JPH11313299A - Video information distribution method to mobile object by digital radio communication, central station device and mobile terminal used for the same method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video information distribution method or the like to a mobile object by digital radio communication where transmission quality with respect to a code error of distributed video information is ensured. SOLUTION: A mobile terminal 2 requests a central station device 1 to distribute video information through radio communication, and the central station device 1 distributes the requested video information to the mobile terminal 2 by using digital radio communication between the central station device 1 that is installed on the ground and one mobile terminal 2 or over consisting of a terminal installed on a mobile object in this video information distribution method. The mobile terminal 2 sends reception environment information representing its reception environment to the central station device 1 in the case of making a request of distribution, and the central station device 1 selects a method of securing transmission quality with respect to a code error for the distribution of video information to the mobile terminal 2 based on the received environment information sent from the mobile terminal 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for distributing video information to a mobile object by digital wireless communication, a central station used for the method for distributing video information, and a mobile terminal device used for the method for distributing video information. In particular, the present invention relates to a device capable of ensuring transmission quality related to a code error of video information to be distributed.

[0002]

2. Description of the Related Art In CATV broadcasting, conventionally, in response to a request from an arbitrary one of a plurality of terminals, a central office distributes video information to the terminal that has made the request. Also, for example, Japanese Patent Application Laid-Open No. 7-7
No. 728 discloses a pay-per-view pay broadcasting system in which a scrambled program in a satellite TV broadcast is descrambled according to a fee paid by the user to allow the user to view the program. Further, for example, Japanese Patent Application Laid-Open No. 7-283798 discloses a satellite broadcast mobile receiver that realizes switching between a moving image and a still image without displaying a scrambled image when a mobile object receives a scrambled satellite broadcast. Have been.

[0003]

By the way, in response to a request from an arbitrary one of a plurality of mobile terminals including terminals installed in a mobile body, video information is distributed from a central office to the mobile terminal that has made the request. In order to build a paid video information distribution system, it is necessary to ensure the quality of the distributed video information as a prerequisite for charging the distributed video information. , The reception environment of the terminal changes, and therefore, there is a problem that it is difficult to ensure the quality of video information to be distributed.

In this case, even if the conventional method of distributing video information by CATV broadcasting and the structure of a pay broadcasting system disclosed in Japanese Patent Application Laid-Open No. 7-7728 are used,
These devices cannot solve the above-mentioned problem because the moving object is not originally targeted for distribution of the video information.

[0005] Further, the satellite broadcast mobile receiver disclosed in Japanese Patent Application Laid-Open No. 7-283798 is intended to realize switching between a moving image and a still image without displaying a scrambled image. The above problems cannot be solved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has been made in view of the above circumstances, and has been made in view of the above. It is an object of the present invention to provide a method, a central station device used in the video information distribution method, and a mobile terminal device used in the video information distribution method.

[0007]

According to the present invention (claim 1), a method for distributing video information to a mobile unit by digital radio communication is provided by a central station installed on the ground and a terminal installed on the mobile. Between one or more mobile terminal devices, the mobile terminal device requests the central station device to distribute video information via wireless communication, and the requested video information is requested from the central station device. A video information distribution method for distributing to a mobile terminal device using digital wireless communication, wherein the mobile terminal device transmits reception environment information indicating a reception environment of the mobile terminal device to the central office device at the time of the request. Then, the central station apparatus switches a method for securing transmission quality regarding a code error in the distribution of video information to the mobile terminal apparatus based on the reception environment information transmitted from the mobile terminal apparatus. It is what you are as a frog.

According to the present invention (Claim 2), the method for delivering video information to a mobile unit by digital wireless communication is the above-mentioned video information delivery method (Claim 1). It is intended to switch the modulation method in the distribution of the video information to a modulation method having a different strength against occurrence of a code error in the distribution of the video information.

According to a third aspect of the present invention, there is provided a method for distributing video information to a mobile body by digital wireless communication, wherein the method for distributing video information to the mobile object is the method for distributing video information according to the first aspect of the present invention. This is to switch the redundancy of the video information to be distributed.

[0010] According to a fourth aspect of the present invention, there is provided a method for distributing video information to a mobile body by digital wireless communication, wherein the receiving environment information is set as follows.
It is assumed that the information indicates that the mobile terminal device is used.

[0011] According to a fifth aspect of the present invention, there is provided a method for distributing video information to a mobile object by digital wireless communication, wherein the mobile terminal device is the same as the first aspect.
A code error rate in the delivery of the video information is detected and held, and the held code error rate is transmitted to the central station device as the reception environment information at the time of the next request.

[0012] According to the present invention (Claim 6), the method for delivering video information to a moving object by digital wireless communication is as follows.
The position of the moving object on which the mobile terminal device is installed is detected, and the detected position of the moving object is transmitted to the central office as the reception environment information.

[0013] In the video information distribution method according to the present invention (claim 7), the mobile terminal device may include:
Further detecting and holding the code error rate in the delivery of the video information, and transmitting the held code error rate to the central station device as the reception environment information together with the position of the moving object at the time of the next request, The central station device accumulates the position and the bit error rate of the moving object transmitted from the mobile terminal device so as to represent the position and the code error rate as a map indicating the reception environment of the video information distribution area, and receives a request from the mobile terminal device. In such a case, the method for ensuring the transmission quality regarding a code error in the distribution of the video information to the mobile terminal device is switched based on the stored map.

According to the present invention (Claim 8), the method for delivering video information to a mobile object by digital wireless communication is the same as the method for delivering video information (Claim 1).
The speed of the moving object on which the mobile terminal device is installed is detected, and the detected speed of the moving object is transmitted to the central office as the reception environment information.

According to the present invention (Claim 9), the method for distributing video information to a moving object by digital wireless communication is the same as the method for distributing video information (Claim 1).
Using car navigation, the mobile terminal device generates scheduled route information of the moving object on which the mobile terminal device is installed, and transmits the generated planned route information of the moving object to the central station device as the reception environment information. Is what it is.

According to a tenth aspect of the present invention, there is provided a method of distributing video information to a mobile object by digital wireless communication, wherein the mobile terminal device further comprises the generated mobile object. Is obtained, and the acquired road information is transmitted to the central office as the reception environment information together with the planned route information.

A central station device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 11) is a central station device that is installed on the ground and a terminal device installed on the mobile object. A request for distribution of video information from the mobile terminal device to the central station via wireless communication with at least one mobile terminal device, and the mobile terminal requesting the requested video information from the central station A central station device used in a video information distribution method of distributing to a device using digital wireless communication, a receiving unit for receiving reception environment information transmitted together with the request in the wireless communication from the mobile terminal device, A transmitting means for transmitting to the mobile terminal device by the digital wireless communication, and the transmitting means for transmitting video information which is a target of the request received by the receiving means. Transmits to the mobile terminal device the request Te, the method ensures the transmission quality for code error in the transmission, in which a communication control means for switching based on the reception environment information received by the receiving means.

The central station apparatus used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 12) is the central station apparatus (claim 11)
The communication control means may switch a modulation method for transmitting the video information to a modulation method having a different strength against occurrence of a code error in the transmission as a method for securing transmission quality related to the code error. .

The central station apparatus used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 13) is the central station apparatus (claim 11)
The communication control means switches the redundancy of the video information to be transmitted as a method for securing the transmission quality regarding the code error.

The central station apparatus used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 14) is the central station apparatus (claim 11)
The reception environment information is information indicating that the mobile terminal is a mobile terminal, and the communication control unit secures transmission quality related to the code error based on the information that the mobile terminal is received by the reception unit. It is assumed that the method is to be switched.

The central station apparatus used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 15) is the central station apparatus (claim 11)
The reception environment information is a code error rate in the transmission of the video information, and the communication control means switches a transmission quality securing method for the code error based on the code error rate received by the reception means. It is assumed that it is.

