Receiving device, broadcasting system, and receiving method

Abstract

To provide a receiving device, a broadcasting system, and a receiving method that encourage configuration of an antenna capable of ensuring reception quality.SOLUTION: When injection level information indicating an injection level is obtained from a reception signal carrying a data signal and a control signal, antenna level information including notification information indicating transmission of low-power hierarchy signals is output to an output unit. The low-power hierarchy signals are multiplexed in a hierarchy at a signal level lower than that of high-power hierarchy signals in the data signal, and the injection level has a level width of the high-power hierarchy signals.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a receiving device, a broadcasting system, and a receiving method. [Background technology]

[0002] In next-generation terrestrial digital television broadcasting services (hereinafter referred to as "next-generation broadcasting"), the use of Layered Division Multiplexing (LDM) to multiplex multiplex multiplexing signals of multiple formats is being considered. Here, it is being considered to assign the broadcast signal of 2K broadcasting using ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) (hereinafter referred to as "2K signal") and the broadcast signal of 4K broadcasting planned for adoption in next-generation broadcasting (hereinafter referred to as "4K signal") to different signal level layers and multiplex them within the same bandwidth for broadcasting. ISDB-T is a broadcasting format that has been used in terrestrial digital television broadcasting for a long time. 2K broadcasting is a broadcasting format that is used in existing high-definition television (HDTV) broadcasting services. To ensure compatibility between existing 2K broadcasting and next-generation broadcasting, as illustrated in Figure 5, it is being considered to assign 2K signals to the high-power layer (UL: Upper Layer) with a high signal level (output level) and 4K signals to the low-power layer (LL: Lower Layer) with a low signal level during multiplexing.

[0003] The 2K signal assigned to UL is modulated using the OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme defined in ARIB STD-B31 and carried using broadcast waves. ARIB STD-B31 is a standard that defines the transmission method for terrestrial digital television broadcasting based on the ISDB-T system. The 2K signal is constructed by multiplexing data (data signal) that carries audio, video, etc., with a reference signal (pilot signal for synchronous playback) and control signals (TMCC (Transmission and Multiplexing Configuration Control) signal / AC (Auxiliary Channel) signal). The 4K signal assigned to LL is modulated using a predetermined modulation scheme (e.g., OFDM). Patent Document 1 describes a method in which the reference signal and control signals added to the data signal are null.

[0004] Existing 2K broadcast-dedicated receiving equipment (hereinafter referred to as "2K receiving equipment") capable of receiving the above 2K signal can demodulate the 2K signal by treating the low-power components contained in the received signal as noise. A receiving device capable of receiving next-generation broadcasts (hereinafter referred to as a "4K-compatible receiving device") can demodulate the signal assigned to UL (hereinafter sometimes referred to as the "UL signal") from the received data signal as a 2K signal using the same method as a 2K receiving device. The 4K-compatible receiving device can subtract the 2K signal from the received signal and extract the signal assigned to LL (hereinafter sometimes referred to as the "LL signal") as a 4K signal. The 4K-compatible receiving device can also provide 2K broadcasts using the extracted 2K signal. The ratio of the signal levels of the UL signal and the LL signal (hereinafter referred to as the "level ratio") is called the injection level (IL). This injection level corresponds to the signal level ratio of the UL signal. For a 2K receiving device, the IL is approximately equivalent to the C / N (Carrier-to-Noise Ratio) at the transmission point. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-184666 [Patent Document 2] Japanese Patent Publication No. 2002-124931 [Patent Document 3] Japanese Patent Publication No. 2020-150521 [Overview of the project] [Problems that the invention aims to solve]

[0006] Generally, under the same ambient noise level, the C / N measured in the receiving device decreases as the IL increases. Under the same IL, the C / N decreases as the ambient noise level increases. Receiving devices are required to display the antenna level value to facilitate antenna installation when adjusting the direction of the antenna for receiving broadcast waves, in accordance with ARIB TR B-14. As an example, one method of displaying the antenna level is to use twice the value of the input carrier's C / N (dB, 5.6MHz bandwidth) as an approximate conversion value. Therefore, the receiving device needs a function to determine the C / N of the signal component carrying the input carrier. Here, ambient noise includes external noise that does not include LL signals, and noise generated within the receiver. In the above-mentioned C / N, N indicates the level of ambient noise.

[0007] Patent Document 2 describes a measuring device for measuring the C / N of broadcast signals broadcast using the ISDB-T system. This measuring device is capable of measuring the C / N of data signals from A, B, and C layers, which have different frequencies, as well as the C / N of special subcarriers (TMCC signals and AC signals). Recent receiving devices have a C / N measurement function, and there are two types of demodulation chips for this purpose: one that measures only the C / N of data signals, and another that measures only the C / N of TMCC and AC signals. The device that measures the C / N of data signals obtains a noise level (mixed noise level) by adding the amount of LL signal considered as noise to the ambient noise component. Therefore, when broadcasting with multiplexed LL signals begins, the antenna level value, which was calculated from the ratio of ambient noise component to data carrier as in conventional receiving devices, cannot be obtained with this demodulation chip. Thus, because the meaning of the antenna level value differs depending on the demodulation chip used, even if the antenna is set up so that the antenna level value is a certain target value, there is a risk that the expected reception quality will not be obtained. [Means for solving the problem]

[0008] The present invention has been made to solve the above problems, and one aspect of the present invention is a receiving device comprising a receiving processing unit that outputs antenna level information including notification information indicating the transmission of a low-power hierarchical signal to an output unit when injection level information indicating the injection level is obtained from a received signal that carries a data signal and a control signal, wherein the low-power hierarchical signal is multiplexed in the data signal to a hierarchical level with a signal level lower than that of the high-power hierarchical signal, and the injection level is the level ratio of the high-power hierarchical signal and the low-power hierarchical signal. [Effects of the Invention]

[0009] According to an embodiment of the present invention, it is possible to prompt the user to set up an antenna that can ensure reception quality using the same criteria before and after the start of broadcasting with multiplexed LL signals. [Brief explanation of the drawing]

[0010] [Figure 1] It is a schematic block diagram showing a functional configuration example of the broadcast system according to the present embodiment. [Figure 2] It is a schematic block diagram showing a functional configuration example of the broadcast device according to the present embodiment. [Figure 3] It is a schematic block diagram showing a functional configuration example of the receiving device according to the present embodiment. [Figure 4] It is an explanatory diagram showing reception examples of 2K signals and 4K signals transmitted using the LDM method. [Figure 5] It is an explanatory diagram exemplifying the hierarchical structure of data signals. [Figure 6] It is a diagram showing a first example of the antenna setting screen according to the present embodiment. [Figure 7] It is a diagram showing a second example of the antenna setting screen according to the present embodiment. [Figure 8] It is a diagram showing a third example of the antenna setting screen according to the present embodiment. [Figure 9] It is a diagram showing a fourth example of the antenna setting screen according to the present embodiment. [Figure 10] It is an explanatory diagram exemplifying symbol arrangement. [Figure 11] It is an explanatory diagram exemplifying bit allocation to the TMCC carrier. [Figure 12] It is a flowchart showing a first example of the reception processing according to the present embodiment. [Figure 13] It is a flowchart showing a second example of the reception processing according to the present embodiment. [Figure 14] It is a flowchart showing a third example of the reception processing according to the present embodiment. [Figure 15] It is a flowchart showing a fourth example of the reception processing according to the present embodiment. [Figure 16] It is a diagram showing a description example of IL information in the LDM transmission descriptor.

