JPH1174826A - Radio receiver, radio broadcasting system and radio broadcasting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the influence of hit due to a shield, and to obtain satisfactory reception quality by operating a prescribed multi-path receiving processing by a receiving means such as a rake receiver for a synthetic signal from plural antennas. SOLUTION: Antennas 11 and 12 are arranged in the neighborhoods of the front edge and rear edge of a mobile object. Transmission signals obtained by those antennas 11 and 12 are used for a rake receiving processing as different transmission signals arriving through different paths by a rake receiver 14, and used for reception with high S/N using a path diversity effect. That is, a synthesizer 13 simply operates only synthesis without operating any processing such as the phase matching of the transmission signals obtained by the antennas 11 and 12. When the width of a shield is smaller than the width of the antennas 11 and 12 of the mobile object in the preceding direction, or when the shield is positioned only at the upper part of one part of a direction orthogonally crossing the preceding direction of the mobile object, a radio wave can be always received, and any hit can not be generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio receiving apparatus, a radio broadcasting system, and a radio broadcasting apparatus employed in a satellite broadcasting system using a radio signal having a high linearity such as an S band.

[0002]

2. Description of the Related Art Recently, satellite broadcasting has been started in addition to terrestrial broadcasting with the demand for diversification of broadcasting services and development of communication technology. Since satellite broadcasting can provide services to a wide area without having to construct a large-scale infrastructure on the ground, the satellite broadcasting is attracting attention as a medium that can respond to needs even more.

[0003] Conventional satellite broadcasting systems in Japan include BS (Broadcasting Satellite) broadcasting and CC broadcasting.
S (Communication Satellite) broadcasting has already been put into practical use, and digital broadcasting has also started. Satellite broadcasting systems of almost the same size have been developed and put to practical use in other countries.

However, in any of the satellite broadcasting systems, it is necessary to use a parabolic antenna having a diameter of about 40 to 50 cm or a planar array antenna having a size corresponding thereto as a receiving antenna. Further, unless the pointing direction of the antenna is pointed to the satellite with extremely high precision, a sufficient gain cannot be obtained and reception becomes impossible.

[0005] For this reason, reception and viewing indoors are premised, and it is extremely difficult to provide a satellite broadcast receiving apparatus with a simple type of antenna equipment corresponding to the needs for mounting on a mobile object or for portable use. Responding to these needs can be effectively functioned as a means of providing information requiring urgency particularly in the event of a disaster or the like, so that immediate realization is expected.

Accordingly, the present applicant has proposed a satellite broadcasting system and a satellite broadcasting receiving apparatus which can be received by a receiving apparatus with a simple antenna facility corresponding to the needs for mounting on a mobile body and for portable use, as disclosed in Japanese Patent Application No. 9-48318. No. is proposed.

FIG. 8 is a diagram showing a schematic configuration of a satellite broadcasting system according to Japanese Patent Application No. 9-48318. This satellite broadcasting system includes a plurality of broadcasting stations BC1 and BC2 and a broadcasting satellite S
AT. The broadcast stations BC1 and BC2 transmit the program signals created and edited by each broadcaster or the like to the broadcast satellite SAT via the Ka or Ku band uplink transmission path. The broadcast satellite SAT is managed by the satellite tracking control station STCC so as to stop at a predetermined position in a geosynchronous orbit above the equator, for example.

Here, as shown in FIG. 9, for example, a broadcasting satellite SAT is provided on a satellite body 1 with solar battery panels 2 and 3 serving as power sources, a Ka or Ku band antenna 4,
It is configured by attaching a band antenna 5. Note that K
The a or Ku band antenna 4 includes a reflector 41 having a diameter of, for example, 2.5 m and a primary radiator 42. The S-band antenna 5 includes a reflector 51 having a diameter of, for example, 8 to 15 m and a primary radiator group 52.

[0009] The broadcast signal transmitted from each of the broadcast stations BC1 and BC2 is transmitted to the Ka or Ku band antenna 4.
And demodulated and amplified by a signal processing device provided inside the satellite main body 1, and then converted into an S-band signal. Then, the converted broadcast signal is transmitted from the S-band antenna 5 to the service area via the S-band downlink transmission path.

