WO2012131893A1

WO2012131893A1 - Broadcast receiver and broadcast reception processing control method

Info

Publication number: WO2012131893A1
Application number: PCT/JP2011/057776
Authority: WO
Inventors: 宜司中尾; 正宏対馬; 俊人市川
Original assignee: パイオニア株式会社
Priority date: 2011-03-29
Filing date: 2011-03-29
Publication date: 2012-10-04

Abstract

On the occasion of reception processing of simultaneous broadcasting in which analog broadcasting and digital broadcasting are simultaneously performed, a level detection unit (140) detects a signal level (ABL) in a frequency band corresponding to the analog broadcasting and a signal level (DBL) in a frequency band corresponding to the digital broadcasting in the selected simultaneous broadcasting. Then, a processing control unit (191) calculates parameter values for controlling respective processing of an AGC processing unit (120), a seek processing unit (192), and an automatic reception control unit, a digital broadcast processing unit and a blend processing unit in a reproduction processing unit (150) on the basis of the ratio between the signal level (ABL) and the signal level (DBL). Thereafter, the processing control unit (191) controls the reception processing in the respective processing units by sending the calculated parameter values to the corresponding processing units.

Description

Broadcast receiving apparatus and broadcast reception processing control method

The present invention relates to a broadcast receiving device, a broadcast reception processing control method, a broadcast reception processing control program, and a recording medium on which the broadcast reception processing control program is recorded.

Conventionally, radio receivers that receive radio broadcast waves and reproduce broadcast contents have become widespread. As such a radio broadcast, an analog broadcast has been traditionally adopted, but in recent years, the adoption of a digital broadcast has progressed.

One such digital broadcasting system is the IBOC (In-Band On-Channel) system adopted in the United States. In this IBOC system, hybrid broadcasting is adopted, and digital broadcasting can be added to analog broadcasting. For this reason, it is possible to improve sound quality using digital broadcasting. Here, in the IBOC hybrid broadcasting, digital broadcasting is performed by using broadcasting channels on both sides adjacent to the broadcasting channel for analog broadcasting on the frequency axis.

By the way, in the past, in the IBOC system, the ratio value between the level of the analog broadcast wave and the level of the digital broadcast wave transmitted from a broadcasting station that performs hybrid broadcasting was determined to be a predetermined constant value. . For this reason, a technique based on the premise that the value of the ratio is a predetermined constant value has been proposed.

As such a technique, when the broadcast by the selected broadcast station is an IBOC hybrid method, the ratio of the signal level in the analog broadcast band and the digital broadcast band (when considering the signal level in decibels (dB) units, A technique has been proposed in which it is determined whether or not the selected broadcast station is performing IBOC hybrid broadcasting by determining whether or not the difference is about the value specified in the IBOC format. (See Patent Document 1: hereinafter referred to as “conventional example”). In the conventional technique, when it is determined that the selected broadcasting station is performing IBOC hybrid broadcasting, either digital broadcasting or analog broadcasting is performed based on the detection result of the signal level. Is selected, and automatic gain control of the signal component of the broadcast band corresponding to the selected broadcast is performed.

JP 2002-26756 A

Starting with the above-described conventional inventions, the proposed technologies related to the IBOC method so far have a predetermined constant ratio between the power of the analog broadcast wave and the power of the digital broadcast wave transmitted from the broadcast station that performs the hybrid broadcast. It was assumed to be a value. However, recently, according to the IBOC standard, the ratio value can be arbitrarily selected within a predetermined range.

As a result, if the broadcasting stations are different, the ratio value can be different. In addition, since it is possible to set different broadcast wave transmission positions for analog broadcasting and digital broadcasting in hybrid broadcasting, a situation may occur in which the ratio value varies depending on the position of the broadcast receiving apparatus. became.

For this reason, there is a need for a technique that can control reception processing so that the advantage of hybrid broadcasting can be utilized even if the value of the ratio between the power of analog broadcasting waves and the power of digital broadcasting waves in hybrid broadcasting changes. . Meeting this demand 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 an object of the present invention is to provide a broadcast receiving apparatus and a broadcast reception processing control method that can appropriately control reception processing of simulcast including hybrid broadcast. To do.

From a first viewpoint, the present invention is a broadcast receiving apparatus that receives a broadcast signal of a simulcast broadcast in which analog broadcast and digital broadcast are simultaneously performed, and the broadcast signal corresponding to a channel selection command is transmitted in an intermediate frequency band. A front-end unit that converts the signal to an intermediate frequency signal, a first detection unit that detects a signal level of a first frequency band corresponding to the analog broadcast in the intermediate frequency signal, and a digital broadcast in the intermediate frequency signal. A second detection unit that detects a signal level of a corresponding second frequency band; and a difference in a selected broadcasting station of a ratio value between a detection result by the first detection unit and a detection result by the second detection unit. And a processing control unit that controls reception processing corresponding to at least one of the accompanying difference and the time change of the ratio value.

From a second viewpoint, the present invention includes a front end unit that converts a broadcast signal corresponding to a channel selection command into an intermediate frequency signal that is an intermediate frequency band signal, and analog broadcasting and digital broadcasting are performed simultaneously. A broadcast reception processing control method used in a broadcast receiving apparatus for receiving a simulcast broadcast signal, the first detection step detecting a signal level of a first frequency band corresponding to the analog broadcast in the intermediate frequency signal; A second detection step of detecting a signal level of a second frequency band corresponding to the digital broadcast in the intermediate frequency signal; a value of a ratio between a detection result in the first detection step and a detection result in the second detection step; A control step of controlling reception processing corresponding to at least one of a difference due to a difference in the selected broadcast station and a time change of the ratio value. It is broadcast reception processing control method according to claim.