The central station apparatus used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 16) is the central station apparatus (claim 11)
The reception environment information is a position of a mobile body in which the mobile terminal device is installed, and the communication control unit determines a transmission quality of the code error based on the position of the mobile body received by the reception unit. This is to switch the securing method.

The central station apparatus used in the method for distributing video information to a mobile body by digital wireless communication according to the present invention (claim 17) is the central station apparatus (claim 16)
The reception environment information is a position of the mobile object and a code error rate in transmission of the video information, and the communication control unit is configured to transmit the position and the code error rate of the mobile body received by the reception unit to the video information. When a request from a mobile terminal device is received through the receiving means, the data is accumulated as represented as a map indicating the reception environment of the distribution area, and when a request for the video information is transmitted to the mobile terminal device which made the request, transmission related to a code error. The quality assurance method is switched based on the stored map.

The central station apparatus used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 18) is the central station apparatus (claim 11)
The reception environment information is a speed of a mobile body on which the mobile terminal device is installed, and the communication control unit determines a transmission quality of the code error based on the speed of the mobile body received by the reception unit. This is to switch the securing method.

The central station apparatus used in the method for distributing video information to a mobile object by digital radio communication according to the present invention (claim 19) is the central station apparatus (claim 11)
The reception environment information is a planned route of a mobile body in which the mobile terminal device is installed, and the communication control unit is configured to determine whether the code error has occurred based on the planned route of the mobile body received by the reception unit. This is to switch the method of ensuring transmission quality.

The central station device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 20) is the central station device (claim 19)
The reception environment information is road information of a planned course of the moving body and a road corresponding to the planned course, and the communication control unit is configured to perform communication based on the planned course and the road information of the moving body received by the receiving unit. , It is intended to switch the method of ensuring the transmission quality related to the code error.

A mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 21) is a mobile terminal device comprising a central station installed on the ground and a terminal installed on the mobile. Between one or more mobile terminal devices, the mobile terminal device requests the central station device to distribute video information via wireless communication, and the requested video information is requested from the central station device. A mobile terminal device used in a video information distribution method for distributing to a mobile terminal device using digital wireless communication, comprising: receiving means for receiving video information transmitted by the digital wireless communication from the central station device; Reproducing means for reproducing the video information received by the means, input means for inputting the request, and a transmitting means for transmitting to the central station device by the wireless communication. And a communication control unit that, when a request is input from the input unit, transmits reception environment information indicating a reception environment of the mobile terminal device to the central station device using the transmission unit together with the request. It is provided.

[0028] The mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 22) is the mobile terminal device according to the present invention (claim 21), wherein The modulation method is transmitted by switching the modulation method among a plurality of modulation methods having different strengths against occurrence of a code error in wireless communication, and the receiving means transmits the transmitted video information to the plurality of predetermined plurality of modulation methods. By providing a plurality of demodulation means respectively corresponding to the modulation schemes, it is possible to perform demodulation.

The mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 23) is the mobile terminal device (claim 21) wherein the video information is The communication control means performs the reproducing means to correct the video information transmitted and received by the receiving means in accordance with the switched redundancy. The reproducing means reproduces the error-corrected video information.

The mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 24) is the mobile terminal device (claim 21), wherein the communication control means is It is assumed that information indicating that the mobile terminal device is used is transmitted as the reception environment information.

The mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 25) is the mobile terminal device (claim 21), wherein the receiving means is the digital device. For detecting a code error rate in wireless communication, the communication control means,
The code error rate detected by the receiving means is held, and the next time a request is input from the input means, the held code error rate is transmitted to the central station device as the reception environment information together with the request. It is what you have to do.

The mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 26) is the same as the mobile terminal device (claim 21). Position information detecting means for detecting the position of the moving object, the communication control means,
The position of the moving object detected by the position information detecting means is transmitted to the central office as the reception environment information.

The mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 27) is the mobile terminal device (claim 26), wherein the receiving means is For detecting a code error rate in wireless communication, the communication control means,
Holding the code error rate detected by the receiving means, the next time a request is input from the input means, the request and the position of the mobile body and the held code error rate, as the reception environment information, This is to be transmitted to the central office device.

The mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 28) is the same as the mobile terminal device (claim 21). Position information detecting means for detecting the speed of the moving body, the communication control means,
The speed of the moving object detected by the position information detecting means is transmitted to the central office as the reception environment information.

The mobile terminal device used in the method for distributing video information to a moving object by digital wireless communication according to the present invention (claim 29) is the mobile terminal device according to claim 21, wherein the mobile terminal device uses a car navigation system. A position information detecting unit configured to generate scheduled route information of the moving object on which the terminal device is installed; and the communication control unit transmits the planned route information of the moving object generated by the position information detecting unit to the reception environment information. Is transmitted to the central office apparatus.

The mobile terminal device used in the method for distributing video information to a mobile object by digital wireless communication according to the present invention (claim 30) is the mobile terminal device (claim 29), wherein the position information detecting means is: Further, the communication control means obtains the road information of the road corresponding to the generated planned route of the moving body, and the communication control means uses the road information obtained by the position information detecting means as the reception environment information together with the planned course information. This is to be transmitted to the central office.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram showing a configuration of a central station device and a mobile terminal device used in a method of delivering video information to a mobile object by digital wireless communication according to Embodiment 1 of the present invention. In the figure, 1 is a central station device installed on the ground (hereinafter simply referred to as a central station), and 2 is a mobile terminal device installed on a mobile body (hereinafter, referred to as a central station)
Simply referred to as a mobile terminal), and these central offices 1
One or more mobile terminals 2 and one or more fixed terminals (not shown) composed of terminals installed on the ground perform the method for distributing video information to a mobile body by digital wireless communication according to the first embodiment. Configure the system. In addition, the moving body includes a car, a train, a ship, an airplane, and the like, and the first embodiment will be described by taking a car as an example.

The video information is composed of data including at least image information, and includes video data, data files and the like. The video data includes image information and audio information. The video data includes video data composed of still images used for text broadcast and live view distribution, and video composed of moving images used for distribution of video programs and the like. And data. The data file contains map data, W
Web data, homepage, mail, etc. are included. In the first embodiment, an image composed of still images such as road map data (hereinafter simply referred to as a road map), house map data (hereinafter simply referred to as a house map), and a live view image of an intersection. This will be described using information as an example. Here, the road map and the house map may be either image data of a video or digital data indicating text related to the map such as link information.

The communication line from the mobile terminal 2 to the central office 1 may be a wireless communication line capable of data communication. In the first embodiment, for example, a mobile phone line is used. Further, the method of distributing video information from the central station 1 to the mobile terminal 2 may be any method that uses wireless communication capable of digital data communication. In the first embodiment, for example,
Normal T that emits radio waves to space and distributes video information to terminals
A distribution method based on the V broadcast system is used. Therefore, the transmitting antenna 9 of the central office 1 is installed at a high place on the ground such as a mountain or the roof of a high-rise building. Therefore, the receiving environment of the mobile terminal 2 depends on the area in which the automobile on which the mobile terminal 2 is installed travels. , A multipath fading or a ghost occurs, or the state becomes unreceivable due to the presence of a tunnel.

The central office 1 has a receiving antenna 3 for receiving a communication signal transmitted from the mobile terminal 2 through a mobile phone line.
A central office side receiving means 4 for demodulating / decoding a communication signal received by the receiving antenna 3 to extract a request and reception environment information from the communication signal; a reception environment information storage means 6 for storing reception environment information; A video information storage means 7 for storing a plurality of video information to be delivered to the mobile terminal 2, a transmission antenna 9, and encoding and compressing the received information;
The encoded / compressed information is packetized (multiplexed) into a digital communication signal, a carrier is modulated with the digital communication signal, the digital communication signal is superimposed on the carrier to form a transmission signal, and the transmission signal is transmitted. Mobile terminal 2 from antenna 9
The central station side transmitting means 8 for transmitting by TV radio waves and the video information to be requested by the central station side receiving means 4 are acquired from the video information storage means 7 and transmitted. The reception environment information extracted in step (1) is stored in the reception environment information storage means 6, and based on the reception environment information extracted by the central office reception means 4 or the reception environment information acquired from the reception environment storage means 4, which will be described later. As described above, the communication control unit 5 includes the central office communication control unit 5 that uses the central office transmission unit 8 to switch a method for ensuring transmission quality related to a code error of video information transmitted to the mobile terminal 2. Here, the encoding of the video information in the central office side transmitting means 8 /
The compression is performed by, for example, an encoding method based on MPEG2.