In the service area, as shown in FIG. 8, a fixed station installed in an office or a home and a mobile station MS such as an on-vehicle receiving device or a portable terminal device are broadcast satellite SA.
A broadcast signal from T is received.

In the S-band downlink transmission path, a plurality of channels having a transmission rate of, for example, 64 to 256 kbps / channel are divided into a code division multiplex system alone or a time division multiplex system or a frequency division multiplex system. The multiplexing method is used together to multiplex up to about 900 channels.
When a video signal is transmitted via each channel, the video encoding method is, for example, MPEG4 (Moving Pic).
Nature Expert Group 4) is used.

According to this system, reception can be performed by the rod antenna having directivity in all directions, and reception while moving is possible. However, when a very high frequency such as the S band is used, the radio wave has high linearity, and in an extreme case, the radio wave may be blocked even by a small shield such as an electric wire. In general, when the receiving terminal is moving, a small blocking object frequently enters between the broadcasting satellite SAT and the receiving terminal, so that instantaneous interruptions occur repeatedly, which greatly affects the reception quality. There was a problem that it would occur.

[0013]

As described above, conventionally,
Since a radio wave is cut off even by a small shield, instantaneous interruptions occur repeatedly during movement, which causes a problem that reception quality is deteriorated.

The present invention has been made in view of such circumstances, and an object of the present invention is to reduce the influence of an instantaneous interruption caused by a shield and to obtain a good reception quality. An object of the present invention is to provide a receiving device, a wireless broadcasting system, and a wireless broadcasting device.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method of modulating a signal by a predetermined modulation scheme for multipath transmission (for example, a spread spectrum modulation scheme) which utilizes an indirect wave in addition to a direct wave. For example, in a wireless receiving apparatus used in a wireless communication system such as a satellite broadcast system for wirelessly transmitting a transmitted signal, for example, the moving direction of a moving object and the direction orthogonal to the moving direction are offset from each other, and viewed from above. Signals obtained by each of a plurality of antennas arranged apart from each other by arranging them near two points at which the linear distance between them becomes maximum on the contour of the moving object are mutually separated by signal synthesizing means. A predetermined multipath receiving process is performed on the combined signal obtained by the combining using a receiving unit such as a rake receiver. It was.

By taking such a measure, if any one of a plurality of antennas can receive a transmission signal, reception is continued by a signal obtained from the antenna. Therefore, even if there is a shield that does not block all of the radio waves arriving at each of the multiple antennas, instantaneous interruption due to the influence of the shield can be avoided, and the influence of a relatively small object can be avoided. This prevents instantaneous interruptions from occurring repeatedly.

Further, in order to achieve the above object, the present invention provides:
For example, in a wireless receiving apparatus used in a wireless communication system such as a satellite broadcast system for wirelessly transmitting a predetermined transmission signal, transmission data demodulated by receiving means such as a rake receiver from the transmission signal wirelessly transmitted is at least a predetermined value. For example, it is stored in a storage means such as a signal buffer over a period. Then, the occurrence of an instantaneous interruption to the transmission signal received by the receiving unit is monitored by an instantaneous interruption detecting unit such as an instantaneous interruption judging device, and when an instantaneous interruption is detected, the instantaneous interruption is stored in the storage unit. Based on the transmission data or in response to a retransmission request by a retransmission request unit such as a retransmission request processing unit, demodulated from a transmission signal retransmitted by a retransmission unit such as a retransmission processing unit provided in the wireless broadcasting device. By using the transmission data, the transmission data corresponding to the transmission signal portion where the instantaneous interruption is detected is compensated by a compensation means such as a signal missing portion compensating device.

By taking such a measure, even if a radio wave arriving at the antenna is shielded by a shield and a momentary interruption occurs, the missing part due to the momentary interruption is compensated,
Continuous transmission data is obtained.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a diagram showing a configuration of a satellite broadcast receiving apparatus according to a first embodiment of the present invention. This satellite broadcast receiving apparatus is used in the satellite broadcast system shown in FIG. 8, and is obtained by applying the wireless receiving apparatus according to the first aspect of the present invention.

As shown in FIG. 1, the satellite broadcast receiving apparatus according to the present embodiment has two antennas 11 and 12 and a signal combiner 1.
3, a rake receiver 14, an audio / video separation circuit 15, an audio decoder 16, a speaker 17, a video decoder 18, a liquid crystal display (LCD) 19, and a controller 20.