Mode for Carrying Out the Invention

[0011] Embodiments of the present invention will be described below with reference to the drawings. First, an overview of the broadcasting system 1 according to this embodiment will be described. Figure 1 is a schematic block diagram showing an example of the functional configuration of the broadcasting system 1 according to this embodiment. Broadcasting system 1 consists of a broadcasting device 10 and a receiving device 20. In the example in Figure 1, there is one receiving device 20, but generally there can be multiple.

[0012] The broadcasting device 10 transmits a broadcast signal that includes a data signal multiplexed using the LDM method. The broadcasting device 10 generates a broadcast signal by multiplexing a data signal, a reference signal, and a control signal. The data signal is a signal that carries the content data of the broadcast program. The data signal is formed by multiplexing signals of multiple layers for different signal level ranges. In the following description, as illustrated in Figure 5, the case in which a group of data signals is constructed by multiplexing two layers of signals with different signal levels according to the LDM method is mainly considered. Of the two layers of signals, the signal assigned to UL, which is the layer with the higher signal level, corresponds to the "high-power layer signal," and the signal assigned to LL, which is the layer with the lower signal level, corresponds to the "low-power layer signal." The control signal is a signal for controlling the reception of the broadcast signal in the receiving device 20. As described in Patent Document 3, IL information indicating IL may be transmitted, for example, by including it in the TMCC signal of the control signal. The broadcasting device 10 sends the broadcast signal generated using a predetermined broadcasting method to the broadcasting transmission path BT. Furthermore, the broadcasting method for high-power hierarchical signals may differ from the broadcasting method for low-power hierarchical signals. For example, the broadcasting device 10 assigns a 1st tier signal based on the ISDB-T method to UL and generates a transmission signal as a high-power hierarchical signal. If only one signal is provided to the broadcasting device 10, the broadcast signal may be transmitted using the LDM method without multiplexing it with the low-power hierarchical signal.

[0013] The broadcast transmission path BT is a transmission path that transmits broadcast signals unidirectionally to an unspecified number of destinations to the receiving device 20. The broadcast transmission path BT is typically composed of broadcast waves in a predetermined frequency band. The broadcast transmission path BT may also include a communication network as part of its configuration. Such a communication network may be any type of network, such as the Internet, a public wireless network, a local area network, or a dedicated line.

[0014] When the receiving device 20 is not transmitting data signals for LL based on the LDM method (until transmission begins), it receives data signals assigned to UL without multiplexing using the ISDB-T method. When data signals based on the LDM method are transmitted, the receiving device 20 receives data signals including low-power hierarchical signals assigned to LL. The receiving device 20 receives broadcast signals transmitted on the broadcast transmission path BT as received signals. The receiving device 20 separates data signals, reference signals, and control signals from the received signals. The receiving device 20 monitors the control signals or data signals and determines whether or not IL information indicating IL is acquired. When IL information is acquired, the receiving device 20 generates notification information indicating that low-power hierarchical signals are being transmitted and antenna level information indicating the reception status of the data signal, and outputs these. For example, the receiving device calculates the C / N of the data signal and generates antenna level information based on the mixed noise level based on the calculated C / N and the ambient noise level calculated using IL. The receiving device may calculate the C / N of the control signal and generate antenna level information based on the mixed noise level calculated using the ambient noise level based on the calculated C / N and the IL.

[0015] The broadcasting equipment 10 may be equipment that constitutes business equipment used by businesses such as broadcasters and content distributors. The receiving equipment 20 may be user equipment mainly used by general users. The receiving equipment 20 may be a dedicated television receiving device, recording device, set-top box, etc., or it may be an electronic device that does not have receiving as its primary function, as long as it has the function of receiving television broadcasts. The receiving equipment 20 may be, for example, a multifunction mobile phone (smartphone), a tablet device, a personal computer (PC), etc.

[0016] High-power tier signals transmit content related to general-purpose services. Low-power tier signals transmit, for example, content with a higher service level than high-power tier signals, or information to improve the service level related to high-power tier signals. In the following explanation, we will mainly consider the case where the first broadcast signal and the second broadcast signal are applied as high-power tier signals and low-power tier signals, respectively, as shown in Figure 4. The signal level of the transmitted signal is sometimes called the "output level," and the signal level of the received signal is sometimes called the "received level" to distinguish them.

[0017] Next, an example of the functional configuration of the broadcasting device 10 according to this embodiment will be described. Figure 2 is a schematic block diagram showing an example of the functional configuration of the broadcasting device 10 according to this embodiment. The broadcasting device 10 is composed of a first broadcast signal acquisition unit 122, a second broadcast signal acquisition unit 124, a level adjustment unit 126, a hierarchical multiplexing unit 128, a frame configuration unit 130, a modulation unit 132, and a transmission unit 134.

[0018] The first broadcast signal acquisition unit 122 acquires a first broadcast signal. The first broadcast signal consists of a first data carrier symbol in a first frequency band based on a first broadcasting system. For example, a 2K signal is acquired as the first broadcast signal. For example, the ISDB-T system is used as the first broadcasting system. For example, data packets are input to the first broadcast signal acquisition unit 122 from outside the broadcasting device 10, and the input data packets are converted into a first data carrier symbol. The data packets may be, for example, TS (Transport Stream) packets as defined in MPEG-2 Systems, or MMT packets as defined in MMT (MPEG Media Transport). The first broadcast signal acquisition unit 122 performs error correction coding, interleaving, and mapping on the input data packets to generate a first data carrier symbol. In error correction coding, the first broadcast signal acquisition unit 122 generates, for example, Reed-Solomon codes. The first broadcast signal acquisition unit 122, in interleaving, rearranges the order of the error-corrected encoded bit data in a predetermined order according to the broadcasting scheme for the first broadcast signal. In mapping, the first broadcast signal acquisition unit 122 converts the rearranged bit data into IQ (In-phase Quadrature-phase) coordinates of signal points according to a predetermined modulation scheme and coding rate, and defines symbols to represent the converted IQ coordinates. For example, the first broadcast signal acquisition unit 122 uses 64QAM (Quadrature Amplitude Modulation) as the modulation scheme and sets the coding rate to 3 / 4. The first broadcast signal acquisition unit 122 outputs the first data carrier symbol to the hierarchical multiplexing unit 128.

[0019] The second broadcast signal acquisition unit 124 acquires the second broadcast signal. The second broadcast signal consists of a second data carrier symbol in a second frequency band based on the second broadcasting system. For example, a 4K signal is acquired as the second broadcast signal. For example, the advanced terrestrial broadcasting system is used as the second broadcasting system. The second broadcast signal acquisition unit 124 performs error correction coding, interleaving, and mapping on data packets input from outside the broadcasting device 10 to convert them into a second data carrier symbol. In error correction coding, the second broadcast signal acquisition unit 124 generates, for example, a BCH (Bose Chaudhuri Hocquenghem) code as the outer code and an LDPC (Low Density Parity Check) code as the inner code. In interleaving, the second broadcast signal acquisition unit 124 rearranges the order of the error-corrected coded bit data to a predetermined order according to the broadcasting system for the second broadcast signal. The second broadcast signal acquisition unit 124 converts the reordered bit data into IQ coordinates of signal points according to a predetermined modulation scheme and coding rate, and defines symbols to represent the converted IQ coordinates. The second broadcast signal acquisition unit 124 may perform mapping with a lower coding rate than the first broadcast signal. This increases resistance to noise. For example, the second broadcast signal acquisition unit 124 may use 64QAM, 1 / 2, 16QAM, and 1 / 2 as a set of modulation scheme and coding rate. The second broadcast signal acquisition unit 124 outputs the second data carrier symbol to the level adjustment unit 126.