Also, the central office side transmitting means 8 has 64 QAM
(quadrature amplitude shift keying) A modulator that modulates with the modulation method and QPSK (quadrature phase shift keyi
ng) A modulator that modulates with the modulation method is provided (not shown), and as described later, the two modulators are switched by a command from the central office communication control means 5 to the transmission circuit. By connecting, the received video information can be switched to one of the two modulation methods and modulated. Here, the 64QAM modulation scheme has a relatively large transmission capacity, but is relatively weak against the occurrence of code errors in the transmission path. The QPSK modulation scheme has a relatively small transmission capacity, but has a relatively small transmission capacity. Ghost and multi-path fading hardly occur.

As will be described later, the central office communication control means 5 sets the redundancy of the transmission data including the video information in three stages, and generates an error correction code having a bit width corresponding to the redundancy in each stage. In addition, it is configured to add to the video information acquired from the video information storage means 7 and send it to the central office side transmission means 8.

The central office communication control means 5 is constituted by, for example, a CPU of a computer, the reception environment information storage means 6 is constituted by, for example, a main memory of the computer, and the video information storage means 7 is constituted by, for example, It comprises an information recording medium such as a hard disk and an information recording medium driving means such as a hard disk drive.

The mobile terminal 2 receives a transmission signal transmitted from the central station 1 by TV radio waves, and demodulates the transmission signal received by the reception antenna 10 to extract a digital communication signal. A mobile terminal-side receiving means 11 for detecting a code error rate (hereinafter, referred to as a reception error rate) of a digital communication signal, and a digital communication signal extracted by the mobile terminal-side receiving means 11, separated from the digital communication signal to obtain a code. TS separating means 12 for extracting the encoded / compressed video information, decoding and expanding the encoded / compressed video information extracted by the TS separating means 12 to reproduce the original video information, Data reproducing means 13 for extracting and outputting an error correction code from the obtained video information, image display means, audio output means, and request can be inputted It has an input means (not shown), and for the video information reproduced by the data reproducing means 13, the image information is displayed as an image on the screen of the image display means, and the audio information is output as audio from the audio output means. An input / output unit 14, a transmitting antenna 18, and a mobile terminal-side transmitting unit 17 that encodes / modulates the received information into a communication signal, and transmits the communication signal to the central office 1 through the transmitting antenna 18 and the mobile phone line. And information indicating that the mobile terminal is a mobile terminal and the reception error rate detected by the mobile terminal side receiving means 11 as reception environment information together with the request input from the input / output means 14 and the mobile terminal side transmitting means 1.
7 and, based on the error correction code output from the data reproducing means 13, the data reproducing means 13
Mobile terminal side communication control means 15 for performing error correction on decoded / decompressed video information when reproducing the video information.
And Then, the TS separating means 12, the data reproducing means 13, and the input / output means 14 constitute the reproducing means 19.

Here, the mobile terminal side receiving means 11 has 64
There are two demodulators (not shown), a demodulator that demodulates by the QAM modulation scheme and a demodulator that demodulates by the QPSK modulation scheme, and the two demodulators are connected in parallel to the receiving circuit. Therefore, the received signal modulated by switching the modulation method to the 64QAM modulation method or the QPSK modulation method is the same as that of the above 2
When the signal is input to one of the modulators, the one that matches the modulation scheme of the input received signal operates to demodulate the input received signal and output it to the receiving circuit.

The input / output means 14 has, for example, a liquid crystal panel as an image display means, and as input means, for example, inputs character information and user's instructions with an input pen through an input screen displayed on the liquid crystal panel. And a speaker, for example, as a sound output unit.

The mobile terminal side communication means 15 is composed of, for example, a CPU of a microcomputer and has an internal memory (not shown) composed of a main memory of the microcomputer. The internal memory constitutes storage means for temporarily holding the reception error rate detected by the mobile-side receiving means 11.

The mobile terminal side communication control means 15 of the mobile terminal 2 sends an ID number for receiving the video information distribution and charging information for the video information distribution together with the request together with the request of the central office 2 for the central office communication control. The central office communication control means 5 performs the charging process based on the charging information, checks the ID number, and, as a result of the checking, registers the mobile terminal that has made the request. If it is authenticated, a decryption key is added to the requested video information and distributed to the mobile terminal 2. In the mobile terminal 2, the mobile terminal-side communication control means 15 transmits the video encoded by the decryption key. The information is decrypted, and based on the decryption result, the TS separating means 12 and the data reproducing means 1
3 to reproduce the distributed video information. Since the authentication processing and the charging processing do not directly relate to ensuring the transmission quality related to a code error according to the present invention, the description of the authentication processing and the charging processing will be omitted in the following description.

Next, a description will be given of the configuration of the means for ensuring the transmission quality with respect to a code error when transmitting video information. FIG.
FIG. 5 is a diagram showing a transmission quality management table used by the central office communication control means to secure transmission quality related to a code error when transmitting video information.

In the figure, in the transmission quality management table, the reception environment is roughly classified into a fixed terminal and a mobile terminal. In the case of a mobile terminal, the reception error rate is “small” and the reception error The case is divided into three cases where the rate is “medium” and the reception error rate is “large”. The modulation scheme is 6 when the reception environment is a fixed terminal.
When the reception environment is a mobile terminal, a 64 QAM modulation scheme is used when the reception error rate is “small”, and a QPSK modulation scheme is used when the reception error rate is “medium”. If the reception error rate is "large", the QPSK modulation method is used. The data redundancy is “small” when the reception environment is a fixed terminal, and “small” when the reception error rate is “small” when the reception environment is a mobile terminal. If the reception error rate is “medium”, “medium”, and if the reception error rate is “large”, “large”. When the reception error rate is unknown, such as when the request from the mobile terminal is the first request, the reception error rate is treated as “medium”. Also, the reception error rate,
The ranges of “small”, “medium”, and “large” of the data redundancy are appropriately set based on experiments and the like. Also, when there are requests from a plurality of mobile terminals, the modulation scheme is selected to match the reception environment of the mobile terminal in the worst reception environment, and the data redundancy is an error for changing the data redundancy. Since the correction code is added to the video information to be distributed, it is possible to correspond to each mobile terminal. Therefore, the correction code is selected for each mobile terminal according to the reception environment. Here, in order to ensure the transmission quality related to code errors, it is permitted to increase the data redundancy despite the reduction in transmission capacity. This is because a large transmission capacity is not necessarily required.

When the communication control means of the central office acquires the reception environment information, the modulation method,
And data redundancy, thereby ensuring transmission quality regarding code errors when transmitting video information.

Next, the configuration of the portion for switching the data redundancy will be described. FIG. 3 is a block diagram showing a configuration of a part of the central office communication control means for adding an error correction code to video information.

In the figure, reference numeral 104 denotes a redundancy control unit, and the central control means performs any one of “small”, “medium”, and “large” based on the environmental information as described with reference to FIG. Is selected, the selected redundancy is input to the redundancy control unit 104 as a data redundancy instruction signal.
Then, the redundancy control unit 104 determines the length of one data of the data obtained by dividing the video information (hereinafter referred to as divided data) according to the data redundancy indicated by the data redundancy instruction signal, and 1 An error correction code to be added to one divided data is indicated. At this time, when increasing the data redundancy, the redundancy control unit 104 shortens the length of the divided data or adds more error correction codes. In the first embodiment, for example, an error correction code having a large bit width is added.

