JPH09214374A - Fm multiplex broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a data reception section small in size and to enhance a data transfer efficiency from the data reception section to a personal computer. SOLUTION: An FM multiplex broadcast signal received by an antenna 12 and FM-demodulated by an FM tuner section 14 is demodulated by a demodulator LSI 20 and resulting data are fed sequentially to a CPU 26 for each packet. After the CPU 26 eliminates undesired data from the received data, the CPU 26 supplies the resulting data to a CPU 40 of a personal computer 120 via a buffer 29 without a delay. The CPU 40 of the personal computer 120 re-configures program data based on the transferred data and displays the program onto a display section 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FM multiplex signal receiving apparatus capable of displaying character data or the like transmitted by FM multiplex broadcasting on the screen of a personal computer.

[0002]

2. Description of the Related Art In recent years, as one of broadcasts providing new services, development and commercialization of FM multiplex broadcasting in which a digital signal is multiplexed and transmitted in a vacant spectral region of a baseband signal of FM stereo broadcasting has been advanced. Have been.

FM multiplex broadcasting is a new medium for newly multiplexing digital signals in a frequency band higher than the audio signals of the current FM stereo broadcasting and broadcasting traffic information, character / graphic information and the like. The features are that frequencies can be effectively used, broadcasting equipment can be easily realized, and data can be received by a mobile unit so that traffic information and the like can be easily transmitted to the mobile unit such as an automobile.

Therefore, the FM multiplex broadcasting is provided as a means for transmitting traffic congestion information and the like in real time to a vehicle equipped with a receiver, or for a user having a handy type receiver to always provide necessary information. Some have been put into practical use as a means of providing an inexpensive transmission path that can be accessed anywhere.

Before describing the configuration of a conventional FM multiplex broadcast receiving apparatus, an outline of the data structure in FM multiplex broadcast will be described first. In FM multiplex broadcasting, factors that deteriorate the reception state include multipath interference and fading interference. In particular, in the case of mobile reception, the transmission path characteristics are generally very poor. Even in that case, it is desirable to have a system that can completely receive the data once. However, in actuality, there is a case where the data transmitted in one reception cannot be completely received, and in that case, it is assumed that the data to be retransmitted is received and the data that cannot be received is supplemented. . The FM multiplex broadcast service area is preferably the same as the FM stereo broadcast service area, but there are places where the average bit error rate is large even in this service area. Therefore, the structure of the data to be transmitted has its error correction method and frame configuration determined in consideration of such poor transmission line characteristics.

In particular, an error caused by an extreme voltage drop due to fading interference is fatal, and error correction may not be possible. Therefore, if an error that cannot be corrected is generated by adjusting the unit data length of the data to be transmitted to the average burst length of the error caused by fading, the unit data retransmitted together with the unit data described above. It becomes possible to complement by replacing with.

Furthermore, since the error correction effect is high, a product code in which two block codes are arranged orthogonally is used as the error correction method. Therefore, the data has a two-dimensional frame structure including an error correction code in both the vertical and horizontal directions.

The transmission data has a hierarchical data structure having the data in one frame as a basic unit. As a specific example of what has been described above, further reference is made to the document (Proc. Of Vehicle Navigator).
Ion & Information Systems
Conference (1994) A4-2 pp.
The FM multiplex broadcasting system disclosed in 111-116) will be described.

FIG. 6 shows the specifications of the hierarchical structure of the above data. In layer 1, transmission path characteristics are specified.
Ordinary FM stereo broadcast signal L + R signal and L
The multiplexed signal is superimposed on the higher frequency side than the -R signal.

This superposition method considers that the interference from the multiplex signal to the voice signal becomes significant when the voice modulation degree is small, and LMSK (which controls the level of the multiplex signal by the modulation degree of the LR signal is used. Level contro
lled Minimum Shift Keying
) Method is adopted.

