JPH05102799A - Rds radio reception method - Google Patents

Abstract

PURPOSE:To receive a desired program in an excellent way even when a vehicle is in existence-in an area in which no substitute station is found out and the reception state is deteriorated. CONSTITUTION:While a main tuner 3 and a sub tuner 6 are tuned to a same desired station for a prescribed time, a diversity control circuit 13 applies changeover control to a changeover circuit 12 in a better reception state to allow sound output. After lapse of a prescribed time, the sub tuner 6 searches a substitute station and when no substitute station is found out, the sub side is tuned to the same desired station as the main side again. When the station is found out by the search of the substitute station and the reception state is not excellent than that of the desired station, so long as a station is found out, the search of the substitute station is repeated and when no station is found out, the desired station is selected. When a substitute station whose reception state is better than that of the desired station through the search of substitute stations, the main tuner 3 is turned to the substitute station and so long as a station is found out at the sub side, the search of the substitute station is implemented with respect to the desired station after the revision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RDS radio receiving method, and more particularly, to an on-vehicle RDS radio receiving method in which two RDS radio receiving means are used, one station receives a desired station and the other station searches for an alternative station. Method for receiving RDS radio on a mobile device.

[0002]

2. Description of the Related Art In a car radio, when a vehicle moves out of a service area while receiving a desired station, the station is automatically reselected to a new station broadcasting the same program, or When traffic information broadcasting starts, it is convenient to automatically switch to radio broadcasting from another source or increase the volume. In order to realize these functions, RDS (Radio Data System) has been proposed and put into practical use by the European Broadcasting Union.

This RDS is for multiplexing various kinds of digital data on an FM broadcast signal and transmitting the same. The transmitted message is (1) Program identification code (PI) (PI) of the currently received FM broadcast. 2) Program name (PS) (3) Frequency list of the same program network (A
F) (4) Program content identification code (PTY) (5) Transmission status identification code (DI) (6) Music or conversation identification code (M / S), and (7) Traffic information broadcasting station identification code ( TP) (8) There is an identification code (TA) in the traffic information broadcast.

In this way, the F received by the RDS is
Since messages related to M broadcasting are transmitted in a multiplex manner, it is possible to perform a special operation that has never been done by using the messages. For example, if the vehicle moves to the edge of the service area of the broadcasting station that is currently receiving it, the reception status will deteriorate and you will not be able to listen to the desired program. Had to find another station that was On the other hand, in RDS, a sub-tuner is provided in addition to the main tuner for receiving the desired station, and, for example, when the received electric field strength of the desired station becomes a certain value or less, the AF list previously obtained from the desired station is used. Then, the sub tuner searches for another alternative station broadcasting the same program as the desired station, and if an alternative station with a better reception condition is found than the main side, the main side is tuned to the frequency of the alternative station. Alternatively, while the main tuner receives the desired station, the sub-tuner constantly searches for another alternative station that is broadcasting the same program as the desired station using the AF list obtained from the desired station, and the main station receives the signal. If a good alternative station is found, the main side is tuned to the frequency of the alternative station. By doing so, it is possible to automatically continue listening to the same program even if the user deviates from the service area of the desired station.

[0005]

However, in the above-mentioned conventional RDS radio receiver, the vehicle is in the service area of the desired station, and the service area of any other alternative station broadcasting the same program is changed. Even if the reception condition deteriorates due to multipath interference or the like when it is out of the range, there is a problem that it is not possible to deal with anything and the desired program cannot be heard.

From the above, the object of the present invention is to make it possible to satisfactorily receive a desired program even when there is a vehicle in an area where an alternative station cannot be found and the reception condition is about to deteriorate.
It provides the S radio reception method.

[0007]

SUMMARY OF THE INVENTION The above-mentioned problems are solved by the present invention.
In one, the two RDS radio receiving means individually connected to the two antennas are tuned to the same desired station for a certain predetermined time period to obtain the AF list, and the two RDS radio receiving means are received. Compare the states,
A means for selecting a better one and outputting the sound, and after a lapse of a certain time, while one RDS radio receiving means continues to receive the desired station, the other RDS radio receiving means searches for an alternative station using the AF list. If the alternative station is not found, the means for tuning the two RDS radio receiving means together to the desired station again, and if the station is found by the alternative station search, the reception condition is better than the desired station. If there is no station, as long as a station is found, repeat the search for an alternative station to find an alternative station with a better reception condition than the desired station, and if no station is found, tune both RDS radio receiving means to the same desired station. If an alternative station having a better reception status than the desired station is found, the desired station being received by one of the RDS radio receiving means is changed to the alternative station, and the AF list is entered from the changed desired station. After that, the alternative list is searched again by the other RDS radio receiving means using the AF list, and when the alternative station is not found, the two RDS radio receiving means are tuned to the same desired station again, and the alternative station is replaced. When a station is found by the station search, it is achieved by providing means for searching an alternative station having a better reception status than the desired station.