Each of the two antennas 11 and 12 receives a radio wave arriving via a downlink transmission path and generates a corresponding electric signal (transmission signal). This antenna 1
Numerals 1 and 12 are, for example, rod antennas, and are desirably arranged as far apart as possible.

The transmission signals obtained by these antennas 11 and 12 are combined with each other by a signal combiner 13 and then supplied to a rake receiver 14. The transmission signal synthesized by the signal synthesizer 13 is down-converted to an intermediate frequency or a baseband frequency in a rake receiver 14, a digital signal processing,
Despread spectrum processing in multiple systems, 1 in multiple systems
Integration process over symbol period, synthesis process of integration results of multiple systems, deinterleaving process, Viterbi decoding process,
Alternatively, known processes such as an error correction decoding process are sequentially performed to obtain received data.

The received data obtained by the rake receiver 14 is supplied to an audio / video separating circuit 15, where it is separated into audio data and video data. The audio data is subjected to audio decoding and conversion into an analog signal by the audio decoder 16 and is converted into an audio signal.
And output from the speaker 17. In addition, the video data is converted into, for example, MPEG data by the video decoder 18.
After being decoded by the four methods, it is given to the liquid crystal display 19 and displayed on the liquid crystal display 19 as a corresponding image.

The channel selection control of the rake receiver 14 and the separation control of the audio / video separation circuit unit 15 are performed by the control unit 20 based on a preset control program. FIG. 2 is a perspective view showing an example of an installation state of the antennas 11 and 12 on a moving body.

In this figure, the antennas 11 and 12 are respectively installed near the left end of the front end and the right end of the rear end of the moving body 21 (car in this figure). Thus, since the outline of the automobile when viewed from above is substantially rectangular, the antennas 11 and 12 are arranged near the diagonal of the rectangle. This also causes the antennas 11 and 12 to be offset from each other in the traveling direction of the moving body 21 (the direction indicated by arrow A in FIG. 2) and the direction perpendicular to the traveling direction (the direction indicated by arrow B in FIG. 2). It is in a state of having been done.

According to such a configuration, as shown in FIG. 3A, there is no shield 22 or the like between the mobile unit 21 equipped with the satellite broadcast receiving apparatus of the present embodiment and the broadcast satellite SAT. If not, the radio waves emitted from the broadcasting satellite SAT can be received by both of the two antennas 11 and 12.

At this time, a transmission signal is obtained by each of the antennas 11 and 12, but a phase difference may occur between the two transmission signals. However, the transmission signals obtained by each of the antennas 11 and 12 are provided to a rake receiver 14 after being combined with each other by a signal combiner 13, so that the transmission signals obtained by each of the antennas 11 and 12 are received by a rake receiver. The device 14 is used for rake reception processing as separate transmission signals arriving via different paths, and is used for reception at a high SN ratio using the path diversity effect. That is, in the signal combiner 13, the antenna 1
The synthesis is simply performed without performing processing such as phase adjustment of the transmission signals obtained in each of the steps 1 and 12.

Now, from the state shown in FIG.
Assuming that 1 moves in the moving direction shown in FIG. 3 and the state shown in FIG. 3B is reached, the radio wave to reach the antenna 11 is shielded by the shield 22 and the radio wave is received by the antenna 11. You will not be able to do it.

However, in this state, the radio wave reaching the antenna 12 is not shielded by the shield 22, and the antenna 12 can receive the radio wave, so that the receiving operation is continued.

Further, the moving body 21 moves in the moving direction shown in FIG. 3B from the state shown in FIG. 3B, and radio waves to reach the antenna 12 are blocked by the shield 22 as shown in FIG. Even if the antenna 12 is shielded and cannot receive radio waves, if the width of the shield 22 is smaller than the width of the antenna 11 and the antenna 12 in the traveling direction of the moving body 21, the antenna 12 When the radio wave to be reached is shielded by the shield 22, the radio wave reaching the antenna 11 is not affected by the shield 22. Therefore, as shown in FIG. 3C, the antenna 11 can receive radio waves, and thus the receiving operation is continued.