[0020] Furthermore, the bandwidth of the second frequency band is wider than the bandwidth of the first frequency band, and the second frequency band may include the first frequency band. The first frequency band is the band in which the first and second data carriers are multiplexed (hereinafter sometimes referred to as the "LDM band"). The part of the second frequency band that does not include the first frequency band is sometimes referred to as the "non-LDM band".

[0021] The level adjustment unit 126 adjusts the amplitude of the second data carrier symbol input from the second broadcast signal acquisition unit 124 so that it is lower than the output level of the second data carrier by a level difference corresponding to the IL. The level adjustment unit 126 outputs the second data carrier with the adjusted amplitude to the hierarchical multiplexing unit 128. The hierarchical multiplexing unit 128 multiplexes the data carrier symbols input from the first broadcast signal acquisition unit 122 according to the LDM method, such that the first data carrier symbol input from the first broadcast signal acquisition unit 122 is assigned to UL and the second data carrier symbol input from the level adjustment unit 126 is assigned to LL. The hierarchical multiplexing unit 128 adjusts the amplitude of the data carriers so that the output level of the data signals forming the multiplexed data carriers becomes a predetermined signal level C. The hierarchical multiplexing unit 128 outputs the amplitude-adjusted data carrier symbols to the frame constructor unit 130. The first broadcast signal represented by the first data carrier symbol is multiplexed as a high-power hierarchical signal, and the second broadcast signal represented by the second data carrier symbol is multiplexed as a low-power hierarchical signal.

[0022] The frame structuring unit 130 receives data carrier symbols from the hierarchical multiplexing unit 128, assigns them to the data carrier, and constructs an OFDM frame having a reference carrier that forms a reference signal and a control carrier that forms a control signal. The reference carrier includes, for example, an SP (Scattered Pilot) carrier. The control carrier includes, for example, a TMCC carrier, an AC (Auxiliary Channel), etc. The frame structuring unit 130 assigns the data carrier, reference carrier, and control carrier, each acquired according to a predetermined symbol arrangement for each predetermined period, to the carrier symbol positions, thereby constructing a transmission signal for each frame. The symbol arrangement indicates the assignment of each type of symbol to each of the multiple carrier symbol positions in a predetermined period and frequency band. Each carrier symbol position is indicated by a pair of channel (frequency) and symbol (time), which are units of transmission resources. The frame structuring unit 130 outputs the broadcast signal constructed for each frame to the modulation unit 132. As a reference signal, for example, a 15th-order M sequence, which is a type of pseudorandom number sequence, is used. IL information may be transmitted using a TMCC carrier that constitutes a TMCC signal.

[0023] In the LDM band, the SP carrier, TMCC carrier, and AC carrier are placed at common carrier symbol positions for the first and second data carriers. The SP carrier, TMCC carrier, and AC carrier added to the second data carrier may each be set to null. Since other signals are not substantially multiplexed onto the SP carrier, TMCC carrier, and AC carrier added to the first data carrier, degradation of characteristics is prevented. In the non-LDM band, the carrier symbol positions for the SP carrier, TMCC carrier, and AC carrier may be set independently for the second data carrier.

[0024] The modulation unit 132 receives the broadcast signal from the frame building unit 130 and outputs the modulated broadcast signal to the transmission unit 134 using a predetermined modulation scheme. As the predetermined modulation scheme, the modulation unit 132 can use, for example, the OFDM (Orthogonal Frequency Division Multiplexing) scheme.

[0025] The transmitter 134 sends the broadcast signal input from the modulation unit 132 to the broadcast transmission line BT. When a broadcast wave is used as the broadcast transmission line BT, the transmitter 134 upconverts the input baseband broadcast signal to a broadcast signal in the frequency band corresponding to the broadcast channel, and supplies the upconverted broadcast signal to the antenna. The antenna radiates a broadcast wave that carries the broadcast signal. If the second broadcast signal is not acquired, the data signal will include the first broadcast signal and be assigned to UL. In that case, the IL information will not be carried by the broadcast signal.

[0026] Next, an example of the functional configuration of the receiving device 20 according to this embodiment will be described. Figure 3 is a schematic block diagram showing an example of the functional configuration of the receiving device 20 according to this embodiment. In the following description, the case in which the receiving device 20 is a 4K-compatible receiving device will be used as an example. However, by omitting the function of the second decoding unit 218 and the receiving processing unit 230 to present the content of the broadcast program transmitted by the second broadcast signal, it can also function as a 2K receiving device.

[0027] The receiving device 20 comprises a receiving unit 212, a demodulation unit 214, a first decoding unit 216, a second decoding unit 218, a multiplexed signal separation unit 222, a noise estimation unit 224, and a receiving processing unit 230. Parts of the receiving device 20, such as the first decoding unit 216, the second decoding unit 218, and the noise estimation unit 224, or all or part of them, may be configured with a dedicated integrated circuit (chip). Furthermore, the integrated circuit forming the noise estimation unit 224 may have the functions of all or part of the other functional units, such as the receiving unit 212, the demodulation unit 214, the first decoding unit 216, the second decoding unit 218, and the multiplexed signal separation unit 222. The receiving device 20 may also include a processor, which may perform the functions of the receiving processing unit 230 by executing processes instructed by instructions written in a predetermined program.

[0028] The receiving unit 212 receives broadcast signals transmitted via the broadcast transmission path BT as received signals. When broadcast waves are used as the broadcast transmission path BT, the receiving unit 212 downconverts the frequency band of the broadcast signal based on the broadcast waves received using the antenna from the frequency band corresponding to the broadcast channel to the base band. The broadcast channel is notified using tuning information input from the receiving processing unit 230. The receiving unit 212 outputs the downconverted received signal to the demodulation unit 214. The receiving unit 212 includes, for example, a tuner.

[0029] The demodulation unit 214 demodulates the received signal input from the receiving unit 212 using a predetermined demodulation method. The predetermined demodulation method can be any demodulation method corresponding to the modulation method used for modulating the broadcast signal in the modulation unit 132. The demodulation unit 214 identifies the carrier symbol positions of data symbols, control symbols, and reference symbols using a predetermined assignment setting, and separates them into data signals, control signals, and reference signals. Specific examples of the assignment setting will be described later. The demodulation unit 214 outputs the separated data signals and control signals to the first decoding unit 216 and the second decoding unit 218.

[0030] The first decoding unit 216 decodes the data signal, TMCC signal, and AC signal input from the demodulation unit 214. The first decoding unit 216 comprises a demapping unit 216a, a deinterleaving unit 216b, and an error correction decoding unit 216c, and performs the following processing on the data signal, TMCC signal, and AC signal. The demapping unit 216a performs demapping on the first broadcast signal, i.e., the signal corresponding to the high-power hierarchical signal. The demapping unit 216a converts the IQ coordinates of the signal points represented by symbols constituting the signal into bit data using a demapping method corresponding to the mapping method used for mapping the first broadcast signal, and outputs it to the deinterleaving unit 216b. At this stage, components of the second broadcast signal are removed as noise. The demapping unit 216a also calculates the MER (Modulation Error Ratio) on the data signal or control signal using a known method, and outputs the calculated MER to the noise estimation unit 224. MER is an index value that indicates the magnitude of fluctuation from a predetermined reference value in the value of a symbol representing a signal.