In another embodiment of the present invention, two RDS radio receiving means individually connected to two antennas are tuned to the same desired station to obtain an AF list and two RDS radios are obtained. A means for comparing the receiving states of the receiving means, selecting a better one and outputting the sound, and when the receiving state of the desired station in the two RDS radio receiving means deteriorates by a certain amount or more, one of the RDS radio receiving means desires. While continuing the reception of the station, the other RDS radio receiving means searches the alternative station using the AF list, and when the alternative station is not found, the two RDS radio receiving means are tuned to the same desired station again. If a station is found by means of a means and a search for an alternative station and the reception condition is not better than that of the desired station, the alternative station search is repeated until the station is found. The station searches for an alternative station with a good reception condition, and when no station is found, there is again a means for tuning the two RDS radio reception means to the same desired station and an alternative station with a better reception status than the desired station. If found, the desired station received by one of the RDS radio receiving means is changed to the alternative station, the AF list is obtained from the changed desired station, and then the other RDS radio receiving means is used by using the AF list. When the alternative station is searched again with, and the alternative station is not found, the two RDS radio receiving means are tuned to the same desired station again, and when the station is found by the alternative station search, the desired station is selected. This is achieved by providing means for searching for an alternative station having a good reception condition.

[0009]

According to one aspect of the present invention, (1) AF is performed by tuning two RDS radio receiving means individually connected to two antennas to the same desired station for a certain predetermined time.
While obtaining the list, compare the reception status of the two RDS radio receiving means, select the better one to output the sound, (2) After a certain period of time, one of the RDS radio receiving means selects the desired station. While continuing the reception, the other RDS radio receiving means searches the alternative station by using the AF list, and when the alternative station is not found, returns to (1) again and sets both the two RDS radio receiving means to the desired station. If a station is found in the alternative station search in (3), (a) and (2) by tuning, an alternative station with a good reception condition is searched for from the desired station, and if no station is found, The alternative station search is repeated to find an alternative station with a good reception condition from the desired station. If no station is found, return to (1), (b).
If an alternative station having a better reception condition than the desired station is found in (a), the desired station being received by one of the RDS radio receiving means is changed to the alternative station and the AF list is obtained from the changed desired station. Then, (c) using the AF list, the other R
The alternative station is searched again by the DS radio receiving means, and when the alternative station is not found, the procedure returns to (1) again, and (d) and (c).
If a station is found in the search for an alternative station in (a)
Return to and search for an alternative station with good reception from the desired station. As a result, when a vehicle arrives at the end of the service area of the desired station that overlaps with the service area of a certain alternative station that is broadcasting the same program as the desired station, the alternative station that has been regularly performed until then. Since the station will be found by the search of, the alternative station is continuously searched thereafter, and if the reception state of the alternative station is better than the desired station, the desired station is changed to the alternative station. You can continue listening to your desired program without searching for alternative stations by manual tuning. On the other hand, if there is a vehicle in the service area of the desired station and it is out of the service area of any other alternative station that is broadcasting the same program, the station will be searched periodically for the alternative station. Since it is not found, most of the two RDS radio receiving means are tuned to the same desired station, and the one with the better receiving condition is selected and the voice is output. Even if the reception state of the RDS radio receiving means which is outputting the voice is getting worse, the other RDS radio receiving means which is not disturbed is switched to the voice output and the desired program can be listened to satisfactorily.