On the other hand, the shield 22 is shown in FIG.
As shown in (b), in a situation where it is located only above a part of the direction orthogonal to the traveling direction of the moving body 21, even if the shield 22 blocks a radio wave to reach one antenna, Since the radio wave reaches one antenna of the network, the receiving operation is continued.

In such a state, even if the shield 22 extends along the traveling direction of the moving body 21 longer than the width of the antenna 11 and the antenna 12 in the traveling direction of the moving body 21. The receiving operation is continued.

Thus, the width of the shield 22 is smaller than the width of the antenna 11 and the antenna 12 in the traveling direction of the moving body 21, or the shield 22 is a part of the direction orthogonal to the traveling direction of the moving body 21. If it is located only above, the mobile unit 21 can always receive radio waves even when it passes under the shield 22, and no instantaneous interruption occurs.

Even if the width of the shield 22 is larger than the width of the antennas 11 and 12, the time during which both the antennas 11 and 12 cannot receive radio waves is shortened. Can be shortened.

Note that the satellite broadcast receiving apparatus of the present embodiment
As shown in FIG. 5, antennas 11 and 12 and signal combiner 13
And low noise amplifiers 23 and 24 may be added between them, and the transmission signal after low noise amplification may be modified so as to be synthesized by the signal synthesizer 13.

A space diversity system for performing reception using a plurality of antennas as in the present embodiment is well known. However, the known space diversity system is for reducing the effect of fading caused by multipath transmission, and is unnecessary in a system such as the present embodiment using a multipath transmission system. At first glance, the configuration featured by this embodiment may seem to be similar to a well-known space diversity system. However, in this embodiment, multi-path signals are actively used to receive signals with a high SN ratio. Therefore, the effect of fading caused by multipath transmission is not reduced at all. Therefore, the configuration of the present embodiment is achieved under a technical idea completely different from that of the space diversity system.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention.
It is a figure showing the composition of the satellite broadcast receiving set concerning an embodiment. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

This satellite broadcast receiving apparatus is used in the satellite broadcast system shown in FIG.
The wireless receiver according to the invention described in (1) is applied.

As shown in FIG. 6, the satellite broadcast receiving apparatus according to the present embodiment includes an antenna 11, a rake receiver 14, an audio / video separation circuit 15, an audio decoder 16, a speaker 17,
Video decoder 18, liquid crystal display 19, control unit 2
0, a signal buffer 25, an instantaneous interruption determiner 26, and a signal missing portion compensation circuit 27.

The signal buffer 25 stores the received data obtained by the rake receiver 14 for a predetermined period of time and then supplies the data to the audio / video separation circuit 15. The signal buffer 25 also serves as a work field for receiving data processing by the signal missing portion compensation circuit 27.

The instantaneous interruption determiner 26 monitors the operation state of the rake receiver 14 (for example, the output state of received data) and detects occurrence of an instantaneous interruption. This instantaneous interruption determiner 26
When the occurrence of an instantaneous interruption is detected, the fact is notified to the signal missing portion compensating device 27.

The signal missing part compensating circuit 27 is provided with
6, a process for compensating the received data (missing portion) when the occurrence of the instantaneous interruption is detected. Next, the operation of the satellite broadcast receiving apparatus configured as described above will be described.

First, if the radio wave transmitted from the broadcasting satellite SAT reaches the antenna 11 normally, the rake receiver 14 normally takes out the reception data from the transmission signal obtained by the antenna 11. The received data thus obtained by the rake receiver 14 is stored and held in the signal buffer 25, and is sequentially supplied to the audio / video separation circuit unit 15 every predetermined time. Here, if the radio wave continues to reach the antenna 11 normally, the occurrence of the instantaneous interruption is not detected by the instantaneous interruption determiner 26, and the signal loss compensating device 27 is stored in the signal buffer 25. No processing is performed on the received data. Therefore, the received data is only delayed in the signal buffer 25 for a predetermined time.

Now, the moving object equipped with the satellite broadcast receiving apparatus of this embodiment moves, and the broadcast satellite SAT and the antenna 11 are moved.
If a shield enters between the two, the broadcast satellite SAT
The radio wave transmitted from the antenna 11 is shielded by the shield, and does not reach the antenna 11. At this time, the transmission signal is not supplied to the rake receiver 14, and the output of the received data from the rake receiver 14 is also in a no-signal state.

