JPH08330994A - Signal processor for fm receiver - Google Patents

Abstract

PURPOSE: To provide the signal processor for an FM receiver which efficiently receives FM multiplex broadcasting. CONSTITUTION: Received and demodulated multiplexed data is successively stored to constitute a program by a program constitution part 42. Meanwhile, an update flag discrimination part 50 discriminates whether update flags of received multiplexed data and multiplexed data received before coincide with each other or not in the case of coincidence between service discrimination codes, program numbers, and page numbers of these two multiplexed data. When update flags coincide with each other, a station change permission signal is generated; and thus, multiplexed data of another FM multiplex broadcasting station can be received in the transmission period of the same multiplexed data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a configuration of an FM receiver and a signal processing device used therein, and more particularly to a configuration of an FM receiver having a reception function of FM multiplex broadcasting in which data such as character information is multiplexed.

[0002]

2. Description of the Related Art Recently, FM multiplex broadcasting has been started in which character information is multiplexed with FM broadcasting for broadcasting. In this FM multiplex broadcasting, character information or the like is encoded into digital data having a hierarchical structure and multiplexed with an FM stereo signal of an existing FM broadcasting station to be broadcast, and FM multiplex data is demodulated by a conventional FM receiver. The service can be received by adding a decoder for displaying and a display for displaying the demodulated data. At present, text programs such as news are being broadcast. Also, program broadcasting of graphic information, traffic jam information, etc., which is useful for automobile navigation systems, etc., is being studied.

[0003]

However, although the FM multiplex broadcasting can be received in a vehicle or a mobile body such as a portable FM receiver, a large amount of information cannot be transmitted according to the FM multiplex broadcasting standard. It is difficult, and it takes about several tens of milliseconds until a program can be constructed and displayed from the received multiplex data. Therefore, it is desired to efficiently receive FM multiplex broadcasting.

However, in the FM multiplex broadcasting, for example, in programs such as news and weather forecast, multiplex data having the same content is often repeatedly broadcast. And
On the other hand, when one broadcasting station is being received, the FM multiplex broadcasting of another broadcasting station cannot be received, and especially when receiving a program in which data is repeatedly broadcasted, a useless reception time is received. There was the problem of becoming longer.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a signal processing device of an FM receiver capable of efficiently receiving FM multiplex broadcasting.

[0006]

In order to achieve the above object, the signal processing device of the FM receiver of the present invention has the following features.

A signal processing device used in an FM receiver for demodulating and displaying multiplex data from a received signal of FM multiplex broadcast, wherein the multiplex data received this time and the multiplex data received previously are two multiplexed data. It is characterized by having an update judging section for judging whether or not the data contents of (1) are the same, and for generating the station change permission signal when they are the same.

In addition, the update judging section 2 is provided with respect to the multiplex data received this time and the multiplex data received last time.
When the service identification number, the program number and the page number of one multiplex data are all the same, it is determined whether or not the update codes of the two multiplex data match, and if they match, a station change permission signal is generated. Characterize.

Further, a program composing section for composing program data from the demodulated multiplexed data, a plurality of program holding storage sections for storing the program data corresponding to each broadcasting station, and a broadcasting station selected. And a switching unit for switching the program holding storage unit according to the above.

[0010]

In the signal processing apparatus of the FM receiver according to the present invention, it is determined whether or not the received and demodulated multiplex data and the previously received multiplex data have the same contents. In the case of the same, the update determination unit generates a station change permission signal, and thus the FM receiver is in a state in which it is possible to change the reception broadcast station, that is, the reception frequency. Therefore, if the receiving broadcast station is changed based on the generation of this station change permission signal, it is possible to receive FM multiplex broadcasts of other broadcast stations during the same data transmission period without repeatedly receiving the same multiplex data. The reception efficiency is improved.

To determine whether the multiplex data is the same, for example, the service identification number, program number and page number attached to the FM multiplex data are referred to. If they are the same, the update determining unit determines whether or not the update code given to the multiplex data is the same. If the update codes match, the currently received multiplex data is the same as the previous multiplex data. Generates a station change permission signal.