From a third aspect, the present invention is a broadcast reception processing control program that causes a calculation unit to execute the broadcast reception processing control method of the present invention.

From the fourth viewpoint, the present invention is a recording medium in which the broadcast reception processing control program of the present invention is recorded so as to be readable by an arithmetic unit.

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 block diagram which shows the structure of the reproduction | regeneration processing unit of FIG. It is a block diagram which shows the structure of the control unit of FIG. It is a figure for demonstrating the frequency distribution of the hybrid broadcast signal used as the object of a reception process with the apparatus of FIG. It is a flowchart for demonstrating the process by the process control part of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. In the following description, 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. The broadcast receiving apparatus 100 is a broadcast receiving apparatus that can receive and reproduce an IBOC frequency modulation (FM) radio broadcast.

As shown in FIG. 1, the broadcast receiving apparatus 100 includes an antenna 110, an RF processing unit 120 as a front end unit, and an automatic gain control (AGC) processing unit 130 as an automatic gain control unit. The broadcast receiving apparatus 100 also includes a level detection unit 140 as first and second detection units, a reproduction processing unit 150, and a designated volume adjustment unit 160. Furthermore, the broadcast receiving apparatus 100 includes a speaker unit 170, an operation input unit 180, and a control unit 190.

The antenna 110 receives a broadcast wave transmitted from a broadcast station. The reception result by the antenna 110 is sent to the RF processing unit 120 as a reception signal RFS (hereinafter referred to as “signal RFS”).

The RF processing unit 120 receives the signal RFS transmitted from the antenna 110. The RF processing unit 120 performs channel selection processing in accordance with the channel selection command CSL sent from the control unit 190, and performs automatic gain control in accordance with the gain control command AGV sent from the AGC processing unit 130, A channel selection signal IFD having a predetermined intermediate frequency whose level is controlled (hereinafter referred to as “signal IFD”) is generated. The signal IFD thus generated is sent to the level detection unit 140 and the reproduction processing unit 150.

Also, the RF processing unit 120 detects the signal level in the frequency band of the analog broadcast component of the IBOC broadcast wave in the signal RFS. The signal level thus detected is sent to the AGC processing unit 130 as the narrowband signal level NBL.

The AGC processing unit 130 receives the narrowband signal level NBL sent from the RF processing unit 120. When the narrowband signal level NBL is equal to or higher than the automatic gain control start level value ASV sent from the control unit 190, the AGC processing unit 130 is for digital broadcasting for setting the level of the signal IFD to a predetermined constant value. A gain control command AGV is generated. The gain control command AGV thus generated is sent to the RF processing unit 120.

The level detection unit 140 receives the signal IFD sent from the RF processing unit 120. The level detection unit 140 detects the signal level of the frequency band of the IBOC analog broadcast component in the signal IFD and detects the signal level of the frequency band of the IBOC digital broadcast component in the signal IFD.

The detection result of the signal level of the analog broadcast component frequency band by the level detection unit 140 is sent to the reproduction processing unit 150 and the control unit 190 as an analog broadcast signal level ABL. The detection result of the signal level in the frequency band of the digital broadcast component by the level detection unit 140 is sent to the control unit 190 as the digital broadcast signal level DBL.

The reproduction processing unit 150 receives the signal IFD sent from the RF processing unit 120. Subsequently, the reproduction processing unit 150 performs reproduction processing on the analog broadcast component in the signal IFD and also performs reproduction processing on the digital broadcast component in the signal IFD. Here, in the reproduction process based on the analog broadcast component, an automatic reception control (ARC) process based on the analog broadcast signal level ABL sent from the level detection unit 140 is performed.

Then, the playback processing unit 150 performs a blending process of the playback processing result for the analog broadcast component and the playback processing result for the digital broadcast component in accordance with the blend control command BLC sent from the control unit 190. The result of the blend process is sent to the designated volume adjustment unit 160 as a blend signal BPD (hereinafter referred to as “signal BPD”). Here, the signal BPD is composed of two signals, a left channel (hereinafter “L channel”) signal and a right channel (hereinafter “R channel”) signal.

The configuration of the reproduction processing unit 150 will be described later.

The designated volume adjustment unit 160 receives the signal BPD sent from the reproduction processing unit 150. Then, the designated volume adjustment unit 160 generates an output audio signal AOS under the control of the control unit 190 and sends it to the speaker unit 170.

The designated volume adjustment unit 160 having such a function includes a DA (Digital-to-Analogue) conversion unit, a volume adjustment unit, and a power amplification unit. Here, the DA converter receives the signal BPD sent from the reproduction processing unit 150. The DA converter then converts the signal BPD into an analog signal. Note that the DA conversion unit includes two DA converters configured similarly to each other, corresponding to the L channel signal and the R channel signal included in the signal BPD. The analog conversion result by the DA conversion unit is sent to the volume adjustment unit.

