JP2001016150A - Multiplex broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiplex broadcast receiver capable of preventing the reception interference to a main receiving station by an adjacent station by monitoring the relevant station adjacent to the main receiving station while effectively utilizing respective tuners. SOLUTION: This device has a main tuner 10 for receiving the main receiving station, a sub-tuner 20 for searching and receiving a receiving frequency adjacent to that of the main receiving station, a memory 6 for storing the receiving frequency of the main receiving station and the receiving frequency of a subordinate station under broadcasting the same program as this main receiving station, and microcomputer 3 for making the sub-tuner 20 receive the subordinate station and switching the reception of this subordinate station to the main tuner 10 when it is discriminated by the sub-tuner 20 that the reception level of the adjacent station corresponding to the receiving frequency under search reception is higher than a prescribed level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex broadcast receiving apparatus for receiving multiplex broadcasts such as a radio data system (RDS) system which provides various services to listeners of FM radio broadcasts. And a multiplex broadcast receiving apparatus employing a double tuner method.

[0002]

2. Description of the Related Art Conventionally, such a multiplex broadcast has been
Information related to the program broadcast and information such as traffic information are multiplexed as data into the broadcast radio wave of the M radio broadcast, and the receiving side demodulates the multiplexed data, so that the listener of the FM radio broadcast can receive the data. There is an RDS system that can provide various services.

[0003] Such an RDS system is mainly adopted in Europe, and a broadcasting station network is provided so that the same program as a currently receiving broadcasting station, a main receiving station, can be heard even while traveling around Europe. For example, in addition to the broadcast program, an alternative frequency (AF) list that lists reception frequencies of a main reception station that is currently receiving and alternative stations that are broadcasting the same program as the main reception station is listed. The network configuration is such that it is multiplexed as RDS data into broadcast radio waves and distributed to each multiplex broadcast receiving device.

[0004] In other words, under such an RDS network configuration, according to a multiplex broadcast receiving apparatus employing a normal single tuner system, the same program that can be replaced based on an AF list obtained from RDS data is used. By muting for a certain period of time in order to follow the alternative station that broadcasts, an alternative station having a good reception level can be searched and received.

However, according to the multiplex broadcast receiving apparatus employing such a single tuner system, a situation has arisen in which it is impossible to search and receive an alternative station having a good reception level unless mute is applied for a certain period of time.

Further, according to the multiplex broadcast receiving apparatus employing such a single tuner system, it is necessary to search for and receive an alternative station based on the AF list and to switch to an alternative station having a good reception level. When the conditions are met, it takes a certain amount of time to tune to the alternative station with a good reception level by detuning with the currently receiving main reception station, which may cause switching noise. Was.

In order to overcome such a situation, a multiplex broadcast receiving apparatus employing a double tuner system, in which a tuner for normal reception and a tuner for following an alternative station are separately provided, has been known in recent years. According to the multiplex broadcast receiving apparatus adopting such a double tuner system, the alternative station tracking tuner is provided with the alternative station tracking tuner while performing the normal reception with the main receiving station by the normal reception tuner. By doing so, it is possible to efficiently search and receive an alternative station having a good reception level without muting for a certain period of time.

Further, according to the multiplex broadcast receiving apparatus employing such a double tuner system, a tuner for following an alternative station is kept in a standby state in synchronization with the alternative station, and is currently being received by a tuner for normal reception. If it is detuned from the main receiving station, switching reception can be performed instantaneously, so that switching noise does not occur.

As described above, according to the multiplex broadcast receiving apparatus employing the double tuner system, the efficiency of searching for an alternative station can be greatly improved, and the switching noise can be significantly reduced.

[0010]

However, according to the multiplex broadcast receiving apparatus employing the above-mentioned conventional double tuner system, only when the reception level of the main receiving station receiving by the tuner for normal reception deteriorates, Since the tuner for following the alternate station is used for the following operation or the switching reception operation of the substitute station, for example, when the reception level of the main receiving station receiving by the normal receiving tuner is good, the tuner for following the alternative station is used. Was not used.

Further, according to the multiplex broadcast receiving apparatus employing the conventional double tuner system, for example, even if the receiving level of the main receiving station being received by the tuner for normal reception is good, the receiving level of the main receiving station can be improved. If there is an adjacent station adjacent to the reception frequency, there is a problem that the reception of the main receiving station currently receiving is obstructed by the adjacent station.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to monitor an adjacent station of a main receiving station while effectively utilizing each tuner so that the adjacent station can be monitored. It is an object of the present invention to provide a multiplex broadcast receiving apparatus capable of preventing in advance the reception interference of a main receiving station due to the above.