Further, program data is constructed from the multiplexed data demodulated by the program construction unit, and this program data is stored in a program holding storage unit provided corresponding to each broadcasting station. In this way, by storing the program data of the broadcasting station corresponding to each program holding storage unit, when receiving a program in which the same data is repeatedly broadcast, the multiplexed data of a plurality of broadcasting stations received efficiently Can be held.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

[Overall Configuration of FM Receiver] FIG. 1 is a diagram showing a main configuration of an FM receiver according to an embodiment.

Broadcast radio waves received by the antenna are supplied to the tuner 10. The tuner 10 mixes the signal of the frequency shifted by 10.7 MHz with respect to the frequency of the desired station with the radio wave received by the antenna, converts the signal of the desired station into an intermediate frequency (IF = 10.7 MHz), and takes it out.

The extracted signal of the desired station is amplified and detected by the IF amplification detection circuit 12, and the detection signal is output from the IF amplification detection circuit 12.

The detection signal output from the IF amplification detection circuit 12 is supplied to the MPX 14, and the normal FM stereo signal is demodulated by the MPX 14 and supplied to the speaker 18 as the L signal and the R signal via the amplifier 16.
Stereo sound is output from the speaker 18.

Further, the reception broadcasting station is changed by the tuning microcomputer 22 automatically changing the reception frequency based on the generation of the station change permission signal from the update flag judging section 50, or by the operator selecting the station. This is done by operating the key 20. Then, the tuning microcomputer 22 supplies tuning data corresponding to the requested broadcasting station to the tuner 10, whereby the receiving broadcasting station in the tuner 10 is changed. Note that the normal selection of the desired broadcasting station is performed by the operator operating the channel selection key 20, as in the conventional FM receiver.

Further, in this embodiment, the IF amplification detection circuit 1
A band pass filter (BPF) 30 for demodulating the FM multiplex data and an FM multiplex decoder 3 on the output side of 2.
2, and a data processing unit 40 for processing the demodulated FM multiplex data is provided.

The BPF 30 is a filter which passes a signal of 76 kHz which is a carrier frequency of FM multiplex data, extracts a signal in the band of 76 kHz from the detection signal output from the IF amplification detection circuit 12, and detects the detection signal by LMSK modulation. FM multiplexed data (LMSK)
Signal). L taken out by BPF30
The MSK signal is supplied to the FM multiplex decoder 32, where it is demodulated into digital data of "1" and "0". Further, the FM multiplex decoder 32 detects a block identification code (BIC) or the like from the demodulated digital data, establishes frame synchronization and block synchronization based on this code, and forms a frame structure of multiplex data as shown in FIG. Reproduce.

The reproduced multiplex data is sequentially supplied to the data processing section 40. The data processing unit 40 supplies the obtained multiplex data to the program composing unit 42, and the program composing unit 42
Composes the program data by accumulating this multiplex data. The configured program data is provided for each broadcasting station under the control of the display RAM switching control unit 52 (station A, station B).
Program holding storage units 44, 46 (hereinafter, RAM 2, RAM
(Denoted as 3) and selectively stored. Further, the display RAM switching control unit 52 controls the RAM 2, R 2
Program data is selectively read out from any of AM3 and displayed on a display device 48 such as a liquid crystal display. In the figure, the Kanji font ROM 47 stores the Kanji font corresponding to the character code, and the display unit 48
It is referred to when displaying characters in.

Further, the data processing section 40 is provided with an update flag determining section 50, and the update flag determining section 5 is provided.
0 determines whether or not the received multiplex data is update data based on the update code (update flag) attached to the obtained multiplex data, and generates a station change permission signal when it is not update data. The channel selection microcomputer 22 is connected to the update flag determination unit 50, and the update flag determination unit 5
When 0 generates a station change permission signal, this is supplied to the channel selection microcomputer 22.

[Operation of FM Receiver] FM multiplexed data which is multiplexed and broadcast with an FM stereo signal is, for example, DARC.
In the case of (DATA RADIO CHANNEL) standard, as shown in FIG. 3, it has a frame structure of 288 × 272 bits.

As shown in FIG. 4, one row (block: 288 bits) of a frame includes a 16-bit block identification code (BIC) and an error correction code (14-bit CRC, for correcting an error in received data). 82 bits of parity) and 176 bits of data packets. A data packet for one block is composed of a leading 32-bit prefix and a 144-bit data block following the prefix.

