JPH02105731A - Method for controlling rds receiver - Google Patents

Abstract

PURPOSE:To always perform a desirable preset channel selecting operation by monitoring the priority of frequencies of broadcasting stations at every network which changes as a vehicle moves and reflecting monitored results in the content of a preset channel memory. CONSTITUTION:When a same program following button 26 is operated, whether or not the receiving signal level VS of broadcast waves at a receiving frequency fD is lower than a set level V1 is discriminated from the output of a station detection circuit. When a receiving state where the receiving signal level VS is lower than the set level V1 continues for more than a prescribed period of time (t), one AF data fAF is read out from station frequency AF date lists f1-fn written in a memory 15 and the read out data fAF are set in the frequency divider of a PLL circuit 2a and the receiving frequency changes to the broadcast frequency of another broadcasting station of the same network. When the received signal level VS is higher than the set level V1, the received frequency data in the memory 15 are updated to the AF data fAF to maintain the same state. Therefore, frequency data for obtaining the best receiving state at the current location are stored at every network at the first station of each preset channel.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a radio data system receiver (hereinafter referred to as RDS).
(referred to as a receiver).

Background Art When a broadcast station broadcasts, broadcast-related information such as information related to the program content is transmitted as data through multiplex modulation, and the receiving side can select the desired program content based on the demodulated data. The Radio Data System (RD), which was able to provide its services to radio listeners,
There is S).

In this radio data system, 3 of the 19KHz stereo pilot signal is outside the frequency band of the FM modulated wave.
The next harmonic, 57 KHz, is used as a subcarrier, and this subcarrier is filtered and biphase (Blpha).
se) The radio data signal is amplitude-modulated using a data signal indicating broadcast-related information such as coded program content, and the amplitude-modulated subcarrier is frequency-modulated to the main carrier and then broadcast. There is.

As is clear from FIG. 5, which shows the baseband coding structure of the radio data signal, 104 bits are divided into 1
Multiplex transmission is repeated as a group. A group consists of four blocks of 26 bits each, and each block consists of a 16 bit information word and a 10 bit check word. In Figure 6, block 1 contains the program identification (PI) code representing the network, block 2 contains the traffic program identification (TP) code and traffic announcement identification (TA) code, and block 3 contains the program that broadcasts the same program. station frequency (AF
) data, and block 4 contains program service name information (PS) data such as broadcasting station names and network names. Furthermore, each group is classified into 16 types, 0 to 15, using 4 bits according to its content, and two versions, A and B, are defined for each type (0 to 15), and these The identification code is placed in block 2. Note that the AF data of the network station is transmitted only in the type 3A group, and the PS data is transmitted in the type OA and OB groups.

Further, in the type 3 group, information related to other network stations different from the own network is transmitted. Figure 7 shows the format of a type 3A group, where block 3 of the type 3A group is filled with A of another network station.
F data is arranged, and block 4 contains information related to other network stations such as PI code and program number (PI
N) Any one of the code, TP code, program type (PTY) code, TA code, and AF data is arranged according to the contents of the codes CI and CO of block 2.

The information of this block 4 is also transmitted in block 4 of the type 3B group. Store address code D2 of block 2 is used to determine the type of other network during transmission considering that there are multiple different other networks.
, D I , and Do are provided, and information related to up to eight other networks can be transmitted.

On the other hand, in an RDS receiver, a group of network stations broadcasting the same program is stored in advance in each preset channel memory for each channel button by operating a preset channel selection button, and The method for selecting the optimal frequency was proposed in a patent application filed in 1982-21.
No. 2224.

However, the reception status of broadcast waves may change due to movement of the vehicle. Therefore, if broadcast waves cannot be received well at the preset frequency, it becomes necessary to preset the receiving frequency again. However, the operation of presetting the reception frequency in the preset channel memory is troublesome, and particularly in the case of a vehicle-mounted receiver, there is a possibility that the reception frequency must be frequently preset again.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a control method for an RDS receiver that can always perform a desired preset channel selection operation even if the channel frequency data at the time of preset operation becomes inappropriate due to movement of the vehicle. .

The RDS receiver control method of the present invention does not fix the contents of the preset channel memory, but monitors the priorities of broadcasting station frequencies for each network, which change as the vehicle moves, and reflects this in the contents of the preset channel memory. It is. That is, each preset channel is provided with a preset channel memory having storage locations for a plurality of frequency data, and is capable of receiving RDS broadcast waves including data signals indicating the broadcast frequencies of network stations, and is capable of receiving a readout command from the preset channel memory. A preset reception function reads out frequency data using a preset reception function, and receives a frequency corresponding to the read frequency data.In order to keep the reception level above a predetermined level, the preset reception function reads the frequency data from the current reception and receives the frequency according to the read frequency data. This is a control method for an RDS receiver that has a same program following function that changes the received frequency according to the frequency.It is a control method for an RDS receiver that has a same program following function that changes the received frequency. When the frequency changes, the data signal is extracted from the received broadcast wave after the change, the broadcast frequency data of the network station group is read, and the frequency data of the preset channel memory is rewritten with the read broadcast frequency data of the network station group. It is said that

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

In the RDS receiver to which the control method of the present invention is applied, as shown in FIG. After that, the signal is supplied to the FM detector 4 via the IF amplifier 3.