Reference numeral 105 denotes a data storage unit for storing data; 101, a data division unit for dividing the video information obtained from the video information storage means into a length designated by the redundancy control unit 104; An error correction unit that adds an error correction code to the divided data divided by the unit 101;
Numeral 03 stores the divided data to which the error correction code has been added by the error correction section 102 in the storage section 105, combines a predetermined number of the stored divided data in a predetermined order, and forms transmission data. This is a transmission data generation unit to be transmitted to the station side transmission means.

FIG. 4 is a diagram showing the data processing operation of the data division unit and the error correction generation unit of FIG. 3. FIG. 4A is a schematic diagram showing a state where one piece of video information is divided. (b)
FIG. 4C is a schematic diagram illustrating a state in which divided data attribute information is added to one divided data, and FIG. 4C is a schematic diagram illustrating a state in which an error correction code is added to one divided data to which divided data attribute information is added. .

In the figure, the data division unit first divides the video information (file) into the number specified by the redundancy control unit. In the figure, for example, a file A is divided into n pieces of divided data (A1 to An). Next, for each of the divided data, for example, divided data attribute information such as a delimiter, a file identifier, and a division number is added before the divided data. This is because when the transmission data generation unit combines the divided data into a data string, it is possible to recognize the break of each divided data in a series of data, and thereby, when reproducing video information on the mobile terminal, Is to be recombined. Here, instead of adding a delimiter to the beginning of the divided data, a terminal symbol may be added to the end of the divided data. The error correction generation unit adds an error correction code specified by the redundancy control unit after the divided data to which the divided data attribute information has been added.

The divided data processed as described above is combined by the transmission data generating unit as described above.
The order of combining the divided data at this time does not necessarily have to be the order in which the files were divided, and may be combined at random. If random, errors are dispersed in video data such as still images and moving images, which is effective for improving error correction capability. In addition to combining divided data, when transmitting a plurality of files, it is also possible to combine files. It is also possible to make the order of combining the files random.

In the mobile terminal, the transmitting means and the data reproducing means on the mobile terminal side divide the received transmission data into divided data with an error correction code based on a delimiter, perform error correction, and perform file identification. Restore the file based on the name and the division number. In this case, even if a delimiter is lost during transmission, data can be reproduced by keeping the data length after adding the error correction code constant for a predetermined period.

Next, the operation of the central office 1 and the mobile terminal 2 configured as described above will be described with reference to FIGS. Here, the video information storage means 7 stores a road map of 1: 50,000, a road map of 1: 25,000, a house map, and a video of an intersection which is a live view. The user requests the delivery of the 1 / 50,000th road map for the first time, the delivery of the 1 / 25000th road map for the second time, the delivery of the video of the intersection for the third time, It is assumed that a request for distribution of a house map is made for the fourth time.

In FIGS. 1 and 2, first, at the mobile terminal 2, the user inputs from the input / output means 14 a request to distribute a 1: 50,000 road map. In response to this input, the mobile terminal side communication control means 15 checks whether or not the reception error rate is held in the internal memory. This request is the first request, and the reception error rate is not held in the internal memory. Therefore, the input request and the information indicating that the user is a mobile terminal are transmitted to the mobile terminal-side transmitting means 17.

In response to this transmission, the mobile terminal side transmitting means 17
Encodes / modulates the transmitted request and information indicating that the mobile terminal is a mobile terminal, and converts the communication signal into a communication signal through the transmitting antenna 18 and the mobile phone line.
Send to The received communication signal is received by the receiving antenna 3 of the central office 1, and the received communication signal is sent to the central office receiving means 4.

Upon receiving this transmission, the central office side receiving means 4
The transmitted communication signal is demodulated / decoded to extract a request and information indicating that the terminal is a mobile terminal. In response to the transmission, the central office communication control means 5 stores the information indicating that it is a mobile terminal in the reception environment information storage means 6 with respect to the transmitted request and the information that it is a mobile terminal. The video information of the requested 1 / 50,000 road map is acquired from the video information storage means 7. Next, by referring to the transmission quality management table, it is determined that the modulation scheme should be the QPSK modulation scheme because the reception environment of the mobile terminal 2 is the mobile terminal, and since the reception error rate is unknown, data redundancy is determined. It is determined that the degree should be “medium”. Next, an error correction code having a bit width corresponding to the data redundancy “medium” is added to the acquired video information of the 1: 50,000 road map to obtain transmission data, and this transmission data is transmitted to the central office side transmitting means 6. At the same time, a command to set the modulation method to QPSK is output to the central office transmitting means 6.

Upon receiving the transmission data of the 1 / 50,000 road map transmission and the output of the command, the central office transmitting means 6
First, the transmitted 1 / 50,000th road map transmission data is converted into a coded / multiplexed digital communication signal by the MPEG2 coding method, and then the digital communication signal is converted to QPSK.
The transmission signal is modulated by using a modulator of a modulation method, and the transmission signal is transmitted to the mobile terminal 2 through the transmission antenna 9 by TV waves.

The transmission signal transmitted by this TV radio wave is received by the receiving antenna 10 of the mobile terminal 2, and the received transmission signal is transmitted to the mobile terminal side receiving means 11. In response to the transmission, the mobile terminal side receiving means 11 demodulates the transmitted transmission signal to extract a digital communication signal, transmits the digital communication signal to the TS separation means 12, and checks the reception error rate of the extracted communication signal. This is detected and output to the mobile terminal side communication control means 15. Here, it is assumed that the reception error rate is “large” because the automobile in which the mobile terminal 2 is installed is currently traveling in an area where radio waves from the central office 1 are difficult to reach.

In response to this output, the mobile terminal side communication control means 15 stores the output “large” reception error rate in the internal memory. On the other hand, receiving the above transmission, the TS separation means 1
2 extracts the transmitted digital communication signal, extracts the encoded / compressed 1: 50,000th road map transmission data, and sends it to the data reproducing means 13.

In response to this transmission, the data reproducing means 13
It decodes and decompresses the transmitted encoded / compressed transmission data to extract and hold the transmission data, and outputs the transmission data to the mobile terminal side communication control means 15. Upon receiving the output, the mobile terminal side communication control means 15
Checks the output transmission data for a code error, and sends error correction information to the data reproducing unit 13 based on the check result. In response to the transmission, the data reproducing means 13 corrects the error according to the transmitted error correction information, reproduces the video information of the original 1 / 50,000 road map from the transmission data, and The image information of the first road map is sent to the input / output means 14.

In response to the transmission, the input / output means 14 displays, on the liquid crystal panel, an image of the 1: 50,000th road map image information of the transmitted 1 / 50,000th road map image information. Then, the audio information is output as audio from a speaker. This allows the user to view the requested 1 / 50,000th road map video information.

Next, a case where the user makes a second request will be described. In this case, in the mobile terminal 2, the user inputs from the input / output means 14 a request to distribute a 1 / 25th of the road map. In response to this input, the mobile terminal side communication control means 15 checks whether or not the reception error rate is held in the internal memory, and determines the held “large” reception error rate as the input request and the self request. Is transmitted to the mobile terminal side transmitting means 17 together with information indicating that the mobile terminal is a mobile terminal.

The transmitted request, the information that the mobile terminal is the mobile terminal, and the reception error rate of “large” are transmitted from the mobile terminal 2 to the central station 1 in the central station 1 in the same manner as in the first request. The control means 5 is reached.