Further, as shown in FIG. 5, the 32-bit prefix is a 4-bit service identification code indicating a service type such as characters, figures, traffic information, etc. of an FM multiplex broadcast program and received multiplex data. It is composed of a 2-bit update code indicating whether it is update data, an 8-bit program number, a 6-bit page number, and the like.

The detection of the update data in the FM multiplex data of the standard as described above is performed by the procedure shown in FIG. Hereinafter, this detection procedure will be described with reference to FIGS. 1 and 2.

First, the FM multiplex data is received (S
1), the multiplexed data is demodulated as described above, and this is sequentially stored in the program composing unit 42 of the data processing unit 40.
The program configuration unit 42 compares the service identification code (SI) of the previously received multiplex data stored in the comparison memory (RAM1) provided therein with the SI of the multiplex data obtained this time, and the same. Is determined (S2).

When it is determined that they have the same SI, the program composing unit 42 next determines whether or not the program numbers of the prefixes in FIG. 5 are the same (S3).

In either S2 or S3, if the SI or the program number of the previously received multiplex data and the currently received multiplex data are not the same, that is, if it is determined that they are new multiplex data, this new multiplex data Is stored in the comparison memory (RAM1) of the program composing unit 42 (S
5). Further, the program composing unit 42 composes the program data by sequentially accumulating the new multiplex data, and the corresponding RAM
2, this program data is transferred to one of the RAM3.

On the other hand, if it is determined in S2 and S3 that the SI and the program number of the previously received multiplex data and the currently received multiplex data are the same, the process proceeds to the next step, and the process shown in FIG. It is determined what the 6-bit page number is (S4).

As a result of the page number determination made by the program composing unit 42, for example, when it is determined that page number = 1, the update flag determination unit 50 causes the update flag of the obtained multiplex data (2 bits shown in FIG. 5 to be obtained. (The update code of S) matches the update flag of the previously received multiplex data (S)
6). Here, the update flags are "00", "01",
If either “10” or “11” is added, and the previous update flag is “00” and the update flag of the data received this time is “00”, the multiplex data of this time will be The content of the following data block is the same as the previous time.

As described above, when it is determined that the update flags are the same, the update flag determination section 50 generates a station change permission signal, which is supplied to the channel selection microcomputer 22 to change the reception frequency. (S10).

On the other hand, if it is determined in S6 that the update flags are not the same, the update flag determination unit 50 does not generate a station change permission signal (S11), and the received multiplex data is program configuration as update data. The program data is stored in the comparison memory (RAM1) of the section 42, and at the same time, program data is constructed from this update data (S12).

In the same manner, the program composing section 42 uses S7 to S9.
For each page number = 2 ... N multiplexed data,
It is determined whether the update flag is the same as the previous received data of the same page. If the same as the previous time, the update flag determination unit 50 generates a station change permission signal (S1
0), if they are not the same, the station change permission signal is not generated (S1
1) The updated data is stored in the comparison memory (RAM1) of the program composing unit 42, and the program data is composed and transferred to one of the corresponding RAM2 and RAM3.

As described above, as a result of the determination, when the update flag determination section 50 generates the station change permission signal, the channel selection microcomputer 22 changes the reception frequency in the tuner 10 in response to this.

For example, when the program of station A is received,
Under the control of the display RAM switching control unit 52, the program data of the station A configured by the program configuration unit 42 is transferred to and stored in the RAM 2. Then, the obtained program of station A is displayed on the display 48.

When the update flag determination section 50 generates a station change permission signal on the assumption that the received multiplex data is the same as the already received multiplex data, the channel selection microcomputer 22 responds to this by the station selection microcomputer 22. Generate data. As a result, the reception frequency of the tuner 10 is changed from the A station to the reception frequency of the B station.

After the reception frequency is changed, the F of the station B received is received.
The M multiplexed data is demodulated, and the program composing unit 42 composes the program data of the B station. At this time, the display RAM switching control unit 52 determines that the RAM 2 is based on the generation of the station change permission signal.
The control signal for switching from the RAM to the RAM 3 is supplied to the program composing unit 42, and the B composing unit composed of the program composing unit 42 is thereby supplied.
The program data of the station is transferred to the program holding storage unit 42 of the B station.