[0031] The deinterleaving unit 216b performs deinterleaving on the bit data input from the demapping unit 216a, rearranging the order of the bit data. In the deinterleaving process, the deinterleaving unit 216b changes the order of the converted bit data to match the order of the bit data representing the first broadcast signal before interleaving. The deinterleaving unit 216b outputs the rearranged bit data to the error correction decoding unit 216c.

[0032] The error correction decoding unit 216c performs error correction decoding on the reordered bit data input from the deinterleaving unit 216b to obtain the first broadcast signal. In error correction decoding, the error correction decoding unit 216c uses an error correction decoding method corresponding to the error correction coding method used for error correction coding of the first broadcast signal in the broadcasting device 10. The error correction decoding unit 216c outputs the decoded first broadcast signal to the second decoding unit 218 and the multiplex signal separation unit 222.

[0033] The second decoding unit 218 decodes the second broadcast signal from the received signal input from the demodulation unit 214 and the first broadcast signal input from the first decoding unit 216. The second decoding unit 218 includes an error correction coding unit 218a, an interleaving unit 218b, a mapping unit 218c, a multiplication unit 218d, a delay unit 218e, a subtraction unit 218f, a demapping unit 218g, a deinterleaving unit 218h, and an error correction decoding unit 218i.

[0034] The error correction coding unit 218a performs error correction coding on the first broadcast signal input from the error correction decoding unit 216c and outputs the obtained bit data to the interleaving unit 218b. In error correction coding, the error correction coding unit 218a uses the error correction coding scheme used for error correction coding on the first broadcast signal in the broadcasting device 10.

[0035] The interleaving unit 218b rearranges the bit data input from the error correction coding unit 218a in the same order as the bit data based on the first broadcast signal in the broadcasting device 10. The interleaving unit 218b outputs the rearranged bit data to the mapping unit 218c.

[0036] The mapping unit 218c converts the reordered bit data input from the interleaving unit 218b into IQ coordinates of signal points corresponding to the modulation scheme and coding rate similar to those used for mapping the first broadcast signal in the broadcasting device 10, and defines symbols to represent the converted IQ coordinates. The mapping unit 218c outputs a first data carrier symbol consisting of the defined symbols to the multiplication unit 218d.

[0037] The multiplier unit 218d multiplies the first data carrier symbol input from the mapping unit 218c by the power ratio and outputs the power-adjusted first data carrier symbol to the subtraction unit 218f. The power ratio is set to be the ratio of the power of the received signal input from the delay unit 218e to the power of the first data carrier symbol output from the mapping unit 218c. This makes the power of the first data carrier symbol equal to the power of the received signal.

[0038] The delay unit 218e delays the time it outputs to the subtraction unit 218f relative to the received signal input from the demodulation unit 214. The delay time relative to the received signal corresponds to the time required from the time the received signal is supplied to the demapping unit 216a until the time the first data carrier symbol is input via the deinterleaving unit 216b, error correction decoding unit 216c, error correction coding unit 218a, interleaving unit 218b, mapping unit 218c, and multiplication unit 218d. As a result, the received signal from the demodulation unit 214 and the first data carrier symbol from the multiplication unit 218d are synchronized.

[0039] The subtraction unit 218f subtracts the first data carrier symbol input from the multiplication unit 218d from the received signal input from the demodulation unit 214 to remove the component based on the first broadcast signal. The subtraction unit 218f outputs the second data carrier symbol, which forms a low-power hierarchical signal obtained by subtraction, to the demapping unit 218g.

[0040] The demapping unit 218g performs demapping on the second data carrier symbol input from the subtraction unit 218f. The demapping unit 218g converts the IQ coordinates of the signal points represented by the second data carrier symbol into bit data using a demapping method corresponding to the mapping method used for mapping to the second broadcast signal, and outputs it to the deinterleaving unit 218h.

[0041] The deinterleaving unit 218h performs deinterleaving on the bit data input from the demapping unit 218g, rearranging the order of the bit data. In the deinterleaving process, the deinterleaving unit 218h changes the order of the converted bit data to match the order of the bit data representing the second broadcast signal before interleaving. The deinterleaving unit 218h outputs the rearranged bit data to the error correction decoding unit 218i.

[0042] The error correction decoding unit 218i performs error correction decoding on the reordered bit data input from the deinterleaving unit 218h to obtain the second broadcast signal. In error correction decoding, the error correction decoding unit 218i uses an error correction decoding method corresponding to the error correction coding method used for error correction coding of the second broadcast signal in the broadcasting device 10. The error correction decoding unit 218i outputs the decoded second broadcast signal to the multiplex signal separation unit 222.

[0043] Therefore, as illustrated in Figure 4, when high-power hierarchical signals and low-power hierarchical signals are transmitted by hierarchical multiplexing, the first decoding unit 216 extracts a high-power hierarchical signal (corresponding to the 2K signal, or first broadcast signal) from the received signal, which has a level width corresponding to the IL transmitted by the control signal. As will be described later, in the receiving device 20, the low-power hierarchical signal component (corresponding to the 4K signal, or second broadcast signal) included in the high-power hierarchical signal is not successfully decoded and is considered noise. The second decoding unit 218 extracts the low-power hierarchical signal by subtracting the high-power hierarchical signal from the received signal.

[0044] The multiplexed signal separation unit 222 monitors control signals or data signals and determines whether or not they contain IL information. The multiplexed signal separation unit 222 has pre-set types and regions of signals that may contain IL information, and monitors symbols assigned to the set regions among the set types of signals. The multiplexed signal separation unit 222 can determine that a second broadcast signal is being transmitted if the control signal contains valid IL information. The reception status processing unit 234 can determine that valid IL information has been detected, for example, if it has successfully decoded a predetermined symbol to which IL information is assigned among the TMCC signals, and the IL indicated by the IL information is within a predetermined range. When valid IL information is detected, the multiplexed signal separation unit 222 can determine that the data signals included in the first broadcast signal and the data signals included in the second broadcast signal are multiplexed using the LDM method. Otherwise, the multiplexed signal separation unit 222 can determine that the data signals are not multiplexed using the LDM method. This determination is performed regardless of whether or not the receiving device 20 is a receiving device capable of providing broadcast services based on the second broadcast signal. The multiplex signal separation unit 222 separates IL information from control signals or data signals and outputs the separated IL information to the receiving processing unit 230. When it is determined that a broadcast signal is being transmitted using the LDM method, the multiplex signal separation unit 222 separates the data signal from the second broadcast signal input from the second decoding unit 218 and outputs the separated data signal to the receiving processing unit 230.

[0045] The noise estimation unit 224 calculates the C / N ratio using a portion of the received signal and outputs the calculated C / N ratio as the noise level to the receiving processing unit 230. This C / N ratio can also be considered as a normalized noise level with the signal level C of the received signal set to 1. The noise estimation unit 224 has either a first-type function or a second-type function. The first-type function calculates the C / N ratio based on the data signal as part of the received signal. As illustrated in Figure 4, in the first-type function, the low-power hierarchical signal (second broadcast signal) among the data signals separated from the first broadcast signal is considered noise, and the C / N ratio of the first broadcast signal is calculated. The second-type function calculates the C / N ratio of the first broadcast signal based on the control signals included in the first broadcast signal as part of the received signal. Either the TMCC signal or the AC signal, or both, are used as the control signals. The noise estimation unit 224 having the first-type function calculates the C / N ratio based on the MER ratio of the data signal calculated by the demapping unit 216a. The noise estimation unit 224, which has a second type of function, estimates the C / N ratio based on the MER of the control signal calculated by the demapping unit 216a. The noise estimation unit 224 can convert the MER to C / N using a predetermined known conversion formula.