Regarding the arrived request, information indicating that the mobile terminal is a mobile terminal, and the reception error rate of “large”,
The central office communication control means 5 stores the information indicating that the mobile station is a mobile terminal and the reception error rate of "large" in the reception environment information storage means 6, and stores the requested one-fifth of a 25,000th road. The video information of the map is obtained from the video information storage means 7.
Next, referring to the transmission quality management table, the mobile terminal 2
Since the receiving environment of the mobile terminal is a mobile terminal, the modulation method is QPS
It is determined that the K modulation scheme should be used, and it is determined that the data redundancy should be “large” because the reception error rate is “large”. Next, an error correction code having a bit width corresponding to the data redundancy “large” is added to the acquired video information of the 1 / 25,000 road map, and the resulting information is transmitted to the central office side transmitting means 6. Is output to the central office side transmitting means 6.

The transmitted image information of 1 / 25000th of the road map is modulated by the modulator of the QPSK modulation system.
Other points are the same as for the first request,
The signal is transmitted from the central office 1 to the mobile terminal side receiving means 11 of the mobile terminal as a transmission signal.

The mobile terminal side receiving means 11 demodulates the arriving transmission signal with a QPSK modulation type demodulator to extract a digital communication signal, sends it to the TS separation means 12, and outputs the digital communication signal. The reception error rate is detected and output to the mobile terminal side communication control means 15. Here, the car on which the mobile terminal 2 is installed is still traveling in an area where radio waves from the central station are difficult to reach,
It is assumed that the reception error rate has decreased within the range of “large”. The output reception error rate is set in the same manner as in the case of the first request.
Is stored in the internal memory.

The transmitted digital communication signal is subjected to code error correction in the same manner as in the case of the first request, and then the video information of the original 1 / 25,000 road map is obtained. The image information is displayed as an image on the liquid crystal panel of the input / output means 14, and the audio information is output as audio from the speaker. This allows the user to view the requested 1 / 25,000th of the road map video information.

Next, a case where the user makes a third request will be described. In this case, in the mobile terminal 2, the user inputs from the input / output unit 14 a request to distribute the video of the intersection.

The input request is transmitted from the mobile terminal 2 to the central office 2 in exactly the same manner as in the case of the second request, and the video information of the requested intersection is displayed in the second request. In exactly the same way as in the case, the central station 1 to the mobile terminal side receiving means 11 of the mobile terminal 2
Is transmitted as a transmission signal.

The mobile terminal side receiving means 11 demodulates the arriving transmission signal, extracts a digital communication signal, sends it to the TS separation means 12, and detects the reception error rate of the extracted communication signal. This is output to the mobile terminal side communication control means 15. Here, it is assumed that the automobile in which the mobile terminal 2 is installed is moving to an area where the reception of radio waves from the central office is good, and the reception error rate is “small”. This output reception error rate is held in the internal memory of the mobile terminal side communication control means 15 in the same manner as in the case of the second request.

The transmitted digital communication signal is subjected to code error correction in the same manner as in the case of the second request, and is then reproduced as video information of the video at the original intersection. Is displayed on the liquid crystal panel of the input / output means 14, and the audio information is output from the speaker as audio. Thereby, the user can view the video information of the video of the requested intersection.

Next, a case where the user makes a fourth request will be described. In this case, in the mobile terminal 2, the user inputs from the input / output means 14 a request for distribution of the house map.

In response to this input, the mobile terminal side communication control means 15 moves the “small” reception error rate held in the internal memory together with the input request and information indicating that the mobile terminal is the mobile terminal. It is sent to the terminal side transmitting means 17. The transmitted request, the information that the mobile terminal is the mobile terminal, and the reception error rate of “small” reach the central communication control unit 5 of the central office 1 from the mobile terminal 2 in the same manner as described above. I'm sullen.

For the request that has arrived, the information that it is a mobile terminal, and the reception error rate of “small”,
The central office communication control means 5 stores the information indicating that the mobile terminal is a mobile terminal and the reception error rate of "small" in the reception environment information storage means 6, and stores the requested house map image information as image information. It is obtained from the means 7. Next, referring to the transmission quality management table, since the reception environment of the mobile terminal 2 is the mobile terminal and the reception error rate is “small”, the modulation scheme is set to 64QAM and the data redundancy is set to “small”.
Is determined to be. Next, an error correction code having a bit width corresponding to the data redundancy "small" is added to the acquired image information of the house map and transmitted to the central office side transmitting means 6, and the modulation method is set to 64QAM modulation method. The command is output to the central office side transmitting means 6.

The sent image information of the house map is transmitted from the central office 1 to the mobile terminal 2 in the same manner as described above, and is reproduced as the image information of the original house map. And an audio output. This allows the user to view the requested house map video information.

As described above, in the first embodiment, the mobile terminal 2 transmits the reception environment information to the central office 1 at the time of the request.
To the central office 1 based on the reception environment information,
Since the method of ensuring the transmission quality for code errors in the delivery of the requested video information has been switched,
It becomes possible to select a method for ensuring transmission quality related to code errors according to the reception environment of the mobile terminal 2.
Transmission quality related to a code error of the video information to be distributed to the user.

In the above description, the distribution of the video information from the central station 1 to the mobile terminal 2 is performed by a normal TV broadcast, but may be performed by a satellite communication broadcast. In the above description, the modulation scheme is switched between two modulation schemes, but may be switched between three or more modulation schemes. Further, in the above description, information composed of still images is used as video information, but information composed of moving images such as video programs may be used. Further, in the above description, one video request is requested in one request. However, when a plurality of video information is requested in one request, the central office 1 requests the plurality of video information. The information may be delivered exactly as described above. In the above description, the input / output unit 14 of the mobile terminal 2 inputs the request using the input screen and the input pen. However, the request may be input by voice.

Embodiment 2 FIG. 5 is a block diagram showing a configuration of a central station device and a mobile terminal device used in a method of distributing video information to a mobile object by digital wireless communication according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. In the second embodiment, the mobile terminal-side receiving means 11 does not detect the reception error rate in the mobile terminal 2, and instead, As information, position information detecting means 16 for detecting own vehicle position, own vehicle speed, planned course, and road information is provided. In the central office 1, the central office side communication control means 5 performs communication based on the reception environment information. The second embodiment differs from the first embodiment in that the modulation scheme and the data redundancy of the video information to be transmitted are switched.

That is, the position information detecting means 16 comprises a car navigation device, and utilizes the car navigation system to determine the position of the vehicle, the speed of the vehicle, the planned course of the vehicle,
And road information. For example, position information detecting means 1
6 detects the position of the vehicle using a GPS (global positioning system) satellite and detects the speed of the vehicle using a speedometer. In addition, a planned route of the vehicle is created based on the position of the vehicle and the input of the user, and road information such as traffic congestion information of a road corresponding to the planned route of the vehicle and presence / absence of road construction by the user's operation is obtained. Obtained from the navigation system center.

Then, the mobile terminal side communication control means 15
The vehicle location, the vehicle speed, the planned course of the vehicle, and the road information are used as reception environment information together with the request and the information that the vehicle is a mobile terminal, and the central office via the mobile terminal side transmitting means 17. Send to 1.

On the other hand, in the central office 1, the central office communication control means 5 receives the request and the reception environment information transmitted from the mobile terminal 2 via the receiving antenna 3 and the central office receiving means 4, Based on this reception environment information,
The modulation method and data redundancy of the video information to be transmitted are switched.

Then, the central office communication control means 5 performs this switching in accordance with the transmission quality management table shown in FIG. In FIG. 6, in this transmission quality management table,
The reception environment is roughly classified into a fixed terminal and a mobile terminal. In the case of a mobile terminal, it is divided into a case where a tunnel does not exist on a planned route and a case where a tunnel exists. If not, the vehicle speed is "high"
And the case where the own vehicle speed is “small”. Then, when the reception environment is a fixed terminal, the modulation scheme is the 64QAM modulation scheme and the data redundancy is “small” as in the first embodiment. If the receiving environment is a mobile terminal and there is a tunnel on the scheduled route, the distribution of the requested video information is rejected. If the reception environment is a mobile terminal and there is no tunnel on the planned route, if the own vehicle speed is “high”, the modulation method is 64QAM modulation method and the data redundancy is “small”. When the vehicle speed is “small”, the modulation method is QP
The SK modulation method and the data redundancy are set to “medium”.

