast station is selected in the front end 2 and the intermediate frequency (I
F) and is amplified by the IF amplifier 3. The front end 2 has a mixer 2a and a PLL circuit 2b, and obtains a local oscillation signal to the mixer 2a by a PLL synthesizer method using a PLL path 2b including a programmable frequency divider (not shown), The frequency division ratio of the programmable frequency divider is controlled by the controller 10 which will be described later to perform a tuning operation.

The FM signal of 10.7 MHz amplified by the IF amplifier 3 and sufficiently limited is processed by the FM detector 4.
Is converted into an audio signal by the stereo demodulation circuit 5 and is separated into L (left) channel and R (right) channel audio signals in the case of stereo broadcasting by the stereo demodulation circuit 5 and output as a reproduced audio signal through the muting circuit 6. Further, the level detector 7 that detects the received signal level (electric field strength) based on the IF signal level in the IF amplifier 3.
And a station that outputs a station detection signal indicating that a reception station is detected when the reception signal level is equal to or higher than a predetermined level and the detection output of the S-shaped curve characteristic of the FM detector 4 is within the predetermined level range. A detector 8 is provided.

In addition, from the detection output of the FM detector 4, RDS
An RDS signal detector 9 for detecting a signal (data) is provided, and RDS data output from the RDS signal detector 9, a received signal level output from the level detector 7 and a station detector 8 are provided. The station detection signal that is output is
Both are supplied to the system controller 10 having a microcomputer configuration.

The controller 10 fetches the information word of each block in the RDS signal input in group units, that is, PI code, AF data, PS data, etc. and stores them in the memory 11. The memory 11 serves as a storage unit that stores, for each network, alternative frequency data (AF data) representing a frequency of a broadcast signal belonging to the network as an AF list. In addition, based on a tuning command accompanied by a reception frequency from the operation unit 12 or based on AF data read from the AF list at the time of network follow-up, the frequency division ratio of the programmable frequency divider constituting the front end is set. By controlling, a desired broadcast station or another broadcast station of the same network as the broadcast station being received is selected. Also, it outputs a switching signal for turning on the muting circuit 6 at the time of tuning. The operation unit 12 and the display unit 13 are provided on the front panel of the RDS receiver. As a result of automatic channel selection processing such as network follow, the display unit 13 does not detect the network identification data for identifying the network corresponding to the designated channel (that is, the network to be tuned), that is, the PI code, when the designated channel is not detected. Is responsible for notifying that the broadcast of the network corresponding to is unreceivable, and displays according to the display control signal from the system controller 10.

The specific structure of the RDS signal detector 9 is shown in FIG. In FIG. 3, the detection output of the FM detector 4 passes through the filter 14 and is amplitude-modulated by the biphase-coded data signal.
Hz subcarrier, that is, RDS signal component is extracted and P
It is demodulated by the LL circuit 15. This demodulated output is supplied to the digital (D) PLL circuit 16 and the decoder 17. The D-PLL circuit 16 generates a data demodulating clock based on the demodulated output of the PLL circuit 15. The generated clock is supplied to the gate circuit 18. The lock detection circuit 19 detects that the D-PLL circuit 16 is locked, generates a lock detection signal, supplies the lock detection signal to the gate circuit 18, and controls the circuit 18 to be in an open state. In the decoder 17, the PLL circuit 15
The bi-phase coded data signal, which is the demodulation output of, is decoded in synchronization with the clock generated by the D-PLL circuit 16.

As shown in FIG. 1, the output data of the decoder 17 is composed of four blocks of 26 bits 104.
It is a group unit series of bits and is sequentially supplied to the block / group synchronization & error detection circuit 20. The block / group synchronization & error detection circuit 20 establishes group synchronization with the block based on the 10-bit offset word assigned to the 10-bit check word of each block, and also provides 16-bit information based on the check word. Word error detection is performed. Then, the data in which the error is detected is error-corrected by the error correction circuit 21 in the next stage and then supplied to the controller 10.