Then, the instantaneous interruption judging device 26 detects the occurrence of the instantaneous interruption, and notifies the signal missing portion compensating device 27 of the occurrence. In response to this, the signal missing portion compensating device 27 sets the predetermined data around the missing portion in the received data of the normal portion stored and held in the signal buffer 25 (for example, data of a portion having a high correlation with the missing portion). , The compensation data of the missing portion is created by, for example, copying or estimation. Then, the signal missing portion compensating device 27 writes the compensation data thus created in the signal buffer 25 to compensate for the missing portion.

As described above, according to the present embodiment, even if a radio wave is shielded by a shield and a momentary interruption occurs, a missing portion generated in the received data is thereby determined based on the surrounding received data in which the missing portion is normally obtained. Compensation is performed and reception data without any missing part is created, so that a decrease in reception quality can be kept small.

(Third Embodiment) FIG. 7 shows a third embodiment of the present invention.
FIG. 1 is a diagram illustrating a main configuration of a satellite broadcast system according to an embodiment. 1 and 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The overall image of this satellite broadcasting system is the satellite broadcasting system shown in FIG. 8, which is obtained by applying the radio broadcasting system according to the second aspect of the present invention. Note that FIG. 7 shows a main configuration of one of the satellite broadcast receiving devices 100 mounted on the mobile station MS in FIG. 8 and one of the satellite broadcast devices 200 installed on the broadcast station BC in FIG. ing.

As shown in FIG. 7, the satellite broadcast receiving apparatus 100 according to the present embodiment comprises an antenna 11, an audio / video separation circuit 15, an audio decoder 16, a speaker 17, a video decoder 18, a liquid crystal display 19, a control unit 20, Rake receiver 28, signal buffer 29, signal loss compensation circuit 30, instantaneous interruption determiner 31, retransmission request processor 32, transmitter 3
3 and an antenna 34.

The transmission signal obtained by the antenna 11 is subjected to reception processing similar to that of the rake receiver 14 in the first embodiment in the rake receiver 28, and reception data is obtained. However, the rake receiver 28 has the broadcast channel Bc
h, in addition to the extraction of the reception data relating to an arbitrary channel, the extraction of the reception data relating to a predetermined retransmission channel Rch is performed in parallel.
Received data relating to an arbitrary channel in the channel ch is supplied to the signal buffer 29, and received data relating to the retransmission channel Rch is supplied to the signal loss compensator 30.

The received data related to the broadcast channel Bch is stored and held in the signal buffer 29 for a predetermined time, is delayed for a predetermined time, and is supplied to the audio / video separation circuit unit 15. Also, the retransmission channel Rch
The received data is used by the signal missing portion compensating device 30 to compensate for the missing portion.

The signal missing portion compensation circuit 30 includes the instantaneous interruption determiner 3
1 to perform processing for compensating received data (missing portion) when the occurrence of an instantaneous interruption is detected using received data relating to the retransmission channel Rch.

The instantaneous interruption determiner 31 monitors the operation state of the rake receiver 28 (for example, the output state of received data relating to the broadcast channel Bch) and detects occurrence of an instantaneous interruption. When the instantaneous interruption determining unit 31 detects the occurrence of the instantaneous interruption, it notifies the signal loss unit compensating device 30 and the retransmission request processing unit 32 of the fact.

The re-request processing unit 32 creates re-transmission request data for requesting re-transmission of a missing part in response to the detection of occurrence of an instantaneous interruption by the instantaneous interruption determiner 31. The retransmission request data generated by the retransmission request processing unit 32 is converted into a predetermined transmission signal for wireless transmission by the transmitter 33, and then transmitted from the antenna 34 to the request channel Dch toward the satellite broadcasting device 200. Is done.

On the other hand, the satellite broadcasting device 2 in the present embodiment
00 is a transmitter 35, a memory unit 36, a retransmission processing unit 37,
It has antennas 38 and 39 and a receiver 40. In the satellite broadcasting device 200, transmission data created by a transmission data creation unit (not shown) and the like is provided to the transmitter 35, and is also provided to the memory unit 36 and stored and held as transmitted transmission data.