Here, upon receiving the reception environment information, the central office side communication control means, for example, when a tunnel exists on the planned course of the mobile terminal, the speed of the mobile terminal and the road construction and traffic obtained from the road information. If it is determined that the mobile terminal is approaching the tunnel at the time of distributing the requested video information based on information such as the presence or absence of traffic congestion, the reception environment of the mobile terminal is treated as "with tunnel" and determined not to be In this case, the reception environment of the mobile terminal is treated as “no tunnel”. The operations of the central office 1 and the mobile terminal 2 after the transmission of the requested video information are the same as in the first embodiment.

As described above, according to the second embodiment, the mobile terminal 2 detects the speed of the vehicle on which the mobile terminal 2 is installed, and transmits the detected speed to the central office 1 as reception environment information. Therefore, since the reception error rate changes depending on the speed of the vehicle, it is possible to select a transmission quality ensuring method for code errors according to the speed of the vehicle. It is possible to accurately assure the transmission quality of the data.

Also, in the second embodiment, mobile terminal 2
However, car navigation is used to generate scheduled route information of the vehicle in which the mobile terminal 2 is installed, and this is transmitted to the central office 2 as reception environment information. It is possible to select a method of securing transmission quality related to code errors depending on whether or not to perform the transmission, and it is possible to more accurately secure transmission quality related to code errors of video information delivered to the mobile terminal 2.

Embodiment 3 FIG. 7 is a block diagram showing a configuration of a central station device and a mobile terminal device used in a method for distributing video information to a mobile object by digital wireless communication according to Embodiment 3 of the present invention. In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. In the third embodiment, the mobile terminal 2 is provided with position information detecting means 16 for detecting the own vehicle position as further reception environment information, In the central office 1, the central office communication control means 5 creates a map indicating the reception environment of the broadcast area using the vehicle position and the reception error rate, and based on the created map,
This embodiment is different from the first embodiment in that the modulation scheme and the data redundancy of the video information to be transmitted are switched.

That is, the position information detecting means 16 is composed of a car navigation device, and acquires the position of the own vehicle using a car navigation system. Then, the mobile terminal-side communication control means 15 transmits the information indicating that the mobile terminal is a mobile terminal, the reception error rate, and the position of the own vehicle as reception environment information together with the request to the central station 1 via the mobile terminal-side transmission means 17. Send to

On the other hand, in the central office 1, the central office communication control means 5 receives the request and the reception environment information transmitted from the mobile terminal 2 via the receiving antenna 3 and the central office receiving means 4, This reception environment information is stored in the reception environment information storage means 6. Here, the central office communication control means 5 estimates the position of the mobile terminal 2 when receiving the video information requested by the mobile terminal 2 from the position of the mobile terminal 2 detected each time the mobile terminal 2 makes a request. The reception error rate at the time of receiving the requested video information corresponds to the estimated position of the mobile terminal 2,
A map representing the reception error rate with respect to the position in the broadcast area is created, and the created map is stored in the reception environment information storage means 6. Is received, the map is read out from the reception environment information storage means 6, and is corrected using the received mobile terminal's own vehicle position and reception error rate.
Is updated to the corrected map. Then, the central office communication control means 5 switches the modulation method and the data redundancy according to the transmission quality management table shown in FIG.

The transmission quality management table of FIG. 8 differs from the transmission quality management table of FIG. 2 only in that a predicted reception error rate is used instead of the reception error rate. That is, when transmitting the requested video information to the mobile terminal, the central office communication control unit estimates the reception error rate of the mobile terminal based on the updated map and the own vehicle position received at the time of the request. Then, the modulation scheme and data redundancy are switched to the modulation scheme and data redundancy corresponding to the predicted error rate (predicted error rate) in the transmission quality management table of FIG. The subsequent operations of the central station 1 and the mobile terminal are the same as in the first embodiment.

As described above, in the third embodiment, the mobile terminal 2 detects the reception error rate in the distribution of the video information, and transmits the reception request to the central station 1 as the reception environment information together with the position of the vehicle at the time of the next request. The central office 1 accumulates the position and the reception error rate of the transmitted automobile in such a manner that the position and the reception error rate are represented as a map indicating the reception environment of the TV broadcast area. Based on the map, the method of ensuring the transmission quality regarding the code error in the distribution of the video information to the mobile terminal 2 is switched, so that the reception error rate of the mobile terminal 2 at the time of the request based on the map is reduced. Since it is possible to predict, it is possible to select a transmission quality ensuring method for code errors based on the predicted reception error rate, Transmission quality for code error of the video information to be distributed to end 2 can be accurately secured.

[0097]

As described above, according to the present invention, the mobile terminal device transmits the reception environment information to the central office at the time of the request, and the central office transmits the reception environment information to the central office. Based on the information, the method for ensuring the transmission quality regarding the code error in the delivery of the requested video information is switched, so that the method for ensuring the transmission quality regarding the code error can be selected according to the reception environment of the mobile terminal device. As a result, it is possible to secure transmission quality related to a code error of video information distributed to the mobile terminal device.

According to the second and twelfth aspects of the present invention, in the first and the eleventh aspects of the present invention, the method for securing the transmission quality related to a code error comprises:
Since it is assumed that the modulation method is switched to a modulation method having a different strength against occurrence of a code error, transmission quality relating to a code error of video information to be delivered to the mobile terminal device can be ensured by a simple method.

According to the inventions of claims 3, 13 and 23, in the invention of claims 1, 11 and 21, the method for securing transmission quality relating to code errors switches the redundancy of video information to be distributed. Since the error correction code for changing the redundancy is added to the video information to be distributed, even if there is a time overlapping request from a plurality of mobile terminal devices, Accordingly, transmission quality relating to code errors can be ensured in correspondence with each mobile terminal device.

According to the inventions of claims 4, 14, and 24, in the inventions of claims 1, 11, and 21, the reception environment information is information indicating that the mobile terminal device is used. When terminals and mobile terminals coexist, it is possible to enhance the method of securing transmission quality for code errors in the case of mobile terminals, and secure transmission quality for code errors of video information delivered to mobile terminals. can do.

According to the fifth, fifteenth, and twenty-fifth aspects of the present invention, in the first, twenty-first and twenty-first aspects, the mobile terminal apparatus detects a code error rate in the distribution of video information and determines the next request. At this time, the transmission environment information is transmitted to the central office apparatus, so that it is possible to select a method for ensuring the transmission quality related to a code error based on the result of actually distributing the video information. The transmission quality related to the code error of the video information can be accurately ensured.

According to the inventions of claims 6, 16, and 26, in the inventions of claims 1, 11, and 21, the mobile terminal device detects a position of a mobile body on which the mobile terminal device is installed. Since this is transmitted to the central office as reception environment information, for example, if the code error rate for the position in the distribution area of the video information is known,
Utilizing this, it is possible to accurately assure the transmission quality related to a code error of the video information distributed to the mobile terminal device.

According to the inventions of claims 7, 17, and 27, in the inventions of claims 6, 16, and 26, the mobile terminal apparatus further detects a code error rate in the distribution of the video information and requests the next request. At the time of transmission to the central office apparatus as the reception environment information together with the position of the mobile body, the central office apparatus, the transmitted position and code error rate of the mobile body, as a map indicating the reception environment of the video information distribution area In the case where there is a request from the mobile terminal device, the method of ensuring the transmission quality regarding the code error in the distribution of the video information to the mobile terminal device is switched based on the stored map, Since it is possible to predict the code error rate of the mobile terminal device when a request is made based on the map, the code is calculated based on the predicted code error rate. It becomes possible to select a method ensuring Rinikansuru transmission quality, it is possible to accurately secure the transmission quality related code error of the video information to be distributed to the mobile terminal device.