However, control signals are supplied to the circuits 20 and 21 from the system controller 10, respectively.
The output data of the decoder 17 is kept as it is under the control of the system controller 10 as will be described later, and therefore the RDS in which each synchronization and error detection / correction are not performed.
It may be output as received data. In the RDS receiver having such a configuration, the system controller 10 receives the reception frequency data value that determines the frequency division ratio of the programmable frequency divider of the PLL circuit 2b in response to the user's tuning operation (or channel recall) of the operation unit 12. A channel selection operation is performed by controlling.

If a broadcast wave from one broadcast station A belonging to a certain network is selected and the broadcast wave is received, a signal indicating the signal level of the received radio wave is obtained from the level detector 7. Also, station detection signals are obtained from the station detector 8, and these signals are supplied to the system controller 10. From the RDS signal, data such as PI code, AF data, and PS data is fetched by the system controller 10 via the RDS signal detector 9 and written in the memory 11. By writing to the memory 11, a predetermined storage area of the memory 11 stores the broadcast waves transmitted by n broadcast stations belonging to the network to which the broadcast station A currently transmitting the broadcast wave belongs. The frequencies f ₁ , f ₂ , ..., F _n are stored as an AF list.

Next, an example of a network follow processing procedure executed by the system controller 10 in the RDS receiver will be described with reference to the flowchart of FIG. In FIG. 4, the controller 10 is
When the reception condition of the broadcast wave deteriorates, or when a command for selecting one of the broadcasting stations belonging to the network corresponding to the preset channel is received, the network follow process is activated, First, a mute command signal is supplied to the audio mute, that is, the muting circuit 6 so as to cut off the output of the audio signal obtained by reception (step S11).
Next, tuning control is performed based on the AF list established in advance in the memory 11 (step S12). This is responsible for the tuning control process, reads one of the AF data corresponding to the PI code (set PI code) set before the start of the network follow from the memory 11, and receives the reception frequency according to the read AF data. PLL circuit 2
This is the control set to b. In the front end 2, the tuning operation for the set reception frequency is performed by this control. And P
As a wait time for stabilizing a so-called reception system including the LL circuit 2b, a first predetermined time is waited (step S13).

After the wait time has elapsed, the controller 10 determines whether or not the receiving system has been able to receive the broadcast wave (step S14). Here, the received signal level obtained from the level detector 7 exceeds a predetermined level, and the broadcast wave can be received only when the station detector 8 detects a station (current reception point or reception environment can be received. It is determined that there is a broadcasting station that transmits a broadcast wave), but it is also possible to make a determination using only the level detector 7.

When it is determined in step S14 that the broadcast wave can be received, the controller 10 determines the output RDS data D _R of the decoder 17 in the RDS signal detector 9 based on the broadcast wave reception signal (FM detection output). 1
The blocks are fetched (step S15). This step is responsible for the reception data acquisition process, and the data D _R is data before block and group synchronization and error detection / correction (data by differential decoding output, or data detected by block). This is realized by supplying a control signal from the controller 10 to each circuit so that the predetermined processing is not executed in the error detection circuit 20 and the error correction circuit 21.

Next, the controller 10 reads from the memory 11 the block data D _S containing the PI code (setting PI code) corresponding to the network station to be selected. This set PI code is the PI code that is already held before the start of network follow, and more specifically, the PI code specified by the user from the operation unit 12 or the memory 11 in response to the preset channel recall described above. It is the PI code read from or the PI code included in the broadcast wave received before the start of this network follow. Also, the block data D _S
Is block data having the set PI code, that is, 1
All of the 26-bit data of the first block in one group is held in the memory 11 or only the amount necessary for the comparison processing in step S17 described later. That is, the data of one block or more includes the group type data of the second block, and since it is not possible to perform coincidence comparison, the comparison target is one block (26 bits) at the maximum.
Becomes Since the PI code is 16 bits,
The minimum is 16 bits.