[0046] The reception processing unit 230 provides broadcast programs based on the received broadcast signals and performs processing related to such provision. The reception processing unit 230 comprises a reception control unit 232, a reception status processing unit 234, and a content processing unit 236. The reception control unit 232 controls the reception of broadcast programs based on operation signals input from the input unit 250. The reception control unit 232 performs actions such as determining whether reception is necessary and setting (tuning) the broadcast channels to be received. The reception control unit 232 outputs tuning information indicating the set broadcast channels to the reception unit 212. When IL information is input from the multiplex signal separation unit 222, the reception control unit 232 may select either the data signal separated from the first broadcast signal or the data signal separated from the second broadcast signal based on the operation signal. The reception control unit 232 outputs the selected data signal to the content processing unit 236.

[0047] The reception status processing unit 234 determines an index indicating the reception status of the broadcast signal as antenna level information based on the noise level input from the noise estimation unit 224 and the IL information input from the multiplex signal separation unit 222. The reception control unit 232, for example, when an operation signal input from the input unit 250 instructs a reception status inquiry, configures a display screen with antenna level information as an antenna setting screen, and outputs display data showing the configured antenna setting screen to the output unit 240. Reception status inquiries may be instructed, for example, when setting up the receiving device 20, setting up the antenna for broadcast signal reception, adjusting the direction, or during the initial startup.

[0048] When the data signal is not multiplexed using the LDM method, that is, when IL information is not input from the multiplexed signal separation unit 222, the reception status processing unit 234 adopts the noise level input from the noise estimation unit 224. The adopted noise level will be approximately the same value regardless of whether the noise estimation unit 224 has a first-class function or a second-class function. The reception status processing unit 234 converts the adopted noise level N into an antenna level value. The antenna level value is used as an indicator value that makes it easier to understand whether the reception status is good or bad. The reception status processing unit 234 configures an antenna setting screen where the calculated antenna level value is displayed. For example, the reception status processing unit 234 can set the antenna level value to twice the positive / negative inverted value of the adopted noise level N (unit: dB) (-2N).

[0049] When data signals are multiplexed using the LDM method, that is, when IL information is input from the multiplexed signal separation unit 222, the reception status processing unit 234 configures an antenna setting screen that displays notification information indicating the transmission of the second broadcast signal, which is a low-power hierarchical signal, and an antenna level value calculated using the noise level of the first broadcast signal, which is a high-power hierarchical signal. The notification information may, for example, represent the value of IL transmitted in the IL information. This is because the noise level of the first broadcast signal notified by the noise estimation unit 224 may differ depending on whether the noise estimation unit 224 has a first-type function or a second-type function. The notification information may be represented by a string of characters, symbols, patterns, etc., indicating the transmission of a low-power hierarchical signal, instead of the value of IL, or together with the value of IL. Therefore, a user viewing the antenna setting screen can learn that the second broadcast signal is being transmitted by encountering the notification information. Consequently, the user can become aware of fluctuations in the antenna level value caused by the transmission of the second broadcast signal.

[0050] When the noise estimation unit 224 has a first type of function, the C / N ratio is based on the signal level C of the high-power hierarchical signal, which also includes the low-power hierarchical signal as part of the noise component. LL This is obtained. In other words, the noise component of the high-power hierarchical signal can be considered as mixed noise, which is a mixture of the ambient noise component and the low-power hierarchical signal component, as illustrated in Figure 5. The signal level of the mixed noise (hereinafter referred to as the "mixed noise level") N LL As illustrated in Figure 5, this corresponds to the sum of the signal level LL of the low-power hierarchical signal (second broadcast signal) and the environmental noise level N (hereinafter referred to as "environmental noise level"). Therefore, C / N LL This is lower than the C / N ratio, which is defined as the ratio of the signal level C of the high-power hierarchical signal to the signal level N of the ambient noise obtained when no low-power hierarchical signal is transmitted.

[0051] Therefore, the receiving state processing unit 234 adjusts the mixed noise level N as shown in equation (1). LL The environmental noise level N can be calculated by subtracting IL in the real domain from this value. N = 10 log (10(NLL / 10) - 10 (-IL / 10) ) … (1) In Equation (1), the units of the environmental noise level N, the mixed noise level N LL , and the injection level IL are all dB. Here, it is normalized so that the signal level C of the high-power layer signal becomes 1 (0 (dB)). Therefore, the positive / negative inversion value -N obtained by inverting the positive / negative of the environmental noise level N is obtained as C / N, which is the ratio of the signal level C of the high-power layer signal.

[0052] The reception state processing unit 234 converts the environmental noise level N and the mixed noise level N LL into antenna level values, respectively. For example, the reception state processing unit 234 calculates, as antenna level values, twice the positive / negative inversion value of the environmental noise level (-2N) and twice the positive / negative determination value of the mixed noise level (-2N LL ). This antenna level value corresponds to an approximate conversion value that is twice C / N. The reception state processing unit 234 configures, as notification information indicating the transmission of the low-power layer signal, for example, an antenna setting screen in which IL and the calculated antenna level value are arranged. The reception state processing unit 234 outputs display data indicating the configured antenna setting screen to the output unit 240.

[0053] When the noise estimation unit 224 has the second type of function, C / N is obtained from the MER of the control signal that is not affected by the low-power layer signal. Therefore, the environmental noise level N obtained from the noise estimation unit 224 cannot be immediately used as the noise level of the high-power layer signal. A data signal is a signal that transmits contents such as video and audio, and since the antenna level of the high-power layer data signal is important information for determining the reception quality of the received signal, it is highly necessary to display it on the antenna setting screen.

[0054] Therefore, as shown in Equation (2), the reception state processing unit 234 adds the signal level of the low-power layer signal to the environmental noise level N in the real number domain to obtain the mixed noise level N LLThe following is calculated. In equation (2), the signal level of the low-power hierarchical data signal is normalized such that the signal level C of the high-power hierarchical signal is 1 (0 (dB)). Therefore, the mixed noise level N LL The value for determining whether something is positive or negative is -N LL This is the mixed noise level N LL C / N is the ratio of the signal level C of a high-power hierarchical signal to the signal level C of a high-power hierarchical signal. LL It is obtained as follows. N LL = 10 log(10 (-IL / 10) +10 (N / 10) ) … (2)

[0055] The reception status processing unit 234 determines the ambient noise level N and the mixed noise level N. LL These can be converted into antenna level values ​​using the method described above. The reception status processing unit 234 outputs, as notification information, for example, IL and display data showing an antenna setting screen with the calculated antenna level values ​​to the output unit 240.