Layer 2 defines the frame structure of data including an error correction method. Each frame is composed of 272 blocks in the column direction, and a 16-bit BI
C (Block Identification Co
de) is added, and frame synchronization and block synchronization are performed based on this BIC. Of the 272 blocks in the column direction, 190 blocks are packets for transmitting data, and 82 blocks are parity packets for transmitting parity in the column direction. 1 for each packet in the row direction
76-bit information section, 14-bit CRC (Cyclic Redundancy Cod) which is an error detection code
e) and a parity part of 82 bits.

That is, the transmission data is first subjected to error correction at this stage using this one frame as a basic unit.
When the packet is actually transmitted, as shown in FIG. 9, packets and parity packets are rearranged in a predetermined order in the vertical direction and then transmitted.

Layer 3 defines the structure of a data packet. The data packet is BI out of each row in the frame.
It consists of 176 bits excluding C, CRC and parity. Further, this data packet is composed of a prefix and a data block. The prefix includes information for identifying the content of the data, and specifies, for example, which program content described later the data packet belongs to.

Layer 4 defines the structure of the data group. A data group is composed of one or more data blocks. That is, based on the information in the prefix in the data packet, the data packet numbers are arranged in the order of the data packet numbers from "0" to the data blocks with the information end flag in the prefix. This data group also includes a CRC which is an error detection code, and transmission data is error-detected also in this layer.

One data group corresponds to one display unit, that is, one page of data. Tier 5 is F
A set of information data transmitted by M multiplex broadcasting,
That is, it defines the structure of program data. FIG. 7 shows the structure of this program data. A program of character and graphic information is composed of a plurality of data groups, and the first data group is composed of coded information related to the entire program such as a program number and the total number of pages as program management data. Following the program management data, there are a plurality of page data, and the data for each page is encoded.

The program data and page data are composed of a data header section and a data unit group. The data unit group is composed of a plurality of data units, such as a character data section and a photographic graphic data section, which are divided for each encoding.

That is, in the above-mentioned data structure, the program data constitutes a group of data indicating a group of information on the receiving side. For example, in the case of traffic information, the program information indicates the congestion status at each junction of a specific route (highway, etc.), and in the case of a weather forecast, it indicates the weather forecast information in a specific area.

By the way, the display in the FM multiplex broadcast receiving apparatus for receiving the above-mentioned FM multiplex broadcast is generally one page of display area (15.5 characters in Japanese display × 2.5).
(Corresponding to rows) is done on the LCD screen. .

For this reason, there is a drawback that the display area is narrow and difficult to see in a program or the like which extends over a plurality of pages. In order to solve this problem, the received multiplex data is taken into a personal computer (hereinafter referred to as a personal computer),
The method of displaying on the display screen on this personal computer has been proposed.

FIG. 8 shows a block diagram of a conventional example of an FM multiplex broadcast receiving apparatus using a personal computer. The FM multiplex broadcast receiving apparatus 100 includes an antenna 12 that receives FM radio waves.
An FM tuner unit 14 for receiving the output of the antenna 12 and performing FM demodulation; and an FM multiplex decoding unit 15 for receiving the output of the FM tuner unit 14 to perform extraction and error correction of a baseband signal and output a corresponding digital signal. And a personal computer 120 (data analysis processing unit) which receives the digital signal to form display unit data (page data) and displays corresponding characters and the like.

The FM multiplex broadcast signal received by the antenna 12 is synchronously detected by the local oscillating wave output from the PLL circuit 4 in the FM demodulation circuit 2 in the FM tuner unit 14, and is FM multiplex decoded via the buffer 6. It is output to the unit 15.

The FM multiplex decoding section 15 receives the FM demodulated signal via the buffer circuit 8, extracts the signal component in a predetermined frequency region by the band pass filter 18, and then the LMSK demodulation and synchronization detection in the demodulation LSI 20. And error correction. The CPU 26 controls the demodulation LSI 20
In response to a data transfer request that occurs every 18 msec, the received data from the demodulation LSI 20 is read. At this time, if there is packet data that cannot be error-corrected, this data is deleted in this CPU 26, and only the data necessary for display is selected and output.

