JP2008085419A - Receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a receiver capable of performing stable reception irrespective of a change in reception environment. <P>SOLUTION: A radio wave status analyzer 100 disposed on the front of a train moving direction has a first antenna, and generates radio wave status analysis data on the basis of the status of radio waves received by the first antenna. A data reproducer 200 disposed at the rear of the train moving direction has a second antenna, and reproduces the digital data on the basis of the radio waves received by the second antenna. The data reproducer 200 controls the second antenna depending on the radio wave status analysis data generated in the analyzer 100. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a receiver for receiving digitally transmitted digital data by a train.

  In the conventional receiving apparatus, the reception performance is improved so that the reception quality can be received without degrading the reception quality even in an environment where a direct wave generated in mobile reception cannot be received or an environment where the reception electric field is reduced. One countermeasure is to select a signal having a good reception state from signals received by a plurality of antennas so that a good reception state can be maintained at all times (see, for example, Patent Document 1). .

  According to the above-mentioned patent, there are two systems including an antenna, a tuner, a demodulator, and an error correction circuit. Based on the error flag of the transport stream (hereinafter also referred to as TS) output from the two error correction circuits, The presence / absence is determined, switching is performed so that only packets with no errors are selected and passed, and MPEG2 which is a video and audio coding method used in digital television broadcasting is decoded. In other words, the data received by the two antennas can be selected in real time in a good reception state, and the good reception state can always be maintained.

JP 2001-136113 A (summary, FIG. 1)

  However, the above-described digital broadcast receiving apparatus has two antennas, a tuner, a demodulator, and an error correction circuit, so that it is possible to select in real time one of the data received by the two antennas in a good reception state. For example, if the receiving device is moving from one broadcast station area to another broadcast station (including relay stations) and the reception power of both broadcast areas is weak, When the reception environment changes, such as when it cannot be received, the reception status of the two antennas, tuner, demodulator, and error correction circuit deteriorates or cannot be received. It may be cut off.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a receiving apparatus that can perform stable reception regardless of changes in the reception environment.

  A receiving device according to the present invention is a receiving device that receives digital data wirelessly transmitted from a broadcasting station by a train, and is disposed on the train in front of the traveling direction of the train, and has a first antenna. A radio wave condition analysis device that generates radio wave condition analysis data based on the radio wave condition received from one antenna, and is disposed on the train behind the direction of travel of the train and has a second antenna and is received from the second antenna And a data reproducing device for reproducing the digital data based on the received radio wave, and the data reproducing device controls the second antenna in accordance with the radio wave condition analysis data generated in the radio wave condition analysis apparatus.

  A receiving device according to the present invention is a receiving device that receives digital data wirelessly transmitted from a broadcasting station by a train, and is disposed on the train in front of the traveling direction of the train, and has a first antenna. A radio wave condition analysis device that generates radio wave condition analysis data based on the radio wave condition received from one antenna, and is disposed on the train behind the direction of travel of the train and has a second antenna and is received from the second antenna And a data reproducing device for reproducing the digital data based on the received radio wave, and the data reproducing device controls the second antenna in accordance with the radio wave condition analysis data generated in the radio wave condition analysis apparatus. Therefore, even when the receiving device moves from one broadcast station area to another broadcast station area and the reception environment changes, it is possible to stably output good reproduction data without interruption. Become. That is, stable reception can be performed regardless of changes in the reception environment.

  Hereinafter, embodiments of the present invention will be described using a receiving apparatus to which the present invention is applied. In the first to third embodiments, the antenna directivity is controlled so as to maintain a good reception state in an SFN (Single Frequency Network) system that relays and transmits the same program at the same frequency (channel). In the fourth to seventh embodiments, in MFN (Multi Frequency Network) that broadcasts the same program on a plurality of frequencies (channels), a frequency is selected (that is, a broadcasting station is selected) so as to maintain a good reception state. It is. As a result, even when the receiving device moves from one broadcast station area to another broadcast station area and the reception environment changes, it is possible to stably output good reproduction data without interruption. It becomes. In the following embodiment, it is assumed that an OFDM (Orthogonal Frequency Division Multiplexing) signal used in digital terrestrial broadcasting in Japan is received and MPEG2 which is a video and audio encoding method is decoded. However, the present invention is not limited to this.

<Embodiment 1>
FIG. 1 is a block diagram showing a configuration of a digital broadcast receiving apparatus (hereinafter simply referred to as a receiving apparatus) according to Embodiment 1 of the present invention. This receiving device is for receiving a video signal or an audio signal (digital data) wirelessly transmitted from a broadcasting station by a SFN system in a train.

  In FIG. 1, the receiving apparatus according to the present embodiment includes a radio wave condition analyzing apparatus 100 and a data reproducing apparatus 200. Here, the radio wave condition analysis device 100 is disposed in front of the traveling direction of the train, and the data reproducing device 200 is disposed in the rear of the traveling direction of the train. That is, the radio wave situation received by the radio wave situation analysis apparatus 100 is arranged to become the radio wave situation received by the data reproducing apparatus 200 after a few seconds.

  The radio wave condition analysis device 100 includes an antenna directivity control device 10, a tuner 11, a demodulation device 12, an error correction device 13, an error number calculation device 14, and a reception state determination device 15.

  The antenna directivity control device 10 controls an antenna (first antenna) that is a receiving element that receives a digital broadcast signal broadcast from a broadcasting station and the antenna (for example, directivity for an antenna having directivity). For controlling the direction of the screen).