In the transmitter 35, the transmission data is subjected to error correction coding processing, convolution coding processing, interleaving processing, spectrum spreading processing, analog signal processing, up-conversion processing to a frequency for the broadcast channel Bch, or power amplification processing. After such processing is performed, the signal is transmitted from the antenna 38 to the satellite broadcast receiving apparatus 100 via the broadcast satellite SAT.

When a transmission signal transmitted via the request channel Dch is given to the receiver 40 via the antenna 39, the receiver 40 receives the signal and reproduces retransmission request data. Then, the retransmission request data is provided to the retransmission processing unit 37. Then, the retransmission processing unit 37
The transmission data of the portion indicated by the retransmission request data is extracted from the memory unit 36, retransmission data including the transmission data is created, and the retransmission data is provided to the transmitter 35.

In the transmitter 35, the retransmission data is subjected to error correction coding, convolutional coding, interleaving, spectrum spreading, analog signal conversion, up-conversion to the frequency for the retransmission channel Rch, or power amplification. After such processing is performed, the signal is transmitted from the antenna 38 to the satellite broadcast receiving apparatus 100 via the broadcast satellite SAT.

Next, the operation of the satellite broadcasting system configured as described above will be described. First, if the radio wave transmitted from the broadcasting satellite SAT reaches the antenna 11 normally,
Extraction of received data from the transmission signal obtained by the antenna 11 is normally performed by the rake receiver 28. The received data on the broadcast channel Bch obtained by the rake receiver 28 in this way is stored and held in the signal buffer 29, and is sequentially supplied to the audio / video separation circuit unit 15 every predetermined time. . Here, if the radio wave continues to reach the antenna 11 normally, the occurrence of the instantaneous interruption is not detected by the instantaneous interruption determiner 31, and the signal loss compensating device 30 is stored in the signal buffer 29. No processing is performed on the received data. Accordingly, the received data relating to the broadcast channel Bch is only delayed in the signal buffer 29 for a predetermined time.

In such a state, the retransmission request processing unit 32 does not create the retransmission request data. Therefore, if all the other satellite broadcast receivers are in the normal state as described above, the transmission signal is not transmitted on the request channel Dch. Not transmitted. Therefore, the retransmission request data is not obtained by the receiver 40, and the retransmission processing unit 37 is not provided with the retransmission request data. As a result, the retransmission processing unit 37 does not generate and output retransmission data.

Now, the satellite broadcast receiving apparatus 10 of the present embodiment
Assuming that the moving object on which the “0” is mounted moves and a shield enters between the broadcast satellite SAT and the antenna 11, the radio wave transmitted from the broadcast satellite SAT is shielded by the shield and does not reach the antenna 11. At this time, no transmission signal is given to the rake receiver 28, and the rake receiver 28
The output of the received data from is also in a no-signal state.

Then, the instantaneous interruption determiner 31 detects the occurrence of the instantaneous interruption, and notifies the signal loss part compensating device 30 and the retransmission request processing unit 32 of the fact. In response to this, the retransmission request processing unit 32 creates and outputs retransmission request data for requesting retransmission of transmission data of the missing part caused by the instantaneous interruption that has occurred. Then, the retransmission request data reaches retransmission processing section 37 via transmitter 33, antenna 34, request channel Dch, antenna 39, and receiver 40.

When the retransmission processing unit 37 receives the retransmission request data in this manner, it extracts the transmission data of the portion requested by the retransmission request data from the memory unit 36 and creates retransmission data including the transmission data. . Then, the retransmission data reaches signal dropout compensation device 30 via transmitter 35, antenna 38, retransmission channel Rch, antenna 11, and rake receiver 28. In response to this, the signal missing portion compensating device 30 writes the retransmission data into the signal buffer 29 to compensate for the missing portion.

As described above, according to the present embodiment, even if the radio wave is shielded by the shield and an instantaneous interruption occurs, the retransmission of the transmission data of the missing portion caused in the reception data due to this causes the satellite broadcast receiver 100 to retransmit the transmission data. Satellite broadcasting device 200 upon request
The satellite broadcast receiving apparatus 100 compensates for the missing part using the retransmission data and creates received data without the missing part, so that a decrease in the reception quality can be suppressed.