[0013]

According to a first aspect of the present invention, there is provided a multiplex broadcast receiving apparatus comprising:
First receiving means for receiving a broadcasting station, second receiving means for searching for a receiving frequency adjacent to a receiving frequency of a main receiving station which is a broadcasting station being received by the first receiving means, and the main receiving station Alternative frequency storing means for storing the receiving frequency of the alternative station which is broadcasting the same program as the main receiving station, and the receiving level of the adjacent station corresponding to the receiving frequency which is being searched and received by the second receiving means. Is an adjacent station level determining means for determining whether or not is a predetermined level or more,
If the adjacent station level determining means determines that the reception level of the adjacent station is equal to or higher than the predetermined level, the first receiving means changes the reception frequency of the alternative station corresponding to the main reception station being received by the alternative frequency. Control means for reading from the storage means, causing the second receiving means to receive the alternative station based on the read reception frequency, and causing the first receiving means to switch and receive the alternative station being received by the second receiving means; It is characterized by having.

Therefore, according to the multiplex broadcast receiving apparatus of the first aspect of the present invention, during the reception of the main receiving station by the first receiving means, the search reception to the receiving frequency adjacent to the main receiving station is performed by the second receiving means. When the reception level of the adjacent station received by the search reception is equal to or higher than a predetermined level, it is determined that the adjacent station causes a reception disturbance to the main reception station, and the first reception means performs the reception. Since the main receiving station is switched to the alternative station for reception, monitoring the adjacent station of the main receiving station while effectively utilizing the second receiving means prevents the receiving interference of the main receiving station by the adjacent station in advance. This can be prevented, and the user can enjoy the same program.

In the multiplex broadcast receiving apparatus according to a second aspect of the present invention, in addition to the configuration according to the first aspect, the control means sequentially receives an alternative station of the main receiving station by the second receiving means. The first receiving means switches and receives the substitute station having the best reception level among the substitute stations.

Therefore, according to the multiplex broadcast receiving apparatus of the second aspect of the present invention, in addition to the effect of the first aspect, an alternative station of the main receiving station is sequentially received by the second receiving means. Of the alternative stations, the one with the best reception level is the first one.
Since the receiving means is switched to receive, the same program can be enjoyed by the user in a state of good reception sensitivity.

In the multiplex broadcast receiving apparatus according to a third aspect of the present invention, in addition to the configuration according to the first or second aspect, the search receiving target of the second receiving means is being received by the first receiving means. ± 100K from receiving frequency of main receiving station
The reception frequency is in the range of Hz.

Therefore, according to the multiplex broadcast receiving apparatus of the third aspect of the present invention, in addition to the effect of the first or second aspect, the main receiving station which is most liable to interfere with reception at the main receiving station. ± 100KH from reception frequency
Since the adjacent stations within the range of z are set as search reception targets, by monitoring the main receiving station by the adjacent station in the optimum range, it is possible to prevent the adjacent station from interfering with the reception of the main receiving station in an optimum state in advance. Can be prevented.

In the multiplex broadcast receiving apparatus according to a fourth aspect of the present invention, in addition to the configuration according to the first, second or third aspect, the control means further comprises: The reception frequency of the main reception station and the reception frequency of the alternative station broadcasting the same program as the main reception station are extracted, and the extracted reception frequency of the main reception station and the reception frequency of the alternative station are stored in the alternative frequency storage means. It is characterized by doing.

Therefore, according to the multiplex broadcast receiving apparatus of the fourth aspect of the present invention, in addition to the effects of the first, second, or third aspect, the multiplex broadcast receiving apparatus of the present invention is provided with an alternative station corresponding to the currently receiving main receiving station. Enable switching reception.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An RDS receiver according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration inside the RDS receiver shown in the present embodiment.

An RDS receiver 1 shown in FIG. 1 is a main tuner for receiving via an antenna 2 receiving a program broadcast and FM multiplex broadcast including RDS data multiplexed on the program broadcast, which are broadcasted by a plurality of broadcast stations. 10 and sub tuner 2
This is a double tuner system consisting of 0s.

The main tuner 10 according to the present invention is configured as follows.
The antenna 2 corresponds to the first receiving means described above.
A front end 11 for selecting a desired station from the FM multiplex broadcast received at step 1, converting the reception frequency of the desired station to an intermediate frequency and amplifying the same, and an FM detection for FM detecting the intermediate frequency signal amplified by the front end 11 A circuit 12 and a multiplexer 13 for demodulating a detection output signal of the FM detection circuit 12 into an audio signal and separating the signal into audio signals of L (left) and R (right) channels in the case of stereo broadcasting;
A reception level detection circuit for detecting a reception level from a detection output signal of the M detection circuit; and a microcomputer for controlling the reception level detected by the reception level detection circuit for controlling the entire RDS receiver. To be transmitted.

