JP2788015B2 - RDS broadcast receiver - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to receiving a multiplex broadcast wave on which alternative frequency data of at least one broadcast station belonging to the same network and program identification data corresponding to the network are superimposed, and receiving the multiplex broadcast wave. A radio data system having a function of holding alternative frequency data and program identification data obtained from a wave and selecting one of the alternative frequency data of broadcast stations belonging to the same network as the set network based on the held data The present invention relates to a preset receiver (hereinafter, referred to as an RDS preset receiver).

2. Description of the Related Art At the time of program broadcasting of a general broadcasting station, broadcast-related information such as information related to the program content is transmitted as data by multiplex modulation, and the desired program content is demodulated on the receiving side based on the data. There is a radio data system (RDS) that allows the user to select a service and provide that service to radio listeners.

In this radio data system, 57 kHz, which is the third harmonic of the 19 kHz stereo pilot signal outside the frequency band of the FM modulated wave, is used as a subcarrier, and the subcarrier is filtered and biphase coded. A radio data signal is amplitude-modulated by a data signal indicating information related to broadcasting such as contents, and the amplitude-modulated sub-carrier is frequency-modulated to a main carrier for broadcasting. Has been proposed by the European Broadcasting Union (EBU).

As is clear from FIG. 3 showing the baseband coding structure of the radio data signal, 104 bits correspond to 1 bit.
It is repeatedly multiplexed and transmitted as a group. One group is composed of four blocks each having a 26-bit configuration, and each block is composed of a 16-bit information word and a 10-bit check word. Each group is classified into 16 types of types 0 to 15 by 4 bits according to the contents, and two versions of A and B are defined for each type (0 to 15).

FIGS. 4 (a) and 4 (b) show the formats of the type 0A and 0B groups, respectively. In the type 0A group (a), block 1 includes 16-bit program identification data (hereinafter referred to as PI data) including a country code, an area code, and a program code, and block 2 includes a group type code and a version code. (B ₀ ), various codes such as a traffic information broadcasting station identification (TP) code and a program content identification (PTY) code are stored in block 3 as station frequency data (hereinafter referred to as AF) of a network station broadcasting the same program. In the block 4, broadcast station name data (hereinafter, abbreviated as PS data) is arranged.
On the other hand, in the type 0B group (b), block 3
Is different from the type 0A group.
In block 3, PI data is arranged. That is,
The AF data of the network station is transmitted only in the type 0A group, and the PS data is transmitted in the type 0A and 0B groups.

As described above, the radio data signal of the type 0A group includes the AF data of the network station that is broadcasting the same program as the currently receiving broadcast station. Therefore, during reception, the AF data and PI
Take in the data and store it as an AF list. Select another station,
In addition, the so-called network follow (Netw
With the ork follow function, the same program can always be heard in a good reception state without being affected by disturbance.

By the way, the RDS preset receiver includes a preset channel memory having a storage area corresponding to each of a plurality of preset stations, and each storage area of the preset channel memory includes AF data indicating a reception frequency of each preset station, A plurality of AF data (AF list) and PI data of the same network station group superimposed on the broadcast wave of the preset station are stored. Then, when any one of the preset stations is selected together with the channel selection command and the reception sensitivity is low, the network follow processing is performed based on the AF list corresponding to the preset station.

In this RDS preset receiver, when selecting a preset station, conventionally, once in the receiving state of the designated preset station, the received signal level is checked, and the network follow processing is performed for the first time when the received signal level is lower than the set level. Was supposed to run. Therefore, if the reception status of the designated preset station is poor, the network follow processing is performed after a sound such as noise is output once, which gives the user a sense of discomfort. Further, when the received signal level is equal to or higher than the set level, the preset station is selected and received, so that a station having PI data different from the PI data preset in the preset channel memory is received as it is, and the user desires. There is a case where a broadcast different from the broadcast is selected.

SUMMARY OF THE INVENTION [Object of the Invention] Accordingly, the present invention provides a method for selecting a preset station by outputting noise or the like without obtaining a corresponding broadcast sound until a broadcast corresponding to the preset station is received. It is an object of the present invention to provide a broadcast receiver that can eliminate a sense of discomfort at the time of broadcasting.

[Configuration of the Invention] A receiver according to the present invention receives a multiplex broadcast wave on which alternative frequency data of at least one broadcast station belonging to the same network and program identification data corresponding to the network are superimposed, and receives the received multiplex broadcast wave. RDS broadcast receiver having a function of holding the alternative frequency data and the program identification data obtained from, and selecting one of the reception frequencies of the broadcasting stations belonging to the same network as the setting network based on the held data. A preset reception frequency memory for storing preset frequency data and the alternative frequency data corresponding to the preset station and the program identification data for each preset station; and a tuning command for starting tuning of any of the preset stations. And a voice muting operation in response to the channel selection command. Muting activation means for starting operation, and reading out the program identification data corresponding to the preset target station selected by the channel selection command from the preset reception frequency memory, and reading the preset frequency data of the channel target. A first tuning means for performing a first tuning process for reading and setting a receiving frequency indicated by the read preset frequency data; and a receiving level of a received broadcast wave in the first tuning process. A broadcast station corresponding to a reception frequency set when it is determined that the program identification data included in the broadcast wave is equal to or higher than a predetermined level and matches the program identification data read from the preset reception frequency memory. As a confirmed broadcast station, and first control means for continuing to select the detected confirmed broadcast station; When the first control means cannot detect the confirmed broadcast station with respect to the broadcast wave received by the first tuning process, the tuning target of the tuning target guided by the tuning command from the preset reception frequency memory. A second tuning unit that sequentially reads alternative frequency data and performs a second tuning process for setting a reception frequency indicated by the read alternative frequency data; and a broadcast received in the second tuning process. A reception frequency set when it is determined that the reception level of the wave is equal to or higher than a predetermined level and the program identification data included in the broadcast wave matches the program identification data read from the preset reception frequency memory. Second control means for detecting a broadcasting station corresponding to the determined broadcasting station as a confirmed broadcasting station, and allowing the detected confirmed broadcasting station to continue tuning. It is characterized in that in response to the detection; and a muting releasing means for releasing the audio muting operation.

According to the receiver of the present invention, preset frequency data, alternative frequency data, and program identification data corresponding to each preset station are stored in the memory, and any one of the preset stations is stored in the memory. Is issued, the program identification data corresponding to the preset station to be tuned is read out from the memory, and the preset frequency data or the alternative frequency data is sequentially read out therefrom, and the corresponding reception is performed. A tuning process for setting a frequency is performed. In this channel selection processing, it is first determined that the reception level of the received broadcast wave is equal to or higher than a predetermined level and that the program identification data included in the received broadcast wave matches the program identification data read from the memory. Then, the broadcast station corresponding to the reception frequency set at this time is detected as the confirmed broadcast station, and the selection of the confirmed broadcast station is continued. An audio muting operation is performed during the period from the generation of the channel selection command to the detection of the confirmed broadcasting station.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram schematically showing a basic configuration of an RDS preset receiver to which a tuning method according to the present invention is applied. In the figure, a desired station is selected by a front end 2 from an FM multiplex broadcast wave received by an antenna 1 and converted to an intermediate frequency (IF).
Supplied to The front end 2 adopts, for example, a PLL synthesizer method using a PLL circuit including a programmable frequency divider, and performs a channel selection operation by controlling the frequency division ratio of the programmable frequency divider by a controller 13 described later. Has become. The detection output of FM detector 4 is MP
The signal is supplied to an X (multiplex) demodulation circuit 5, and is separated into L (left) and R (right) channel audio signals in the case of a stereo broadcast, and becomes a reproduced audio output via a muting circuit 18. On / off control of the muting circuit 18 is performed by the controller 13.

When the detection output of the FM detector 4 passes through the filter 6, a 57 KHz subcarrier amplitude-modulated by the biphase-coded data signal, that is, a radio data signal is extracted and demodulated by the PLL circuit 7. . This demodulated output is supplied to a digital (D) PLL circuit 8 and a decoder 9.
Supplied to In the D-PLL circuit 8, a clock for data demodulation is generated based on the demodulated output of the PLL circuit 7. The decoder 9 decodes the biphase-coded data signal having the demodulated output of the PLL circuit 7 in synchronization with the clock generated by the D-PLL circuit 8. The lock detecting circuit 10 detects the locked state and the unlocked state of the D-PLL circuit 8, and outputs the PLL circuit 7 and the D-PLL based on the detection output.
The lock range of the circuit 8 is switched and controlled.

As shown in FIG. 3, the output data of the decoder 9 is in units of 104 bits consisting of four blocks each having a 26-bit configuration, and is sequentially supplied to the group / block synchronization & error detection circuit 11. The group / block synchronization & error detection circuit 11 synchronizes the group with the block based on the 10-bit offset word assigned to the 10-bit check word of each block, and 16-bit information based on the check word. Word error detection is performed. Then, the error-detected data is supplied to the controller 13 after the error is corrected by the error correction circuit 12 at the next stage.

The controller 13 is constituted by a microcomputer, and reads AF data indicating the reception frequency of the currently receiving broadcast station read from data sequentially input in groups from the error correction circuit 12 by key input of the preset key 15a on the operation unit 15. The AF data of one preset station is stored in a predetermined area of the memory 14, and a plurality of AF data of the same network station group superimposed on the broadcast wave is used as an AF list, and the PI data corresponds to each preset station. When the preset station is selected by inputting any one of the preset station keys 15b of "1" to "6", the AF data of the designated preset station is stored in the memory area.
A tuning operation is performed by reading from 14 corresponding storage areas and controlling a frequency division ratio of a programmable frequency divider (not shown) of a PLL circuit constituting a part of the front end 2 based on the AF data. Further, when the designated preset station cannot be received due to the deterioration of the reception state, a network follow function for selecting the same network station having a good reception state based on the AF list corresponding to the preset station is executed.

Also, a level detection circuit 16 for detecting a reception signal level (electric field strength) based on the IF signal level in the IF amplifier 3.
And a station detection circuit for detecting a receiving station and outputting a station detection signal when the IF signal level in the IF amplifier 3 is equal to or higher than a predetermined level and the detection output of so-called S curve characteristics in the FM detector 4 is within a predetermined level range. 17 is provided,
The received signal level detected by the level detection circuit 16 and the station detection signal output from the station detection circuit 17 are supplied to the controller 13.

Next, the processing procedure at the time of preset channel selection executed by the processor of the controller 13 will be described with reference to the flowchart of FIG. Note that this routine is called and executed by a preset channel selection command by inputting any one of the preset station keys 15b of “1” to “6” on the operation unit 15.

In response to the preset channel selection command, the processor first turns on the muting circuit 18 to mute the audio (step S1), then reads out the AF data of the designated preset station from the corresponding storage area of the memory 14 and reads the AF data of the designated preset station. The signal is output to a PLL circuit (not shown) in the end 2 (step S2), and at the same time, a PLL timer for a time necessary for the PLL circuit to lock is set (step S3). The AF data supplied to the PLL circuit is set in a programmable frequency divider in the PLL circuit, so that the reception frequency changes to the frequency of the designated preset station until the PLL timer times out.

After the expiration of the PLL timer (step S4), the processor determines whether or not the broadcast of the preset station is an RDS broadcast (step S5).
The received signal level Vs of the DS station is taken in from the level detection circuit 16 (step S6). Whether or not it is an RDS broadcast can be determined by whether or not radio data can be taken from the error correction circuit 12. Next, the processor determines whether or not the received reception signal level Vs is equal to or higher than the set level Vth (step S7). If the received signal level Vs is equal to or higher than the set level Vth, the processor sets a PI timer for a predetermined time (step S8). Then, PI data of the RDS station is taken in (step S9).

When the PI timer times out (step S10),
The processor performs a PI check to determine whether or not the captured PI data matches the PI data preset in the memory 14 in advance corresponding to the designated preset station (step
S11) If the PI data match, the muting circuit 18 is turned off to release the audio mute (step S12). As a result, the received signal level becomes the set level V
This means that the same RDS station as the PI data whose PI data is not less than th and whose preset PI data is selected is selected.

If it is determined in step S5 that the broadcast is not an RDS broadcast,
In step S7, the received signal level Vs is set to the set level Vth
If it is determined that the PI data is less than or equal to the PI data in step S11, the processor
First, the AF data of the AF list stored in advance corresponding to the designated preset station is read out (step S13), and this AF
Data is output to the PLL circuit (step S14), and the PLL is
The timer is set (step S15).

After the expiration of the PLL timer (step S16), the processor determines whether or not there is a receiving station by monitoring the output of the station detection signal from the station detecting circuit 17 (step S17). If so, the received signal level Vs of the receiving station is fetched (step S18), and it is determined whether the received signal level Vs is equal to or higher than the set level Vth (step S19). If the received signal level Vs is equal to or higher than the set level Vth, the processor determines whether or not the broadcast of the receiving station is an RDS broadcast (step S20).
If it is a broadcast, capture the PI data (step S2
1) Then, a PI check is performed to determine whether or not the fetched PI data matches the PI data preset in the memory 14 (step S22).

If it is determined in step S17 that there is no receiving station, if it is determined in step S19 that the received signal level Vs is less than the set level Vth, or if it is determined in step S22 that the PI
If the data is determined to be inconsistent, the processor
It is determined whether or not the network follow processing has been completed for all of the lists (step S24). If not, the process returns to step S13 to repeat the above-described processing. If it is determined in step S22 that the PI data matches, the processor turns off the muting circuit 18 and cancels the audio mute (step S2).
3). By this network follow processing, the RD of the reception frequency given by any one of the AF data in the AF list
This means that an S station whose received signal level Vs is equal to or higher than the set level Vth and whose PI data obtained from the broadcast wave matches preset PI data is selected.

If it is determined in step S24 that the network follow has been completed without finding a broadcast corresponding to all of the AF list, the processor reads the AF data of the preset station designated this time from the corresponding storage area of the memory 14 again ( In step S25, the AF data is output to the PLL circuit (step S26). At the same time, the PLL timer is set (step S27), and after the time is up (step S2).
8), the muting circuit 18 is turned off to release the audio mute (step S29). As a result, the received signal level Vs is set to the set level Vth by the network follow processing based on the AF list corresponding to the designated preset station.
If the RDS station whose PI data obtained from the broadcast wave matches the preset PI data cannot be received, the reception frequency of the broadcast wave not received at the time of the previous preset even if the reception condition is poor. That is, the designated preset station is selected at the reception frequency corresponding to the AF data read first in step S2.

Effects of the Invention As described above, according to the receiver of the present invention, preset frequency data and alternative frequency data and program identification data corresponding to each preset station are stored in the memory for each preset station. When any one of the station selection commands is issued, the program identification data corresponding to the preset station to be selected is read out from the memory, and the preset frequency data or the alternative frequency data is sequentially read out therefrom. , A channel selection process for setting the corresponding reception frequency is performed. In this channel selection processing, it is first determined that the reception level of the received broadcast wave is equal to or higher than a predetermined level and that the program identification data included in the received broadcast wave matches the program identification data read from the memory. Then, the broadcast station corresponding to the reception frequency set at this time is detected as the confirmed broadcast station, and the selection of the confirmed broadcast station is continued. An audio muting operation is performed during the period from the generation of the channel selection command to the detection of the confirmed broadcasting station.

As a result, a network program corresponding to the preset station to be selected and a broadcast having good reception sensitivity can be obtained during the audio mute, so that noise or the like is output until the channel selection is completed as in the related art. This can eliminate the sense of discomfort to the user caused by the above. Further, since the alternative frequency data is used for selecting a preset station, it is efficient without setting useless reception frequencies.