[0056] If the receiving state processing unit 234 has a first type of function, it will combine the environmental noise level N calculated by equation (1) and the mixed noise level N. LL From this, or, if it has a second type of function, the mixed noise level to ambient noise level ratio NLL / N corresponding to the C / N of the low-power hierarchical signal can be determined from C / N and IL derived from the ambient noise level N as shown in equation (3). NLL / N = (C / N) × 1 / IL … (3) The reception status processing unit 234 may convert the calculated NLL / N into an antenna level value for the effective low-power hierarchical signal level LL, and configure an antenna setting screen that further includes the obtained antenna level value. This is because, if the receiving device 20 is a receiver capable of receiving the second broadcast signal, it is more necessary to display the low-power hierarchical signal level LL transmitted in the low-power hierarchical layer and to set the antenna taking the displayed low-power hierarchical signal level LL into consideration. In the antenna settings screen described above, the antenna level value and IL may be illustrated using bar graphs, the number of antennas, etc. The display method for the antenna level value and IL, such as color and brightness, may vary depending on the type (for example, ambient noise level, mixed noise level of high-power hierarchical signals, low-power hierarchical signal level, etc.).

[0057] The reception status processing unit 234 may determine, based on the calculated ambient noise level, whether the reception status of the received signal is better than the reception status indicated by a predetermined recommended value. For example, the reception status processing unit 234 may determine whether the C / N corresponding to the ambient noise level N is equal to or greater than the recommended value. As the recommended value, for example, the required CN ratio described in ARIB STD-B21 may be used, or a value obtained by adding a predetermined positive value as a margin to this required CN ratio may be used. The required CN ratio is determined for each combination of modulation scheme and coding rate.

[0058] The content processing unit 236 performs processing to present the content of a broadcast program transmitted by data signals input from the multiplex signal separation unit 222. The content processing unit 236 decodes content data representing the content of a broadcast program transmitted by the input data signals. For example, the content processing unit 236 separates encoded video data and encoded audio data carried by the data signals. The content processing unit 236 generates video data by performing video decoding processing on the separated encoded video data and generates audio data by performing audio decoding processing on the separated encoded audio data.

[0059] The content processing unit 236 generates presentation data for presenting the content transmitted by the decoded content data, and outputs the generated presentation data to the output unit 240. The content processing unit 236 generates display data representing a display screen on which the decoded video is arranged, and outputs it to the output unit 240. The content processing unit 236 also generates playback data for playing the decoded audio, and outputs it to the output unit 240.

[0060] The output unit 240 presents the content of the broadcast program based on the presentation data input from the reception processing unit 230. The output unit 240 includes, for example, a display and a speaker. The display shows the broadcast program screen according to the display data input from the content processing unit 236. The speaker plays audio according to the playback data input from the content processing unit 236. The display may also show a display screen including the antenna level value according to the display data input from the reception status processing unit 234.

[0061] The input unit 250 receives user input and generates an operation signal in response to the input. The input unit 250 outputs the generated operation signal to the receiving processing unit 230. The input unit 250 may be equipped with dedicated components such as buttons, knobs, and dials, or with general-purpose components such as touch sensors, mice, and keyboards. A touch sensor functioning as the input unit 250 may be configured as a touch panel integrated with a display functioning as the output unit 240. The input unit 250 may also be equipped with a sensor that receives operation signals from other devices (e.g., remote controllers, multifunction mobile phones). The input unit 250 may output the received operation signal to the receiving device 20.

[0062] (Antenna settings screen) Next, an example of the antenna setting screen according to this embodiment will be described. Figure 6 is a diagram showing a first example of the antenna setting screen according to this embodiment. The antenna setting screen in this example is displayed when low-power hierarchical signals are transmitted without multiplexing. In the example of Figure 6, the antenna level value is 80, and a message is displayed indicating that 40 or higher is the recommended value for the antenna level. This antenna setting screen indicates that the antenna level value exceeds the antenna level reference value, conveying that sufficient reception quality can be expected.

[0063] Figure 7 shows a second example of the antenna setting screen according to this embodiment. The antenna setting screen in this example is displayed when the receiving device 20 is a 2K receiving device, low-power hierarchical signals are multiplexed and transmitted based on the LDM method, valid IL information is extracted in the multiplex signal separation unit 222, it is determined that low-power hierarchical signals are being sent, and the noise estimation unit 224 has the function of type 1. In the example in Figure 7, 50 is displayed as the antenna level value based on the ambient noise level, 30.97 as the antenna level value based on the mixed noise level, and 16 is displayed as the IL value extracted by the multiplex signal separation unit 222.

[0064] In this example, the antenna level value based on the mixed noise level is displayed as the "data domain antenna level" and the reception quality related to the data signal. A message is also included stating that an antenna level of 40 or higher is the recommended value. Users who see the displayed antenna level value and message are encouraged to adjust the antenna's position and orientation so that the displayed antenna level value is 40 or higher when installing the antenna. Since this value remains unchanged from the value before low-power layer signals are transmitted (before 4K broadcasting began), it avoids confusing the user. On the other hand, the data domain antenna level is related to the C / N ratio mentioned above. LL This value corresponds to the effective signal quality of high-power layer signals and should ideally be displayed when adjusting the antenna. Furthermore, the injection level may change depending on the prevalence of receivers compatible with low-power layer signals (i.e., 4K-compatible receivers), and may vary depending on the broadcasting station, broadcasting channel, etc. This injection level is displayed as useful information for antenna adjustment.

[0065] Figure 8 shows a third example of the antenna setting screen according to this embodiment. The antenna setting screen in this example is displayed when the receiving device 20 is a 2K receiving device, low-power hierarchical signals are multiplexed and transmitted based on the LDM method, and the noise estimation unit 224 has a second type of function. The antenna setting screen in this example displays the same items as the antenna setting screen illustrated in Figure 7. In the example in Figure 8, 80 is displayed as the antenna level value based on the ambient noise level, 45.83 as the antenna level value based on the mixed noise level, and 16 as the IL. This allows the user to adjust the antenna while viewing a display that is the same as when the noise estimation unit 224 has a first type of function.

[0066] Figure 9 shows a fourth example of the antenna setting screen according to this embodiment. The antenna setting screen in this example is displayed when the receiving device 20 is a 4K-compatible receiving device and the low-power hierarchical signal is multiplexed and transmitted based on the LDM method. This antenna setting screen may include common items regardless of whether the noise estimation unit 224 has a first-type function or a second-type function. In the example in Figure 9, the antenna level value based on the ambient noise level is 80, the antenna level value based on the mixed noise level for the high-power hierarchical signal is 45.83, the antenna level value based on the low-power hierarchical signal level is 48, and the IL is 16. In this example, the antenna level value based on the mixed noise level for the high-power hierarchical signal is labeled "Antenna level in the 2K data area," and the antenna level value based on the low-power hierarchical signal level is labeled "Antenna level in the 4K data area," indicating that these are the reception quality for the high-power hierarchical signal and the low-power hierarchical signal, respectively. Additionally, a message is placed stating that 40 or higher is the recommended antenna level value for high-power layer signals, and a message is also placed stating that 36 or higher is the recommended antenna level value for low-power layer signals.

[0067] In this example, both the antenna level value based on the ambient noise level and the antenna level value based on the mixed noise level for high-power layer signals are above the antenna level reference value. The antenna level value based on the low-power layer signal level is also above the antenna level reference value based on the low-power layer signal level. Users viewing this antenna settings screen are informed that both the antenna level value for high-power layer signals and the antenna level value for low-power layer signals are above their respective antenna level reference values, and that sufficient reception quality can be expected for both 2K broadcasts provided with high-power layer signals and 4K broadcasts provided with low-power layer signals.