The above volume adjustment unit receives the signal of the analog conversion result sent from the DA conversion unit. Then, the volume adjustment unit performs volume adjustment processing on the analog conversion result signals corresponding to the L channel and the R channel in accordance with the volume adjustment command VLC sent from the control unit 190. Note that the volume adjustment unit is configured to include two electronic volume elements configured in the same manner, corresponding to the L channel and the R channel. The signal of the volume adjustment result by the volume adjustment unit is sent to the power amplification unit.

The above power amplification unit receives the signals of the volume adjustment results of the L channel and the R channel sent from the volume adjustment unit. The power amplification unit power-amplifies the signal of the volume adjustment result. The power amplifying unit includes two power amplifiers configured similarly to each other, corresponding to the L channel and the R channel. An output audio signal AOS that is an amplification result by the power amplification unit is sent to the speaker unit 170.

The above speaker unit 170 includes an L channel speaker and an R channel speaker. The speaker unit 170 reproduces and outputs audio in accordance with the output audio signal AOS sent from the designated volume adjustment unit 160.

The operation input unit 180 is configured by a key unit provided in the main body of the broadcast receiving apparatus 100 or a remote input device including the key unit. Here, as a key part provided in the main body, a touch panel provided in a display unit (not shown) can be used. Moreover, it can replace with the structure which has a key part, and can also employ | adopt the structure which inputs a voice. The result of operation input to the operation input unit 180 is sent to the control unit 190 as operation input data IPD.

The control unit 190 controls the operation of the broadcast receiving apparatus 100. The configuration of the control unit 190 will be described later.

Next, the configuration of the reproduction processing unit 150 will be described. As shown in FIG. 2, the reproduction processing unit 150 includes an analog broadcast processing unit 151 as a first reproduction processing unit, a digital broadcast processing unit 152 as a second reproduction processing unit, and a blend processing unit 153. Yes.

The analog broadcast processing unit 151 receives the signal IFD sent from the RF processing unit 120. Then, the analog broadcast processing unit 151 performs a reproduction process on the analog broadcast component in the signal IFD. The reproduction processing result by the analog broadcast processing unit 151 is sent to the blend processing unit 153 as an analog broadcast processing signal ABD (hereinafter referred to as “signal ABD”).

The analog broadcast processing unit 151 having such a function includes a detection unit 156, an automatic reception control unit 157, and a stereo demodulation unit 158.

The detection unit 156 receives the signal IFD sent from the RF processing unit 120. And the detection part 156 performs a detection process by the predetermined method with respect to the signal component of the frequency band of the analog broadcast component in signal IFD. The detection result by the detection unit 156 is sent to the automatic reception control unit 157 as a detection signal DTD (hereinafter referred to as “signal DTD”).

The automatic reception control unit 157 receives the signal DTD sent from the detection unit 156. Then, the automatic reception control unit 157 estimates the variation in the reception status of the radio wave transmitted from the selected broadcast station based on the analog broadcast signal level ABL sent from the level detection unit 140, and the estimation result In accordance with this, separation control, auto high cut control and soft mute control are performed. Here, the separation control, auto high cut control, and soft mute control are the types of control designated by the automatic reception control designation ACC in which the analog broadcast signal level ABL is part of the blend control command BLC sent from the control unit 190. This is performed when the level is equal to or lower than the corresponding control start signal level. The result of the control process by the automatic reception control unit 157 is sent to the stereo demodulation unit 158 as a signal ARD.

The stereo demodulator 158 receives the signal ARD sent from the automatic reception controller 157. Then, the stereo demodulation unit 158 performs stereo demodulation processing on the signal ARD. This stereo demodulation result is sent to blend processing section 153 as signal ABD. The signal ABD is composed of two signals, an L channel signal and an R channel signal.

The digital broadcast processing unit 152 receives the signal IFD sent from the RF processing unit 120. Then, the digital broadcast processing unit 152 performs a reproduction process on the digital broadcast component in the signal IFD. The reproduction processing result by the digital broadcast processing unit 152 is sent to the blend processing unit 153 as a digital broadcast processing signal DBD (hereinafter referred to as “signal DBD”).

The digital broadcast processing unit 152 having such a function includes an OFDM (Orthogonal Frequency Division Multiplexing) demodulating unit, a decoding unit, and a data error monitoring unit.

The OFDM demodulator receives the signal IFD sent from the RF processing unit 120. Then, the OFDM demodulator performs OFDM demodulation processing on the signal component in the frequency band of the digital broadcast component in the signal IFD. The result of demodulation by this OFDM demodulator is sent to the decoder as an OFDM demodulated signal.

The above decoding unit receives the OFDM demodulated signal sent from the OFDM demodulating unit. The decoding unit decodes the OFDM demodulated signal. The result of decoding by the decoding unit is sent to the blend processing unit 153 as a signal DBD. The signal DBD is also composed of two signals, an L channel signal and an R channel signal, like the signal ABD.

The data error monitoring unit receives the OFDM demodulated signal sent from the OFDM demodulation unit. Subsequently, the data error monitoring unit monitors the data error in the OFDM demodulated signal, and the switching error frequency SWR (the second error frequency in which the data error frequency in the OFDM demodulated signal is a part of the blend control command BLC sent from the control unit 190. It is determined whether or not the threshold switching error frequency specified by a part of the switching parameters is equal to or higher. If the result of the determination is affirmative, the data error monitoring unit determines that the digital broadcast reproduction is inappropriate. On the other hand, if the result of the determination is negative, the data error monitoring unit determines that digital broadcast reproduction is appropriate.