A speaker 5 is connected to an output terminal of the multiplexer 13 via a power amplifier 4.

Further, the main tuner 10 is connected to a PLL circuit 15 which oscillates an oscillation signal having a reception frequency corresponding to a desired station to be received and supplies the oscillation signal to the front end 11. By changing the frequency division ratio data of the program frequency divider in the PLL circuit 15 in response to a channel selection command from 3, the main tuner 10 controls the reception frequency tuned to the desired station.

The sub-tuner 20 corresponds to the second receiving means described in claim 1 of the present application, and substitutes for the same program based on the AF list in the RDS data extracted from the FM multiplex broadcast received by the antenna 2. , A front end 21 for converting the reception frequency of the substitute station to an intermediate frequency and amplifying the same, an FM detection circuit 22 for FM detecting the intermediate frequency signal amplified by the front end 21, and an FM detection circuit It comprises a reception level detection circuit 25 for detecting the reception level from the 22 detection output signals.

The circuit for demodulating RDS data from each detection output signal output from the main tuner 10 and the sub tuner 20 is an FM detection circuit 1 of the main tuner 10.
A switching circuit 23 that can select the detection output signal from the FM detection circuit 2 and the detection output signal from the FM detection circuit 22 of the sub-tuner 20 as appropriate under the control of the microcomputer 3; From the detected output signal
An RDS decoder 24 for demodulating data and transmitting the demodulated RDS data to the microcomputer 3 is provided.
The switching timing of the switching circuit 23 is determined by the microcomputer 3
Is switched in response to the control of the main tuner 10.
It demodulates S data, and achieves each purpose of RDS data demodulation relating to an alternative station when switched to the sub-tuner 20 side.

The RDS data includes an AF list indicating the reception frequency of an alternative station broadcasting the same program, a program identification (P
I) A configuration including data such as a code and a program format (PTY) code indicating program contents, and storing an AF list, a program identification code, and the like obtained from the RDS data in a memory 6 connected to the microcomputer 3. And

The sub-tuner 20 is connected to a PLL circuit 26 that oscillates an oscillation signal having a reception frequency corresponding to a desired station to be received and supplies the oscillation signal to the front end 21. By changing the frequency division ratio data of the program frequency divider in the PLL circuit 26 in response to a channel selection command from the sub-tuner 20, the sub-tuner 20 controls the reception frequency tuned to the desired station.

When the main tuner 10 is receiving the main receiving station, the microcomputer 3 detects the receiving level of the main receiving station by the receiving level detecting circuit 14, and if this receiving level is not higher than the predetermined level, , The memory 6
Based on the AF list stored in the main station, the reception frequencies of the alternative stations broadcasting the same program as the main reception station are sequentially read out, the sub-tuner 20 performs the reception operation of each alternative station, and detects the reception level. The circuit 25 detects the reception level of each alternative station, and controls the main tuner 10 so that the alternative station having the best reception level is switched and received.

When the main tuner 10 is receiving the main receiving station, the microcomputer 3 detects the receiving level of the main receiving station by the receiving level detecting circuit 14, and when the receiving level is higher than a predetermined level. If so, the sub-tuner 20 performs search reception within a range of ± 100 KHz from the reception frequency of the main reception station, and further determines that there is an adjacent station whose reception level is equal to or higher than a predetermined level within this search range. Then, the reception frequency of the substitute station of the same program as the main reception station is read from the AF list,
Based on this AF list, the main tuner 10 is controlled so that the alternative station having the best reception level is switched and received.

The adjacent station level judging means and control means described in claim 1 of the present application correspond to the microcomputer 3, and the alternative frequency storage means corresponds to the memory 6.

Next, the operation of the RDS receiver 1 shown in this embodiment will be described. FIG. 2 shows RD shown in this embodiment.
5 is a flowchart illustrating a processing operation of the microcomputer 3 in the adjacent station detection switching processing of the S receiver 1.

Normally, RDS receiver 1 shown in the present embodiment
If the reception level of the main receiving station currently being received by the main tuner 10 is not equal to or higher than the predetermined level, an alternative station of the main receiving station is sequentially sent to the sub tuner 20 based on the AF list stored in the memory 6. As shown in FIG. 3, the alternative station having a good reception level switches and receives the main tuner 10 as shown in FIG. 3, so that the alternative station having a good reception level always performs switching reception.