The RAM 28 accumulates data from the CPU 26 at a rate of 1 packet every 18 msec, and operates as a buffer for outputting the data to the interface 30.

In the address decoder 32, the CPU 26
When it is detected that the personal computer 120 is accessed, data is output from the interface 30. Controller 34 normally receives output data from interface 30 and outputs the data to personal computer 120. However, when starting up the device,
Based on the data stored in the ROM 36, the interface is initialized.

The personal computer 120 receives the packet data output from the FM multiplex decoding section 15 via the interface 38. The CPU 40 uses the interface 38
Receiving the output data from i.e. packet data,
According to the hierarchical structure shown in FIG. 6, a data block is extracted from the data packet, a data group is reconstructed from the data block, and error detection is performed on the data group. Further, the CPU 40 extracts the data header and the data unit group corresponding to the page data from the data group data in the data group, and reconstructs the program data.

The reconstructed program data is sequentially stored in the memory 44 in page data units for each program. CP
U40 selects a predetermined number of page data,
Output to the display unit 42, and the display unit 42 outputs corresponding character information or graphic information based on the received page data.

Here, the display unit 42 is, for example, a liquid crystal flat panel display in a notebook personal computer, and its display area is 640 × 4.
It has a resolution of 00 dots or more.

[0028]

According to this method, since a plurality of pages can be displayed at once, it is possible to easily display a program that extends over a plurality of pages.
Further, since the multiple data can be taken in by the personal computer and processed and edited, the data can be used for various purposes.

However, in the above device, F
The RAM 28 for temporarily storing the demodulated data in the M multiplex decoding unit 15 is required, and when the data receiving unit is unitized such as a PC card, it becomes a bottleneck for downsizing.

Further, the received data is temporarily stored in the RAM, and the data is transferred to the personal computer 120 based on a calling command from the CPU 40 on the personal computer side. Since the program analysis processing is performed there, from the data reception to the signal processing. There is a drawback that a time delay occurs and the display is delayed.

Since the time delay is not constant,
There is a drawback that the signal processing performed on the basis of data reception is not stable. Also, demodulation L in the data receiving unit
Since all the data demodulated by SI is transferred to the personal computer without being selected and only the necessary data is selected and processed on the personal computer side, there is a drawback that the data transfer efficiency to the personal computer is poor.

The present invention solves the above-mentioned drawbacks, and an object thereof is to transfer data to a personal computer each time one packet is received, thereby eliminating the need for a RAM in the data receiving section and reducing the size of the data receiving section. It is an object of the present invention to provide an FM multiplex broadcast receiving device capable of performing the above.

Another object of the present invention is to provide an FM multiplex broadcast receiving apparatus in which there is no time delay between the data reception in the data receiving section and the signal processing in the personal computer. Still another object is to provide an FM multiplex broadcast receiving apparatus with improved transfer efficiency from the data receiving section to the personal computer side.

[0034]

DISCLOSURE OF THE INVENTION The present invention is a data for receiving an FM multiplex broadcast transmitted by FM-modulating after transmitting additional information data separately from the main audio signal. In an FM multiplex broadcast receiving apparatus including a receiving unit and a data analysis processing unit configured to analyze a data transferred from the data receiving unit to form a display screen, the data receiving unit receives the decoded data as predetermined data. A first control unit is provided for controlling the data to be transferred to the data analysis processing unit at regular time intervals in units of long data, and the data analysis processing unit is provided with an analysis process for the data transferred from the first control unit. A second control means for reconstructing the screen data that can be displayed on the screen is provided.