  The tuner 11 obtains an IF signal from the RF signal received by the antenna directivity control device 10 by selecting a broadcast wave desired by the user. Then, the OFDM-IF signal of the selected broadcast wave is input to the demodulator 12.

  The demodulator 12 demodulates the broadcast wave OFDM signal obtained by the tuner 11.

  The error correction device 13 performs error detection and error detection on the OFDM signal demodulated from the demodulation device 12 by performing a procedure reverse to the error correction processing performed by the transmission device (not shown) on the sender side. Error correction is performed to reproduce a transport stream (hereinafter also referred to as TS) (first TS reproducing means). As a result, data damaged by noise or fading during transmission is restored.

  The error number calculation device 14 counts and outputs the number of errors included in the TS reproduced by the error correction device 13.

  The reception state determination device 15 can determine the reception state at the first antenna based on the number of errors obtained by the error number calculation device 14 (for example, determination is made by comparing with a preset threshold), and includes the number of errors. Information including the antenna directivity information (for example, the direction of the antenna) obtained from the antenna directivity control device 10 that has received the TS and the number of errors is generated as radio wave state analysis data and input to the data reproduction device 200. (Radio wave condition analysis data generation means).

  The data reproduction device 200 includes an antenna directivity control device 20, a tuner 21, a demodulation device 22, an error correction device 23, an error number calculation device 24, an antenna directivity switching device 27, and a decoding device 28. ing.

  The antenna directivity control device 20 includes an antenna (second antenna) that is a receiving element that receives a digital broadcast signal broadcast from a broadcasting station, and a device that controls the antenna. When antenna directivity information is received from an antenna directivity switching device 27 described later, the antenna directivity is controlled based on the received information.

  The tuner 21 obtains an IF signal from the RF signal received by the antenna directivity control device 20 by selecting a broadcast wave desired by the user, similarly to the tuner 11. Then, the selected broadcast wave OFDM-IF signal is input to the demodulator 22. In the tuners 11 and 21, it is assumed that the same broadcast wave is selected.

  The demodulator 22 demodulates the OFDM signal obtained by selecting a broadcast wave with the tuner 21.

  Similar to the error correction device 13, the error correction device 23 is demodulated from the demodulation device 22 by performing a procedure reverse to the process for error correction performed by the transmission device (not shown) on the sender side. Error detection and error correction are performed on the OFDM signal to reproduce the TS (second TS reproducing means).

  The error number calculation device 24 counts and outputs the number of errors included in the TS reproduced by the error correction device 23.

  The antenna directivity switching device 27 can grasp the current reception state by knowing the reception state at the second antenna from the number of errors obtained by the error number calculation device 24. Further, the antenna directivity switching device 27 receives the directivity information and the number of errors of the first antenna obtained from the received signal in the radio wave condition preceding the data reproducing device 200 output from the radio wave condition analyzing apparatus 100. Since it is possible to know what radio wave state the directivity direction of the second antenna currently controlled by the antenna directivity control device 20 will be in a few seconds, the second antenna is set so that the reception state is improved. A signal for controlling the directivity of the antenna is input to the antenna directivity control device 20.

  Further, the antenna directivity switching device 27 obtains the timing for switching the directivity of the second antenna from the input train speed information 1. Since the distance between the radio wave condition analyzing apparatus 100 and the data reproducing apparatus 200 is known, knowing the speed of the train (delay) time until the data reproducing apparatus 200 passes through the place where the radio wave condition analyzing apparatus 100 has passed. Is obtained. For example, if the length of the train is 400 m (437.6 m for the 700 series and 16-car train) and the speed is 300 km per hour, the train will pass after about 5.25 seconds. The train speed information 1 may be obtained from a device (for example, a speed measuring device) provided in an existing train, or a speed sensing device may be newly provided.

  The decoding device 28 separates the audio data and the video data from the TS reproduced by the error correction device 23, further decodes the separated audio data and the video data to obtain an analog audio signal and a video signal. Reproduce. The reproduced audio signal is output by a speaker (not shown), and the reproduced video signal is output by a liquid crystal display device (not shown). Note that the video signal and the audio signal may be supplied to a recording apparatus.

  Next, the operation of the receiving apparatus according to this embodiment will be described.

  When the data reproducing apparatus 200 operates alone, when the user selects a desired channel, frequency information of the selected channel is sent from the control microcomputer (not shown) to the tuner 21, and the broadcast wave of the desired channel of the user is transmitted. An OFDM signal is output. The OFDM signal output from the tuner 21 is demodulated into digital data by the demodulator 22, subjected to error detection and error correction by the error correction device 23 at the subsequent stage, and output as TS. From the output TS, the error number calculation device 24 obtains the error number, and the decoding device 28 obtains an audio signal and a video signal. The antenna directivity switching device 27 grasps the current reception status from the number of errors from the error count calculation device 24, and controls the second antenna according to this reception status (whether or not to switch the directivity of the second antenna). Is output to the antenna directivity control device 20).

  Since the radio wave condition received by the radio wave condition analysis apparatus 100 is arranged so as to become the radio wave condition received by the data reproducing apparatus 200 after a few seconds, when using this, the radio wave condition analysis apparatus 100 can obtain the radio wave condition. The radio wave condition is analyzed, and the directivity direction of the antenna capable of receiving the best signal is detected. Therefore, in the radio wave condition analysis apparatus 100, when the user selects a desired channel, frequency information of the selected channel is sent from the control microcomputer (not shown) to the tuner 11, and the broadcast wave of the channel desired by the user is OFDM. A signal is output. The OFDM signal output from the tuner 11 is demodulated into digital data by the demodulator 12, subjected to error detection and error correction by the error correction device 13 at the subsequent stage, and output as TS. The reception state determination device 15 obtains the number of errors from the TS output from the error correction device 13 by the error number calculation device 14, and determines the number of errors and the directivity direction of the first antenna that has received the TS including the number of errors. obtain.