According to the invention of claims 8, 18 and 28, in the invention of claims 1, 11 and 21, the mobile terminal device detects the speed of the mobile body on which the mobile terminal device is installed. Since this is transmitted to the central office as reception environment information, the bit error rate varies depending on the speed of the mobile unit. Therefore, a method for securing the transmission quality regarding code errors is selected according to the speed of the mobile unit. It is possible to
It is possible to accurately ensure transmission quality related to a code error of video information distributed to a mobile terminal device.

According to the ninth, nineteenth, and twenty-ninth aspects of the present invention, in the first, eleventh, and twenty-first aspects of the present invention, the mobile terminal is provided with the mobile terminal using car navigation. Generates planned route information for
Since the information is transmitted to the central station as reception environment information, it is possible to select a method for ensuring the transmission quality related to a code error according to whether or not a radio communication obstacle exists on the scheduled route, etc. The transmission quality related to the code error of the video information distributed to the terminal device can be more accurately secured.

According to the tenth, twentieth and thirty aspects of the present invention, in the ninth, nineteenth and twenty-ninth aspects of the present invention, the mobile terminal further obtains road information of the road corresponding to the generated planned route of the moving body. Then, this is transmitted to the central office as reception environment information together with the planned route information. Therefore, when a radio communication obstacle exists on the planned route of the mobile terminal, the speed of the mobile terminal, Based on information such as road construction and traffic congestion obtained from the information, it is determined whether or not the mobile terminal device approaches the wireless communication obstacle at the time of delivering the requested video information, and the determination result It is possible to select a method for ensuring the transmission quality related to code errors based on the transmission quality, and to more accurately and reliably determine the transmission quality related to code errors of video information delivered to the mobile terminal device. It can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a central station device and a mobile terminal device used in a method for delivering video information to a mobile object by digital wireless communication according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a transmission quality management table used by a central office communication control means in the central office apparatus of FIG. 1 to secure transmission quality related to a code error when transmitting video information.

FIG. 3 is a block diagram showing a configuration of a part for adding an error correction code to video information in the central office communication control means of FIG. 1;

4 is a diagram showing a data processing operation of a data division unit and an error correction generation unit in FIG. 3, and is a schematic diagram showing a state in which one piece of video information is divided (FIG. 4A); FIG. 4B is a schematic diagram illustrating a state in which divided data attribute information is added to data, and FIG. 4B is a schematic diagram illustrating a state in which an error correction code is added to one divided data to which divided data attribute information is added. c)).

FIG. 5 is a block diagram illustrating a configuration of a central station device and a mobile terminal device used in a method for distributing video information to a mobile object by digital wireless communication according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a transmission quality management table used by the central office communication control means in the central office apparatus of FIG. 5 to secure transmission quality relating to a code error when transmitting video information.

FIG. 7 is a block diagram showing a configuration of a central station device and a mobile terminal device used in a method for distributing video information to a mobile object by digital wireless communication according to a third embodiment of the present invention.

8 is a diagram showing a transmission quality management table used by the central office communication control means in the central office apparatus of FIG. 7 to secure transmission quality related to a code error when transmitting video information.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Central station 2 Mobile terminal 3, 10 Receiving antenna 4 Central office side receiving means 5 Central office side communication control means 7 Video information storage means 8 Central office side transmitting means 9, 18 Transmission antenna 11 Mobile terminal side receiving means 12 TS separation means Reference Signs List 13 data reproducing means 14 input / output means 15 mobile terminal side communication control means 16 position information detecting means 17 mobile terminal side transmitting means 19 reproducing means 101 data division section 102 error correction generation section 103 transmission data generation section 104 redundancy control section 105 data Storage unit

Claims (30)