According to another aspect of the present invention, (1),
The two RDS radio receiving means individually connected to the two antennas are tuned to the same desired station together to obtain the AF list, and the receiving states of the two RDS radio receiving means are compared, and the better one is selected. (2) When the receiving condition of the desired station in the two RDS radio receiving means is deteriorated by a certain degree or more, the selected RD is output while continuing the reception of the desired station by one RDS radio receiving means.
The S radio receiving means searches the alternative station using the AF list, and when the alternative station is not found, returns to (1) again,
When a station is found in the alternative station search in (3), (a) and (2), the desired station is searched for an alternative station having a good reception state. If no station is found, the alternative station is searched as long as the station is found. Repeat the search to find an alternative station with a good reception condition from the desired station. If no station is found, return to (1), (b)
If an alternative station having a better reception condition than the desired station is found in (a), the desired station being received by one of the RDS radio receiving means is changed to the alternative station and the AF list is obtained from the changed desired station. Then, (c) using the AF list, the other R
The alternative station is searched again by the DS radio receiving means, and when the alternative station is not found, the procedure returns to (1) again, and (d) and (c).
If a station is found in the search for an alternative station in (a)
Return to and search for an alternative station with good reception from the desired station. As a result, when the vehicle arrives at the end of the service area of the desired station and the service area of a certain alternative station that is broadcasting the same program as the desired station, the reception status by the two RDS radio receiving means is changed. Both became worse, and while one RDS radio receiving means continued to receive the desired station, the other RD
The S radio receiving means continuously searches for alternative stations,
If the reception status of the alternative station is better than that of the desired station received by one of the RDS radio receiving means, the desired station is changed to the alternative station. Therefore, even if the alternative station is not searched for by manual tuning, the desired program continues. Can be heard. On the other hand, when the vehicle is in the service area of the desired station and is out of the service area of any other alternative station that is broadcasting the same program, the reception status of both RDS radio reception means deteriorates. Since it is rare to do so, the two RDS radio receiving means are almost always tuned to the same desired station, and the one with the better reception state is selected and the voice is output. If the receiving condition of the radio receiving means is only deteriorated, the other RDS radio receiving means which is not disturbed is immediately switched to the audio output, so that the desired program can always be listened to satisfactorily.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vehicle mounted R according to an embodiment of the present invention.
It is a whole block diagram which shows a DS radio receiver.

Reference numeral 1 is a main antenna, and 2 is a main side P for converting main frequency control data into a corresponding control voltage.
LL circuit, 3 is a main tuner for receiving program broadcasting of a desired station and RDS data, and 3a is a main antenna 1
A front end 3b for extracting a broadcast signal having a frequency corresponding to the control voltage input from the main side PLL circuit 2 from the received signal and converting it to an intermediate frequency signal, 3b is an intermediate frequency amplifier for amplifying the intermediate frequency signal and performing FM detection. Detection circuit (IF /
DET), 3c is an S meter circuit for DC-detecting an intermediate frequency signal to obtain a reception electric field strength signal (S meter signal), 3d is a station detector, and is within a frequency deviation Δf (bandwidth) of the reception signal. When the received electric field strength is equal to or higher than a predetermined level, it is determined that the receiving station exists. That is, the station detect signal SD _M is L
In the case of the level, even if the received electric field strength detected by the S meter circuit 3c is large, there is no broadcasting station at the tuning point, and it is judged that the detected received electric field strength is influenced by the adjacent station. Reference numeral 3e is an RDS decoder that demodulates RDS data from the FM detection signal.

Reference numeral 4 is a sub-antenna, 5 is a sub-side PLL circuit for converting sub-frequency control data into a corresponding control voltage, and 6 is a sub-tuner for receiving a program broadcast of a desired station or an alternative station and RDS data. , 6a is a front end for extracting a broadcast signal having a frequency corresponding to the control voltage input from the sub-side PLL circuit 5 from the received signal of the sub-antenna 1 and converting it to an intermediate frequency signal, and 6b is amplification of the intermediate frequency signal and FM detection. Intermediate frequency amplification / detection circuit (IF /
DET) and 6d are station detectors, which determine that a receiving station exists when they are within the frequency deviation Δf (bandwidth) of the received signal and the received electric field strength is equal to or higher than a predetermined level. That is, when the station detect signal SD _S is at the L level, even if the received electric field strength detected by the S meter circuit 6c is large, there is no broadcasting station at the tuning point, and the detected received electric field strength is that of the adjacent station. Judged as being affected. Reference numeral 6e is an RDS decoder that demodulates RDS data from the FM detection signal.