Then, based on the result of the determination, the data error monitoring unit sends a blend flag BLF to the blend processing unit 153 that the digital broadcast reproduction is inappropriate or the digital broadcast reproduction is appropriate. Here, when the transition is made from the state where the digital broadcast reproduction is inappropriate, or when the transition is made from the state where the digital broadcast reproduction is inappropriate, the blend flag BLF is changed to the previous time. When the switching transition time designated by the minimum switching cycle time SWT (part of the second switching parameter) that is a part of the blend control command BLC sent from the control unit 190 has elapsed The content of the blend flag BLF is quickly switched.

The blend processing unit 153 receives the signal ABD sent from the analog broadcast processing unit 151 and the signal DBD sent from the digital broadcast processing unit 152. Then, the blend processing unit 153 selects the signal ABD or the signal DBD according to the content of the blend flag BLF sent from the digital broadcast processing unit 152, and sends it to the designated volume adjustment unit 160 as the signal BPD.

The blend processing unit 153 specifies the level of the signal ABD and the level of the signal DBD as an adjustment level BLL (part of the first switching parameter) that is a part of the blend control command BLC sent from the control unit 190. Adjust to signal level. In addition, the blend processing unit 153 uses a part of the blend control command BLC sent from the control unit 190 when switching the selection signal from the signal ABD to the signal DBD or switching the selection signal from the signal DBD to the signal ABD. In the period of time designated as a certain switching transition time BLS (part of the first switching parameter), the level of the signal before switching is gradually lowered and the level of the signal after switching is gradually raised. . Then, the blend processing unit 153 completes the selection signal switching at the end of the period.

Next, the configuration of the control unit 190 will be described. As shown in FIG. 3, the control unit 190 includes a processing control unit 191, a seek processing unit 192, and a tuning volume control unit 193.

The processing control unit 191 receives the analog broadcast signal level ABL and the digital broadcast signal level DBL sent from the level detection unit 140. Subsequently, the processing control section 191, the value R _DA of the ratio of the analog broadcasting signal level ABL and the digital broadcasting signal level DBL, is calculated by the following equation (1).
R _DA = DBL / ABL (1)

Based on the value R _DA calculated in this way, the process control unit 191 calculates the automatic gain control start level value ASV. The automatic gain control start level value ASV is calculated from the viewpoint of appropriately performing automatic gain control when the signal level of the digital broadcast component according to the IBOC method is a signal level at which digital broadcast can be reproduced. Done. The automatic gain control start level value ASV calculated in this way is sent to the AGC processing unit 130.

Further, based on the calculated value R _DA , the process control unit 191 calculates a seek threshold value SKS. The calculation of the seek threshold value SKS is performed from the viewpoint that the digital broadcast component according to the IBOC method is not recognized as an adjacent wave transmitted from an adjacent station in the seek operation by the seek processing unit 192. The seek threshold value SKS calculated in this way is sent to the seek processing unit 192.

Furthermore, based on the calculated value R _DA , the process control unit 191 generates a blend control command BLC. The blend control command BLC is generated from the viewpoint of reducing a listener's uncomfortable feeling when switching between an analog broadcast reproduction result and a digital broadcast reproduction result. The blend control command BLC generated in this way is sent to the reproduction processing unit 150.

Details of processing by the processing control unit 191 will be described later.

When the seek processing unit 192 receives a seek command SSK sent from the channel selection volume control unit 193, the seek processing unit 192 executes a seek process. In such seek processing, the seek processing unit 192 selects a broadcast channel selected as a broadcast channel adjacent to the broadcast channel to which the center frequency of the selected IBOC hybrid broadcast station belongs in the designated frequency direction. The broadcast channels are sequentially selected along the frequency direction specified by the seek command SSK until the analog broadcast signal level ABL corresponding to the signal power of the channel is equal to or higher than the seek threshold value SKS specified by the processing control unit 191. To do.

When the analog broadcast signal level ABL is less than the seek threshold value SKS, the seek processing unit 192 selects a broadcast channel being selected in the designated frequency direction in order to sequentially select broadcast channels in the seek process. The next station request CSN of the adjacent broadcast channel is sent to the channel selection volume control unit 193. Then, when the analog broadcast signal level ABL becomes equal to or higher than the seek threshold value SKS, the seek processing unit 192 sends a seek end report STP to the channel selection volume control unit 193.

The channel selection volume control unit 193 receives the operation input data IPD sent from the operation input unit 180. If the content of the operation input data IPD is a channel selection designation, the channel selection volume control unit 193 generates a channel selection command CSL corresponding to the designated desired station and sends it to the RF processing unit 120. When the content of the operation input data IPD is volume adjustment designation, the tuning volume control unit 193 generates a volume adjustment command VLC corresponding to the designated volume adjustment designation, and designates the designated volume adjustment unit 160. Send to.

Further, when the content of the operation input data IPD is seek designation, the channel selection volume control unit 193 sends a seek command SSK to the seek processing unit 192. When the channel selection volume control unit 193 receives the next station request CSN sent from the seek processing unit 192, the channel selection volume control unit 193 selects a broadcast channel adjacent to the selected broadcast channel in the frequency direction specified in the seek designation. The channel selection command CSL is generated and sent to the RF processing unit 120.