Further, according to the present invention, a data receiving unit for receiving additional multiplex data separately from the main audio signal, receiving FM multiplex broadcast which is FM-modulated and transmitted, and decoding the multiplex data, In an FM multiplex broadcast receiving apparatus including a data analysis processing unit configured to analyze a data transferred from the data receiving unit to form a display screen, the data receiving unit receives the decoded data from the data analysis processing unit. After deleting unnecessary data, the data analysis processing unit is provided with a first control unit for controlling the data unit of a predetermined data length to be transferred to the data analysis processing unit at regular intervals. A second control means for analyzing the data transferred from the first control means and reconstructing the data into screen data that can be displayed on the screen is provided.

[0036]

1 is a block diagram showing a configuration of an FM multiplex broadcast receiving apparatus according to an embodiment of the present invention. The same parts as those in the conventional example of FIG. Omit it. 1 is different from FIG. 8 in that the address decoder and the RAM are deleted and a buffer 29 is arranged between the CPU 26 and the controller 34. This buffer 29 is a data buffer unit for accumulating 1 packet (24 bytes) of data from the CPU 26, CP
It is composed of a status buffer section for accumulating a 1-byte status from U26 and a command buffer section for accumulating a 2-byte command from the CPU 40 of the personal computer 120, each of which is composed of a shift register.
The hardware configuration of the personal computer 120 is the same as the conventional one.

Here, as shown in FIG. 2, the data for one packet accumulated in the data buffer unit is the data of layer 3 (22 bytes), the block number of the packet (1 byte), and the packet horizontally. It is composed of a status (1 byte) indicating whether it is processed data or vertically processed data.

The CPU 26 receives one packet of data every 18 msec, and determines whether the received data is data to be transferred to the personal computer 120 or not. That is, parity packet, erroneous data, pay program data, different ID
If it is unnecessary data such as paging data, fill packet, or data designated as unnecessary on the PC side, it is not transferred to the PC side. Other data, along with the interrupt status signal to the CPU 40 of the personal computer,
PC 1 via buffer 29 and controller 34
Transfer to 20.

On the other hand, the CPU 40 receives the packet data from the FM multiplex decoding unit 15 via the interface 38, analyzes the program and displays it. Further, it sends a command such as a tuning command to the CPU 26.

Next, the operation of the FM multiplex broadcast receiving apparatus,
In particular, the operation of the CPU 26 will be described. FIG.
It is a flowchart which shows the main routine of PU26.

First, the CPU 26 determines the presence or absence of a command such as a tuning command from the personal computer 120 (step S10), and when there is a command, for example, when the command is a channel selection command, a predetermined channel selection frequency is set. Command processing is performed (step S1)
1). After the tuning frequency is set, the monaural / stereo and FM are stored in the status buffer section of the buffer 29.
The reception status of broadcast undetected / detected is set as the status (step S12). If there is no command in step S10, the process directly goes to step 12. Step 1
When the process of 2 is completed, the process returns to step 10 again, and the main routine is repeated.

FIG. 4 is a flow chart showing the reception interrupt routine of the CPU 26. 18m for CPU 26
One packet of data is transferred from the demodulation LSI 20 every sec, and an interrupt occurs (step S20). The status and data indicating the state of the packet are read from the output of the LSI 20 (step S21). Then, it is determined whether or not this packet data is unnecessary (step S22). This judgment is based on the demodulation LSI 20.
This is performed based on the output status and the command from the personal computer set in the command buffer section of the buffer 29. If it is not unnecessary data, the data is set in the data buffer section of the buffer 29 (step S23), and then an interrupt request is output to the CPU 40 on the personal computer side.

Frame synchronization ON / OFF and block synchronization O are added to the status buffer section of the buffer 29.
Reception states such as N / OFF and presence / absence of error are set as statuses (step S25). If the data is unnecessary in step 22, the process proceeds to step 25 without issuing an interrupt request. When the process of step 25 ends, the interrupt routine ends.

Next, FIG. 5 shows the FM multiplex broadcast receiving apparatus 100 shown in FIG. 1 as a notebook personal computer and PCMCI.
The schematic diagram in the case of using an A card (hereinafter referred to as a PC card) is shown.