From the memory 11, the block data D
_S Is read, the block comparison process
LA 10 is for one block captured in step S15
Data D_R And the block data read in step S16
TA D_S Is compared (step S17). Comparative
Result, data D_R And data D_S Is a disagreement with
When the determination is made, the controller 10 determines the broadcast wave reception signal.
In the RDS signal detector 9 based on (FM detection output)
Output RDS data D of the decoder 17_R 1 bit
Then, one block is loaded (step S18).
Then, by the timed processing of step S19, the second predetermined time
Data D until time passes_R And data D _S Match comparison with
And data D_R 1-bit shift is repeated. Ste
As a result of the comparison in step S17, the contents of each data match each other.
If it is determined that the broadcast wave is received, the received broadcast wave is
Have a network, that is, belong to the desired network
It is judged that it was transmitted from the broadcasting station, and the received audio is output.
As a power stroke, the muting circuit 6 is muted.
The mute command signal is erased to cancel the
Step S20). This ensures that the broadcast wave is received and
Has confirmed that the broadcast wave of has the set PI code
The broadcast sound is output above.

If the broadcast wave cannot be received in step S14, the PI code matching control is not performed and the process proceeds to step 12 to perform channel selection control based on a new AF list. In step S19, if the predetermined time has passed, that is, even if the predetermined time has passed, the data D
_If the match between _R and the data D _S cannot be determined, the broadcast wave was received but the received broadcast wave was set to PI.
It is determined that the data is transmitted from a broadcasting station that does not have a code and belongs to a different network, and the process proceeds to step S12.
In step S12, each time the processing (tuning control at the reception frequency according to one AF data) is executed, the AF data different from the AF data read from the memory 11 last time is displayed.
The reception frequency corresponding to the F data is set in the PLL circuit 2b.

Therefore, among the reception frequencies corresponding to the AF data included in the AF list, only when the reception frequency capable of receiving the broadcast wave having the set PI code is set in the PLL circuit 2b, the reception is performed via step S20. Audio output by broadcast waves will be performed. In addition, the presence or absence of the set PI code when the broadcast wave is received is checked without group synchronization, and the received RDS data D _{R for} one block is detected by the block detection before error detection / correction. And the block (first block) data including the set PI code that is held in advance. Therefore, the time required for synchronization detection is reduced as compared with the conventional technology in which the presence or absence of the PI code is confirmed after the group synchronization is performed, and the time required for the PI code detection is eliminated because the correction processing of the RDS data is unnecessary. Shortened. Thus, not only the time until the broadcast wave having the set PI code is received and the audio output of the broadcast is made, but also the time spent for the network follow can be significantly reduced.

FIG. 5 shows another example of the network follow processing procedure executed by the system controller 10 in the RDS receiver. 5, the same parts as those in FIG. 4 are designated by the same reference numerals, and different parts are as follows.
An arrival discrimination processing step S31 of a predetermined channel selection timing is executed immediately after the network follow is activated.

This step S31 is responsible for the timing detection process, and after the network follow is activated, and after step S19-YES has been passed in order to perform the tuning operation by the new AF data, the step S31.
This is to measure the timing of shifting to the processing from 11 onward, and will be specifically described with reference to FIGS. 6 and 7. FIG. 6 is a conceptual diagram showing a form of a broadcast network constructed using the same RDS encoder (RDS data generation circuit). The output of the encoder 1 is for transmitting broadcast waves to at least area A. And a transmitting antenna 3 for transmitting a broadcast wave to the B area are supplied via a cable. Broadcast signals including RDS data supplied to each transmission antenna are radiated as broadcast waves, and these are captured by, for example, an RDS receiver mounted on an automobile.

In this case, the RDS received by the RDS receiver
The data is as shown in FIG. In FIG. 7, (a) shows R obtained by receiving the broadcast wave radiated from the transmitting antenna 2.
DS data, and (b), RDS data obtained by receiving the broadcast wave radiated from the transmitting antenna 3 are shown in time series. As shown in this figure, RD of (a)
A difference in propagation delay occurs between the S data and the RDS data in (b) due to the difference in the propagation path from each transmission antenna (strictly speaking, from the encoder 1) to the RDS receiver. However, it can be considered that there is practically no such delay difference,
It is very effective to set the channel selection timing as described below.

