JP2647672B2 - Data multiplex broadcasting receiver - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a radio data system receiver (hereinafter referred to as RD).
S receiver).

BACKGROUND ART When a broadcast station broadcasts, broadcast-related information such as information related to the program content is transmitted as data by multiplex modulation, and a desired program content can be selected on the receiving side based on the demodulated data. Radio data system (RD)
S) there.

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 modulation wave, is used as a subcarrier, and the subcarrier is filtered and biphase-coded. The radio data signal is amplitude-modulated by a data signal indicating information related to the broadcast such as the content, and the amplitude-modulated subcarrier is frequency-modulated to the main carrier for broadcasting.

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. In FIG. 4, block 1 broadcasts program recognition (PI) data representing a network, block 2 broadcasts traffic program recognition (TP) data and traffic announcement recognition (TA) data, and block 3 broadcasts the same program. In the block 4, the frequency (AF) data of the group of network stations is arranged, and in the block 4, program service name information (PS) data such as a broadcast station name and a network name are arranged. In addition, each group has 4 bits of type 0 to 15 according to its contents.
There are 16 different types, and two versions of A and B are defined for each type (0 to 15). These recognition codes are arranged in block 2. In addition,
The AF data of the network station is transmitted only by the type OA group.

By the way, in the case of an in-vehicle receiver, the reception state of the broadcast wave being received may deteriorate as the vehicle travels. However, in the case of RDS broadcasting, as described above, 1
When receiving two RDS broadcast waves, it is possible to obtain AF data of a group of network stations broadcasting the same program, and use this AF data to set the reception frequency to the frequency of another network station with good reception conditions. It is possible to switch.

Also, for example, in the standby state of TA interruption by TA data, TA interruption can be performed by taking in TA data obtained by demodulating a received broadcast wave, but demodulation of data from the received broadcast wave at the current reception frequency is possible. If it becomes impossible, the TA data cannot be taken in, so that interrupt processing by the data cannot be performed. Therefore, the user may miss the traffic information while waiting while the demodulation is disabled.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a data multiplex broadcast receiver that allows a user to take an appropriate response when an interrupt becomes impossible in an interrupt standby state. With the goal.

A receiver according to the present invention is a receiver capable of receiving a multiplex broadcast wave on which a broadcast-related data signal including interrupt data is multiplexed, wherein the receiver receives the multiplex broadcast wave and demodulates the broadcast-related data signal. Means, and clock generation means for generating a decoding clock signal synchronized with a broadcast-related data signal obtained by demodulation by the reception demodulation means;
Decoding means for performing a decoding process on a broadcast-related data signal obtained by demodulation by the reception demodulation means based on the decoding clock signal; and interrupt waiting for performing an interrupt process in response to the interrupt data. And control means for performing a process of notifying the occurrence of loss of synchronization of the decoding clock signal with the broadcast-related data signal in the clock generation means in the mode. .

Another receiver according to the present invention is a receiver capable of receiving a multiplex broadcast wave formed for each data group formed by at least one data block and multiplexed with a broadcast-related data signal including interrupt data. Receiving demodulation means for receiving the multiplex broadcast wave and demodulating the broadcast-related data signal, and performing a decoding process on the broadcast-related data signal demodulated by the reception demodulation means while synchronizing the data group. A decoding unit, and a process of notifying when the decoding unit determines that the data group has become out of synchronization in an interrupt standby mode for waiting to perform an interrupt process in response to the interrupt data. And control means for performing the following.

Still another receiver according to the present invention is a receiver capable of receiving a multiplex broadcast wave formed for each data group formed by at least one data block and multiplexed with a broadcast-related data signal including interrupt data. Receiving demodulation means for receiving the multiplex broadcast wave and demodulating the broadcast-related data signal; and performing decoding processing while synchronizing the data block with the broadcast-related data signal demodulated by the reception demodulation means. When the decoding means determines that the data block has become out of synchronization in the decoding means to be applied and in an interrupt standby mode for waiting to perform an interrupt process in response to the interrupt data, the fact is notified. And control means for performing processing.

Still another receiver of the present invention is a receiver capable of receiving a multiplex broadcast wave in which a broadcast-related data signal including interrupt data is multiplexed, wherein the receiver receives the multiplex broadcast wave and converts the broadcast-related data signal. Receiving demodulating means for demodulating, decoding means for performing decoding processing while performing error detection processing on a broadcast-related data signal obtained by demodulation by the receiving demodulating means, and performing interrupt processing in response to the interrupt data In an interrupt standby mode for waiting, the decoding means determines a decoding state based on a data error rate obtained from a result of the error detection processing, and notifies the fact that the decoding state is determined to be bad. And control means for performing processing.