The present invention is not limited to the above embodiments. For example, in each of the above embodiments, the present invention is applied to a satellite broadcast receiving device or a satellite broadcast device used in a satellite broadcast system, but the present invention is also applicable to other wireless communication systems.

In the first embodiment, a spread spectrum modulation method is used as a modulation method for multipath transmission. For example, an OFDM (Orthogonal Frequency Divide) is used.
The invention described in claim 1 is also applicable to a wireless communication apparatus used in a system using another modulation scheme such as a multi-carrier modulation scheme used in sionMultiplex (orthogonal frequency division multiplexing).

In the first embodiment, the number of antennas is three.
The present invention can be applied to the case where the number is more than one. In addition, the first
In the embodiment, the antenna 11 and the antenna 12 are installed near the front end left binding and the rear end right binding of the moving body 21, respectively, but the present invention is not limited to this.

Further, in the first embodiment, an automobile is exemplified as the moving body 21. However, the wireless receiving device of the present invention can be mounted on other moving bodies such as a train.
In the case of a train, the antenna 11 and the antenna 12
Can be installed at diagonal positions in each vehicle, and can also be installed at the front end of the leading vehicle and the rear end of the tail vehicle.

The configuration of the antennas 11 and 12 and the signal combiner 13 in the first embodiment can be incorporated in the second embodiment or the third embodiment. In addition, various modifications can be made without departing from the spirit of the present invention.

[0070]

According to the present invention, there is provided a radio receiving apparatus used in a radio communication system for radio transmitting a transmission signal modulated by a predetermined modulation scheme for multipath transmission utilizing an indirect wave in addition to a direct wave. A predetermined multipath receiving process is performed by a receiving unit on a synthesized signal obtained by synthesizing signals obtained by a plurality of antennas arranged at a distance from each other by a signal synthesizing unit.

According to another aspect of the present invention, there is provided a wireless receiving apparatus used in a wireless communication system for wirelessly transmitting a predetermined transmission signal, wherein transmission data demodulated by receiving means from the transmission signal transmitted wirelessly is transmitted at least for a predetermined period. Over the storage means. Then, the occurrence of an instantaneous interruption to the transmission signal received by the receiving means is monitored by an instantaneous interruption detection means, and based on transmission data stored in the storage means, or in response to a retransmission request by retransmission request means, Using transmission data demodulated from a transmission signal retransmitted by retransmission means provided in the radio broadcasting device,
The transmission data corresponding to the transmission signal portion where the instantaneous interruption is detected is compensated by the compensation means. By these,
It is possible to reduce the effect of the instantaneous interruption due to the shield, and obtain good reception quality.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a satellite broadcast receiving device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an example of an installation state of antennas 11 and 12 on a moving body.

FIG. 3 is a diagram showing a change in the state of arrival of radio waves to the satellite broadcast receiving device when a moving object equipped with the satellite broadcast receiving device shown in FIG. 1 crosses below a shield.

FIG. 4 is a diagram showing the state of arrival of radio waves to the satellite broadcast receiving device when a moving object equipped with the satellite broadcast receiving device shown in FIG. 1 crosses below a shield;

FIG. 5 is a diagram showing a modified configuration example of the satellite broadcast receiving device according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a satellite broadcast receiving device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a main configuration of a satellite broadcast system according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a schematic configuration of a satellite broadcasting system proposed by the present applicant.

FIG. 9 is an exemplary perspective view showing an external configuration of a broadcasting satellite SAT in FIG. 8;

[Explanation of symbols]

 11, 12 Antenna 13 Signal Combiner 14 Rake Receiver 15 Audio / Video Separation Circuit 16 Audio Decoder 17 Speaker 18 Video Decoder 19 Liquid Crystal Display (LCD) 20 Control Unit 21 Moving Object 22 ... shields 23 and 24 ... low noise amplifier 25 ... signal buffer 26 ... instantaneous interruption determiner 27 ... signal missing part compensation circuit 28 ... rake receiver 29 ... signal buffer 30 ... signal missing part compensation circuit 31 ... instantaneous interruption determiner 32 ... retransmission request processing unit 33 ... transmitter 34 ... antenna 35 ... transmitter 36 ... memory unit 37 ... retransmission processing unit 38,39 ... antenna 40 ... receiver 100 ... satellite broadcast receiver 200 ... satellite broadcast device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoichi Koishi 1 Kosuka Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Inside Toshiba Komukai Plant