Reference numeral 7 is a noise component detection circuit for detecting a noise component such as multipath included in the received electric field intensity signal S _M input from the S meter circuit 3c and outputting a noise component detection signal N _M , and 8 is an S meter circuit 6c. A noise component detection circuit that detects a noise component such as multipath included in the received electric field strength signal S _S input from the device and outputs a noise component detection signal N _S , and 9 is a received electric field strength signal S _M and a noise component detection signal N S
A reception state detection circuit that outputs a reception state detection signal indicating the degree of reception state on the main side from _M indicates the degree of reception state on the sub side based on the reception electric field strength signal S _S and the noise component detection signal N _S. A reception state detection circuit that outputs a reception state detection signal indicating that the reception state detection circuit 11 compares the reception states of the main side and the sub side to determine which reception state is better, and a determination signal (H: main side good, L: sub side). The reception state comparison circuit that outputs the side good), and 12 is the FM detection signal output from the intermediate frequency amplification / detection circuit 6b on the main side and the FM detection signal output from the intermediate frequency amplification / detection circuit 6b on the sub side. , A switching circuit for selecting and outputting one, 13 is a receiving state among the main side and the sub side based on a comparison signal input from the reception state comparison circuit 11 and a data comparison signal input from a controller described later. Switching circuit 1 to a better person
A diversity control circuit for performing switching control for 2, a noise cut / multiplexer (NC / MP)
X) and the FM selected and output from the switching circuit 12
Noise detection and stereo demodulation of the detection signal (stereo composite signal) are performed and a stereo audio signal is output.
Reference numeral 15 is an amplifier (AM for amplifying a stereo audio signal)
P) and 16 are speakers.

Reference numeral 17 denotes a controller for controlling the tuning of the main tuner 3 to the desired station, controlling the tuning of the sub tuner 6 to the desired station, or the AF list obtained from the RDS decoder 3e on the main side. Based on the above, search control of an alternative station broadcasting the same program as the desired station at a predetermined time is performed, and a station (same PI code) broadcasting the same program as the desired station is found by the search control of the alternative station. At this time, if the alternative station on the sub side is in a better reception state than the desired station on the main side, the alternative station performs tuning control of the main tuner 3 to change the desired station. In addition, the controller 17 measures and compares the error rate of the RDS data on the main side and the sub side, outputs the comparison result to the diversity control circuit 13, and controls the display of the receiving state on the main side with respect to the display unit described later. To do

Reference numeral 17a denotes a data comparison unit, which measures and compares the error rate of the RDS data input from the RDS decoders 3e and 6e in real time, and indicates that the main side is good when the error rate on the main side is smaller. , A data comparison signal indicating that the sub-side is good when the error rate on the sub-side is smaller, or 0 when the error rate on the sub-side is equal or unmeasurable, is output to the diversity control circuit 13. Reference numeral 17b is a data registration unit for registering the RDS data input from the main RDS decoder 3d, and 17c outputs predetermined frequency control data to the main PLL circuit 2 and the sub PLL circuit 5 so that the main tuner 3 and the sub tuner 3 are connected to each other. This is a tuning control unit that performs predetermined tuning control for the side tuner 6 and display control. 18
Is a display unit for displaying a tuning frequency on the main tuner 3 and a receiving display based on the station detect signal SD _M.

The diversity control circuit 13 switches the switching circuit 12 to the main side when the data comparison signal is 1, switches to the sub side when the data comparison signal is 2, and when the data comparison signal is 0, according to the judgment signal input from the reception state comparison circuit 11, When the determination signal indicates that the main side is good, the switching circuit 12 is switched to the main side, and conversely, when the sub side is good, the switching circuit 12 is switched to the sub side.

FIG. 2 is a flow chart showing the operation of the controller 17, and FIG. 3 is an explanatory diagram showing the relationship between the vehicle position and the receiving operation, which will be described below with reference to these figures.

First, the tuning controller 17c is the main side PLL.
The same frequency control data regarding the desired station is output to the circuit 2 and the sub-side PLL circuit 5, and the main-side tuner 3 and the sub-side tuner 6 are tuned to the same desired station (same frequency) (step 101 in FIG. 2, here). Then, the desired station is station A. See Figure 3). At this time, the tuning control unit 17c causes the display unit 18 to display the frequency of the desired station. The broadcast signal of the desired station A received by the main antenna 1 is amplified and converted into an intermediate frequency signal by the front end 3a, and then the intermediate frequency signal is amplified and FM detected by the intermediate frequency amplification / detection circuit 3b. , FM detection signal is output. The FM detection signal is output to the switching circuit 12 and also demodulated by the RDS decoder 3e to output RDS data to the controller 17. The intermediate frequency signal is input to the S meter circuit 3c to detect the received electric field strength, and the noise component detection circuit 7 further detects a noise component such as multipath noise.
Reception state detection circuit 9 together with reception electric field strength detection signal S _M
A reception state detection signal indicating the quality of the reception state is output. When the desired station A is received by the main tuner 3, the H-level station detect signal SD _M is output from the station detector 3d,
The tuning control unit 17c, which has received the signal, displays on the display unit 18 that the desired station A is being received (step 102).