If FM multiplex broadcasts of other broadcasting stations are received while the same multiplex data is transmitted as described above, a plurality of FM multiplex broadcasts can be stored in the program holding storage section in a short time. Can be stored as a display 48 in a shorter period of time.
It is possible to display each program on. Therefore, the reception efficiency of FM multiplex broadcasting is improved.

The update flag is set to 3 as shown in FIG.
It is attached in the 2-bit prefix, and it is possible to determine whether to update by looking at this prefix. Therefore, in the case of the same data, the change to the reception frequency of another broadcasting station can be started early without processing the multiplex data in the same frame received thereafter.

In this embodiment, when the SI, the program number and the page number are the same, the update flag is determined. However, depending on the program being broadcast and the performance of the FM receiver, a plurality of pages can be displayed. There is also a program that spans. For this reason,
It is also possible to determine whether or not the update flags are the same for all pages of the program and to generate the station change permission signal only when the update flags of all the pages are the same.

Further, in the FM multiplex broadcasting, the program number and page number are within the prefix (layer 3) according to the standard.
Not only that, it is also attached in the data header (layer 5) attached to the beginning of the data group data in the data block of FIG. Therefore, the program number and page number of layer 5 may be determined instead of the program number and page number of layer 3 as in this embodiment.

[0043]

As described above, according to the signal processing apparatus of the FM receiver of the present invention, if the multiplex data received this time is the same as the previously received multiplex data, it is detected. Generates a station change permission signal. Then, in response to the generation of the station change permission signal, the station change in the FM receiver,
That is, the reception frequency can be changed. Therefore, if the receiving broadcast station is changed based on the generation of the station change permission signal, the multiplex data of other FM multiplex broadcast stations can be received during the transmission period of the data without repeatedly receiving the same multiplex data. You can Thereby, it becomes possible to efficiently receive the FM multiplex broadcast.

Further, the same determination of the multiplex data refers to, for example, the service identification number, the program number and the page number given to the FM multiplex data, and when they are the same, the multiplex data currently received is updated. This can be easily done by determining whether the code matches the previous one.

Further, by storing the configured program data in the program holding storage section corresponding to the selected broadcasting station, when receiving a program in which the same data is repeatedly broadcast, a plurality of efficiently received programs can be received. It is possible to hold the multiplexed data of the broadcasting station.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a main part of an FM receiver according to an embodiment of the present invention.

FIG. 2 is a diagram showing a procedure for detecting update data according to the embodiment of this invention.

FIG. 3 is a diagram showing a frame structure of FM multiplex data.

FIG. 4 is a diagram showing a structure of a data packet of FM multiplex data.

FIG. 5 is a diagram showing a structure of a prefix of FM multiplex data.

[Explanation of symbols]

10 tuner, 12 IF amplification detection circuit, 14 MP
X, 16 amps, 18 speakers, 20 tuning keys,
22 channel selection microcomputer, 40 data processing section, 42 program configuration section, 44 A station program holding storage section, 46 B station program holding storage section, 48 display unit, 50 update flag determination section, 52 display RAM switching control section.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiko Masumoto 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inoue Munehiro Suka 2-5 Keihanmoto, Moriguchi City, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Shizuka Ishimura 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd. (72) Toshiyuki Ozawa 2 Keihan Hondori, Moriguchi City, Osaka Prefecture 5-5, Sanyo Electric Co., Ltd.

Claims (3)

[Claims] 1. A signal processing device used in an FM receiver for demodulating and displaying multiplex data from a received signal of FM multiplex broadcast, wherein the multiplex data received this time and the multiplex data previously received are A signal processing device for an FM receiver, comprising: an update determination unit that determines whether or not the data contents of multiplex data are the same, and generates a station change permission signal when the data contents are the same. 2. The signal processing device for an FM receiver according to claim 1, wherein the update determination unit identifies the service of the multiplex data received this time and the multiplex data received last time. When the numbers, program numbers and page numbers are all the same, it is determined whether the update codes of the two multiplexed data match, and if they match, a station change permission signal is generated. Signal processing equipment. 3. The signal processing device for an FM receiver according to claim 1 or 2, further comprising a program configuration unit configured to configure program data from the demodulated multiplexed data, and the program data to each broadcasting station. A signal processing of an FM receiver, comprising: a plurality of program holding storage sections which are stored corresponding to each other; and a switching section which switches the program holding storage section corresponding to a selected broadcasting station. apparatus.