  In the antenna directivity switching device 27 of the data reproduction device 200, the directivity direction and the number of errors of the first antenna obtained from the received signal in the radio wave situation preceding the data reproduction device 200 output from the radio wave situation analysis device 100 are obtained. By receiving it, it is possible to know what radio wave state the directivity direction of the second antenna currently controlled by the antenna directivity control device 20 will be in a few seconds, so the switching timing is determined from the train speed information 1 Thus, a signal for controlling the directivity of the second antenna is input to the antenna directivity control device 20 so that the reception state is good.

  Thus, in the receiving apparatus according to the present embodiment, the radio wave condition received by radio wave condition analyzing apparatus 100 is arranged to be the radio wave condition received by data reproducing apparatus 200 after a few seconds. By using this to control the second antenna, even if the receiving device moves from one broadcast station area to another broadcast station area and the reception environment changes, good reproduction data can be obtained. It becomes possible to output stably without interruption. That is, stable reception can be performed regardless of changes in the reception environment.

  In the above-described embodiment, the radio wave condition analyzing apparatus 100 and the data reproducing apparatus 200 have been described with the means for controlling the directional antenna (directional antenna). However, the means using the adaptive array antenna is described. You may use and the means using a diversity antenna may be used.

  Further, the number of errors obtained from the reproduced TS is used to know the reception state, but the present invention is not limited to this. For example, the C / N value of the received signal may be used. In the above description, the data reproducing apparatus 200 has been described with respect to the case where the second antenna is always controlled according to the radio wave condition analysis data. Alternatively, the data reproducing apparatus 200 may perform an operation other than the control of the second antenna. For example, in the data reproduction device 200, both the radio wave condition analysis device 100 and the data reproduction device 200 are in the reception area of one broadcast station, or the radio wave condition analysis device 100 and the data reproduction device 200 are both in the other broadcast station. When the reception area is reached, the second antenna is controlled according to the radio wave condition analysis data, the radio wave condition analysis apparatus 100 reaches the reception area of the other broadcast station, and the data reproduction apparatus 200 is still in the reception area of the one broadcast station. In this case, diver reception may be performed together with the radio wave condition analyzing apparatus 100.

<Embodiment 2>
In the first embodiment, the case has been described in which radio wave state analysis data is generated based on an error associated with TS reproduction. However, the present invention is not limited to this, and may be generated based on noise power.

  FIG. 2 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 2 of the present invention. In FIG. 2, the same components as those of the receiving apparatus according to Embodiment 1 shown in FIG.

  The receiving apparatus according to the present embodiment is the same as the receiving apparatus of FIG. 1 according to the first embodiment, except that a radio wave condition analyzing apparatus 101 is provided instead of the radio wave condition analyzing apparatus 100. The radio wave condition analyzing apparatus 101 is different from the radio wave condition analyzing apparatus 100 of FIG. 1 in that a power calculating device 16 is provided instead of the demodulating device 12, the error correcting device 13, and the error number calculating device 14.

  The power calculation device 16 calculates power information representing the power of noise by detecting the spread of the scattered pilot signal inserted in the OFDM signal from the OFDM-IF signal of the broadcast wave output from the tuner 11. (Power calculation means). By replacing the obtained power information with the number of errors obtained by the error number calculation device 14 in the first embodiment, the same effect as in the first embodiment can be obtained.

  Further, by adopting such a configuration, the circuit scale of the radio wave condition analyzing apparatus 101 can be reduced, so that power consumption can be suppressed.

  Thus, according to the receiving apparatus according to the present embodiment, in addition to the effect of the first embodiment, an effect that power consumption can be suppressed is obtained.

  In the present embodiment described above, the radio wave condition analysis apparatus 101 and the data reproduction apparatus 200 may use a means for controlling a directional antenna (directional antenna) or an adaptive array antenna. Means may be used, or means using a diversity antenna may be used.

<Embodiment 3>
In the first embodiment, the TS reproduced by the error correction device 23 is reproduced by the decoding device 28 into an audio signal and a video signal. However, the TS reproduced by the error correction device 13 is converted into an audio signal and a video signal. Does not play. However, the present invention is not limited to this, or the TS reproduced by the error correction device 13 may be reproduced as an audio signal and a video signal by the decoding device 28 (digital data reproduction means).

  FIG. 3 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 3 of the present invention. In FIG. 3, the same components as those of the receiving apparatus according to Embodiment 1 shown in FIG.

  The receiving apparatus in the present embodiment is the same as the receiving apparatus in FIG. 1 according to the first embodiment except that a data reproducing apparatus 201 is provided instead of the data reproducing apparatus 200. The data reproduction device 201 is obtained by adding a reception state determination device 25 and a reproduction data selection device 29 to the data reproduction device 200 of FIG.

  The reception state determination device 25 can determine the reception state at the second antenna based on the number of errors obtained by the error number calculation device 24 (for example, as in the reception state determination device 15, compared with a preset threshold value). judge).

  The reproduction data selection device 29 receives the TS reproduced by the error correction device 13, the TS reproduced by the error correction device 23, and the reception state determination result by the reception state determination device 25. Depending on whether the reception state is good or bad, switching is made so that one of these TSs is selected, and good reproduction data is output (TS selection means).