The broadcast signal of the desired station A received by the sub antenna 4 is amplified by the front end 6a and converted into an intermediate frequency signal, and then the intermediate frequency amplification / detection circuit 6b amplifies the intermediate frequency signal. And FM detection is performed, and an FM detection signal is output. The FM detection signal is switched to the switching circuit 12
In addition to being output to the controller 17, the RDS decoder 6e demodulates the data and outputs the RDS data to the controller 17. Further, the intermediate frequency signal is input to the S meter circuit 6c to detect the received electric field strength, and the noise component detection circuit 8 further detects noise components such as multipath noise, and the reception state together with the received electric field strength detection signal S _S. The detection signal is input to the detection circuit 10 and a reception state detection signal indicating the quality of the reception state is output. Then, the reception state comparison circuit 11 determines the reception state from the reception state detection signals on the main side and the sub side. When the reception state on the main side is good, it is H, and when the sub side is good, it is L. The determination signal is input to the diversity control circuit 13.

On the other hand, the RDS data demodulated by the RDS decoders 3e and 6e is input to the controller 17, the main RDS data (including the AF list) is registered in the data registration unit 17b (step 103), and the data is also acquired. The comparison unit 17a measures and compares the error rates of the RDS data on the main side and the RDS data on the sub side, and the result is input to the diversity control circuit 13 as a data comparison signal (step 104).

Now, the reception state of multipath noise and received electric field strength is much better on the main side, and the RDS on the main side is much better.
When the data error rate is smaller, the data comparison signal is 1
Then, the diversity control circuit 13 outputs a switching signal to the main side to the switching circuit 12, and noise-cuts the FM detection signal related to the desired station A received on the main side.
Output to the multiplexer 14. This noise cut /
The noise detection and stereo demodulation of the FM detection signal are performed by the multiplexer 14, the stereo audio signal is amplified by the amplifier 15, and the sound is output from the speaker 16. As a result, it is possible to listen to the broadcast of the desired station A that is received in good condition on the main side.

After that, when the reception condition becomes much better on the sub side due to the movement of the vehicle and the error rate of the RDS data on the sub side becomes smaller, the data comparison signal becomes 2 (step 104), diversity control circuit 13
Outputs the switching signal to the sub side to the switching circuit 12 and outputs the FM detection signal for the desired station A received on the sub side to the noise cut / multiplexer 14. Here, noise cutting and stereo demodulation are performed, and the stereo audio signal is amplified by the amplifier 15 and is acoustically output from the speaker 16. As a result, it is possible to listen to the broadcast of the desired station A that is received in good condition on the sub side.

When the reception conditions on both the main side and the sub side deteriorate and no data is output from the RDS decoders 3e and 6e, the data comparison circuit 17a cannot compare the data error rates, so the data comparison signal is set to 0. (Step 104). In this case, the reception status comparing circuit 11 compares the reception statuses of the main side and the sub side, which are obtained in an analog manner by the reception status detecting circuits 9 and 10, and if the main side is better, the diversity control circuit 13 causes the switching circuit 12 to operate. To the main side, and if the sub side is better, switch to the sub side. Thereafter, the same operation is repeated, and as a result, the program broadcast of the desired station A can always be heard under a better reception condition.

When the antenna diversity operation is performed for a certain time in this way, the data comparison unit 17a sets the data comparison signal to 0 (step 106), and then the tuning control unit 1
7c performs alternative station search control. That is, the data registration unit 1
Using the AF list registered in 7b, first, the frequency control data relating to the first alternative station is output to the sub-side PLL circuit 5, the sub tuner 6 is tuned to the first alternative station (step 107), and the station detector is detected. The output of 6d is checked to determine whether there is a station (step 108).
If there is no station, the frequency control data for the next alternative station in the AF list is output to the sub PLL circuit 5, and the sub tuner 6 is tuned to the second alternative station (steps 110, 1).
11) After inputting a station detect signal SD _M from the station detector 3d on the main side to display the presence / absence of station reception on the main side (step 112), return to step 108 to determine whether there is a receiving station on the sub side. If no station is found even if all stations in the AF list are searched even if no station is found (NO in step 113), the tuning control unit 17c determines that there is no station. Then, the sub tuner 6 is again tuned to the same desired station A as the main side, and the antenna diversity operation is performed in the same manner as described above for a certain period of time, and a reception signal with a better reception state is used on the main side and the sub side The audio output. When a certain time has passed, again
Search for an alternative station, and if the station does not find it,
Return to step 101.