[Operation]
Next, the IBOC broadcast reception operation of the broadcast receiving apparatus 100 configured as described above will be described mainly focusing on the processing in the processing control unit 191.

First, prior to the description of the broadcast reception operation by the broadcast receiving apparatus 100, the frequency distribution of the signal level of the signal corresponding to the broadcast wave of the IBOC hybrid FM broadcast in the signal RFS sent from the antenna 110 will be described. It is assumed that the center frequency f _j of a physical channel (hereinafter also simply referred to as “channel”) used for FM radio broadcasting is predetermined. Then, the center frequency f _j of the channel, the frequency difference between the center frequency f _j-1 or f _{j + 1} of the adjacent channel (hereinafter, also referred to as "channel spacing") is as a constant value 2 · [Delta] F ₀ To do.

Center frequency f _j of the selected channel is, in the RF processing unit 120, when it is converted into a predetermined frequency F _C in the intermediate frequency band, the frequency distribution of the signal levels in the signal IFD corresponding to the hybrid broadcast, 4 As shown in That is, the analog broadcast component is included in the range of the frequency (F _C −ΔF ₁ (<ΔF ₀ )) to (F _C + ΔF ₁ ). Further, the upper component of digital broadcasting is included in the range of frequencies (F _C + ΔF ₁ ) to (F _C + ΔF ₀ ), and the lower component of digital broadcasting is frequencies (F _C −ΔF ₀ ) to (F _C − It is included in the range of ΔF ₁ ). That is, in the IBOC hybrid broadcasting including both analog broadcasting and digital broadcasting, a frequency band corresponding to three channels, that is, a channel having a center frequency f _j and upper and lower adjacent channels is used. Yes.

Next, the IBOC broadcast reception operation of the broadcast receiving apparatus 100 will be described. As a premise, the channel selection designation of the broadcasting station that is already performing the IBOC hybrid broadcasting is input to the operation input unit 180 by the user, and the channel selection command CSL corresponding to the designated desired station is RF processed. Assume that it is sent to the unit 120. Further, it is assumed that a volume adjustment designation has already been input to the operation input unit 180 by the user, and a volume adjustment command VLC corresponding to the designated volume adjustment mode has been sent to the designated volume adjustment unit 160 ( (See FIG. 1).

In this state, when a broadcast wave is received by the antenna 110, the signal RFS is sent from the antenna 110 to the RF processing unit 120. Then, in the RF processing unit 120, the signal of the desired station to be selected is converted into a signal in the intermediate frequency band. The signal IFD corresponding to the frequency conversion result is sent to the level detection unit 140 and the reproduction processing unit 150 (see FIG. 1).

Upon receiving the signal IFD, the level detection unit 140 detects the signal level of the IBOC analog broadcast component frequency band in the signal IFD and detects the signal level of the IBOC digital broadcast component frequency band in the signal IFD. Then, the level detection unit 140 sends the detection result of the signal level in the frequency band of the analog broadcast component to the control unit 190 as the analog broadcast signal level ABL, and the detection result of the signal level in the frequency band of the digital broadcast component, The digital broadcast signal level DBL is sent to the control unit 190 (see FIG. 1). In this way, the processing control unit 191 in the control unit 190 that receives the analog broadcast signal level ABL and the digital broadcast signal level DBL sent from the level detection unit 140 performs processing in the AGC processing unit 130, seek processing unit 192, and reproduction processing unit 150. Take control.

<Process control in the process control unit 191>
As shown in FIG. 5, the process control unit 191 first collects a new analog broadcast signal level ABL and digital broadcast signal level DBL in step S11, as shown in FIG. Subsequently, in step S12, the processing control section 191, the above-described (1) to calculate the value R _DA of the ratio of the analog broadcasting signal level ABL and the digital broadcasting signal level DBL.

Next, in step S13, the processing control section 191, based on the calculated values R _DA, calculates a parameter value AGC processing unit 130, the seek processing unit 192 and reproduction processing unit 150 refers. Then, the processing control unit 191 sends the calculated parameter value to the AGC processing unit 130, the seek processing unit 192, and the reproduction processing unit 150.

<Calculation of automatic gain control start level value>
The processing control unit 191 calculates an automatic gain control start level value ASV as a parameter value referred to by the AGC processing unit 130. When calculating the automatic gain control start level value ASV, the processing control unit 191 can appropriately perform automatic gain control when the signal level is such that the digital broadcast can be reproduced in the selected hybrid broadcast. Calculate possible values. For example, as the value R _DA increases, the process control unit 191 calculates a smaller value as the automatic gain control start level value ASV. Then, the processing control unit 191 sends the calculated automatic gain control start level value ASV to the AGC processing unit 130 (see FIG. 3).

In the present embodiment, the value R _DA is used in the case of the conventional IBOC standard in which the value of the ratio between the power of the analog broadcast wave and the power of the digital broadcast wave is defined as a predetermined constant value. When the value is larger than the predetermined value (hereinafter referred to as “predetermined value”), the automatic gain control start level value ASV is newly calculated. On the other hand, when the value _RDA is smaller than the default value, the automatic gain control start level value ASV is adopted as the automatic gain control start level value ASV employed in the case of the default value. Even when the value _RDA is smaller than the predetermined value, the automatic gain control start level value ASV may be newly calculated.