Claims (7)

[Claims] 1. A wireless receiver used in a wireless communication system for wirelessly transmitting a transmission signal modulated by a predetermined modulation scheme for multipath transmission using an indirect wave in addition to a direct wave, and mounted on a mobile body. A signal synthesizing means for synthesizing signals obtained by a plurality of antennas arranged apart from each other; and a receiving means for receiving a synthesized signal obtained by the signal synthesizing means and performing a predetermined multipath receiving process. Wireless receiving apparatus comprising: 2. A method according to claim 1, wherein two of the plurality of antennas are arranged on the moving body so as to be offset from each other in a traveling direction of the mounted moving body and a direction orthogonal to the moving direction. The wireless receiving device according to claim 1. 3. The two antennas provided on the moving body in a state of being offset from each other in a traveling direction of the mounted moving body and a direction orthogonal to the moving direction, the two antennas of the moving body viewed from above. 2. The radio receiving apparatus according to claim 1, wherein the radio receiving apparatus is arranged near two points on a contour where a straight line distance between the two points is maximum. 4. A wireless receiving system used in a wireless communication system for wirelessly transmitting a predetermined transmission signal and mounted on a mobile body, comprising: receiving means for demodulating transmission data from the wirelessly transmitted transmission signal; Storage means for storing the transmission data obtained by the means for at least a predetermined period; and instantaneous interruption detection means for detecting when an instantaneous interruption occurs in the transmission signal received by the receiving means. And a compensating means for compensating transmission data corresponding to the transmission signal portion in which the instantaneous interruption has been detected by the instantaneous interruption detecting means based on the transmission data stored in the storage means. Receiver. 5. A wireless broadcasting system for wirelessly broadcasting a predetermined transmission signal from a wireless broadcasting device to a wireless receiving device, wherein the receiving device is provided in the wireless receiving device and demodulates transmission data from the wirelessly broadcasted transmission signal. Means, provided in the wireless receiving apparatus, for delaying transmission data obtained by the receiving means for at least a predetermined period of time, provided in the wireless receiving apparatus, and received by the receiving means An instantaneous interruption detecting means for detecting when an instantaneous interruption occurs in the transmission signal, provided in the radio receiving apparatus, and retransmitting a transmission signal of a portion where the instantaneous interruption is detected by the instantaneous interruption detecting means, Retransmission request means for requesting a broadcasting device, provided in the wireless broadcasting device, and in response to receiving a retransmission request by the retransmission request device, transmitting a transmission signal of a requested portion. Retransmission means for transmitting using a fixed retransmission channel; and a transmission signal provided in the radio receiving apparatus and transmitted by the retransmission means in response to a request made by the retransmission request means and arriving via the retransmission channel. From the transmission data demodulated by the receiving means, and compensates for the transmission data corresponding to the transmission signal portion in which the instantaneous interruption is detected by the instantaneous interruption detecting means in the transmission data delayed by the delay means. Wireless broadcasting system comprising: 6. A wireless receiving system used in a wireless broadcasting system for wirelessly broadcasting a predetermined transmission signal from a wireless broadcasting device to a wireless receiving device. Receiving means for demodulating data; delay means for delaying transmission data obtained by the receiving means for at least a predetermined period; and when an instantaneous interruption occurs in a transmission signal received by the receiving means, Instantaneous interruption detecting means for detecting this; retransmission requesting means for requesting the radio broadcasting apparatus to retransmit the transmission signal of the portion where the instantaneous interruption is detected by the instantaneous interruption detecting means; Using the transmission data demodulated by the receiving means from a transmission signal transmitted by the wireless broadcasting device and arriving via a predetermined retransmission channel, Radio reception apparatus instantaneous by the interruption detecting means in the transmission data after being cast is characterized by comprising a compensating means for compensating transmission data corresponding to the transmission signal portion has been detected. 7. A wireless broadcasting device used in a wireless broadcasting system for wirelessly broadcasting a predetermined transmission signal from a wireless broadcasting device to a wireless receiving device, wherein a request for retransmission is received from the wireless receiving device. A radio broadcast apparatus comprising retransmission means for transmitting a transmission signal of a requested portion using a predetermined retransmission channel.