If no station is found in the alternative station search in this way, the vehicle is in the service area of the desired station A, as indicated by point P ₁ in FIG.
It is out of the service area of C ,.
Therefore, except that the alternative station search is periodically performed, the sub tuner 6 is tuned to the same desired station A as the main side, and the reception signal on the side with a better reception state is selected and output as voice. It is possible to listen to a desired program under a good reception condition while avoiding a decrease in the reception electric field strength due to noise or some circumstances. During the search for the alternative station, the data comparison signal is set to 0, and the reception state on the sub side is deteriorated most of the time. Therefore, the diversity control circuit 13
Since the switching circuit 12 is switched to the main side, the voice output of the desired station A is not interrupted.

After that, when the vehicle comes to the end of the service area of the desired station A and enters the end of the service area of the alternative station B as shown in P ₂ of FIG. When 6 is tuned to the alternative station B, an H level station detect signal SD _S is output from the station detector 6d, and the tuning control section 17c of the controller 17 determines in step 108 that there is a station. At this time, the tuning control unit 17c inputs the sub-side RDS data from the RDS decoder 6e, and determines whether the PI code matches the main-side PI code registered in the data registration unit 17b (step 109). When they match, the receiving station of the sub-tuner 6 is an alternative station of the desired station A. Therefore, a determination signal is subsequently input from the receiving state comparison circuit 11 and the receiving state of either the main side or the sub side is good. It is determined whether or not (step 114). When the vehicle is closer to the desired station A than the alternative station B and the main side has a better reception condition, the process proceeds to step 110, and if there is no other alternative station with the same PI code as the main side, there is a receiving station. An alternate station was found at least once in this search (step 113).
YES), do not return to step 101
Returning to step 7, the alternative station is searched again.

Then, as shown in P ₃ of FIG. 3, the vehicle further approaches the alternative station B, and after YES in both steps 108 and 109, in step 114, the sub side is in a receiving state from the main side. If it is judged to be good, the tuning controller 17c outputs the frequency control data for the alternative station B to the main side PLL circuit 2 and causes the main tuner 3 to change the desired station to be tuned from A to B (step 115). At this time, the tuning control unit 17c displays the frequency of the station B on the display unit 18. As a result, even if it becomes difficult to receive the desired station A, the station automatically switches to the station B that is broadcasting the same program, so that the user does not have to manually search for another same program station. .. At this time, since the main side and the sub side temporarily receive the same station B, the voice output of the station B is performed regardless of which reception state is good. After step 115, the tuning control unit 17c inputs the changed RDS data (including the AF list) from the desired station B output from the RDS decoder 3e, and the data registration unit 17b.
(Step 116).

Then, returning to step 107, the tuning control section 17c controls the search for the alternative station by using the AF list obtained from the desired station B this time. At this time, the desired station A has been an alternative station to the station B, and the sub tuner 6
Is tuned to the alternative station A, the vehicle is still in the service area of station A, so YES is determined in steps 108 and 109, and then the reception states of the main side and the sub side are compared (step 114). ). If the main side is better, the desired station is not changed, and if no station is found for other alternative stations, the alternative station search is performed again based on the AF list obtained from the current desired station B. Control is performed (YES in step 112). Incidentally, the vehicle is a little station A
(See P _{4 in} FIG. 3), and when tuning to the alternative station A, the tuning control section 17c tunes the main tuner 3 to the original station A if the sub-side has a better reception state. Then, the alternative station search control is performed based on the AF list obtained from the station A (YES in step 114, 115,
116, 107), where the main side remains tuned to the desired station B, the search for an alternative station based on the AF list obtained from the desired station B is continued.

In this way, when either station is found in the search for the alternative station, the vehicle is indicated by the shaded portions ab and ab in FIG.
As shown by c and ac, they are in the overlapping part of the service areas of stations A and B. Therefore, if the alternative station is constantly searched, the alternative station is found, and if the reception status is better than the desired station receiving on the main side, the alternative station immediately wants to receive on the main side. Since frequency diversity operation for changing stations is performed, desired programs can be continuously and automatically listened to. Further, the voice output does not become silent during the search for the alternative station.

After that, the vehicle further approaches the present desired station B, moves out of the service area of the alternative station A, and P _{5 in} FIG.
Comes with the (a P ₅ other stations within the service area of the desired station B located in the range b that does not overlap with the service area), no longer in search of alternative stations to be made by the sub-tuner 6, the same PI code The station will not be found. At this time, the tuning control unit 17c determines NO in step 113 after completing one round of search based on the AF list,
Returning to step 101, the sub tuner 6 is tuned to the same desired station B as the main side tuner 3, and the antenna diversity operation is performed by the main side and the sub side. Therefore, while moving in the service area of the desired station B, avoiding a decrease in the received electric field strength due to multipath noise or some reason,
The desired program can be listened to under good reception conditions.