In this case, the FM multiplex decoding unit 15 is the PC
It is made into a card and can be attached to and detached from the personal computer 120. The FM tuner unit 14 includes an FM multiplex decoding unit 15
And the connection cord. With the above-described configuration, the FM tuner unit 14 can be kept away from the personal computer 120, and it is possible to prevent noise from the personal computer 120 from being mixed in the received signal. Of course, as shown in FIG. 5, the FM tuner unit 14 and the FM multiplex decoding unit 15 are not connected by a connecting cord, but by integrating them, it is possible to make them more convenient to carry. is there.

[0046]

As described above, according to the present invention, since the RAM is not required for the data receiving section, the data receiving section can be
When the C card is used, the size can be reduced.

Further, since it is possible to reduce the unnecessary time delay from the data reception in the data receiving unit to the signal processing in the data analysis processing unit (personal computer) to the minimum, the display screen can be updated quickly. You can

Furthermore, it is possible to improve the transfer efficiency from the data receiving unit to the data analysis processing unit and to improve the reliability.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an FM broadcast receiving apparatus of the present invention.

FIG. 2 is a diagram showing a structure of transfer data of one packet in the present invention.

FIG. 3 is a flowchart showing a main routine of CPU 26.

FIG. 4 is a flowchart showing a reception interrupt routine of CPU 26.

FIG. 5 is a diagram showing an appearance of an FM multiplex broadcast receiving apparatus according to the present invention.

FIG. 6 is a diagram showing specifications of FM multiplex broadcasting.

FIG. 7 is a diagram showing a structure of program data.

FIG. 8 is a schematic block diagram of a conventional FM multiplex broadcast receiving apparatus.

FIG. 9 is a diagram showing a structure of a transmission frame in FM multiplex broadcasting.

[Explanation of symbols]

 2FM demodulation circuit 4PLL circuit 6,8,29 buffer circuit 12 antenna 14 tuner 15 FM multiplex decoding unit 16,20 demodulation LSI 26,40 CPU 28 RAM 30,38 interface circuit 32 address decoder 34 controller 36 ROM 42 display unit 44 memory 100 FM multiplex broadcasting receiver

Claims (4)

[Claims] 1. A data receiving section for receiving additional multiplexed data separately from the main audio signal, receiving FM multiplex broadcast which is FM-modulated and transmitted, and decoding the multiplexed data, and a data receiving section. A data analysis processing unit that analyzes the data transferred from the computer and creates a display screen.
In the M multiplex broadcast receiving apparatus, the data receiving unit is provided with a first control unit for controlling the decoded data to be transferred to the data analysis processing unit in a data unit of a predetermined data length at regular time intervals, and An FM multiplex broadcast receiving apparatus, characterized in that the data analysis processing section is provided with a second control means for analyzing the data transferred from the first control means and reconstructing it into screen data which can be displayed on a screen. . 2. A data receiving unit for receiving an FM multiplex broadcast, which is FM-modulated and transmitted after multiplexing additional information data separately from the main audio signal, and a data receiving unit for decoding the multiplexed data. A data analysis processing unit that analyzes the data transferred from
In the M-multiplex broadcast receiving device, the data receiving unit deletes unnecessary data from the decoded data, and then the data analyzing unit performs data unit of a predetermined data length at regular time intervals. A second control means is provided for controlling so as to transfer the data, and the data analysis processing section analyzes the data transferred from the first control means to reconfigure it into screen data that can be displayed on a screen. An FM multiplex broadcast receiving apparatus, characterized in that the control means is provided. 3. The FM multiplex broadcast receiving apparatus according to claim 2, wherein the unnecessary data is data designated by the data analysis processing unit. 4. The FM multiplex broadcast receiving apparatus according to claim 1, wherein the data analysis processing unit is included in a personal computer, and the data receiving unit is connected to the personal computer through a removable interface unit.