The AGC processing unit 130 that has received the automatic gain control start level value ASV calculated in this way sets the level of the signal IFD when the narrowband signal level NBL is equal to or higher than the automatic gain control start level value ASV sent from the control unit 190. A gain control command AGV for generating a predetermined constant value is generated and sent to the RF processing unit 120. As a result, when the signal level is such that the digital broadcast of the selected hybrid broadcast can be reproduced, the RF processing unit 120 generates a signal IFD that has been subjected to automatic gain control so as to be substantially constant. Is done.

<< Calculation of seek threshold >>
The processing control unit 191 calculates a seek threshold value SKS as a parameter value referred to by the seek processing unit 192. When calculating the seek threshold value SKS, the processing control unit 191 uses, as the seek threshold value SKS, a signal level value that does not allow the IBOC digital broadcast component to be recognized as an adjacent wave transmitted from an adjacent station in the seek operation by the seek processing unit 192. calculate. For example, as the value R _DA increases, the process control unit 191 calculates a larger value as the seek threshold value SKS. Then, the processing control unit 191 sends the calculated seek threshold value SKS to the seek processing unit 192 (see FIG. 3).

In the present embodiment, when the value _RDA is larger than the predetermined value, a seek threshold value is newly calculated. On the other hand, when the value _RDA is smaller than the default value, the seek threshold value used in the case of the default value is set as the seek threshold value SKS. The seek processing unit 192 that has received the seek threshold value SKS thus calculated ends the seek process when the analog broadcast signal level ABL is equal to or higher than the seek threshold value SKS sent from the processing control unit 191.

<< Calculation of parameter values included in automatic reception control designation ACC >>
The processing control unit 191 calculates control start signal level values for separation control, auto high cut control, and soft mute control as parameter values referred to by the automatic reception control unit 157. When calculating the control start signal level, the processing control unit 191 calculates a parameter value that can reduce the listener's uncomfortable feeling when switching between the reproduction result of the analog broadcast and the reproduction result of the digital broadcast.

Here, the higher the value R _{DA, the} lower the level of the analog broadcast component when switching between the analog broadcast playback result and the digital broadcast playback result is performed. If separation control, auto high cut control, and soft mute control are performed at the time of switching between the analog broadcast playback result and the digital broadcast playback result, the listener feels uncomfortable. To reduce the discomfort of such listener, the processing control section 191, the larger the value R _DA, separation control, so that each of the control start signal level value of the auto high-cut control and soft mute control becomes low.

The process control unit 191 sends the automatic reception control designation ACC designating the control start signal level value thus calculated to the automatic reception control unit 157 (see FIG. 2). The automatic reception control unit 157 that has received the automatic reception control designation ACC sent from the processing control unit 191 is when the analog broadcast signal level ABL is equal to or lower than the control start signal level value designated by the automatic reception control designation ACC. , Separation control, auto high cut control and soft mute control.

<< Calculation of switching error frequency, minimum switching cycle time, adjustment level and switching transition time >>
The processing control unit 191 calculates a switching error frequency SWR and a minimum switching cycle time SWT as parameter values referred to by the data error monitoring unit in the digital broadcast processing unit 152. Further, the process control unit 191 calculates the adjustment level BLL and the switching transition time BLS as parameter values that the blend processing unit 153 refers to. When calculating the parameter value, the processing control unit 191 calculates a parameter value that can reduce the listener's uncomfortable feeling when switching between the reproduction result of the analog broadcast and the reproduction result of the digital broadcast.

The calculation algorithm is determined in advance based on experiments, simulations, experiences, and the like from the viewpoint of reducing the listener's uncomfortable feeling. In the present embodiment, the processing control unit 191 internally stores a table in which the value R _{DA is associated} with the previously determined switching error frequency, minimum switching cycle time, adjustment level, and switching transition time control. Has to have.

The processing control unit 191 sends the calculated switching error frequency SWR and the minimum switching cycle time SWT to the digital broadcast processing unit 152. Further, the process control unit 191 sends the calculated adjustment level BLL and switching transition time BLS to the blend processing unit 153 (see FIG. 2).

The data error monitoring unit in the digital broadcast processing unit 152 that has received the switching error frequency SWR and the minimum switching cycle time SWT calculated in this way monitors the data error in the OFDM demodulated signal, and the data error frequency in the OFDM demodulated signal is the switching error. By determining whether or not the frequency is SWR or higher, it is determined whether or not digital broadcast reproduction is appropriate. Then, when the result of the determination changes, the data error monitoring unit quickly switches the content of the blend flag BLF when the switching transition time specified by the minimum switching cycle time SWT has elapsed.

Receiving the calculated adjustment level BLL and switching transition time BLS, the blend processing unit 153 converts the level of the signal ABD sent from the analog broadcast processing unit 151 and the level of the signal DBD sent from the digital broadcast processing unit 152 to the adjustment level BLL. Adjust according to Also, the blend processing unit 153 switches the switching transition time BLS when switching the selection signal from the signal ABD to the signal DBD or switching the selection signal from the signal DBD to the signal ABD when the content of the blend flag BLF is switched. In this period length, the level of the signal before switching is gradually lowered and the level of the signal after switching is gradually increased. Then, the blend processing unit 153 completes the selection signal switching at the end of the period.