That is, the arrival of the predetermined channel selection timing as shown in FIG. 7 is detected before proceeding to step S11 (FIG. 5). This detection is performed using the timing of block synchronization performed before the start of this network follow. In such block synchronization, the first block (A) having the PI code, the second, third, and fourth blocks (B, C, D), and these are sequentially received upon recognition by the system controller 10. Can be predicted. Further, based on this block synchronization, processing for synchronizing each bit of the block data is also performed at the same time.

On the premise of such synchronization processing, the predetermined channel selection timing in step S31 is determined, and in step S31, the time point that is traced back from the time point of receiving the first bit of block A by the time period required for the channel selection operation from step S11 to step S14. It is determined whether (predetermined channel selection timing) has arrived. As a result, at the time of shifting to step S15, since the head bit of block A is received, all the data of block A is fetched in step S15. Therefore, the data of the first block can be taken in immediately after the completion of the tuning operation,
The confirmation processing of the set PI code can be performed quickly, and the audio mute in step S11 is activated in the shortest time, which contributes to shortening the mute time.

FIGS. 8 and 9 show still another example of the network follow processing procedure executed by the system controller 10 in the RDS receiver, and the same parts as those in FIG. 5 are designated by the same reference numerals. In this embodiment,
A broadcast wave having the set PI code is received, and step S2
When the audio mute is canceled at 0, the reception RDS data corresponding to the next three blocks is taken in (step S52), and it is determined whether or not the synchronization is established (step S53). To control. This determination is an example of the synchronization circuit 20 based on the group synchronization detection rule as described in the section of the prior art, and includes A to D of the received RDS data of 3 blocks captured in step S52. If any two offset words can be confirmed, it is determined that synchronization has been achieved. When the synchronization circuit 20 determines that the synchronization is not achieved in step S53, the controller 20 receives this and shifts to step S52 until a predetermined time elapses (step S54), shifts by 1 bit, and again for 3 blocks. Capture the received RDS data of.

In this synchronization introduction process, step S5
When it is determined that synchronization has been achieved by 3, the error correction circuit 2 performs an error correction process as an error correction process.
A control signal is generated at 1 (step S55). And
The PI code existing in the first block is fetched from this error-corrected RDS data (step S56), the fetched PI code (reception PI code) is compared with the set PI code, and it is determined whether or not they match. Is determined (step S57). As a result of the comparison in the final comparison process, if it is determined that they match, the controller 1
0 determines that the broadcast wave having the set PI code is officially received with synchronization detection, finishes the network follow, and shifts to the steady reception mode instructed in the main flow not shown.

When the predetermined time has elapsed in step S54, that is, when the predetermined time has elapsed and synchronization has not been achieved, or the received PI code obtained after error correction in step S57 does not match the set PI code. In this case, step S31, which is the timing detection process.
Move to In this case, it is rare because, after confirming the set PI code once in step S17, synchronization cannot be established or the received PI code after error correction does not match the set PI code.

Thus, in this embodiment, after the broadcast wave having the set PI code is received based on the received RDS data before the error correction and the audio mute is released, the synchronization introduction process is performed and the received RDS data after the error correction is further obtained. Based on the confirmation of the set PI code, the system shifts to the steady reception mode. Therefore, the PI code can be confirmed as accurately as the conventional one in a short mute time.

In the above embodiment, the received voice output is muted during network follow. However, the present invention is not limited to this, and the present invention can be applied to network follow without such mute. Yes, it has a considerable effect.

[0039]

As described in detail above, according to the network follow processing method of the present invention, one block of RDS data is fetched from the broadcast wave that has been selected and received, and the fetched RDS data and tuning are selected. The block data including the network identification data that identifies the setting network to which the broadcasting station to be performed is matched and compared. If they match each other, the broadcast wave transmitted from the broadcasting station that belongs to the setting network has been received. Is recognized,
The time spent following the network can be reduced.

[Brief description of drawings]

FIG. 1 is a baseband RDS data configuration diagram.