[0068] Next, an example of symbol arrangement for a broadcast signal will be described. The carrier symbol positions to which the carrier symbols of the data signals, reference signals, and control signals that constitute the broadcast signal are assigned are defined in a predetermined assignment setting. Figure 10 shows an example of the assignment setting according to this embodiment. Figure 10 illustrates mode 3 as an example of symbol arrangement. Figure 10 shows that there are 203 rows and 432 columns of carrier symbol positions per frame. Each row shows the OFDM symbol number, and each column shows the carrier number. The OFDM symbol number corresponds to the time assigned to each individual OFDM symbol. The carrier number indicates each carrier, i.e., the frequency.

[0069] In Figure 10, the unfilled individual rectangles indicate the carrier symbol locations to which data signals are assigned. The shaded, vertically striped, and horizontally striped areas indicate the carrier symbol locations to which SP signals, TMCC signals, and AC signals are assigned, respectively. Each carrier symbol constituting the SP signal is distributed and assigned to one carrier symbol location within the data area to which data signals are assigned. The TMCC and AC signals are assigned to a certain carrier over a continuous period of time. The carriers to which the TMCC and AC signals are assigned are called the TMCC carrier and the AC carrier, respectively.

[0070] IL information is transmitted, for example, as part of the TMCC signal. Figure 11 shows an example of bit allocation for a TMCC carrier. In the example in Figure 11, 204 bits of information are carried per frame using the TMCC carrier. The TMCC carrier carries 1 bit of demodulation reference signal, 16 bits of synchronization signal, 3 bits of segment format identification, 102 bits of TMCC information, and 82 bits of parity bits. IL information is transmitted as 5 bits, included with the TMCC information. IL information is represented using bits 110 to 114. Figure 11 is accompanied by a table illustrating the meaning of the IL information values. A value of 0 or 31 indicates that the LL signal is not transmitted, while a value from 1 to 30 indicates that the LL signal is transmitted and represents the actual transmitted IL value.

[0071] Furthermore, IL information may be transmitted as part of the AC signal instead of the TMCC signal, or as part of the Software Download Trigger Table (SDTT). The SDTT is a table defined in ARIB STD-B21 that is multiplexed with the content data of the broadcast program by the data signal. IL information may be transmitted using the Network Information Table (NIT). The NIT is an information table defined in Ministry of Internal Affairs and Communications Ordinance No. 88 of February 20, 2009. The NIT is a table mainly used to transmit information that associates transmission path information, such as modulation frequency, with broadcast programs. When transmitting IL information, for example, it is written to the NIT using an LDM transmission descriptor (LDM_transmission_descriptor). Figure 16 shows an example of how IL information is written in an LDM transmission descriptor. When this descriptor is sent as part of the NIT, it indicates that an LL signal is being sent. The IL value is written in 5 bits in the injection level feed of this descriptor, and it represents a dB value of one from 1 to 31. Note that both NIT and SDTT are included in the data signal.

[0072] Next, an example of the broadcast signal reception processing according to this embodiment will be described. Figure 12 is a flowchart of the first example of the reception processing according to this embodiment. Figure 12 shows an example where the receiving device 20 is a 2K receiving device and the noise estimation unit 224 has a first type of function.

[0073] (Step S102) The receiving unit 212 receives the broadcast signal transmitted via the broadcast transmission line BT as a received signal. The demodulation unit 214 demodulates the received signal. The demodulated received signal is decoded into a high-power hierarchical signal (first broadcast signal), and the data signal and control signal are input to the demapping unit 216a, which calculates the MER of the data signal and passes it to the noise estimation unit 224. (Step S104) The noise estimation unit 224 calculates C / N from the MER of the data signal that has been passed.

[0074] (Step S106) The multiplex signal separation unit 222 monitors the control signal or data signal and attempts to acquire IL information from a predetermined area. (Step S108) The multiplexed signal separation unit 222 determines whether the data signal is multiplexed using the LDM method based on the success or failure of acquiring valid IL information. If it is determined that the signal is multiplexed using the LDM method (Step S108 YES), the process proceeds to step S110. If it is determined that the signal is not multiplexed using the LDM method (Step S108 NO), the process proceeds to step S114.

[0075] (Step S110) The reception state processing unit 234 calculates the mixed noise level N corresponding to the C / N calculated according to equation (1). LL The environmental noise level N is calculated based on the injection level IL. (Step S112) The reception status processing unit 234 processes the ambient noise level N and the mixed noise level N LLThe system calculates the corresponding antenna level value for each of these parameters. The reception status processing unit 234 configures a display screen that shows the calculated antenna level value and the injection level IL. The reception status processing unit 234 outputs display data indicating the configured display screen to the output unit 240, and displays the display screen on the screen. After that, the process shown in Figure 12 is terminated. (Step S114) The reception status processing unit 234 configures a display screen as the antenna setting screen that shows the antenna level value corresponding to the noise level N based on the calculated C / N. The reception status processing unit 234 outputs display data showing the configured antenna setting screen to the output unit 240 and displays the antenna setting screen. After that, the process shown in Figure 12 is terminated.

[0076] Figure 13 is a flowchart showing a second example of the reception processing according to this embodiment. Figure 13 shows an example where the receiving device 20 is a 2K receiving device and the noise estimation unit 224 has a second type of function. The process in Figure 13 includes steps S124 and S130 instead of steps S104 and S110 in Figure 12. For steps S102, S106, S108, S112, and S114, refer to the explanation in Figure 12.

[0077] (Step S124) The noise estimation unit 224 calculates C / N from the separated control signals. (Step S130) The receiving state processing unit 234 calculates a mixed noise level N based on the ambient noise level and injection level IL corresponding to the C / N calculated according to equation (2). LL Calculate.

[0078] Figure 14 is a flowchart showing a third example of the reception processing according to this embodiment. Figure 14 shows an example where the receiving device 20 is a 4K-compatible receiving device and the noise estimation unit 224 has a first type of function. The process in Figure 14 includes step S142 instead of step S112 in Figure 12, and further includes step S140. For steps S102, S104, S106, S108, S110, and S114, refer to the explanation in Figure 12.

[0079] (Step S140) The reception state processing unit 234 calculates the effective low-power hierarchical signal level LL based on the environmental noise level N and the injection level IL according to equation (3). (Step S142) The reception status processing unit 234 receives the ambient noise level N and the mixed noise level N. LL The system calculates antenna level values ​​corresponding to each of the low-power hierarchical signal levels LL. The reception status processing unit 234 configures a display screen showing the calculated antenna level values ​​and injection level IL. The reception status processing unit 234 outputs display data indicating the configured display screen to the output unit 240, and displays the display screen on the screen.

[0080] Figure 15 is a flowchart showing a fourth example of the reception processing according to this embodiment. Figure 15 shows an example where the receiving device 20 is a 4K-compatible receiving device and the noise estimation unit 224 has a second type of function. The process in Figure 14 includes step S142 instead of step S112 in Figure 13, and further includes step S140. For steps S102, S106, S108, and S114, refer to the explanation in Figure 12. For steps S124 and S130, refer to the explanation in Figure 13. For steps S140 and S142, refer to the explanation in Figure 14.