The reproduction processing unit 150 whose processing is controlled by the processing control unit 191 as described above generates a signal BPD based on the signal IFD sent from the RF processing unit 120. When generating the signal BPD, the analog broadcast processing unit 151 that has received the signal IFD detects the signal IFD by the detection unit 156 and the automatic reception control process by the automatic reception control unit 157 based on the automatic reception control designation ACC. , And the stereo demodulation processing by the stereo demodulation unit 158 is sequentially performed to generate the signal ABD. Then, the analog broadcast processing unit 151 sends the generated signal ABD to the blend processing unit 153 (see FIG. 2).

In addition, the digital broadcast processing unit 152 that has received the signal IFD sent from the RF processing unit 120 sequentially performs OFDM demodulation processing by the OFDM demodulation unit and decoding processing by the decoding unit on the signal IFD, so that the signal DBD Is generated. Then, the digital broadcast processing unit 152 sends the generated signal DBD to the blend processing unit 153 (see FIG. 2).

In addition, the digital broadcast processing unit 152 monitors a data error in the OFDM demodulated signal. Then, the digital broadcast processing unit 152 indicates whether or not the digital broadcast reproduction is appropriate based on the monitoring result and the switching error frequency SWR and the minimum switching cycle time SWT specified by the processing control unit 191. A flag BLF is generated and sent to the blend processing unit 153 (see FIG. 2).

The blend processing unit 153 that has received the signal ABD, the signal DBD, and the blend flag BLF performs blend processing based on the content of the blend flag BLF and the adjustment level BLL and switching transition time BLS specified by the processing control unit 191. . Then, the blend processing unit 153 sends the result of the blend process to the designated volume adjustment unit 160 (see FIG. 2).

In the designated volume adjustment unit 160 that has received the signal BPD sent from the reproduction processing unit 150, the DA conversion unit, the volume adjustment unit, and the power amplification unit sequentially process to generate the output audio signal AOS, and the speaker unit 170. (See FIG. 1). Then, the speaker unit 170 reproduces and outputs sound in accordance with the output sound signal AOS from the designated volume adjustment unit 160.

Next, the seek process performed by the seek processor 192 will be described. The seek processing unit 192 starts upon receiving a seek command SSK sent from the channel selection volume control unit 193 when the content of the operation input data IPD is seek designation.

In the seek process thus started, first, the seek processing unit 192 selects a broadcast channel adjacent in the designated frequency direction to the broadcast channel to which the center frequency of the selected IBOC hybrid broadcast station belongs. The next station request CSN is sent to the channel selection volume control unit 193. As a result, the channel selection volume control unit 193 generates a channel selection command CSL for selecting a broadcast channel adjacent to the selected broadcast channel in the designated frequency direction, and sends it to the RF processing unit 120. As a result, the analog broadcast signal level ABL for the newly selected broadcast channel is detected and sent to the seek processor 192.

Subsequently, the seek processing unit 192 determines whether or not the analog broadcast signal level ABL for the newly selected broadcast channel is greater than or equal to the seek threshold value SKS specified by the processing control unit 191. If the result of this determination is negative, the seek processing unit 192 sends a new next station request CSN to the channel selection volume control unit 193. Then, the seek processing unit 192 continues along the frequency direction specified by the seek command SSK until the analog broadcast signal level ABL related to the selected broadcast channel is equal to or higher than the seek threshold value SKS specified by the processing control unit 191. Repeated selection of broadcast channels.

When the analog broadcast signal level ABL related to the selected broadcast channel becomes equal to or higher than the seek threshold value SKS by the sequential selection, the seek processing unit 192 sends a seek end report STP to the channel selection volume control unit 193. Then, the seek process ends.

As described above, in the present embodiment, in the IBOC hybrid broadcast reception process in which analog broadcast and digital broadcast are simultaneously performed, the signal in the frequency band corresponding to the analog broadcast of the broadcast signal corresponding to the channel selection command CSL A level ABL and a signal level DBL in a frequency band corresponding to digital broadcasting are detected. Subsequently, the processing control unit 191 determines the AGC processing unit 130, seek processing unit 192, automatic reception control unit 157, digital broadcast processing unit 152, and blend processing unit 153 based on the value of the ratio between the signal level ABL and the signal level DBL. A parameter value for controlling the processing in each of the above is calculated. Then, the processing control unit 191 controls the reception process in each processing unit by sending the calculated parameter value to the corresponding processing unit.

Therefore, according to this embodiment, it is possible to appropriately control the reception processing of the IBOC hybrid broadcast.

[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, in response to the ratio value R _DA with analog broadcasting signal level ABL and the digital broadcasting signal level DBL for each hybrid broadcast is tuned, so as to calculate an automatic gain control start level value ASV I made it. On the other hand, when the upper limit value of the value _RDA is determined in the standard to which the hybrid broadcasting complies, the value corresponding to the upper limit value is fixedly adopted as the automatic gain control start level value ASV. You may do it.

In the above embodiment, corresponding to the value R _DA of the ratio of the analog broadcasting signal level ABL and the digital broadcasting signal level DBL for each hybrid broadcast is tuned, and to calculate the seek threshold SKS. On the other hand, when the upper limit value of the value _RDA is defined in the standard to which the hybrid broadcasting complies, the value corresponding to the upper limit value may be fixedly adopted as the seek threshold value SKS. Good.