FIG. 2 is a block diagram showing a basic configuration of an RDS receiver according to an embodiment of the present invention.

3 is a block diagram showing a specific configuration of an RDS signal detector in the RDS receiver shown in FIG.

4 is a flowchart showing an example of a network follow processing procedure executed by a system controller in the RDS receiver shown in FIG. 2;

5 is a flowchart showing another example of a network follow processing procedure executed by the system controller in the RDS receiver shown in FIG. 2;

6 is a conceptual diagram showing an example of the form of a broadcast network when the processing based on the flowchart of FIG. 5 is enabled.

7 is a diagram (a) showing RDS data obtained in time series by receiving the broadcast wave radiated from the transmission antenna 2 in the form of FIG. 5, and the broadcast wave radiated from the transmission antenna 3 is received. The figure which shows the RDS data obtained by doing in a time series (b).

FIG. 8 is a first flowchart (flow to audio mute release processing) showing still another example of the network follow processing procedure executed by the system controller in the RDS receiver of FIG. 2;

FIG. 9 is a second flowchart (synchronization introduction processing flow) showing still another example of the network follow processing procedure executed by the system controller in the RDS receiver of FIG. 2;

[Explanation of symbols for main parts]

 1 antenna 2 front end 2a mixer 2b PLL circuit 3 IF amplifier 4 FM detector 5 stereo demodulation circuit 6 muting circuit 7 level detector 8 station detector 9 RDS signal detector 10 system controller 11 memory 12 operation unit 13 display unit 14 Filter 15 PLL 16 D-PLL 17 Decoder 18 Gate 19 Lock Detector 20 Block Synchronization, Group Synchronization and Error Detection Circuit 21 Error Correction Circuit

Claims (6)

[Claims] 1. A broadcast signal and RDS data including network identification data for identifying a network to which the broadcast signal belongs and RDS data including alternative frequency data representing a frequency of a broadcast signal transmitted from a broadcast station belonging to the network are multiplexed. RDS broadcast wave is received, the network identification data and the alternative frequency data are demodulated in advance, the alternative frequency data is stored in the memory for each network, and a network follow start command is issued while the network to be selected is set. Is issued, the alternative frequency data corresponding to the set network is read from the memory, and a channel follow-up processing method for performing tuning processing based on the read alternative frequency data is read from the memory. Reception according to the alternative frequency data Channel selection control process for performing channel selection control by wave number, reception data acquisition process for acquiring a predetermined number of bits of the RDS data from the broadcast wave selected and received by the channel selection control process, and reception data acquisition process A block comparison step of performing a coincidence comparison between the RDS data for a predetermined number of bits taken in by RDS data and RDS data including network identification data for identifying the set network, and the block comparison step matches each other in the block comparison step. When it is determined, it is recognized that the broadcast wave transmitted from the broadcast station belonging to the setting network is received, and the network follow processing method. 2. The network follow processing method according to claim 1, further comprising: a reception voice output step of canceling interruption of reception voice output when it is determined by the block comparison step that they match each other. . 3. A timing detection process executed before the tuning control process, for detecting a predetermined tuning timing after the network follow process is activated, wherein the tuning control process includes the timing of the predetermined tuning timing. The network follow processing method according to claim 1 or 2, which is executed in response to the detection. 4. A synchronization introduction step of introducing synchronization after the reception voice output step, an error correction step of performing error correction of the received RDS data after synchronization is achieved by the synchronization introduction step, and an error correction step of Corrected reception R
A final comparison step of taking network identification data from the DS data and performing a coincidence comparison with the network identification data for identifying the set network, and the timing detection step if different from each other is determined by the final comparison step. 4. The network follow processing method according to claim 3, wherein the network follow processing is performed. 5. The reception RDS is the predetermined channel selection timing.
5. The network follow processing method according to claim 3, wherein the time is a time point that is traced back from the time point when the first bit of the first block of data is received by the time required for the channel selection operation in the channel selection control process. 6. An RDS receiver performing the network follow processing method according to claim 1, 2, 3, 4 or 5.