In the above embodiment, the data comparison section 17a sets the data comparison signal to 0 during the search for the alternative station, but the data comparison operation may be performed normally during the search. Further, in step 114 of FIG. 2, the one with the better reception state on the main side and the sub side is determined based on the output of the reception state comparison circuit 11, but based on the outputs of the S meter circuits 6c and 6c, The determination may be made, or the data comparison between the RDS data on the main side and the data on the sub side may be made based on the result of comparison by the data comparison unit 17a. Further, when performing the antenna diversity operation, the diversity control circuit 13 may perform switching control of the switching circuit 12 based on only the output of the reception state comparison circuit 11 so that the main side and the sub side have better reception states. Good.

Further, while the antenna diversity operation is being performed, the controller 17 searches for an alternative station at regular intervals, but unlike this, the reception state detection circuits 9 and 10 (or the S meter circuit 3c). And 6c)
The output of is constantly checked, and when the reception conditions on the main side and the sub side both deteriorate below a certain level, the sub station searches for an alternative station, and if no alternative station is found during the search,
Return to the antenna diversity operation and reception status check, if a station is found during the search, further compare the reception status of the desired station and the alternative station, and if the desired station is better, substitute as long as the station is found. Continue searching for stations, and if the alternative station has a better reception condition, change the desired station to be received on the main side to the alternative station and obtain a new AF list from the changed desired station. If the alternative station is not found during the search for the alternative station in frequency diversity operation, the original antenna diversity operation and the reception of the main side and sub side are performed. You may make it return to a state check operation.

[0034]

According to one of the present inventions described above, (1), 2
The two RDS radio receiving means individually connected to one antenna are tuned to the same desired station for a certain predetermined time and the AF list is obtained, and the receiving states of the two RDS radio receiving means are compared. Select the better one and output it as voice (2).
While the DS radio receiving means continues to receive the desired station, the other RDS radio receiving means searches the alternative station using the AF list, and when the alternative station is not found, (1) again
Returning to step 2, the two RDS radio receiving means are both tuned to the desired station, and when a station is found by the search for the alternative station in (3), (a) and (2), the reception condition is better than that of the desired station. If no alternative station is found, as long as the station is found, the alternative station search is repeated to find an alternative station with a better reception status than the desired station. If no station is found, return to (1),
In (b) and (a), if an alternative station having a better reception state than the desired station is found, the desired station being received by one of the RDS radio receiving means is changed to the alternative station, and the changed desired station performs AF.
After obtaining the list, (c) the other RDS radio receiving means is used to search the alternative station again using the AF list, and when the alternative station is not found, the procedure returns to (1) again, and (d)
When a station is found in the alternative station search in (c), the procedure returns to (a), and since it is configured to search for an alternative station with a better reception status than the desired station, it is desired at the end of the service area of the desired station. When a vehicle arrives at an overlapping area with the service area of an alternative station broadcasting the same program as the station, the station will be found by the alternative station search that has been regularly performed until then. After that, the alternative station is continuously searched, and if the alternative station is receiving better than the desired station,
Since the desired station is changed to the alternative station, the desired program can be continuously listened to without searching for the alternative station by manual channel selection. On the other hand, if there is a vehicle in the service area of the desired station and it is out of the service area of any other alternative station that is broadcasting the same program, the station will be searched periodically for the alternative station. Most of the time, 2 RDs not found
Both S radio receiving means are tuned to the same desired station,
Since the one with the better reception condition is selected and the sound is output, even if the reception condition of the RDS radio receiving means which is outputting the sound is deteriorated due to multipath noise interference or the like, the other RDS which is not interfered with is received. It is possible to listen to the desired program satisfactorily by switching to the radio receiving means and outputting audio.