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

FIG. 1 shows an example of the configuration of an RDS receiver to which the control method according to the present invention is applied.
A desired station is selected by the front end 2 from the FM multiplex broadcast wave, converted into an intermediate frequency (IF), and then supplied to the FM detector 4 via the IF amplifier 3. The front end 2 is, for example, a PLL using a PLL circuit including a programmable frequency divider.
It adopts a synthesizer system, and performs a channel selection operation by controlling the frequency division ratio of the programmable frequency divider by a controller 14 described later. FM detector 4
Is output to an MPX (multiplex) demodulation circuit 5, where it 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 function switching circuit 19. . The function switching circuit 19 selectively outputs an audio signal from the MPX demodulation circuit 5 or, for example, the tape player 20, and its switching control is performed by the controller 14.

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 generated clock is supplied to the gate circuit 10. The lock detection circuit 11 detects that the D-PLL circuit 8 is locked, generates a lock detection signal, supplies the lock detection signal to the gate circuit 10, and controls the gate circuit 10 to open the circuit. A lock detection signal is also supplied to the controller 14 as information indicating that the demodulation of the data from the received broadcast wave has been reliably performed. The decoder 9 decodes the biphase-coded data signal, which is the demodulated output of the PLL circuit 7, in synchronization with the clock generated by the D-PLL circuit 8.

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 and block synchronization & error detection circuit 12. The group / block synchronization & error detection circuit 12 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 14 after the error is corrected by the error correction circuit 13 at the next stage.

The controller 14 is constituted by a microcomputer, and the code information of each block in the radio data sequentially inputted in the group unit, that is, the radio data information (the PI data and the AF data described above) related to the program contents of the broadcasting station currently being received. , PS data, etc.) and stores them in the memory 15. Based on a channel selection command from the operation unit 16, a programmable frequency divider (not shown) of the PLL circuit which constitutes a part of the front end 2. The tuning operation is performed by controlling the reception frequency data value that determines the frequency ratio.

Further, a level detection circuit 17 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. 18 and is provided,
The received signal level detected by the level detection circuit 17 and the station detection signal output from the station detection circuit 18 are supplied to the controller 14.

Next, the procedure of the control method according to the present invention executed by the processor of the controller 14 will be described with reference to the flowchart shown in FIG.

The processor first, the flag F _A indicating that TA interruption waiting process is completed, it is determined whether it is "1" (step S
1) If F _A ≠ 1, it is determined whether the TA interrupt button on the operation unit 16 is on (step S2). If TA interrupt button is on, for example, TA interrupt waiting processing is performed (step S3) for controlling the function switching circuit 19 so as to select the audio signal from the tape player 20, followed by the previous flag F _A "1" Then, it is determined whether or not the TP data is being demodulated (step S5). Thereafter, for example, it is determined whether or not a lock detection signal is generated from the lock detection circuit 11 or not. On the other hand, if it is determined in step S1 that F _A = 1, it is determined whether or not TA data is “1” (step S6). If ≠ 1, the process proceeds to step S5.

In step S5, TP is generated by the disappearance of the lock detection signal.
If it is determined that the data cannot be demodulated, the counting operation of the internal alarm timer for a predetermined time is started (step S7), and then it is determined whether the predetermined time has elapsed (step S8). If the predetermined time has not elapsed, the process returns to step S5 to determine whether the TP data is being demodulated again,
If it is determined in step S8 that the TP data cannot be demodulated for a predetermined period of time, an alarm (warning sound) is issued.
To that effect (step S
9). If it is determined in step S5 that the TP data is being demodulated, the alarm timer is reset (step S1).
0) Then, the processing of this routine is terminated. Note that the notification is made by issuing an alarm, but the present invention is not limited to this. For example, it is also possible to use a display having another display function and blink it to make the notification.

As described above, in the standby state of the TA interrupt, when the demodulation of the TP data from the received broadcast wave becomes impossible and the state is continued for a predetermined time, for example, an alarm is issued to notify that effect, and the TA is notified. Since the listener can be notified that the interruption by the data has become impossible, the listener can quickly cope with this and, for example, select another TP station to prevent the traffic information from being overlooked. Become.