The front end 2 obtains the local oscillation signal to the mixer 2b using a PLL synthesizer using a PLL circuit 2a including a programmable frequency divider, and the frequency division ratio of the programmable frequency divider is controlled by a controller 14 described later. The configuration is such that the channel selection operation is performed by F
The detection output of the M detector 4 is supplied to the MPX (multiplex) demodulation circuit 5, and in the case of stereo broadcasting, the detection output is supplied to the L (left)
, R (right) channel audio signals.

Further, when the detection output of the FM detector 4 passes through the filter 6, a 57 KHz subcarrier, that is, a radio data signal, amplitude modulated by the biphase coded 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. In the D-PLL circuit 8, the PLL
A clock for data demodulation is generated based on the demodulated output of the 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 this to the gate circuit 1o, and controls the circuit 10 to be in an open (oven) state. The lock detection signal is also supplied to the AND circuit 17 as a synchronization detection signal indicating that synchronized demodulated data is obtained. In decoder 9, P
A pie-phase encoded data signal, which is the demodulated output of the LL circuit 7, is decoded in synchronization with the clock generated by the D-PLL circuit 8.

As shown in FIG. 5, the output data of the decoder 9 is in groups of 104 bits each consisting of 4 blocks each having a 26-bit configuration, and the data is sequentially grouped.

It is supplied to the block synchronization & error detection circuit 12.

The group and block synchronization & error detection circuit 12 performs group and block synchronization based on the 10-bit offset word assigned to the 10-bit check word of each block, and also performs 16-bit information based on the check word. Word error detection is performed. Then, the error-detected data is error-corrected in the next-stage error correction circuit 13, and then the controller 1
4.

The controller 14 is constituted by a microcomputer, and includes code information of each block in radio data that is sequentially input in groups, that is, radio data information related to the program content of the broadcasting station currently being received (the above-mentioned PI
code, AF data, PS data, etc.) and store them in the memory 15. Also, based on the channel selection command from the operation unit 16, a PLL that constitutes a part of the front end 2
The channel selection operation is performed by controlling the reception frequency data value that determines the frequency division ratio of a programmable frequency divider (not shown) of the circuit 2a. The received frequency data value is, for example, a count value of a counter.

Note that the memory 15 stores received frequency data, P1 code, A
F Non-volatile R where data such as data list is written
AM and RO with programs and data pre-written
It consists of M. This RAM contains the PI code for each preset channel 1ch to 6ch as shown in Figure 2.
A storage area and a preset storage area in which frequency data for eight stations can be written are separately formed.

For example, in the PI storage area, a PI code obtained from input data can be written together with frequency data in a preset mode when RDS broadcasting is being received.

Further, the operation section 16 is provided with a plurality of operation buttons such as a preset button 23, preset channel buttons "1" to r6J25 for preset channel selection, and a same program follow button 26.

In the PI code and AF data read from the data supplied from the error correction circuit 13 by operating the preset button 23, the PI code and its P! AF data of the network station group represented by the code is written into the PI storage area and the preset storage area, respectively. Furthermore, when any of the preset channel buttons "1" to r6J25 is operated, the controller 14 reads out and receives the data of the first station among the plurality of frequency data sequentially stored in the selected preset channel. This is set as frequency data in the frequency divider of the PLL circuit 2a. When the same preset channel button 25 is operated again, the second station data out of the plurality of frequency data is read out and set in the frequency divider of the PLL circuit 2a as received frequency data, and the frequency data for eight stations is stored. If the same preset channel button 25 is operated nine times, the process goes around and returns to reading the frequency data of the first station.

Next, the controller 14 shows the procedure of the control method of the present invention.
FIG. 3(a) shows the operation of the processor.

This will be explained according to the flowchart shown in (b).

As shown in FIG. 3(a), the processor first determines whether preset reception is in progress (step 51).