[Claims] 1. A wireless communication system between a central station device installed on the ground and one or more mobile terminal devices including a terminal device installed on a mobile unit, from the mobile terminal device to the central station device via wireless communication. A video information distribution method for requesting distribution of video information, and distributing the requested video information from the central office device to the requesting mobile terminal device using digital wireless communication, wherein the mobile terminal device includes: Transmitting, at the time of the request, reception environment information indicating a reception environment of the mobile terminal device to the central station device, wherein the central station device transmits the reception environment information based on the reception environment information transmitted from the mobile terminal device; A method for distributing video information to a mobile object by digital wireless communication, wherein a method for securing transmission quality related to a code error in the distribution of video information to a mobile object is switched. 2. The method for distributing video information to a mobile body by digital wireless communication according to claim 1, wherein the method for ensuring transmission quality related to code errors includes: A method for distributing video information to a mobile body by digital wireless communication, characterized by switching to a modulation method having different strength against occurrence of a code error at the time of distribution. 3. The method for distributing video information to a mobile unit by digital wireless communication according to claim 1, wherein the method for securing transmission quality related to the code error is to switch redundancy of the distributed video information. A method for distributing video information to a mobile body by digital wireless communication. 4. The method according to claim 1, wherein the reception environment information is information indicating that the mobile terminal is a mobile terminal device. Video information distribution method to mobile objects. 5. The method for distributing video information to a mobile object by digital wireless communication according to claim 1, wherein the mobile terminal device detects and holds a code error rate in the delivery of the video information, and holds the code error rate. A method of transmitting video information to a mobile unit by digital wireless communication, wherein a code error rate is transmitted to the central office as the reception environment information at the time of the next request. 6. The method according to claim 1, wherein the mobile terminal device detects a position of the mobile device on which the mobile terminal device is installed, wherein the detection is performed. Transmitting the determined position of the moving object to the central station device as the reception environment information. 7. The method for distributing video information to a mobile object by digital wireless communication according to claim 6, wherein the mobile terminal device further detects and holds a code error rate in the delivery of the video information. The code error rate is transmitted to the central office as the reception environment information together with the position of the mobile at the time of the next request, and the central office receives the position and the position of the mobile transmitted from the mobile terminal. The code error rate is accumulated so as to be represented as a map indicating the reception environment of the video information distribution area, and when a request is received from the mobile terminal device, the video to the mobile terminal device is determined based on the stored map. A method for distributing video information to a mobile object by digital wireless communication, characterized by switching a method for ensuring transmission quality related to a code error in information distribution. 8. The method according to claim 1, wherein the mobile terminal device detects a speed of the mobile device on which the mobile terminal device is installed, and further comprises detecting the speed of the mobile device on which the mobile terminal device is installed. Transmitting the obtained speed of the moving object to the central station device as the reception environment information. 9. The method for distributing video information to a mobile object by digital wireless communication according to claim 1, wherein the mobile terminal device uses a car navigation to schedule a mobile object where the mobile terminal device is installed. A method for generating video information to a mobile unit by digital wireless communication, comprising generating information and transmitting the generated planned route information of the mobile unit to the central office as the reception environment information. 10. The method according to claim 9, wherein the mobile terminal device further obtains road information of a road corresponding to the generated planned route of the mobile object. A method for transmitting video information to a mobile object by digital wireless communication, wherein the acquired road information is transmitted to the central office as the reception environment information together with the planned route information. 11. An image between a central station device installed on the ground and one or more mobile terminal devices including a terminal device installed on a mobile unit, from the mobile terminal device to the central station via wireless communication. A central station apparatus used in a video information distribution method for requesting information distribution and distributing the requested video information from the central station to the requesting mobile terminal apparatus using digital wireless communication, Receiving means for receiving reception environment information transmitted together with the request in the wireless communication from the device; transmitting means for transmitting the digital wireless communication to the mobile terminal device; and an object of the request received by the receiving means Is transmitted to the requesting mobile terminal device using the above-mentioned transmitting means, and the transmission quality regarding the code error in this transmission is confirmed. A central control unit for use in a method of distributing video information to a mobile body by digital wireless communication, comprising: a communication control unit that switches a security method based on the reception environment information received by the reception unit. 12. The central station device used in the method of delivering video information to a mobile object by digital wireless communication according to claim 11, wherein the communication control means performs the video image transmission as a method for ensuring transmission quality related to the code error. A central station apparatus used in a method of distributing video information to a mobile object by digital wireless communication, wherein a modulation scheme for transmitting information is switched to a modulation scheme having different strength against occurrence of a code error in the transmission. 13. The central station device used in the method for delivering video information to a mobile unit by digital wireless communication according to claim 11, wherein the communication control means performs the transmission as a method for securing transmission quality related to the code error. A central station device used in a method of distributing video information to a mobile body by digital wireless communication, wherein the central station device switches the redundancy of video information to be transmitted. 14. The central station device used in the method for delivering video information to a mobile object by digital wireless communication according to claim 11, wherein the reception environment information is information indicating that the mobile terminal device is a mobile terminal device. The control means switches the method of ensuring the transmission quality related to the code error based on the information indicating that the mobile terminal apparatus is a mobile terminal device received by the reception means. Central office equipment used for video information distribution methods. 15. The central station device used in the method for delivering video information to a mobile object by digital wireless communication according to claim 11, wherein the reception environment information is a code error rate in the transmission of the video information. A method of distributing video information to a mobile body by digital wireless communication, wherein the communication control means switches a method of ensuring transmission quality related to the code error based on the code error rate received by the reception means. Central office equipment used for 16. The central station device used in the method for delivering video information to a mobile unit by digital wireless communication according to claim 11, wherein the reception environment information is a position of the mobile unit where the mobile terminal device is installed. Wherein the communication control means switches a method of securing transmission quality related to the code error based on a position of the mobile body received by the receiving means, to the mobile body by digital wireless communication. Central station device used in the video information distribution method of the present invention. 17. The central station device used in the method for distributing video information to a mobile unit by digital wireless communication according to claim 16, wherein the reception environment information includes a position of the mobile unit and a transmission status of the video information. The communication control means stores the position and the code error rate of the moving object received by the receiving means as a map indicating a receiving environment of the video information distribution area, and accumulates the information. When a request from the mobile terminal device is received through, the method for ensuring transmission quality related to code errors in transmission of video information to the mobile terminal device that made the request is switched based on the stored map. A central station device used in a method of distributing video information to a mobile object by digital wireless communication. 18. The central station device used in the method for distributing video information to a mobile object by digital wireless communication according to claim 11, wherein the reception environment information is a speed of the mobile object on which the mobile terminal device is installed. Wherein the communication control means switches a method of ensuring transmission quality related to the code error based on the speed of the mobile object received by the receiving means, to the mobile object by digital wireless communication. Central station device used in the video information distribution method of the present invention. 19. The central station device used in the method of delivering video information to a mobile object by digital wireless communication according to claim 11, wherein the reception environment information is a schedule of the mobile object where the mobile terminal device is installed. A communication path, wherein the communication control means switches a method of ensuring transmission quality related to the code error based on a scheduled path of the mobile object received by the receiving means. A central office device used for a method of delivering video information to mobile objects. 20. The central station device used in the method for delivering video information to a mobile object by digital wireless communication according to claim 19, wherein the reception environment information includes a scheduled route of the mobile object and a road corresponding to the scheduled route. Wherein the communication control means switches a method of securing the transmission quality related to the code error based on the planned route and road information of the mobile object received by the receiving means. A central station device used in a method of distributing video information to a mobile object by digital wireless communication. 21. Between a central station device installed on the ground and one or more mobile terminal devices including terminal devices installed on a mobile unit, the mobile terminal device communicates with the central station device via wireless communication. A mobile terminal device used in a video information distribution method for requesting distribution of video information and distributing the requested video information from the central station device to the requesting mobile terminal device using digital wireless communication, Receiving means for receiving video information transmitted by the digital wireless communication from the central station device; reproducing means for reproducing the video information received by the receiving means; input means for inputting the request; A transmitting unit for performing transmission by wireless communication to a station device, and when a request is input from the input unit, a reception ring of the mobile terminal device is transmitted together with the request. And a communication control unit for transmitting reception environment information to the central station device using the transmission unit, the mobile terminal device being used in a method of distributing video information to a mobile body by digital wireless communication. . 22. The mobile terminal device used in the method of delivering video information to a mobile object by digital wireless communication according to claim 21, wherein the video information has a predetermined strength different from a code error occurrence in the digital wireless communication. The modulation means is transmitted by switching the modulation method among the plurality of modulation methods. The reception means includes a plurality of demodulation means respectively corresponding to the predetermined plurality of modulation methods. A mobile terminal device used in a method of distributing video information to a mobile object by digital wireless communication, wherein the mobile terminal device is capable of demodulation. 23. The mobile terminal device used in the method of delivering video information to a mobile object by digital wireless communication according to claim 21, wherein the video information is transmitted by switching the redundancy of the video information. Wherein the communication control means causes the reproduction means to correct an error in the video information transmitted and received by the reception means according to the switched redundancy. A mobile terminal device used for a method of delivering video information to a mobile body by digital wireless communication, wherein the mobile terminal device reproduces the corrected video information. 24. The mobile terminal device used in the method for delivering video information to a mobile object by digital wireless communication according to claim 21, wherein the communication control means is a mobile terminal device as the reception environment information. A mobile terminal device used for a method of delivering video information to a mobile body by digital wireless communication, wherein the mobile terminal device transmits information. 25. A mobile terminal device used in the method of delivering video information to a mobile object by digital wireless communication according to claim 21, wherein said receiving means detects a code error rate in said digital wireless communication. The communication control means holds the code error rate detected by the reception means, and when a request is input from the input means next time, the code error rate held together with the request is stored as the reception environment information. A mobile terminal device used in a method for delivering video information to a mobile body by digital wireless communication, wherein the mobile terminal device transmits the video information to the central station device. 26. A mobile terminal device used in the method for delivering video information to a mobile object by digital wireless communication according to claim 21, wherein position information detection for detecting the position of the mobile object on which the mobile terminal device is installed. Wherein the communication control means transmits the position of the moving object detected by the position information detecting means to the central station device as the reception environment information. A mobile terminal device used in a method for delivering video information to a body. 27. A mobile terminal device used in the method for delivering video information to a mobile object by digital wireless communication according to claim 26, wherein said receiving means detects a code error rate in said digital wireless communication. The communication control means holds the code error rate detected by the receiving means, and when a request is input from the input means next time, the code error rate to be held together with the request and the position of the moving body is held. And transmitting the reception environment information to the central office apparatus, wherein the mobile terminal apparatus is used in a method of distributing video information to a mobile body by digital wireless communication. 28. A mobile terminal device used in the method for delivering video information to a mobile object by digital wireless communication according to claim 21, wherein position information detection for detecting the speed of the mobile object on which the mobile terminal device is installed. Wherein the communication control means transmits the speed of the moving object detected by the position information detection means to the central station device as the reception environment information. A mobile terminal device used in a method for delivering video information to a body. 29. A mobile terminal device used in the method for delivering video information to a mobile object by digital wireless communication according to claim 21, wherein a scheduled course of the mobile object in which the mobile terminal device is installed using car navigation. The communication control means transmits the planned route information of the mobile object generated by the position information detection means to the central station device as the reception environment information. A mobile terminal device used in a method for distributing video information to a mobile object by digital wireless communication, characterized in that: 30. A mobile terminal device used in the method of delivering video information to a mobile object by digital wireless communication according to claim 29, wherein the position information detecting means further includes a generated road object corresponding to the planned course of the mobile object. The communication control means transmits the road information obtained by the position information detection means to the central station device as the reception environment information together with the planned route information. A mobile terminal device used in a method for distributing video information to a mobile object by digital wireless communication.