  That is, when the reception state of the second antenna is poor, the data reproduction device 201 selects a TS reproduced by the radio wave condition analysis device 100 (error correction device 13) instead of the data reproduction device 201 (error correction device 23). Thus, it operates to output better reproduction data.

  In addition to the operation as described above, the data reproduction device 201 is not limited to the operation described above, and the radio wave situation received by the radio wave state analysis device 100 is not the same as the data reproduction device 200 described in the first embodiment. You may utilize that it is arrange | positioned so that it may become the radio wave condition received by 201. FIG. That is, the data reproduction device 201 analyzes the radio wave situation obtained by the radio wave situation analysis device 100 and inputs a signal for controlling the directivity of the second antenna to the antenna directivity control device 20 so that the reception state is good. In addition, when the reception state at the second antenna is poor, it is better to select the TS reproduced by the radio wave condition analysis apparatus 100 (error correction apparatus 13) instead of the data reproduction apparatus 201 (error correction apparatus 23). Operate to output the correct playback data.

  As described above, the receiving apparatus according to the present embodiment can perform more stable reception than the receiving apparatus according to the first embodiment, regardless of changes in the reception environment.

  In the present embodiment described above, the radio wave condition analyzing apparatus 100 and the data reproducing apparatus 201 may use a means for controlling a directional antenna (directional antenna), or an adaptive array antenna. Means may be used, or means using a diversity antenna may be used.

  Further, the number of errors obtained from the reproduced TS is used to know the reception state, but the present invention is not limited to this. For example, the noise power obtained from the OFDM-IF signal of the broadcast wave output from the tuners 11 and 21 may be used, or the C / N value of the received signal may be used.

<Embodiment 4>
In the first to third embodiments, since digital data wirelessly transmitted by the SFN method is received, it is necessary to control the directivity of the antenna in accordance with the radio wave state analysis data so as to maintain a good reception state. However, when receiving digital data wirelessly transmitted by the MFN method, it is not always necessary to control the directivity of the antenna, and as described below, a frequency is selected according to radio wave condition analysis data (that is, (Broadcast station is selected) (or both antenna directivity control and broadcast station selection (channel selection) may be performed).

  FIG. 4 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 4 of the present invention. This receiving device is for selectively receiving video signals or audio signals (digital data) wirelessly transmitted from a plurality of broadcasting stations by a MFN system in a train.

  In FIG. 4, the receiving apparatus according to the present embodiment includes a radio wave state analyzing apparatus 300 and a data reproducing apparatus 400. Here, the radio wave state analysis apparatus 300 is disposed in the front with respect to the traveling direction of the train, and the data reproducing apparatus 400 is disposed in the rear with respect to the traveling direction of the train. That is, the radio wave situation received by the radio wave situation analysis apparatus 300 is arranged to become the radio wave situation received by the data reproduction apparatus 400 after a few seconds.

  The radio wave state analysis device 300 includes an antenna directivity control device 30, a tuner 31, a demodulation device 32, an error correction device 33, an error number calculation device 34, a reception state determination device 35, and a channel selection switching device 37. It has.

  The antenna directivity control device 30 includes an antenna (third antenna) that is a receiving element that receives a digital broadcast signal broadcast from a broadcasting station, and a device that controls the antenna.

  The channel selection switching device 37 selects a broadcast wave desired by the user, or automatically selects a broadcast wave when searching for a broadcast station. Specifically, first, the broadcast wave desired by the user is selected. In the present embodiment, unlike the seventh embodiment to be described later, there is no feedback function to the channel selection switching device 37. Since the operation of detecting the antenna reception state and switching the broadcasting station cannot be performed when the antenna reception state deteriorates, the frequency is constantly switched every moment. In the reception state determination device 35, the frequency information and the reception state are passed to the data reproduction device 400 as radio wave state analysis data. As will be described later, in Embodiment 7, it is possible to search for broadcast stations of the same series that have a feedback function and have different frequencies. Therefore, when the reception state deteriorates, the operation of switching to the broadcast station of the same series is performed. It becomes possible.

  The tuner 31 obtains an IF signal from the RF signal of the broadcast wave selected by the channel selection switching device 37. Then, the OFDM-IF signal of the selected broadcast wave is input to the demodulator 32.

  The demodulator 32 demodulates the broadcast wave OFDM signal obtained by the tuner 31.

  The error correction device 33 performs error detection and error detection on the OFDM signal demodulated from the demodulation device 32 by performing a procedure reverse to the error correction processing performed by the transmission device (not shown) on the sender side. Error correction is performed to reproduce the TS (third TS reproducing means). As a result, data damaged by noise or fading during transmission is restored.

  The error number calculation device 34 counts and outputs the number of errors included in the TS reproduced by the error correction device 33.

  The reception state discriminating device 35 can determine the reception state at the third antenna based on the number of errors obtained by the error number calculating device 34, and the uniqueness of the broadcast station obtained from the tuner 31 that has received the TS including the error number. Information including information (for example, program information) and the number of errors is generated as radio wave state analysis data and input to the data reproduction device 400 (radio wave state analysis data generating unit).

  The data reproduction device 400 includes an antenna directivity control device 40, a tuner 41, a demodulation device 42, an error correction device 43, an error number calculation device 44, a channel selection switching device 47, a decoding device 48, and a channel selection. And an information extraction device 70.

  The antenna directivity control device 40 includes an antenna (fourth antenna) that is a receiving element that receives a digital broadcast signal broadcast from a broadcasting station, and a device that controls the antenna.

  The tuner 41 obtains an IF signal from the broadcast wave RF signal selected by the channel selection switching device 47 described later. Then, the OFDM-IF signal of the selected broadcast wave is input to the demodulator 42.

  The demodulator 42 demodulates the broadcast wave OFDM signal obtained by the selection by the tuner 41.

  Similar to the error correction device 33, the error correction device 43 is demodulated from the demodulation device 42 by performing a procedure reverse to the error correction processing performed by the transmission device (not shown) on the sender side. Error detection and error correction are performed on the OFDM signal to reproduce the TS (fourth TS reproducing means).

  The error number calculation device 44 counts and outputs the number of errors included in the TS reproduced by the error correction device 43.

  The decoding device 48 separates the audio data and the video data from the TS reproduced by the error correction device 43, and further decodes the separated audio data and the video data to obtain an analog audio signal and a video signal. Reproduce. The reproduced audio signal is output by a speaker (not shown), and the reproduced video signal is output by a liquid crystal display device (not shown). Note that the video signal and the audio signal may be supplied to a recording apparatus.

  The channel selection information extraction device 70 extracts, from the reproduced TS, broadcast station specific information (for example, an affiliation ID that is sequence identification information of a BIT (Broadcaster Information Table) signal).

  The channel selection switching device 47 can grasp the current reception status by knowing the reception state at the fourth antenna from the number of errors obtained by the error number calculation device 44. The channel selection switching device 47 receives the broadcast station specific information and the number of errors obtained from the received signal in the radio wave condition preceding the data reproduction device 400 output from the radio wave condition analysis device 300, and extracts the channel selection information. The unique information of the broadcasting station that is consistent with the unique information of the broadcasting station included in the TS extracted (currently reproduced) by the device 70 is found, and the reception status of the broadcasting station currently set by the tuner 41 is several seconds later. Since it is possible to know what happens, switching is performed by inputting such unique information of the broadcasting station to the tuner 41 at a predetermined timing.

  That is, the channel selection switching device 47 has a better reception status than the one broadcasting station currently selected by the radio wave condition analysis device 300 and is broadcasting the same program as this one broadcasting station (the same affiliate as the one broadcasting station). When the other broadcasting station (having an association ID) is found, the tuner 41 is controlled to select the other broadcasting station. Specifically, for example, the channel selection switching device 47 holds unique information and position information for all broadcasting stations in Japan, detects its current position with GPS or the like, and detects all current broadcasting stations and itself. The distance is calculated. The channel selection switching device 47 performs switching from one broadcasting station to the other broadcasting station at a predetermined timing obtained from the train speed information 1 and the radio wave condition analysis data that are input. In the present embodiment, radio wave condition analyzing apparatus 300 does not intentionally switch from one broadcast station to the other broadcast station.

  Note that the train speed information 1 may be obtained from a device (for example, a speed measuring device) installed in an existing train, or a speed sensing device may be newly provided.

  Next, the operation of the receiving apparatus according to this embodiment will be described.

  When the data reproducing device 400 operates alone, when the user selects a desired channel, frequency information of the selected channel is sent from the control microcomputer (not shown) to the channel selection switching device 47, and the broadcast station information is sent to the tuner 41. To output the OFDM signal of the broadcast wave of the channel desired by the user. The OFDM signal output from the tuner 41 is demodulated into digital data by the demodulating device 42, subjected to error detection and error correction by the error correcting device 43 at the subsequent stage, and output as TS. From the output TS, the error number calculation device 44 obtains the error number, and the decoding device 48 obtains an audio signal and a video signal.

  Since the radio wave condition received by the radio wave condition analysis apparatus 300 is arranged so as to become the radio wave condition received by the data reproducing apparatus 400 after a few seconds, when using this, the radio wave condition analysis apparatus 300 can obtain the radio wave condition. Analyze the received radio wave condition and detect the unique information of the broadcast stations that can be received. Therefore, in the radio wave condition analysis apparatus 300, when the user selects a desired channel, frequency information of the selected channel is sent from the control microcomputer (not shown) to the channel selection switching apparatus 37, and the broadcast station information is sent to the tuner 31. By outputting, an OFDM signal of a broadcast wave of a channel desired by the user is output. The OFDM signal output from the tuner 31 is demodulated into digital data by the demodulating device 32, subjected to error detection and error correction by the error correcting device 33 at the subsequent stage, and output as TS. The reception state determination device 35 obtains the number of errors from the TS output from the error correction device 33 by the error number calculation device 34, and obtains the number of errors and the unique information of the broadcasting station that received the TS including the number of errors.

  The channel selection switching device 47 of the data reproduction apparatus 400 receives the broadcast station specific information and the number of errors obtained from the received signal in the radio wave condition preceding the data reproduction apparatus 400 output from the radio wave condition analysis apparatus 300, and selects it. The broadcast station unique information that is consistent with the broadcast station unique information included in the TS extracted (currently reproduced) by the station information extraction device 70 is found, and the broadcast station reception status currently set by the tuner 41 is found. Therefore, switching is performed by inputting such broadcast station specific information to the tuner 41 at a predetermined timing obtained from the train speed information 1 or the like.

  Thus, in the receiving apparatus according to the present embodiment, the radio wave situation received by radio wave situation analyzing apparatus 300 is arranged to become the radio wave situation received by data reproducing apparatus 400 after a few seconds. By using this to select a channel in the tuner 41, even when the receiving apparatus moves from one broadcast station area to another broadcast station area and the reception environment changes, good reproduction data can be obtained. Can be output stably without interruption. That is, stable reception can be performed regardless of changes in the reception environment.

  In the present embodiment described above, the radio wave condition analysis apparatus 300 and the data reproduction apparatus 400 may use means for controlling a directional antenna (directional antenna), or use an adaptive array antenna. Means may be used, or means using a diversity antenna may be used.

  Further, the number of errors obtained from the reproduced TS is used to know the reception state, but the present invention is not limited to this. For example, the C / N value of the received signal may be used. In the above description, the data reproducing apparatus 200 has been described with respect to the case where the second antenna is always controlled according to the radio wave condition analysis data. Alternatively, the data reproducing apparatus 200 may perform an operation other than the control of the second antenna. For example, in the data reproduction device 400, when the radio wave condition analysis device 300 and the data reproduction device 400 are both in the reception area of one broadcasting station, or both the radio wave condition analysis device 300 and the data reproduction device 400 are the other broadcasting station. When the reception area is reached, the fourth antenna is controlled in accordance with the radio wave state analysis data, the radio wave state analysis device 300 reaches the reception area of the other broadcasting station, and the data reproduction device 400 is still in the reception area of the one broadcasting station. In this case, diver reception may be performed together with the radio wave condition analysis apparatus 300.

<Embodiment 5>
In the fourth embodiment, the case has been described in which the radio wave state analysis data is generated based on an error associated with TS reproduction. However, the present invention is not limited to this, and may be generated based on noise power.

  FIG. 5 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 5 of the present invention. In FIG. 5, the same components as those of the receiving apparatus according to Embodiment 4 shown in FIG.

  The receiving apparatus according to the present embodiment is the same as the receiving apparatus of FIG. 4 according to the fourth embodiment except that a radio wave condition analyzing apparatus 301 is provided instead of the radio wave condition analyzing apparatus 300. The radio wave condition analyzing apparatus 301 is the same as the radio wave condition analyzing apparatus 300 of FIG. 4 except that a power calculating device 36 is provided instead of the demodulating device 32, the error correcting device 33, and the error number calculating device 34.

  The power calculation device 36 calculates power information representing the power of noise by detecting the spread of the scattered pilot signal inserted in the OFDM signal from the OFDM-IF signal of the broadcast wave output from the tuner 31. (Power calculation means). By replacing the obtained power information with the number of errors obtained by the error number calculation device 34 in the fourth embodiment, the same effect as in the fourth embodiment can be obtained.

  Further, by adopting such a configuration, the circuit scale of the radio wave condition analyzing apparatus 301 can be reduced, so that power consumption can be suppressed.

  Thus, according to the receiving apparatus according to the present embodiment, in addition to the effect of the fourth embodiment, an effect that power consumption can be suppressed is obtained.

  In the present embodiment described above, the radio wave condition analysis apparatus 301 and the data reproduction apparatus 400 may use means for controlling a directional antenna (directional antenna), or use an adaptive array antenna. Means may be used, or means using a diversity antenna may be used.

<Embodiment 6>
In the fourth embodiment, the TS reproduced by the error correction device 43 is reproduced by the decoding device 48 into an audio signal and a video signal. However, the TS reproduced by the error correction device 33 is converted into an audio signal and a video signal. Does not play. However, the present invention is not limited thereto, or the TS reproduced by the error correction device 33 may be reproduced as an audio signal and a video signal by the decoding device 48 (digital data reproducing means).

  FIG. 6 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 6 of the present invention. In FIG. 6, the same components as those of the receiving apparatus according to Embodiment 4 shown in FIG.

  The receiving apparatus in the present embodiment is the same as the receiving apparatus in FIG. 4 according to the fourth embodiment except that a data reproducing apparatus 401 is provided instead of the data reproducing apparatus 400. The data reproduction device 401 is obtained by adding a reception state determination device 45 and a reproduction data selection device 49 to the data reproduction device 400 of FIG.

  The reception state determination device 45 can determine the reception state of the fourth antenna based on the number of errors obtained by the error number calculation device 44 (for example, as compared with the reception state determination device 35, compared with a preset threshold value). judge).

  The reproduction data selection device 49 receives the TS reproduced by the error correction device 33, the TS reproduced by the error correction device 43, and the determination result of the reception state by the reception state determination device 45, and the reproduction data selection device 49 Depending on whether the reception state is good or bad, switching is made so that one of these TSs is selected, and good reproduction data is output (TS selection means).

  That is, when the reception state of the fourth antenna is poor, the data reproduction device 401 selects the TS reproduced by the radio wave condition analysis device 300 (error correction device 33) instead of the data reproduction device 401 (error correction device 43). Thus, it operates to output better reproduction data.

  In addition to the operation as described above, the data reproducing device 401 is not limited to the operation described above, and the radio wave situation received by the radio wave state analyzing device 300 is a data reproducing device after a few seconds, as in the data reproducing device 400 described in the fourth embodiment. The fact that the radio waves are received at 401 may be used. That is, the data reproduction device 401 analyzes the radio wave situation obtained by the radio wave situation analysis device 300, inputs a signal for switching the broadcasting station so that the reception state is good, and inputs the signal to the tuner 41, and the reception state at the fourth antenna If the data is bad, by selecting the TS reproduced by the radio wave condition analysis device 300 (error correction device 33) instead of the data reproduction device 401 (error correction device 43), the operation is performed so as to output better reproduction data. To do.

  For example, when a train travels along the boundary between the reception area of one broadcast station and the reception area of the other broadcast station, the broadcast station with the best reception status is the one broadcast station and the other broadcast station. It is possible to change every moment. In the present embodiment, since the reproduction data selection device 49 is used to select one of the TS reproduced by the error correction device 33 and the TS reproduced by the error correction device 43, the reception state is better. Even in such a case, it is possible to output good reproduction data.

  As described above, the receiving apparatus according to the present embodiment can perform more stable reception than the receiving apparatus according to the fourth embodiment, regardless of changes in the reception environment.

  In the present embodiment described above, the radio wave condition analysis apparatus 300 and the data reproduction apparatus 401 may use means for controlling a directional antenna (directional antenna), or use an adaptive array antenna. Means may be used, or means using a diversity antenna may be used.

  Further, the number of errors obtained from the reproduced TS is used to know the reception state, but the present invention is not limited to this. For example, the noise power obtained from the OFDM-IF signal of the broadcast wave output from the tuners 31 and 41 may be used, or the C / N value of the received signal may be used.

<Embodiment 7>
In the fourth to sixth embodiments, the channel selection switching device 47 feeds back the TS reproduced by the error correction device 43 via the decoding device 48, the channel selection information extraction device 70, and the like. In 37, the reproduced TS is not fed back. Therefore, even when switching from one broadcasting station to the other broadcasting station is performed in the data reproduction apparatuses 400 to 401, switching is not performed in the radio wave condition analysis apparatuses 300 to 301. However, the present invention is not limited to this, or the reproduced TS may be fed back to the channel selection switching device 37.

  FIG. 7 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 7 of the present invention. In FIG. 7, the same components as those of the receiving apparatus according to Embodiment 6 shown in FIG.

  The receiving apparatus according to the present embodiment is the same as the receiving apparatus of FIG. 6 according to the sixth embodiment except that a radio wave condition analyzing apparatus 302 is provided instead of the radio wave condition analyzing apparatus 300. The radio wave condition analysis device 302 is obtained by adding a decoding device 38, a tuning information extraction device 71, and a tuning comparison device 80 to the radio wave status analysis device 300 of FIG. In FIG. 7, compared with FIG. 6, the feedback signal output from the channel selection information extraction device 70 is added to the channel selection switching device 47 (via the channel selection comparison device 80). Has been entered.

  The decoding device 38 separates audio data, video data, and broadcast station specific information from the TS reproduced by the error correction device 33.

  As with the channel selection information extraction device 70, the channel selection information extraction device 71 extracts, from the reproduced TS, the unique information of the broadcast station including the TS (for example, the BIT signal affiliate ID).

  The channel selection comparison device 80 is input with the broadcast station specific information included in the TS extracted (currently reproduced) by the channel selection information extraction devices 70 and 71. The channel selection / comparison device 80 compares the unique information, so that the unique information of the broadcasting station of the TS reproduced (output) from the radio wave condition analysis device 302 is reproduced (output) from the data reproduction device 401. The tuning switching device 37 is controlled so as to be consistent with the unique information of the broadcasting station.

  In other words, the channel selection / comparison device 80 performs control to switch the channel selection of the radio wave condition analysis device 302 so as to match the data reproduction device 401.

  Thus, in the receiving apparatus according to the present embodiment, the reproduced TS is fed back to channel selection switching apparatus 37 instead of channel selection switching apparatus 47 (in other words, radio wave condition analysis apparatus 302 decodes The channel is selected according to the digital data reproduced by the device 48). Therefore, in addition to the effects of the fourth to sixth embodiments, the radio wave condition analyzing apparatuses 300 to 301 can also switch from one broadcasting station to the other broadcasting station following the data reproducing apparatuses 400 to 401. Is obtained.

  In the present embodiment described above, the radio wave condition analysis apparatus 300 and the data reproduction apparatus 401 may use means for controlling a directional antenna (directional antenna), or use an adaptive array antenna. Means may be used, or means using a diversity antenna may be used.

  Further, the number of errors obtained from the reproduced TS is used to know the reception state, but the present invention is not limited to this. For example, the noise power obtained from the OFDM-IF signal of the broadcast wave output from the tuners 31 and 41 may be used, or the C / N value of the received signal may be used.

  The above description exemplifies an applicable aspect of the present invention, and the radio wave condition analyzing apparatus and the data reproducing apparatus are shown in two configurations, but a plurality of radio wave condition analyzing apparatuses and data reproducing apparatuses are used respectively. It may be configured.

It is a block diagram which shows the structure of the digital broadcast receiver which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the digital broadcast receiver which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the digital broadcast receiver which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the digital broadcast receiver which concerns on Embodiment 4 of this invention. It is a block diagram which shows the structure of the digital broadcast receiver which concerns on Embodiment 5 of this invention. It is a block diagram which shows the structure of the digital broadcast receiver which concerns on Embodiment 6 of this invention. It is a block diagram which shows the structure of the digital broadcast receiver which concerns on Embodiment 7 of this invention.

Explanation of symbols

  1 Train speed information 10, 20, 30, 40 Antenna directivity control device 11, 21, 31, 41 Tuner 12, 22, 32, 42 Demodulation device 13, 23, 33, 43 Error correction device 14, 24, 34, 44 Error number calculation device, 15, 25, 35, 45 Reception state determination device, 16, 36 Power calculation device, 27 Antenna directivity switching device, 28, 38, 48 Decoding device, 29, 49 Playback data selection Device, 37, 47 Channel selection switching device, 70, 71 Channel selection information extraction device, 80 Channel selection comparison device, 100, 101, 300, 301, 302 Radio wave condition analysis device, 200, 201, 400, 401 Data reproduction device.

Claims (14)

A receiving device for receiving digital data wirelessly transmitted from a broadcasting station by a train,
A radio wave condition analyzing device that is disposed in front of the train in the traveling direction on the train and has a first antenna and generates radio wave condition analysis data based on a radio wave condition received from the first antenna;
A data reproducing device arranged on the train behind the direction of travel of the train, having a second antenna and reproducing the digital data based on radio waves received from the second antenna;
The data reproduction device is a receiving device that controls the second antenna according to the radio wave condition analysis data generated by the radio wave condition analysis apparatus. A receiving device for receiving digital data wirelessly transmitted from a broadcasting station by a train,
A radio wave condition analysis device that is disposed in front of the train in the traveling direction on the train, has a first antenna, and generates radio wave condition analysis data based on a radio wave condition received from the first antenna;
A data reproducing device arranged on the train behind the direction of travel of the train, having a second antenna and reproducing the digital data based on radio waves received from the second antenna;
The data reproduction device includes:
When both the radio wave condition analysis device and the data reproduction device are in the reception area of one broadcast station, or when both the radio wave condition analysis device and the data reproduction device are in the reception area of the other broadcast station , Controlling the second antenna according to the radio wave condition analysis data generated in the radio wave condition analyzer,
A receiving apparatus for performing diver reception together with the radio wave condition analyzing apparatus when the radio wave condition analyzing apparatus reaches the receiving area of the other broadcasting station and the data reproducing apparatus is still in the receiving area of the one broadcasting station. The receiving device according to claim 1 or 2,
The radio wave condition analyzer is
First transport stream reproduction means for reproducing a transport stream based on the radio wave received from the first antenna;
A receiving apparatus further comprising: radio wave condition analysis data generating means for generating the radio wave condition analysis data based on an error associated with reproduction of a transport stream in the first transport stream reproduction means. The receiving device according to claim 1 or 2,
The radio wave condition analyzer is
Power calculating means for calculating noise power based on radio waves received from the first antenna;
And a radio wave condition analysis data generating unit configured to generate the radio wave condition analysis data based on the power of the noise calculated by the power calculation unit. The receiving device according to claim 3,
The data reproduction device includes:
Second transport stream reproduction means for reproducing the transport stream based on the radio wave received from the second antenna;
Transport stream selection means for selecting one of the transport stream reproduced in the first transport stream reproduction means and the transport stream reproduced in the second transport stream reproduction means;
A receiving apparatus further comprising digital data reproducing means for reproducing the digital data from the transport stream selected by the transport stream selecting means. A receiving device that selectively receives digital data wirelessly transmitted from a plurality of broadcasting stations by train,
A radio wave condition analysis device that is arranged in front of the train in the traveling direction on the train, has a third antenna, and generates radio wave condition analysis data based on a radio wave situation received from the third antenna;
A data reproduction device arranged on the train behind the direction of travel of the train, having a fourth antenna and reproducing the digital data based on radio waves received from the fourth antenna;
The data reproduction device is a receiving device that selects the broadcasting station according to the radio wave state analysis data generated by the radio wave state analysis device. A receiving device that selectively receives digital data wirelessly transmitted from a plurality of broadcasting stations by train,
A radio wave condition analysis device that is arranged in front of the train in the traveling direction on the train, has a third antenna, and generates radio wave condition analysis data based on a radio wave situation received from the third antenna;
A data reproduction device arranged on the train behind the direction of travel of the train, having a fourth antenna and reproducing the digital data based on radio waves received from the fourth antenna;
The data reproduction device includes:
When both the radio wave condition analysis device and the data reproduction device are in the reception area of one broadcast station, or when both the radio wave condition analysis device and the data reproduction device are in the reception area of the other broadcast station , Controlling the fourth antenna according to the radio wave condition analysis data generated in the radio wave condition analyzer,
A receiving apparatus for performing diver reception together with the radio wave condition analyzing apparatus when the radio wave condition analyzing apparatus reaches the receiving area of the other broadcasting station and the data reproducing apparatus is still in the receiving area of the one broadcasting station. The receiving device according to claim 6 or 7,
The radio wave condition analyzer is
Third transport stream reproduction means for reproducing a transport stream based on the radio wave received from the third antenna;
A receiving apparatus further comprising: radio wave condition analysis data generating means for generating the radio wave condition analysis data based on an error associated with reproduction of a transport stream in the third transport stream reproduction means. The receiving device according to claim 6 or 7,
The radio wave condition analyzer is
Power calculating means for calculating power of noise based on radio waves received from the third antenna;
And a radio wave condition analysis data generating unit configured to generate the radio wave condition analysis data based on the power of the noise calculated by the power calculation unit. The receiving device according to claim 8, wherein
The data reproduction device includes:
A fourth transport stream reproduction means for reproducing a transport stream based on the radio wave received from the fourth antenna;
Transport stream selection means for selecting one of the transport stream reproduced in the third transport stream reproduction means and the transport stream reproduced in the fourth transport stream reproduction means;
A receiving apparatus further comprising digital data reproducing means for reproducing the digital data from the transport stream selected by the transport stream selecting means. The receiving device according to claim 6 or 7,
The radio wave condition analyzing apparatus selects the broadcast station according to the digital data reproduced by the digital data reproducing means in order to follow the switching when the switching of the broadcasting station occurs in the data reproducing apparatus. Receiving device. A receiving device according to any one of claims 1 to 11,
The first to second antennas or the third to fourth antennas are directional antennas. A receiving device according to any one of claims 1 to 11,
The first to second antennas or the third to fourth antennas are adaptive array antennas. A receiving device according to any one of claims 1 to 11,
The first to second antennas or the third to fourth antennas are diversity antennas.

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