That is, it is determined whether or not broadcast waves are being received by operating the preset channel button 25. If the preset is being received, it is determined whether the flag F1 is equal to 1 (step 52). The flag F1 is initially set to 0 when the power is turned on. In the case of Fl-0, it is determined whether or not the same program follow button on the operation unit 16 has been operated (step 53). When the same program follow button 26 is operated, the fact that the same program follow button 26 has been operated is marked in a predetermined register in the processor, for example, by interrupt processing. If the same program follow button 26 is not operated, this routine ends. When the operation of the same program follow button 26 is confirmed, the flag F1 is set to 1 (step 54), and the station detection circuit 20 checks whether the received signal level VS of the broadcast wave at the frequency fD being received is below the set level v1. The determination is made based on the output (step 55). If F, -1 in step 52, since the same program following operation has already started, it is determined whether the same program following operation has been reset (step 62). For example, if the same program following button 26 is operated again, it is determined that the same program following operation has been reset, the flag F1 is set equal to 0 (step 63), and this routine is ended. If the same program following operation has not been reset, the process advances to step 55.

If the reception signal level VS is equal to or lower than the set level v1 in the determination at step 55, it is determined whether the reception state has continued for a predetermined time or longer (step 56). If the receiving state in which the received signal level Vs is lower than the set level v1 does not continue for a predetermined period of time or more, the process returns to step 55. If the received signal level vs is at the set level V, and the reception state below continues for a predetermined period of time, AF data fAF 1 is read out from the AF data list fl, f2...fn written in the memory 15. It is set in the frequency divider of the PLL circuit 2a (step 57). As a result, the reception frequency changes to the broadcast frequency of another broadcast station on the same network. Next, it is determined whether the received signal level vs at the new received frequency based on the AF data list is less than or equal to the set level ■1 (step 58). If the reception signal level Vs is higher than the set level v1, the reception frequency data in the memory 15 is changed to A in order to maintain the reception state.
The F data is updated to fAF (step 59), the preset data rewriting subroutine is executed (step 60), and this routine ends. Therefore, the frequency of the AF data fAF will change to the new receiving frequency f the next time this routine is executed.
D, and the same program following operation is performed. On the other hand, if the received signal level V9 is below the set level v1, the received frequency data in the memory 15 is read out and set in the frequency divider of the PLL circuit 2a in order to return to the original reception of broadcast waves (step 61).

Therefore, by repeating the processing of this routine at a predetermined period, when the received signal level vS of the received broadcast wave at the frequency fD drops below the set level V1 over a predetermined time t, the AF of the same network written in the memory 15 AF data of frequency f1 is read from the data list fl, f2...fn and set in the frequency divider of the PLL circuit 2a, and the reception frequency changes to the broadcast frequency f1 of another broadcast station on the same network. do. The received signal level Vs at this new frequency f1 is the set level V1
If it is larger, this reception state is maintained. However, if the received signal level VS is lower than the set level Vl, the reception of the broadcast wave at the original frequency fD is resumed.

Again, the received signal level V of the received broadcast wave at frequency fD
If S has decreased below the set level V1 for a predetermined time t, the AF data list f,, f2...
AF data of frequency f2 is read from fn and PLL
It is set in the frequency divider of circuit 2a. That is, the frequency f
If the received signal level Vs of the received broadcast wave at D remains lower than the set level V1, the received frequency becomes fD-
The frequency f changes as f, 4f, 4f2...
This process is repeated until a broadcast wave whose received signal level Vs is higher than the set level V1 is detected from among the network station group to which the broadcast station D belongs.

Note that even if the AF data is received at all frequencies from f1 to fn, the received signal level Vs is the set level V1.
If a larger broadcast wave cannot be detected, the same program following mode is no longer used and the receiving state of frequency fD is maintained. Also, during the period when the reception frequency changes to the frequency in the AF data list, a mute circuit (not shown) operates to cut off the output of the audio signal, and if a broadcast wave with the reception signal level Vs higher than the set level v1 is detected, Mute status is canceled.

In the preset data rewriting subroutine, as shown in FIG. 3(b), data from a new broadcasting station on the same network supplied from the error correction circuit 13 is input (step 71), and AF data is read (step 72). , it is determined whether the number n of AF data has been detected (step 73).

As shown in Figures 6 and 7, one group can contain AF data for two stations, so AF data for one or two stations on the same network can be read by transmitting one group. . Furthermore, as shown in Fig. 4, the AF data group for one network has the number of AF data at the beginning, that is, the number of stations data n (the number of broadcast stations that can be received centered on the data sending broadcast station, up to 25 stations). ,and,
The n pieces of frequency data f1, . The head of the AF data group of one network is detected by determining whether or not the number n of AF data has been detected. This A
In the case of other network-related information, the beginning of the F data group may be determined by reading the store address codes D 2 , D I , Do and based on changes in the store address codes D 2 , D 1 , Do.