In the above-described embodiment, the occurrence of the reception state where the TP data cannot be demodulated is detected by detecting the loss of lock (extinction of the lock detection signal) in the lock detection circuit 11. However, as another detection method, It is also possible to detect the occurrence of a reception state where demodulation of TP data is impossible by detecting out-of-synchronization in the group and block synchronization circuit 12 or data error rate.

In the above embodiment, the case of the TA interrupt by the TA data which is the interrupt data has been described. However, the present invention is not limited to this, and PTY (program type) data and M / S
The present invention is also applicable to the case of interruption by interruption data such as (music / speechswitch) data.

Effects of the Invention As described above, according to the present invention, it is possible to provide a data multiplex broadcast receiver that enables a user to take an appropriate response when interruption becomes impossible in an interruption standby state. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a receiver according to an embodiment of the present invention, FIG. 2 is a flowchart showing a procedure of a control process executed by a processor in a controller of FIG. 1, and FIG. FIG. 4 is a diagram showing a signal baseband coding structure, and FIG. 4 is a diagram showing a format of a type OA group. Explanation of reference numerals of main parts 2... Front end 4... FM detector 5... Multiplex demodulation circuit 8... Digital and PLL circuit 9.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-87599 (JP, A) JP-A-59-152840 (JP, U) Nikkei Electronics August 24, 1987, pages 202 to 217 page

Claims (7)

(57) [Claims] 1. A receiver capable of receiving a multiplex broadcast wave on which a broadcast-related data signal including interrupt data is multiplexed, comprising: a receiving demodulator for receiving the multiplex broadcast wave and demodulating the broadcast-related data signal; A clock generation unit that generates a decoding clock signal synchronized with a broadcast-related data signal obtained by demodulation by the reception demodulation unit; and a broadcast obtained by demodulation by the reception demodulation unit based on the decoding clock signal. Decoding means for performing decoding processing on the related data signal; and in an interrupt standby mode for waiting to perform an interrupt processing in response to the interrupt data, the decoding clock signal in the clock generation means corresponding to the broadcast-related data signal. Control means for performing processing for notifying that out-of-synchronization has occurred when it is determined to have occurred; and A data multiplex broadcasting receiver characterized by the above-mentioned. 2. The control means according to claim 1, wherein in said interrupt standby mode, said clock generation means determines occurrence of out-of-synchronization of said decoding clock signal with respect to said broadcast-related data signal for a predetermined time. The receiver according to claim 1, wherein: 3. A receiver capable of receiving a multiplex broadcast wave formed for each data group formed by at least one data block and multiplexed with a broadcast-related data signal including interrupt data, wherein the multiplex broadcast is provided. Receiving demodulation means for receiving a wave and demodulating the broadcast-related data signal, and decoding means for performing a decoding process while synchronizing the data group with respect to the broadcast-related data signal demodulated by the reception demodulation means, A control unit for performing a process of notifying when the decoding unit determines that the data group is out of synchronization in an interrupt standby mode for waiting to perform an interrupt process in response to the interrupt data A data multiplex broadcast receiver comprising: 4. The receiver according to claim 3, wherein said control means determines in said interrupt standby mode that said decoding means has lost synchronization with said data group for a predetermined time. 5. A receiver capable of receiving a multiplex broadcast wave formed for each data group formed by at least one data block and multiplexed with a broadcast-related data signal including interrupt data, wherein the multiplex broadcast is provided. Receiving demodulation means for receiving a wave and demodulating the broadcast-related data signal, and decoding means for performing a decoding process on the broadcast-related data signal obtained by demodulation by the reception demodulation means while synchronizing the data block, A control unit for performing a process of notifying when the decoding unit determines that the data block is out of synchronization in an interrupt standby mode for waiting to perform an interrupt process in response to the interrupt data; A data multiplex broadcast receiver comprising: 6. The receiver according to claim 5, wherein said control means determines in said interrupt standby mode that said decoding means has generated an out-of-synchronization of said data block for a predetermined time. 7. A receiver capable of receiving a multiplex broadcast wave on which a broadcast-related data signal including interrupt data is multiplexed, a receiving and demodulating means for receiving the multiplex broadcast wave and demodulating the broadcast-related data signal. Decoding means for performing decoding processing while performing error detection processing on a broadcast-related data signal obtained by demodulation by the reception demodulation means; and interrupt waiting for performing interrupt processing in response to the interrupt data. In the mode, the decoding means determines a decoding state based on a data error rate obtained from the result of the error detection processing, and performs control processing for notifying the decoding state when the decoding state is determined to be defective. A data multiplex broadcast receiver comprising: