JP4851987B2 - Broadcast receiving apparatus, channel selection method, channel selection program, and recording medium therefor - Google Patents

Description

  The present invention relates to a broadcast receiving apparatus, a channel selection method, a channel selection program, and a recording medium thereof.

  2. Description of the Related Art Conventionally, a broadcast receiving apparatus that receives and reproduces terrestrial digital broadcasts is mounted on many moving objects such as vehicles. The broadcast receiving environment by such a broadcast receiving apparatus changes as the moving body moves. This is because, in terrestrial digital broadcasting, an MFN (Multi Frequency Network) system is adopted as a relay station arranged in each region, and the arrangement of physical channels varies from region to region. For this reason, when a moving body moves across broadcasting areas, it is necessary to appropriately switch the physical channel selected for reproduction in order to continue good viewing of the same broadcast content.

  As a technique relating to such physical channel switching, a technique for automatically switching a physical channel to be selected has been proposed (see Patent Document 1: hereinafter referred to as “conventional example”). In this conventional technique, two sets of antennas and tuners are prepared, and the reception state is confirmed while using one set for viewing. In parallel with the operation of one set, the other set is used to check the reception status of the physical channel of the switching candidate different from the physical channel being viewed. Based on the receiving state of the physical channel being viewed and the physical channel of the candidate for switching, the physical channel that is estimated to be optimal is determined, and the physical channel is set as a new physical channel for viewing. Yes.

JP 2004-320406 A

  In the conventional technique described above, the processing related to the currently viewed physical channel and the processing related to the physical channel to be switched are completely separated for each set of antenna and tuner at each time point. Then, during viewing using one set, the physical channel that is estimated to have a better reception state than the physical channel being viewed that is being received by one set is viewed in the confirmation of the reception state by the other set. If it is issued, the reception processing by the found physical channel is performed using the other antenna and tuner.

  In the conventional technique, the reception state of the physical channel being viewed by the other set is not taken into consideration, so that the viewing by the other set depends on the arrangement position and directivity of the antenna of one set and the antenna of the other set. The reception state of the middle physical channel may be the best. For this reason, it is difficult to accurately estimate the optimum physical channel among the physical channels that can be received. As a result, there is a possibility that the viewing physical channel is frequently switched as the moving body moves.

  For this reason, there is a need for a technique that can accurately estimate an optimal physical channel among physical channels that can be received. Meeting this requirement is one of the problems to be solved by the present invention.

The present invention has been made in view of the above circumstances, and a broadcast receiving apparatus capable of rationally selecting an optimal broadcast physical channel while ensuring continuous viewing of broadcast content being viewed and The purpose is to provide a tuning method.

The invention according to claim 1 is a first antenna group including at least one antenna; and a broadcast signal of a designated first physical channel among signals received by each of the antennas belonging to the first antenna group. select the first tuner means and for converting into a signal of a predetermined frequency band; see contains at least one antenna not belonging to the first antenna group; first detection means and for detecting a reception state according to the first antenna group A second antenna group having a directivity of reception sensitivity different from that of the first antenna group; independent of designation for the first tuner means from signals received by antennas belonging to the second antenna group; Second tuner means for selecting a broadcast signal of the designated second physical channel and converting it to a signal of a predetermined frequency band Second detection means for detecting a reception state by the second antenna group; storage means for storing a frequency band for each of a plurality of physical channels for broadcasting the same content; physical being viewed as the first physical channel While designating a channel, each of the plurality of physical channels stored in the storage means that is broadcasting the same content as the physical channel being viewed is sequentially designated as the second physical channel, and the second physical channel is The detection result by the second detection unit when it is different from the physical channel being viewed, the detection result by the first detection unit when the second physical channel is the same as the physical channel being viewed, and the second detection unit based on the detection result corresponding to better receiving condition among the detection result, optimum physical Ji Search means for searching for a channel; in a search period by the search means, content reproduction processing is performed based on an output signal from the first tuner means, and in a period other than the search period by the search means, reproduction processing means and performing a content reproduction process based on 1 synthesis of the output signal of the output signal from the tuner means from the second tuner means results; the best physical channel which has been searched by said searching means, said first And a channel selection control means that designates the physical channel and the second physical channel.

The invention according to claim 6 is a broadcast via a first physical channel designated from among a first antenna group including at least one antenna; and a signal received by each of the antennas belonging to the first antenna group. select signal, a first tuner means for converting into a signal of a predetermined frequency band; see contains at least one antenna not belonging to the first antenna group, the directivity of the reception sensitivity is different from the first antenna group A broadcast signal through a second physical channel designated independently from the designation of the first physical channel is selected from signals received by the second antenna group and antennas belonging to the second antenna group. And a second tuner means for converting the signal into a signal of a predetermined frequency band; Thus, a physical channel that sequentially designates each of a plurality of physical channels that are broadcasting the same content as the physical channel being viewed as the second physical channel while designating the physical channel being viewed as the first physical channel A designation step; each time the second physical channel is designated, if the second physical channel is different from the viewing physical channel, a broadcast wave via the second physical channel depends on the second antenna group. When the reception state is detected and the second physical channel is the same as the first physical channel, the broadcast wave from the viewing physical channel is received from the reception state by the first antenna group and the viewing physical channel. better reception among the reception state by the second antenna group of broadcast waves A detection step of detecting the state; on the basis of the detection result in the detection step, optimum physical channel determines the determining step and, the best physical channel determined in said determining step, said first physical channel and said second An optimum channel designating step for designating as a physical channel; after the designation in the optimum channel designating step, a content reproduction process based on a synthesis result of the output signal from the first tuner means and the output signal from the second tuner means A synthesizing / reproducing step of performing a channel selection method.

  The invention described in claim 7 is a channel selection program characterized by causing a calculation means to execute the channel selection method described in claim 6.

  The invention described in claim 8 is a recording medium in which the channel selection program described in claim 7 is recorded so as to be readable by the calculation means.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Note that in this embodiment, broadcast reception is performed by receiving and processing a terrestrial digital broadcast wave that is mounted on a vehicle and encoded by the MPEG method and then subjected to OFDM (Orthogonal Frequency Division Multiplex) modulation. The apparatus will be described as an example. In the following description and drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

[Constitution]
FIG. 1 is a block diagram illustrating a schematic configuration of a broadcast receiving apparatus 100 according to an embodiment. As shown in FIG. 1, the broadcast receiving apparatus 100 includes an antenna group 110 ₁ as a first antenna group and an antenna group 110 ₂ as a second antenna group. In addition, the broadcast receiving apparatus 100 includes a control unit 120, a tuner unit 130, and a reproduction processing unit 140. The broadcast receiving apparatus 100 further includes an operation input unit 150, a sound output unit 160, and a display unit 170.

The antenna unit 110 ₁ includes an antenna 111 ₁₁ and an antenna 111 ₁₂ . The antenna unit 110 ₂ includes an antenna 111 ₂₁ and an antenna 111 ₂₂ . These antennas 111 ₁₁ to 111 ₂₂ are arranged in the vehicle CR as shown in FIG. That is, the antennas 111 ₁₁ and 111 ₁₂ belonging to the antenna unit 110 ₁ are disposed at the rear of the vehicle. The antennas 111 ₂₁ and 111 ₂₂ belonging to the antenna unit 110 ₂ are disposed in front of the vehicle.

For this reason, the antenna unit 110 ₁ has directivity of reception sensitivity in the traveling reverse direction, and the antenna unit 110 ₂ has directivity of reception sensitivity in the traveling direction. As a result, when the broadcast base station BSF is on the traveling direction side and the broadcast base station BSB is on the traveling direction side, the antenna unit 110 ₁ is highly sensitive to the broadcast wave from the broadcast base station BSB, The antenna unit 110 ₂ has high sensitivity to broadcast waves from the broadcast base station BSF.

Returning to FIG. 1, the reception result by the antenna 111 ₁₁ is output to the tuner unit 130 as the reception signal RFS ₁₁ . The reception result by the antenna 111 ₁₂ is output to the tuner unit 130 as a reception signal RFS ₁₂ .

A reception result by the antenna 111 ₂₁ is output to the tuner unit 130 as a reception signal RFS ₂₁ . The reception result by the antenna 111 ₂₂ is output to the tuner unit 130 as a reception signal RFS ₂₂ .

  The control unit 120 controls the overall operation of the broadcast receiving apparatus 100. The control unit 120 will be described later.

The tuner unit 130 receives the signals of the physical channels to be selected in accordance with the channel selection commands CSL ₁ and CSL ₂ from the control unit 120 and the automatic gain control signals AGC _{11 to} AGC ₂₂ from the reproduction processing unit 140, and receives signals RFS _{11 to} RFS. _The channel selection process extracted from the channel ₂₂ is performed, and the channel selection signals IFS _{11 to} IFS ₂₂ having a predetermined intermediate frequency are output to the reproduction processing unit 140. The tuner unit 130, as shown in FIG. 3, a ₁ and first tuner unit 131, and a ₂ second tuner unit 131.

The first tuner unit 131 ₁ performs channel selection processing on the reception signals RFS ₁₁ and RFS ₁₂ from the antennas 111 ₁₁ and 111 ₁₂ belonging to the antenna unit 110 ₁ . The first tuner unit 131 ₁ includes tuner circuits 132 ₁₁ and 132 ₁₂ and a local oscillation circuit (OSC) 133 ₁ .

Tuner circuit 132 _11, according to the automatic gain control signal AGC ₁₁ from the local oscillation signal CF ₁ and the reproduction processing unit 140 from the local oscillator circuit 133 _1, extracts a signal of a physical channel to be selected from the received signal RFS _11, extraction The result is output to the reproduction processing unit 140 as a channel selection signal IFS ₁₁ having a predetermined intermediate frequency. Further, the tuner circuit 132 _12, according to the automatic gain control signal AGC ₁₂ from the local oscillation signal CF ₁ and the reproduction processing unit 140 from the local oscillator circuit 133 _1, extracts a signal of a physical channel to be selected from the received signal RFS ₁₂ The extraction result is output to the reproduction processing unit 140 as a channel selection signal IFS ₁₂ having a predetermined intermediate frequency.

The local oscillation circuit 133 ₁ includes an oscillator that can control the oscillation frequency by voltage control or the like. The local oscillation circuit 133 ₁ generates a local oscillation signal CF ₁ having a frequency corresponding to the physical channel to be selected in the first tuner unit 131 ₁ in accordance with the channel selection command CSL ₁ supplied from the control unit 120. The signals are supplied to the circuits 132 ₁₁ and 132 ₁₂ .

The second tuner unit 131 ₂ performs channel selection processing on the reception signals RFS ₂₁ and RFS ₂₂ from the antennas 111 ₂₁ and 111 ₂₂ belonging to the antenna unit 110 ₂ . The second tuner unit 131 ₂ includes tuner circuits 132 ₂₁ and 132 ₂₂ and a local oscillation circuit (OSC) 133 ₂ .

Tuner circuit 132 _21, according to the automatic gain control signal AGC ₂₁ from the local oscillation signal CF ₂ and the reproduction processing unit 140 from the local oscillator circuit 133 _2, extracts the signal of the physical channel to be selected from the received signal RFS _21, extraction The result is output to the reproduction processing unit 140 as a channel selection signal IFS ₂₁ having a predetermined intermediate frequency. Further, the tuner circuit 132 _22, according to the automatic gain control signal AGC ₂₂ from the local oscillation signal CF ₂ and the reproduction processing unit 140 from the local oscillator circuit 133 _2, extracts the signal of the physical channel to be selected from the received signal RFS ₂₂ The extraction result is output to the reproduction processing unit 140 as a channel selection signal IFS ₂₂ having a predetermined intermediate frequency.

Similar to the local oscillation circuit 133 ₁ described above, the local oscillation circuit 133 ₂ includes an oscillator that can control the oscillation frequency by voltage control or the like. This local oscillation circuit 133 ₂ corresponds to the physical channel to be selected in the second tuner unit 131 ₂ in accordance with the channel selection command CSL ₂ supplied independently from the channel selection command CSL ₁ described above from the control unit 120. A local oscillation signal CF ₂ having a frequency is generated and supplied to the tuner circuits 132 ₂₁ and 132 ₂₂ .

Each of the tuner circuits 132 _jk (j = 1, 2; k = 1, 2) includes an input filter 211, a radio frequency amplifier (RF-AMP) 212, and a radio frequency amplifier (RF-AMP) 212, as shown in FIG. , And a band-pass filter (hereinafter also referred to as “RF filter”) 213. Each of the tuner circuits 132 _jk includes a mixer (mixer) 214, an intermediate frequency filter (hereinafter also referred to as “IF filter”) 215, and an intermediate frequency amplifier (IF-AMP: Intermediate Frequency-Amplifier) 216. I have.

The input filter 211 is a high-pass filter that blocks low-frequency components of the reception signal RFS _jk from the corresponding antenna 111 _jk . The high frequency amplifier 212 amplifies the signal that has passed through the input filter 211.

The RF filter 213 selectively passes a signal in a specific frequency range among the signals output from the high frequency amplifier 212. The mixer 214 mixes the signal that has passed through the RF filter 213 and the local oscillation signal CF _j supplied from the local oscillation circuit 133 _j . IF filter 215 selects and passes a signal in a predetermined intermediate frequency range among the signals output from mixer 214.

The intermediate frequency amplifier 216 amplifies the signal that has passed through the IF filter 215. Here, the amplification factor of the intermediate frequency amplifier 216 is controlled by the automatic gain control signal AGC _jk from the reproduction processing unit 140. For this reason, the result of amplification by the intermediate frequency amplifier 216 is at an appropriate level for processing in the reproduction processing unit 140. The result of amplification by the intermediate frequency amplifier 216 is output to the reproduction processing unit 140 as a _channel selection signal IFS _jk .

Returning to FIG. 1, the playback processing unit 140 processes the channel selection signals IFS _{11 to} IFS ₂₂ from the tuner unit 130 under the control of the control unit 120 and supplies the sound data to the sound output unit 160. Image data IDT to be supplied to the ADT and display unit 170 is generated. As shown in FIG. 5, the reproduction processing unit 140 includes an OFDM demodulator 141 and a decoder 142. In addition, the reproduction processing unit 140 includes an audio processing unit 143 and a video processing unit 144.

The OFDM demodulator 141 performs automatic gain control in the tuner unit 130 and performs OFDM demodulation processing based on the channel selection signals IFS _{11 to} IFS ₂₂ from the tuner unit 130. As shown in FIG. 6, the OFDM demodulator 141 includes an AGC controller 221 serving as first and second detection means, a signal synthesizer 222, and a demodulator 223.

The AGC control unit 221 receives the channel selection signals IFS _{11 to} IFS ₂₂ . Then, the AGC control unit 221 detects the respective signal levels of the _channel selection signals IFS _jk (j = 1, 2; k = 1, 2), and automatically gains control signals AGC for setting each signal level to a predetermined level. Generate _jk . The automatic gain control signal AGC _jk generated in this way reflects the reception level at the antenna 111 _jk of the signal of the physical channel to be selected, that is, the reception state of the signal of the physical channel to be selected. The generated automatic gain control signal AGC _jk is output to the control unit 120 and the tuner unit 130.

The signal synthesis unit 222 performs signal synthesis processing under the control of the control unit 120. When the normal synthesis is designated by the synthesis control command SNC from the control unit 120, the signal synthesis unit 222 synthesizes the four signals of the tuning signals IFS _{11 to} IFS ₂₂ . On the other hand, when combining during search is designated by the combining control command SNC from the control unit 120, the signal combining unit 222 combines the two signals of the tuning signals IFS ₁₁ and IFS ₁₂ . The signal synthesis result by the signal synthesis unit 222 is output to the demodulation unit 223 as a synthesis signal SND.

  Demodulator 223 receives synthesized signal SND from signal synthesizer 222. Then, the demodulation unit 223 performs OFDM demodulation on the combined signal SND. A portion related to audio and video in the OFDM demodulation result is output to the decoding unit 142 as a content demodulated signal DMD. On the other hand, the data broadcast portion related to audio and video in the OFDM demodulation result is output to the control unit 120 as a signal DBD. Information included in such a signal DBD includes download data from a broadcasting station, physical channel information that is broadcasting the same content during normal broadcasting, and the like.

  Returning to FIG. 5, the decoding unit 142 receives the content demodulated signal DMD from the demodulating unit 223. Then, the decoding unit 142 decodes the content demodulated signal DMD under the control of the control signal CTD from the control unit 120, and outputs the decoding result related to audio to the audio processing unit 143 as demodulated audio data DAD. Output. In addition, the decoding unit 142 outputs the decoding result related to the video to the video processing unit 144 as demodulated video data DID.

  The audio processing unit 143 generates audio data ADT based on the demodulated audio data DAD. The generated audio data ADT is output toward the sound output unit 160.

  The video processing unit 144 generates image data IDT based on the demodulated video data DID. The generated image data IDT is output toward the display unit 170.

  Returning to FIG. 1, the operation input unit 150 includes a key unit provided in the main body of the broadcast receiving apparatus 100 or a remote input device including the key unit. Here, a touch panel provided in the display unit 170 can be used as the key part provided in the main body. Moreover, it can replace with the structure which has a key part, and the structure which inputs voice can also be employ | adopted. The operation input result to the operation input unit 150 is sent to the control unit 120 as operation input data IPD.

  The sound output unit 160 includes (i) a DA (Digital to Analogue) converter that converts the audio data ADT received from the reproduction processing unit 140 into an analog signal, and (ii) amplifies the analog signal output from the DA converter. And (iii) a speaker that converts the amplified analog signal into sound. The sound output unit 160 outputs broadcast sound from a desired station.

  The display unit 170 includes (i) a display device such as a liquid crystal display panel, an organic EL (Electro Luminescence) panel, a PDP (Plasma Display Panel), and (ii) the display device according to the image data IDT received from the reproduction processing unit 140. And a display control circuit for displaying an image. The display unit 170 displays broadcast video from the desired station.

  The control unit 120 controls the overall operation of the broadcast receiving apparatus 100 as described above. As shown in FIG. 7, the broadcast receiving apparatus 100 includes a process management unit 121 as a channel selection control unit, an optimum station search unit 122 as a search unit, and a storage unit 123 as a storage unit. .

The storage unit 123 stores a frequency list 126 and a channel selection work area 127. Here, as shown in FIG. 8, the frequency list 126 is divided into a plurality of physical channels that broadcast the same content, and has a plurality of list blocks LBK _P (P = 1, 2,...). It is configured. Each list block LBK _P is given a unique block identifier, and the position in the frequency list 126 is specified by the block identifier. List block LBK each _P, as shown in FIG. 9, the physical channel _{(PC PQ (Q = 1,2,} ...)) belonging to the list block LBK _P and the frequency corresponding to the physical channel (PC _PQ) Information (F _PQ ) is registered in association with each other. The frequency list 126 is created based on download data included in the signal DBD from the reproduction processing unit 140, physical channel information that is broadcasting the same content during normal broadcasting, and the like.

  As shown in FIG. 10, the channel selection work area 127 includes a viewing physical channel information area CPC and a work area WKA. Here, as the viewing physical channel information, the viewing physical channel and the identifier of the list block to which the viewing physical channel belongs are stored.

Returning to FIG. 7, the process management unit 121 includes a timer and the like. When the channel selection designation input to the operation input unit 150 is notified as the input data IPD, the process management unit 121 generates channel selection instructions CSL ₁ and CSL ₂ in accordance with the channel designation and sends them to the tuner unit 130. Output toward.

The process management unit 121 issues an optimal station search command SRS to the optimal station search unit 122 periodically during the reception processing period. Upon receiving the search channel selection request CSR from the optimal station search unit 122 that has received the optimal station search command SRS, the process management unit 121 generates a channel selection command CSL _{2 in} accordance with the search channel selection request CSR, and the tuner Output to the unit 130. When the search by the optimum station search unit 122 is completed and the optimum physical channel report OPC is received as a search completion report, the channel selection commands CSL ₁ and CSL ₂ are generated according to the optimum physical channel report OPC and sent to the tuner unit 130. Output toward.

  Further, during the search period by the optimum station search unit 122, the process management unit 121 designates composition during search by a composition control command SNC. On the other hand, the process management unit 121 designates normal synthesis by a synthesis control command SNC during a period other than the search period by the optimum station search unit 122. The process management unit 121 outputs the synthesis control command SNC to the reproduction processing unit 140.

  The process management unit 121 updates the frequency list according to information included in the signal DBD from the reproduction processing unit 140. In addition, the process management unit 121 performs registration and update processing in the viewing physical channel information area CPC in the channel selection work area 127.

The optimum station search unit 122 receives the optimum station search command SRS from the process management unit 121 and searches for the optimum station. In such a search, the optimum station search unit 122 sequentially issues a search channel selection request CSR for each physical channel (PC _PQ ) in the list block LBK _P to which the physical channel being viewed belongs in the physical channel information area CPC being viewed. However, the reception state is collected based on the automatic gain control signals AGC _{11 to} AGC ₂₂ from the reproduction processing unit 140.

Here, when the physical channel corresponding to the search channel selection request CSR matches the physical channel being viewed, the optimum station search unit 122 collects the reception state based on the automatic gain control signals AGC _{11 to} AGC _22. To do. On the other hand, when the physical channel corresponding to the search channel selection request CSR does not match the physical channel being viewed, the optimum station search unit 122 collects the reception state based on the automatic gain control signals AGC ₂₁ and AGC _22. .

When the reception status is collected for all the physical channels (PC _PQ ) in the list block LBK _P , the optimum station search unit 122 determines the optimum physical channel based on the collection result. The determination result is reported to the process management unit 121 as the optimum physical channel report OPC.

[Operation]
The operation of the broadcast receiving apparatus 100 configured as described above will be described mainly focusing on the optimum physical channel search process.

It is assumed that the content of the frequency list 126 in the storage unit 123 of the control unit 120 has been registered. At the beginning, the broadcast receiving apparatus 100 performs normal reception processing by selecting a physical channel (PC _PQ ) corresponding to the channel selection designation according to the channel selection designation from the operation input unit 150. To do. That is, it is assumed that the processing management unit 121 of the control unit 120 generates channel selection commands CSL ₁ and CSL ₂ corresponding to the physical channel (PC _PQ ) and outputs them to the tuner unit 130. The process management unit 121 also includes a physical channel (PC _PQ ) and a list block LBK to which the physical channel (PC _PQ ) belongs in the physical channel information area CPC being viewed in the channel selection work area 127 in the storage unit 123. _{Assume that} the identifier of _P is registered.

With the initial settings as described above, the optimum station search process, which is the optimum physical channel search process, is periodically executed during the broadcast signal reception process via the physical channel (PC _PQ ). The optimum station search process is started when the process management unit 121 issues an optimum station search command SRS to the optimum station search unit 122.

In the optimum station search process, as shown in FIG. 11, first, in step S11, the optimum station search unit 122 refers to the currently viewed physical channel information area CPC and specifies the list block to which the currently viewed physical channel belongs. To do. In this case, the list block LBK _P is specified.

Next, in step S12, the optimum station search unit 122 reads frequency information (F _P1 ) corresponding to the first physical channel (PC _P1 ) in the list block LBK _P. Subsequently, the optimum station search unit 122 sends a search channel selection request CSR designating the read frequency information (F _P1 ) to the process management unit 121.

Upon receiving this search channel selection request CSR, the process management unit 121 generates a channel selection command CSL ₂ corresponding to the frequency information (F _P1 ), outputs it to the tuner unit 130, and outputs the channel selection command CSL ₂ to the reproduction processing unit 140. Designation of composition during search is performed by a composition control command SNC. As a result, for the channel selection signals IFS ₁₂ and IFS ₁₂ related to the physical channel (PC _PQ ) being viewed by the antenna 111 ₁₁ and the antenna 111 ₁₂ belonging to the antenna unit 110 ₁ , only the automatic gain control is performed, Decoding processing is performed in the reproduction processing unit 140. On the other hand, only the automatic gain control is performed for the channel selection signals IFS ₂₁ and IFS ₂₂ related to the physical channel (PC _P1 ) by the antenna 111 ₂₁ and the antenna 111 ₂₂ belonging to the antenna unit 110 ₂ .

Next, in step S13, reception state collection processing for the physical channel (PC _P1 ) is performed. In this reception state collection process, as shown in FIG. 12, first, in step S21, the optimum station search unit 122 refers to the currently viewed physical channel information area CPC and collects the reception state collection target. It is determined whether or not the physical channel (in this stage, the physical channel (PC _P1 )) is the same as the currently viewed physical channel (PC _PQ ).

If the result of the determination in step S21 is affirmative (step S21: Y), the process proceeds to step S22. In this step S22, the optimum station search unit 122 performs a signal via the physical channel (PC _P1 ) by the antennas 111 _{11 to} 111 ₂₂ based on all of the automatic gain control signals AGC _{11 to} AGC ₂₂ from the reproduction processing unit 140. A value corresponding to the maximum value of the received power (for example, the value of the automatic gain control signal) is recorded in the work area WKA in association with the physical channel (PC _P1 ) as the best reception state information. Thereafter, the process of step S13 ends.

If the result of the determination in step S21 is negative (step S21: N), the process proceeds to step S23. In step S23, the optimum station search unit 122 uses the physical channels (PC _P1 ) by the antennas 111 ₂₁ and 111 ₂₂ belonging to the antenna unit 110 ₂ based on the automatic gain control signals AGC ₂₁ and AGC ₂₂ from the reproduction processing unit 140. A value corresponding to the maximum value of the reception power of the signal via the signal (for example, the value of the automatic gain control signal) is recorded in the work area WKA in association with the physical channel (PC _P1 ) as the best reception state information. Thereafter, the process of step S13 ends.

When the process of step S13 is completed as described above, the process proceeds to step S14 of FIG. In the step S14, it determines optimum station search section 122, for all the physical channels in the list block LBK within _P, and whether the collection of the reception state has been completed.

If the result of the determination in step S14 is negative (step S14: N), the process proceeds to step S17. In step S17, the optimum station search unit 122 newly reads frequency information corresponding to the next physical channel (in this stage, the physical channel PC _P2 ) in the list block LBK _P. Subsequently, the optimum station search unit 122 sends a search channel selection request CSR designating the newly read frequency information to the process management unit 121.

Upon receiving this search channel selection request CSR, the process management unit 121 generates a channel selection command CSL ₂ corresponding to the new frequency information and outputs it to the tuner unit 130. As a result, the channel selection signals IFS ₂₁ and IFS ₂₂ related to the physical channel (PC _PQ ) being viewed by the antenna 111 ₁₁ and the antenna 111 ₁₂ belonging to the antenna unit 110 ₁ are subjected to demodulation processing and only after automatic gain control is performed. with the decoding processing is continuously performed in the reproduction processing unit 140, the channel selection signal IFS _21, IFS ₂₂ for the next physical channel by the antenna 111 ₂₁ and the antenna 111 ₂₂ belonging to the antenna unit 110 _2, only the automatic gain control To be done.

  After the setting for collecting the reception state for the next physical channel is made in this way, the process returns to step S13. Hereinafter, the processing of step S13 and step S17 is repeated until the result of determination in step S14 becomes affirmative.

When collection of reception statuses for all physical channels in the list block LBK _P is completed and the determination result in step S14 is affirmative (step S14: Y), the process proceeds to step S15. At this stage, the contents of the work area WKA are associated with each physical channel (PC _P1 , PC _P2 ,...) And the best reception state information is recorded as shown in FIG. It has become.

In step S15, the optimum station search unit 122 refers to the contents of the work area WKA, and is the largest of the best reception state information associated with each physical channel (PC _P1 , PC _P2 ,...). Identify the one corresponding to the received power. Subsequently, the optimum station search unit 122 determines that the physical channel corresponding to the identified best reception state is the optimum physical channel. Then, the optimum station search unit 122 sends information on the determined optimum physical channel to the process management unit 121 as the optimum physical channel report OPC.

Next, in step S16, the process management unit 121 that has received the optimum physical channel report OPC generates channel selection instructions CSL ₁ and CSL ₂ corresponding to the optimum physical channel and outputs them to the tuner unit 130. Designation of normal composition for the reproduction processing unit 140 is performed by a composition control command SNC. As a result, the channel selection signals IFS ₁₁ and IFS ₁₂ related to the optimum physical channel by the antenna 111 ₁₁ and the antenna 111 ₁₂ belonging to the antenna unit 110 ₁ and the selection of the optimum physical channel by the antenna 111 ₂₁ and the antenna 111 ₂₂ belonging to the antenna unit 110 ₂ are selected. After only automatic gain control is performed for all the station signals IFS ₂₁ and IFS ₂₂ , demodulation processing and decoding processing are performed in the reproduction processing unit 140.

  Thereafter, the reception process related to the optimum physical channel determined by this optimum physical channel search process is continued until the next optimum physical channel search process.

As described above, in the present embodiment, in determining the optimum physical channel from among a plurality of physical channels that are used to broadcast the physical channel having the same content being viewed using the received result of the antenna unit 110 ₁ while securing a viewing, a signal extracted from the received result of the antenna unit 110 _2, sequentially switched to those corresponding to a plurality of physical channels. When the physical channel of the signal extracted from the reception result by the antenna unit 110 ₂ matches the physical channel being viewed, all reception results of the antennas 111 _{11 to} 111 ₂₂ belonging to the antenna unit 110 ₁ or the antenna unit 110 ₂ are obtained. Based on the received state, the reception state regarding the physical channel being viewed is collected. On the other hand, when the physical channel of the signal extracted from the reception result by the antenna unit 110 ₂ does not match the physical channel being viewed, the collection target is determined based on the reception result of the antennas 111 ₂₁ and 111 ₂₂ belonging to the antenna unit 110 _2. Collect the reception status of the physical channel. Then, the optimum physical channel is determined based on the collection result.

  For this reason, when determining the optimum physical channel, it is possible to make a rational determination that respects the current reception state of the currently viewed physical channel. Therefore, it is possible to rationally select an optimal broadcast physical channel while ensuring continuous viewing of the broadcast content being viewed.

In this embodiment, the antennas 111 ₁₁ and 111 ₁₂ of the antenna unit 110 ₁ for ensuring continuous viewing during the search period of the optimum physical channel are arranged on the rear side of the vehicle CR, and the search for the optimum physical channel is performed. The antennas 111 ₂₁ and 111 ₂₂ of the antenna unit 110 ₂ for collecting the reception state of each physical channel during the period are arranged on the front side of the vehicle CR. For this reason, it is possible to determine the optimum physical channel that rationally considers the directivity of each antenna and the change in the positional relationship between the broadcast base station and each antenna due to traveling of the vehicle CR.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiment, and various modifications are possible.

For example, in the above embodiment, the number of antennas in the antenna units 110 ₁ and 110 ₂ is two. However, the number of antennas included in each antenna unit may be one, or three or more. May be. Further, the number of antennas in each antenna unit may be different from each other.

In the above embodiment, the two antenna units 110 ₁ and 110 ₂ are provided. However, the number of antenna units provided may be three or more.

Further, in the above embodiment, the antenna units 111 ₁₁ and 111 ₁₂ of the antenna unit 110 ₁ are arranged on the rear side of the vehicle CR, and the antenna unit for collecting the reception state of each physical channel in the search period of the optimum physical channel. 110 ₂ antennas 111 ₂₁ and 111 ₂₂ are arranged in front of the vehicle CR. On the other hand, all the antennas may be arranged on the rear side of the vehicle CR, or all the antennas may be arranged on the front side of the vehicle CR. Even in such a case, when determining the optimum physical channel, it is possible to make a determination that respects the current reception state of the currently viewed physical channel.

  In the above embodiment, the reception power at each antenna is detected as the reception state. However, the sum of the reception powers of the antennas included in the antenna unit can be detected as the reception state at the antenna unit.

  In the above embodiment, the present invention is applied to a broadcast receiving apparatus mounted on a vehicle. However, the present invention may be applied to an apparatus having a broadcast receiving function mounted on a mobile body other than a vehicle. For example, the present invention can be applied to a device having a broadcast receiving function installed in a home or the like.

  Note that a part or all of the control unit 120 in the above embodiment includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like. The computer may be configured as a computing unit provided, and a part of or all of the processing in the above embodiment may be executed by executing a program prepared in advance on the computer. This program is recorded on a computer-readable recording medium such as a hard disk, CD-ROM, or DVD, and is read from the recording medium and executed by the computer. The program may be acquired in a form recorded on a portable recording medium such as a CD-ROM or DVD, or may be acquired in a form of delivery via a network such as the Internet. Also good.

It is a block diagram which shows roughly the structure of the broadcast receiver which concerns on one Embodiment of this invention. It is a figure for demonstrating the arrangement | positioning position of the four antennas in FIG. FIG. 2 is a block diagram illustrating a configuration of a tuner unit in FIG. 1. FIG. 4 is a block diagram illustrating a configuration of a tuner circuit in FIG. 3. It is a block diagram which shows the structure of the reproduction | regeneration processing unit of FIG. FIG. 6 is a block diagram showing a configuration of an OFDM demodulator in FIG. 5. It is a block diagram which shows the structure of the control unit of FIG. It is a figure for demonstrating the structure of the frequency list | wrist of FIG. It is a figure for demonstrating the content of the list block of FIG. It is a figure for demonstrating the structure of the channel selection work area | region of FIG. 3 is a flowchart for explaining an optimum physical channel selection process by the apparatus of FIG. 1. 12 is a flowchart for explaining reception state collection processing in FIG. 11; It is a figure for demonstrating the content of the work area in the process of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Broadcast receiving apparatus 110 ₁ ... Antenna unit (1st antenna group)
110 ₂ ... Antenna unit (second antenna group)
121 ... Processing management unit (tuning control means)
122 ... Optimal station search section (search means)
123 ... Storage section (storage means)
131 ₁ ... First tuner unit 131 ₂ ... Second tuner unit 221... AGC control unit (first and second detection means)

Claims (8)

A first antenna group including at least one antenna;
First tuner means for selecting a broadcast signal of a designated first physical channel from signals received by each of the antennas belonging to the first antenna group and converting the broadcast signal to a signal of a predetermined frequency band;
First detection means for detecting a reception state by the first antenna group;
See contains at least one antenna not belonging to the first antenna group, and the first antenna group and the second antenna group directivity different reception sensitivity;
From the signals received by the antennas belonging to the second antenna group, the broadcast signal of the second physical channel designated independently of the designation to the first tuner means is selected and converted to a signal of a predetermined frequency band. A second tuner means for converting;
Second detection means for detecting a reception state by the second antenna group;
Storage means for storing a frequency band for each of a plurality of physical channels for broadcasting the same content;
While specifying the physical channel being viewed as the first physical channel, each of the plurality of physical channels stored in the storage means that is broadcasting the same content as the physical channel being viewed is sequentially set as the second physical channel. The detection result by the second detection means when the second physical channel is different from the viewing physical channel, and the first detection means when the second physical channel is the same as the viewing physical channel. Search means for searching for an optimum physical channel based on a detection result and a detection result corresponding to a better reception state among detection results of the second detection means;
In the search period by the search means, wherein performs content reproduction processing based on the output signal from the first tuner means, in a period other than the search period by the search means, the output signal from the first tuner means and a reproduction processing unit performs the content playback processing based on the combined result of the output signal from the second tuner means;
Channel selection control means for designating the optimum physical channel searched by the search means as the first physical channel and the second physical channel;
A broadcast receiving apparatus comprising:   The broadcast receiving apparatus according to claim 1, wherein the broadcast receiving apparatus is mounted on a mobile body. The antennas belonging to the first antenna group are arranged in the direction opposite to the traveling direction of the moving body,
The antennas belonging to the second antenna group are arranged toward the traveling direction of the moving body,
The broadcast receiving apparatus according to claim 2. The first detection means detects the reception power of the broadcast wave from the first physical channel in each antenna belonging to the first antenna group,
The second detection means detects the reception power of the broadcast wave from the second physical channel in each of the antennas belonging to the second antenna group;
The broadcast receiving apparatus according to any one of claims 1 to 3, wherein The search means includes
When the second physical channel is different from the first physical channel, every time the second physical channel is sequentially specified, a broadcast wave via the second physical channel in each antenna belonging to the second antenna group. Find the maximum received level of
When the second physical channel is the same as the first physical channel, the maximum value of the reception level of the broadcast wave through the second physical channel in each antenna belonging to the first or second antenna group is obtained.
Determining that the second physical channel corresponding to the maximum obtained maximum value is the optimum physical channel;
The broadcast receiving apparatus according to claim 4. A first antenna group including at least one antenna; and a broadcast signal via a designated first physical channel is selected from signals received by each of the antennas belonging to the first antenna group, and a predetermined frequency band is selected. a first tuner unit for converting the signal; the saw including at least one antenna first not belonging to the antenna group, and the first antenna group and the second antenna group directivity different receiving sensitivity; the second A broadcast signal through a second physical channel designated independently of the designation of the first physical channel is selected from signals received by each of the antennas belonging to the antenna group to obtain a signal of a predetermined frequency band. A tuning method used in a broadcast receiving apparatus comprising: a second tuner means for converting,
A physical channel designating step of designating each of a plurality of physical channels broadcasting the same content as the currently viewed physical channel as the second physical channel while designating the currently viewed physical channel as the first physical channel. When;
Whenever the second physical channel is designated, if the second physical channel is different from the physical channel being viewed, the reception state of the broadcast wave via the second physical channel is detected by the second antenna group. In addition, when the second physical channel is the same as the first physical channel, the reception state of the broadcast wave from the viewing physical channel by the first antenna group and the broadcast wave from the physical channel being viewed A detection step of detecting a better reception state among the reception states by the second antenna group;
A determination step of determining an optimum physical channel based on a detection result in the detection step;
An optimum channel designating step of designating the optimum physical channel determined in the determining step as the first physical channel and the second physical channel;
A synthesis reproduction step of performing content reproduction processing based on a synthesis result of the output signal from the first tuner means and the output signal from the second tuner means after designation in the optimum channel designation step;
A channel selection method comprising:   A tuning program for causing a computing means to execute the tuning method according to claim 6.   8. A recording medium in which the channel selection program according to claim 7 is recorded so as to be readable by an arithmetic means.

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