If the beginning of the AF data group of one network is detected, set the flag F2 to 1 (step 74).
, it is determined whether the information is related to another network (step 75). On the other hand, if it is not the beginning of the AF data group of one network, it is determined whether the flag F2 is equal to 1 (step 76), and if it is 1M-1, it is already A
Since the beginning of the F data group is detected, step 7
Move to 5. If it is not other network related information, it is the AF data of the network currently being received, so the AF data list in the memory 15 f1゜f2...fn
is rewritten to that AF data (step 77), and the variable m is set equal to the current number of preset channels (step 78), and the read AF data for 8 stations is written to the preset storage area corresponding to preset channel m-ch. It is determined whether or not (step 79). If the AF data for eight stations has not been written, the read AF data is written as frequency data into an empty position in the preset storage area corresponding to preset channel m-ch (step 80). If frequency data for eight stations has been written, the read AF data is not written and the flag F2 is reset to 0 (step 81).

On the other hand, if it is other network related information, code C
1. Determine whether co is both O (step 82). If C+ -Co -0, in block 4, as shown in FIG. 7, one PI of other network related information is determined.
Since the code is transmitted, the PI code is read (step 83). Note that flag F2 becomes 0 when the channel selection operation ends.
is initialized to .

Next, the variable m is set equal to 1 (step 84), and it is determined from the P2 storage area of the memory 15 whether the read PI code is allocated to the preset channel m-ch (step 85). If the read PI code is not assigned to the preset channel m-ch, 1 is added to the variable m (step 86), and as a result of the addition, it is determined whether the variable m is greater than 6 (step 86). 87). If m≦6, the process returns to step 85 and searches for the preset channel to which the read PI code is assigned. If m>6, since there is no preset channel to which the read PI code is assigned, the read AF data is not written to the preset storage area.

When the preset channel m-ch to which the read PI code is assigned is found, the process proceeds to steps 79 to 81, where the read AF data is written as frequency data into an empty position in the preset storage area corresponding to the preset channel m-ch.

If F2-0 in Astera 76, if m>6 in step 87, or in step 80 or 8
After executing step 1, it is determined whether all data rewriting has been completed (step 88), and if all data rewriting has not been completed, the process returns to step 71, and if data rewriting has been completed, the process of this subroutine is ended. .

Therefore, by repeating this operation, when the same program tracking function operates during preset reception and the broadcast wave of another same network is received, it will be stored in the preset storage area corresponding to the preset channel that is different for each network until then. The AF data of the placed network can be updated with the AF data of each network obtained from the newly received RDS broadcast wave. As a result, frequency data at which the best reception condition can be obtained at the current location is stored for each network at the first station of each preset channel.

In addition, in the above-mentioned embodiment, the case where each frequency data of the network station group currently being received as well as each frequency data of other network station groups are obtained from the newly received RDS broadcast wave by the operation of the same program tracking function. As described above, when only the frequency data of the network station group currently being received is obtained from the newly received RDS broadcast wave, only the frequency data of the preset channel corresponding to the network station group currently being received is rewritten.

Effects of the Invention As described above, in the RDS receiver control method of the present invention, when the received broadcast wave changes due to the operation of the same program tracking function during preset reception, the data signal is extracted from the received broadcast wave after the change. Since the system reads the broadcast frequency data of the network station group and rewrites the frequency data in the preset channel memory with the read broadcast frequency data of the network station group, there is no need to worry about presetting new reception frequencies in the preset channel memory even after the vehicle is moved. The optimal receiving frequency data for the current location will be stored in the preset channel memory without any manual operation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an RDS receiver to which the control method of the present invention is applied, FIG. 2 is a diagram showing a preset storage area in RAM, and FIGS. FIG. 4 is a flowchart showing the operation of the processor in the controller in the receiver. FIG. 4 is a diagram showing the format of an AF data group of one network. FIG. 5 is a diagram showing the baseband coding structure of a radio data signal. The figure shows the format of the type 3A group, and FIG. 7 shows the format of the type 3A group. Explanation of symbols of main parts 1...Antenna 2...Front end 4...FM detector 5...Multiplex demodulation circuit 8...Digital PLL circuit 9... ... Decoder 14 ... Controller applicant Pioneer Corporation

Claims (1)

[Claims] An RD that includes a preset channel memory having a plurality of frequency data storage locations for each preset channel, and includes a data signal indicating the broadcast frequency of a network station group.
A preset reception function that can receive S broadcast waves, reads frequency data from the preset channel memory in response to a read command, and receives a frequency corresponding to the read frequency data, and a current A method for controlling an RDS receiver having a same program following function of changing the reception frequency of a broadcast wave that is being received and the frequency of another broadcast wave that is broadcasting the same program, the said same program following function during preset reception. The system determines whether or not the received broadcast waves have changed through the operation of A method for controlling an RDS receiver, comprising rewriting frequency data in the preset channel memory using broadcast frequency data of a group of network stations.