According to another aspect of the present invention, (1),
The two RDS radio receiving means individually connected to the two antennas are tuned to the same desired station together to obtain the AF list, and the receiving states of the two RDS radio receiving means are compared, and the better one is selected. (2) When the receiving condition of the desired station in the two RDS radio receiving means is deteriorated by a certain degree or more, the selected RD is output while continuing the reception of the desired station by one RDS radio receiving means.
The S radio receiving means searches the alternative station using the AF list, and when the alternative station is not found, returns to (1) again,
When a station is found in the alternative station search in (3), (a) and (2), the desired station is searched for an alternative station having a good reception state. If no station is found, the alternative station is searched as long as the station is found. Repeat the search to find an alternative station with a good reception condition from the desired station. If no station is found, return to (1), (b)
If an alternative station having a better reception condition than the desired station is found in (a), the desired station being received by one of the RDS radio receiving means is changed to the alternative station and the AF list is obtained from the changed desired station. Then, (c) using the AF list, the other R
The alternative station is searched again by the DS radio receiving means, and when the alternative station is not found, the procedure returns to (1) again, and (d) and (c).
If a station is found in the search for an alternative station in (a)
Since it is configured to search for an alternative station with a good reception condition from the desired station, the overlapping part with the alternative station service area broadcasting the same program as the desired station at the end of the desired station service area When the vehicle arrives at the RD, the reception conditions of the two RDS radio receiving means deteriorate and the RD of one
While the S radio receiving means continues to receive the desired station, the other RDS radio receiving means continuously searches for an alternative station, and the reception state of the alternative station is higher than that of the desired station being received by one of the RDS radio receiving means. If it is good, the desired station is changed to the alternative station, so that the desired program can be continuously listened to without manually searching for the alternative station. On the other hand, when the vehicle is in the service area of the desired station and is out of the service area of any other alternative station that is broadcasting the same program, the reception status of both RDS radio reception means deteriorates. Since it is rare to do so, the two RDS radio receiving means are almost always tuned to the same desired station, and the one with the better reception state is selected and the voice is output. If the receiving condition of the radio receiving means is only deteriorated, the other RDS radio receiving means which is not disturbed is immediately switched to the audio output, so that the desired program can always be listened to satisfactorily.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an on-vehicle RDS radio receiver according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the controller.

FIG. 3 is an explanatory diagram showing a relationship between a vehicle position and a receiving operation.

[Explanation of symbols]

 1 main antenna 3 main tuner 4 sub antenna 6 sub tuner 7, 8 noise component detection circuit 9, 10 reception state detection circuit 11 reception state comparison circuit 12 switching circuit 13 diversity control circuit 17 controller 17a data comparison unit 17b data registration unit 17c tuning Control unit

Claims (2)

[Claims] (1) Two RDS radio receiving means individually connected to two antennas are tuned to the same desired station for a certain predetermined time and an AF list is obtained, and two RDS are received. The receiving states of the radio receiving means are compared, and the better one is selected and voice output is performed. (2) After a certain period of time, one RDS radio receiving means continues to receive the desired station and the other RDS radio receiving When the alternative station is searched using the AF list by the means and no alternative station is found, the procedure returns to (1) and the two RDs are returned.
When both the S radio receiving means are tuned to the desired station and the station is found in the alternative station search in (3), (a) and (2), if the reception condition is not better than the desired station, the station is As long as it is found, the alternative station search is repeated to find an alternative station that is in a good reception state from the desired station. If no station is found, return to (1), and in (b) and (a) If a good alternative station is found, the desired station received by one of the RDS radio receiving means is changed to the alternative station, and the desired desired station after the change is changed to AF.
After the list is obtained, (c) the alternative list is searched again by the other RDS radio receiving means using the AF list, and when the alternative station is not found, the procedure returns to (1) again, and (d) (c When a station is found by the search for an alternative station in), the procedure returns to (a), and an alternative station having a good reception condition is searched for from the desired station. 2. (1) Two RDS radio receiving means individually connected to two antennas are tuned to the same desired station to obtain an AF list and two RDS radio receiving means are tuned.
The receiving states of the DS radio receiving means are compared with each other, and the better one is selected to output the sound. (2) When the receiving states of the desired stations in the two RDS radio receiving means are both deteriorated by a certain amount or more, one RDS is received.
While continuing to receive the desired station with the radio receiving means, the other R
When the alternative station is searched using the AF list by the DS radio receiving means and the alternative station is not found, the procedure returns to (1) again, and the station is searched for the alternative station in (3), (a) and (2). If found, if the reception condition is not better than the desired station, as long as the station is found, the alternative station search is repeated to find an alternative station with a better reception condition than the desired station, and the station cannot be found. For example, returning to (1), if an alternative station having a better reception condition than the desired station is found in (b) and (a), change the desired station received by one of the RDS radio receiving means to the alternative station, AF from the desired station after the change
After the list is obtained, (c) the alternative list is searched again by the other RDS radio receiving means using the AF list, and when the alternative station is not found, the procedure returns to (1) again, and (d) (c When a station is found by the search for an alternative station in), the procedure returns to (a), and an alternative station having a good reception condition is searched for from the desired station.