In addition, since the broadcast station whose reception level is equal to or higher than the predetermined level and the program identification data included in the received broadcast wave is determined to be appropriate as soon as possible after the generation of the preset channel selection command is determined as the determined broadcast station, the channel selection is continued. In addition, the time required to apply the audio mute can be shortened, and the sense of discomfort to the user due to the interruption of the audio can be reduced. In addition, there is an advantage that the channel selection based on the preset frequency data can be preferentially performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of an RDS preset receiver to which a tuning method according to the present invention is applied, and FIG. 2 shows a processing procedure at the time of preset tuning which is a tuning method according to the present invention. FIG. 3 is a diagram showing a baseband coding structure of radio data, and FIG. 4 is a diagram showing a format of group types 0A (a) and 0B (b). Explanation of main parts 2... Front end, 4... FM detector 5... Multiplexer multiplexer circuit 8... Digital PLL circuit 13... Controller, 14.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Osamu Shishido, Inventor, 25-1, Nishimachi, Kawada-shi, Kawagoe-shi, Saitama Prefecture Pioneer Corporation Kawagoe Plant (72) Inventor Hideaki Kobayashi 25-1, Nishimachi, Yamada-shi, Kawagoe, Saitama Pioneer Inside the Kawagoe Plant Co., Ltd. (72) Keigo Nagai, 25-1, Nishimachi, Yamada, Kawaji-shi, Saitama Prefecture Pioneer Corporation Inside the Kawagoe Plant (72) Isao Matsumoto, 25-1, Nishimachi, Yamada, Kawagoe, Saitama Pioneer Corporation Kawagoe Plant (72) Inventor Koichi Kasa 25-1, Nishimachi, Yamada, Kawajie, Saitama Prefecture Pioneer Corporation Kawagoe Plant (72) Inventor Junichi Nishida 25-1, Nishimachi, Yamagata, Kawagoe, Saitama Pioneer Kawagoe Plant (72) Inventor Yukiyo Hirano 25-1 Nishimachi, Yamada, Kawagoe-shi, Saitama Onia Corporation Kawagoe Factory (56) References JP-A-64-54938 (JP, A) JP-A-64-55917 (JP, A) JP-A-57-95719 (JP, A) JP-A-1-151319 (JP, A)

Claims (2)

(57) [Claims] An alternative frequency data of at least one broadcast station belonging to the same network and a multiplex broadcast wave on which program identification data corresponding to the network are superimposed, the alternative frequency data obtained from the received multiplex broadcast wave, and RDS having a function of holding program identification data and selecting one of the reception frequencies of broadcasting stations belonging to the same network as the setting network based on the held data.
A broadcast receiver, for each preset station, a preset reception frequency memory for storing preset frequency data corresponding to the preset station, the alternative frequency data, and the program identification data; and selecting one of the preset stations. Channel selection command means for issuing a channel selection command to start the operation, muting activation means for starting an audio muting operation in response to the channel selection command, and a selection guided by the channel selection command from the preset reception frequency memory. The program identification data corresponding to the preset station to be read is read, the preset frequency data to be selected is read, and a first tuning process for setting the reception frequency indicated by the read preset frequency data is performed. First tuning means; and receiving the received broadcast wave in the first tuning process. The bell corresponds to a reception frequency set when it is determined that the program identification data included in the broadcast wave is equal to or higher than a predetermined level and matches the program identification data read from the preset reception frequency memory. First control means for detecting a broadcast station as a confirmed broadcast station and continuing to select the detected confirmed broadcast station; and a broadcast wave received by the first control means in the first tuning process. When the determined broadcast station cannot be detected, the alternative frequency data to be tuned in accordance with the tuning instruction is sequentially read from the preset reception frequency memory, and the reception frequency indicated by the read alternative frequency data is read out. A second channel selecting means for performing a second channel selecting process for setting a reception level of the received broadcast wave in the second channel selecting process. The broadcast station corresponding to the reception frequency set when it is determined that the program identification data included in the broadcast wave is equal to or higher than the broadcast frequency and the program identification data read from the preset reception frequency memory. Second control means for detecting a confirmed broadcast station and continuing to select the detected confirmed broadcast station; and muting release means for releasing the audio muting operation in response to the detection of the confirmed broadcast station. A receiver comprising: 2. When the second control means cannot detect the confirmed broadcasting station with respect to all broadcast waves received by the tuning process, the audio muting operation is canceled, and the preset frequency data is The receiver according to claim 1, further comprising resetting means for setting the indicated receiving frequency.