On the other hand, FIG.
In the adjacent station detection switching process shown in (2), if the reception level of the main receiving station currently being received by the main tuner 10 is equal to or higher than a predetermined level, the adjacent station that may interfere with the reception of the main receiving station is monitored. Prevent reception interference by neighboring stations.

The microcomputer 3 shown in FIG. 2 reads out the reception frequency of the substitute station of the main reception station from the AF list stored in the memory 6 (step S21), and substitutes the sub-tuner 20 based on this reception frequency. The station is received (step S22), the reception level of the received alternative station is detected and stored (step S23), and it is determined whether there is another alternative station to be received based on the AF list. Do
(Step S24).

If it is determined that there is no other alternative station to be received, it is determined whether there is an alternative station having a good reception level, that is, an alternative receivable station among the alternative stations received in step S22. (Step S25).

If there is a receivable alternative station, the AF list relating to the alternative station is stored and updated in the memory 6.
(Step S26) The sub-tuner 20 starts a search reception operation within a reception frequency range from the reception frequency of the main reception station to +100 KHz (Step S27),
It is determined whether the sub-tuner 20 has detected an adjacent station during search reception (step S28).

If an adjacent station is detected during the search reception by the sub-tuner 20, as shown in FIG. 3, the reception level detection circuit 25 detects the reception level of the adjacent station (step S29). It is determined whether or not the reception level of the adjacent station has exceeded a predetermined level (Step S
30).

When the reception level of the adjacent station is equal to or higher than a predetermined level, the adjacent station determines that there is a possibility of causing reception disturbance to the main reception station, and the A in the memory 6 is stored.
The reception frequency of the alternative station of the main reception station is read from the F list (step S31), and based on the reception frequency, the main tuner 10 switches and receives the alternative station (step S32). The processing operation ends.

If no adjacent station can be detected in step S28, or if the reception level is not higher than the predetermined level in step S30, the sub-tuner 2
+100 KHz from the receiving frequency of the main receiving station by 0
It is determined whether or not the search receiving process has been completed (step S33).

+10 from the reception frequency of the main reception station
Unless the search reception processing up to 0 KHz has been completed, further search reception processing is continued (step S
34), and proceed to step S28.

If the search reception processing from the reception frequency of the main reception station to +100 KHz is completed in step S33, the sub-tuner 20 performs the search reception operation from the reception frequency of the main reception station to -100 KHz. Is started (step S35), and it is determined whether an adjacent station is detected during the search reception process (step S36).

When the adjacent station is detected, the reception level of the adjacent station is detected (step S37), and it is determined whether or not the reception level of the adjacent station is higher than a predetermined level (step S38).

When the reception level of the adjacent station becomes equal to or higher than a predetermined level, the adjacent station determines that there is a possibility of causing a reception disturbance to the main reception station, and the A stored in the memory 6 is determined.
The process proceeds to step S31 in which the reception frequency of the substitute station of the main reception station is read from the F list.

If it is determined in step S38 that the reception level is not higher than the predetermined level, it is determined whether or not the search reception processing operation from the reception frequency of the main reception station to -100 KHz has been completed (step S39).

If the search reception processing operation up to -100 KHz has been completed, a predetermined time, for example, a 10-second timer is started (step S40), and it is determined whether or not the 10-second timer has expired (step S40). S4
1). If the 10-second timer has expired, step S21 is executed to start the processing operation again.
Move to When the reception level of the main receiving station becomes lower than the predetermined level, the processing shifts to a normal processing operation.

If there is no receivable substitute station in step S25, the process proceeds to step S40.

If no adjacent station is detected during the search reception processing in step S36, the flow shifts to step S39. If the search reception processing up to -100 KHz has not been completed in step S39, the process shifts to step S42 to execute the search continuation process, and shifts to step S36.

According to the present embodiment, the main tuner 1
0, if the reception level of the main receiving station currently receiving is good, the receiving frequency of the alternative station of the main receiving station is read out based on the AF list stored in the memory 6, and the sequentially read out receiving frequencies are read out. On the basis of the frequency, the sub-tuner 20 sequentially receives the substitute stations, extracts the substitute station having the best reception level from the sequentially received substitute stations, and stores and updates the memory 6. As shown in FIG. 3, a search is made for an adjacent station within a range of ± 100 KHz adjacent to the reception frequency of the main reception station. The main tuner 10 is determined to be a broadcasting station that may cause the sub-tuner 20 based on the AF list in the memory 6. While attaining use, by monitoring the neighbor of the main receiving station, the adjacent station can be prevented in advance reception interference in the main receiving station by further can enjoy the same program to the user.