In the above embodiment, the automatic reception control process is performed based on the analog broadcast signal level ABL. However, the automatic reception control process is performed in consideration of the noise level in the frequency band of the analog broadcast component in the signal IFD. You may make it perform.

In the above embodiment, the present invention is applied to the broadcast reception control processing of the IBOC hybrid broadcast. However, the present invention can of course be applied to other types of simultaneous broadcast.

In addition, a part or all of the control unit is configured as a computer as a calculation unit including a central processing unit (CPU: Central Processing Unit), and the program prepared in advance is executed by the computer. The function of the control unit in the embodiment may be realized. 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 distributed via a network such as the Internet. Also good.

Claims

A broadcast receiving device that receives a broadcast signal of a simulcast where analog broadcast and digital broadcast are performed simultaneously,
A front end unit that converts a broadcast signal corresponding to the channel selection command into an intermediate frequency signal that is a signal in an intermediate frequency band;
A first detector for detecting a signal level of a first frequency band corresponding to the analog broadcast in the intermediate frequency signal;
A second detector for detecting a signal level of a second frequency band corresponding to the digital broadcast in the intermediate frequency signal;
Corresponding to at least one of the difference due to the difference in the selected broadcasting station of the ratio value between the detection result by the first detection unit and the detection result by the second detection unit, and the time change of the ratio value A processing control unit for controlling reception processing;
A broadcast receiving apparatus comprising:
An automatic gain controller for adjusting the level of the intermediate frequency signal;
The processing control unit controls level adjustment by the automatic gain control unit based on the value of the ratio.
The broadcast receiving apparatus according to claim 1.
The automatic gain control unit performs the level adjustment based on a detection result of a signal level of the broadcast wave of the analog broadcast,
The processing control unit determines an adjustment start value at which the automatic gain control unit starts the level adjustment based on the value of the ratio, and designates the determined adjustment start value to the automatic gain control unit. To
The broadcast receiving apparatus according to claim 2.
The simulcast is a broadcast that uses one broadcast channel among a plurality of broadcast channels prepared at predetermined frequency intervals and two other broadcast channels that are adjacent to the left and right of the one broadcast channel on the frequency axis. Yes,
The broadcast channel adjacent to the broadcast channel to which the center frequency of the broadcast wave transmitted from the currently selected simulcast station belongs in the specified frequency direction is the departure broadcast channel, and the signal power of the selected broadcast channel is greater than or equal to the specified power. A seek processor that sequentially selects broadcast channels along the designated frequency direction until
The processing control unit specifies the value of the designated power determined based on the value of the ratio to the seek processing unit;
The broadcast receiving apparatus according to any one of claims 1 to 3, wherein
A first reproduction processing unit for performing analog broadcast reproduction processing on the signal component of the first frequency band;
The first reproduction processing unit includes an automatic reception control unit that performs signal processing on the detection result of the signal component of the first frequency band,
The processing control unit specifies a start condition of the signal processing determined based on the value of the ratio to the automatic reception control unit;
The broadcast receiving apparatus according to any one of claims 1 to 4, wherein:
6. The broadcast receiving apparatus according to claim 5, wherein the signal processing performed by the automatic reception control unit includes high cut control processing for attenuating a high frequency component.
The simulcast is a stereo audio broadcast,
The broadcast processing according to claim 5 or 6, wherein the signal processing performed by the automatic reception control unit includes a separation control process for controlling a degree of separation into a left channel audio signal and a right channel audio signal. Receiver device.
A first reproduction processing unit that performs analog broadcast reproduction processing on the signal component of the first frequency band;
A second reproduction processing unit that performs digital broadcast reproduction processing on the signal component of the second frequency band;
A blend processing unit that performs a switching process between a processing result by the first reproduction processing unit and a processing result by the second reproduction processing unit according to a value of the first switching control parameter;
The second regeneration processing unit switches between execution and non-execution of the regeneration operation according to the value of the second switching control parameter,
The processing control unit designates the value of the first switching control parameter determined based on the value of the ratio to the blend processing unit, and the second determined based on the value of the ratio. A value of a switching control parameter is designated for the second reproduction processing unit.
The broadcast receiving apparatus according to any one of claims 1 to 7, wherein:
The first switching control parameter includes a switching transition time and an adjustment level value of a processing result by the second reproduction processing unit,
The second switching control parameter includes a switching error frequency and a minimum switching cycle time.
The broadcast receiving apparatus according to claim 8.
A broadcast receiving device that includes a front end unit that converts a broadcast signal corresponding to a channel selection command into an intermediate frequency signal that is a signal in an intermediate frequency band, and that receives a broadcast signal of a simulcast that simultaneously performs analog broadcast and digital broadcast Broadcast reception processing control method used in
A first detection step of detecting a signal level of a first frequency band corresponding to the analog broadcast in the intermediate frequency signal;
A second detection step of detecting a signal level of a second frequency band corresponding to the digital broadcast in the intermediate frequency signal;
Corresponding to at least one of the difference between the detected value in the first detection step and the detection result in the second detection step due to the difference in the selected broadcasting station, and the time change of the ratio value A control process for controlling reception processing;
A broadcast reception processing control method comprising:
A broadcast reception processing control program for causing a calculation unit to execute the broadcast reception processing control method according to claim 10.
12. A recording medium, wherein the broadcast reception processing control program according to claim 11 is recorded so as to be readable by a calculation unit.