[0051]

According to the multiplex broadcast receiving apparatus according to the first aspect of the present invention, the receiving frequency adjacent to the main receiving station during the reception of the main receiving station by the first receiving means. Is performed by the second receiving means, and when the reception level of the adjacent station received by the search reception is equal to or higher than a predetermined level, it is determined that the adjacent station causes reception interference to the main reception station, and the first reception is performed. Since the main receiving station currently receiving by the receiving means is switched to the alternative station, the adjacent receiving station is monitored by monitoring the adjacent station of the main receiving station while effectively utilizing the second receiving means. It is possible to prevent the reception interference of the receiving station in advance, and it is possible for the user to enjoy the same program.

According to the multiplex broadcast receiving apparatus of the second aspect of the present invention, in addition to the effect of the first aspect, the alternative receiving station of the main receiving station is sequentially received by the second receiving means. Of these, the alternative station having the best reception level is switched and received by the first receiving means, so that the user can enjoy the same program with good reception sensitivity.

According to the multiplex broadcast receiving apparatus of the third aspect of the present invention, in addition to the effect of the first or second aspect, the reception of the main receiving station is most likely to cause the reception interference to the main receiving station. Since an adjacent station within a range of ± 100 KHz from the frequency is set as a search reception target, an adjacent station of the main receiving station is monitored in an optimum range, so that the interference of the main station by the adjacent station can be optimized. The state can be prevented in advance.

According to the multiplex broadcast receiving apparatus of the fourth aspect of the present invention, in addition to the effects of the first, second or third aspect, switching reception to an alternative station corresponding to the main receiving station currently receiving. Enable.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration inside an RDS receiver showing an embodiment in a multiplex broadcast receiving apparatus of the present invention.

FIG. 2 is an operation explanatory diagram briefly showing a processing operation related to an adjacent station detection switching process of the RDS receiver shown in the present embodiment.

FIG. 3 is a flowchart showing a processing operation of a microcomputer relating to a neighboring station detection switching process inside the RDS receiver shown in the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 RDS receiver (multiplex broadcast receiver) 3 Microcomputer (adjacent station level judgment means, control means) 6 Memory (alternative frequency storage means) 10 Main tuner (first reception means) 20 Sub tuner (second reception means)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J103 AA13 BA02 BA06 CA04 CB04 DA05 DA07 FA05 GA06 GA07 GA11 GB05 HA04 JA09 5K020 AA04 BB04 DD27 EE05 JJ02 JJ09 5K052 AA11 BB04 BB15 CC04 DD01 EE19 GG02 GG32 GG33 GG33 GG33 GG33 GG33 GG33 5K061 AA03 AA09 BB04 BB05 BB06 CC11 CC16 CC23 CC27 FF12 FF17

Claims (4)

[Claims] 1. A first receiving means for receiving a broadcasting station, and a second receiving means for searching for a receiving frequency adjacent to a receiving frequency of a main receiving station which is a broadcasting station being received by the first receiving means. An alternative frequency storage unit that stores a reception frequency of the main reception station and a reception frequency of an alternative station that is broadcasting the same program as the main reception station; and a second reception unit that corresponds to a reception frequency during search reception. An adjacent station level determining means for determining whether the reception level of the adjacent station is equal to or higher than a predetermined level; and determining that the reception level of the adjacent station is equal to or higher than the predetermined level by the adjacent station level determining means. The receiving frequency of the alternative station corresponding to the main receiving station being received by the first receiving means is read from the alternative frequency storage means, and the alternative station is received by the second receiving means based on the read receiving frequency. Is allowed, multiplex broadcast receiving apparatus characterized by a control means for switching reception to the first receiving means alternative station being received by the second receiving means. 2. The control means sequentially receives an alternative station of a main receiving station by the second receiving means, and causes the first receiving means to switch and receive an alternative station having the best reception level among the alternative stations. The multiplex broadcast receiving apparatus according to claim 1, wherein: 3. The search receiving object of the second receiving means,
3. The multiplex broadcast receiving apparatus according to claim 1, wherein the receiving frequency is within a range of ± 100 KHz from the receiving frequency of the main receiving station receiving the first receiving means. 4. The control means extracts a reception frequency of the main reception station and a reception frequency of an alternative station broadcasting the same program as the main reception station from a broadcast wave of the main reception station currently receiving, This extracted,
4. The multiplex broadcast receiving apparatus according to claim 1, wherein the receiving frequency of the main receiving station and the receiving frequency of the alternative station are stored in the alternative frequency storage means.