[0081] In addition, depending on the broadcasting station and broadcasting area, broadcasting services may be provided using multiple broadcasting channels (physical channels) rather than just a single broadcasting channel (MFN: Multiple Frequency Network). The reception status processing unit 234 may generate a service list (receivable frequency table) in which service IDs (Identifiers) indicating broadcasting channels among the multiple broadcasting channels whose ambient noise level, mixed noise level, or low-power hierarchical signal level is lower than a predetermined reference level are described. The reception status processing unit 234 may set the generated receivable frequency table in the reception processing unit 230. The reception status processing unit 234 may also perform the process of creating the receivable frequency table when searching for receivable channels (initial scan) when the receiving device 20 is installed or when it is first started up. Furthermore, the reception status processing unit 234 may cause the reception status processing unit 230 to generate a reception status display screen illustrating the ambient noise level, mixed noise level, or low-power hierarchical signal level for each broadcast channel, and display it on the output unit 240. The reception status display screen may show whether reception is possible or whether broadcast services are receivable in different display formats.

[0082] The reception status processing unit 234 may determine whether reception is possible based on the estimated ambient noise level, mixed noise level, or low-power hierarchical signal level for each broadcast channel, and may search for broadcast channels that it has determined to be receivable. The reception status processing unit 234 may also generate a receivable frequency table showing service IDs indicating the receivable channels identified by the search.

[0083] The reception status processing unit 234 may generate a receivable frequency table for each region and set it in the reception control unit 232. The reception control unit 232 may select the set receivable frequency table according to the region in which its device is installed. The reception processing unit 230 can, for example, determine the installation location of its device using GPS signals received from four or more GPS (Global Positioning System) satellites and identify the region included in the installation location by referring to pre-set map information.

[0084] As described above, the receiving device 20 according to this embodiment includes a receiving processing unit 230 that, when injection level information indicating the injection level is obtained from a received signal carrying data signals and control signals, outputs notification information indicating the transmission of a low-power hierarchical signal and antenna level information indicating the reception status of the data signal to the output unit 240. The low-power hierarchical signal is multiplexed in the data signal to a hierarchical level with a lower signal level than the high-power hierarchical signal, and the injection level is the level ratio between the high-power hierarchical signal and the low-power hierarchical signal. In this configuration, when an injection level signal indicating the level ratio of high-power hierarchical signals and low-power hierarchical signals is acquired, notification information indicating the transmission of low-power hierarchical signals and antenna level information indicating the reception status of data signals are output. Since the transmission of low-power hierarchical signals multiplexed with high-power hierarchical signals is notified, users who see the notification information can be prompted to adjust their antenna settings to take into account the change in antenna level information due to the transmission of low-power hierarchical signals.

[0085] The receiving device 20 may include a noise estimation unit 224 that estimates a mixed noise level based on the carrier-to-noise ratio of high-power hierarchical signals. The receiving processing unit 230 calculates the ambient noise level using the mixed noise level and the injection level, and determines antenna level information based on the ambient noise level. With this configuration, when the mixed noise level based on the carrier-to-noise ratio is estimated from a high-power hierarchical signal, antenna level information based on the ambient noise level can be obtained using the injection level. Therefore, by referring to the ambient noise level in addition to the mixed noise level, it is possible to ensure the reception quality of the high-power hierarchical signal.

[0086] The receiving device 20 may include a noise estimation unit 224 that estimates the ambient noise level based on the carrier-to-noise ratio of the control signal carried by the received signal. The receiving processing unit 230 calculates the mixed noise level using the ambient noise level and the injection level, and determines antenna level information based on the mixed noise level. With this configuration, when the ambient noise level is estimated from the control signal based on the carrier-to-noise ratio, antenna level information based on the mixed noise level can be obtained using the injection level. Therefore, by referring to the mixed noise level in addition to the ambient noise level, it is possible to ensure the reception quality of high-power hierarchical signals.

[0087] The control signal may include at least one of the transmission multiplex control signals (TMCC signals) and auxiliary channel signals (AC signals). This configuration allows for the estimation of environmental noise levels without being affected by low-power hierarchical signals contained in the data signal. Furthermore, by transmitting the injection level using existing transmission multiplexing control signals or auxiliary channel signals, it becomes more economically viable than when newly defined signals are used.

[0088] The receiving processing unit 230 may subtract the injection level from the environmental noise level to determine antenna level information based on the signal level of the low-power hierarchical signal. This configuration allows for the acquisition of antenna level information indicating the reception quality of both high-power and low-power hierarchical signals. Therefore, it encourages antenna adjustments that take into account the reception quality of low-power hierarchical signals.

[0089] Furthermore, the receiving processing unit 230 may determine the reception status of the received signal based on the environmental noise level. With this configuration, the suitability of the receiving device 20 for receiving broadcasts can be quantitatively evaluated by using the antenna installation status and the ambient noise level, which depends on the surrounding environment, for each broadcast channel.

[0090] Furthermore, the reception status processing unit 234 may create a list (for example, a service list, a receivable frequency table) for each channel of the received signal that indicates channels in which the ambient noise level is lower than a predetermined level. This configuration allows you to select channels with low ambient noise levels by referring to a list, and avoid channels with higher ambient noise levels. Therefore, you can reliably receive broadcasts from channels with high reception quality.

[0091] Although embodiments of this invention have been described in detail above with reference to the drawings, the specific configurations are not limited to the embodiments described above, and include designs and the like that do not depart from the spirit of this invention. The configurations described in the embodiments described above can be combined in any way.

[0092] The above explanation uses the example of assigning a 2K signal as the first broadcast signal and a 4K signal as the second broadcast signal to the high-power tiered signal and low-power tiered signal, respectively, but it is not limited to this. The high-power tiered signal can be assigned a signal of broadcast program content that provides video at a lower resolution than the low-power tiered signal. For example, the high-power tiered signal and low-power tiered signal may be assigned a 1K signal and a 2K signal, respectively, or they may be assigned a 1K signal and a 4K signal, respectively. A 1K signal is a type of broadcast signal related to the broadcasting system used in High-Definition Television (HDTV) broadcasting services.

[0093] Furthermore, the low-power tier signal may be assigned an additional signal used for supplementary services to the broadcast service provided by the high-power tier signal. In this case, the content processing unit 236 does not discard the high-power tier signal from the data signal, but adopts both the high-power tier signal and the additional signal and uses them to present the content. For example, if a 2K signal is adopted as the high-power tier signal, the difference signal between the 4K signal and the 2K signal may be assigned as the additional signal to the low-power tier signal. The content processing unit 236 synthesizes the 4K signal from the extracted 2K signal and the difference signal, decodes the synthesized 4K signal, and makes it possible to present the 4K broadcast content.

[0094] Furthermore, some components of the receiving device 20 may be omitted, or other components may be added. For example, in the receiving device 20, if one or both of the output unit 240 and the input unit 250 can be connected to other functional units to input and output various types of data, they do not necessarily have to be integrated into the receiving device 20. For example, in a receiving device 20 configured as a set-top box, the content processing unit 236 and the display forming the output unit 240 may be omitted. In a receiving device 20 configured as a recording device, the display forming the output unit 240 may be omitted.

[0095] Furthermore, a program to implement some or all of the functions of the receiving device 20 described above, for example, some or all of the functions of the receiving processing unit 230, may be recorded on a computer-readable recording medium, and these functions may be implemented by loading the program recorded on this recording medium into a computer system and executing it. The functions of the receiving processing unit 230 may also be implemented by executing a browser as an application program. The term "computer system" as used herein includes hardware such as an operating system and peripheral devices. The term "computer system" may also include multiple computer devices connected via a network including communication lines such as the Internet, WAN, LAN, and dedicated lines. [Explanation of Symbols]

[0096] 1…Broadcasting system, 10…Broadcasting equipment, 20…Receiving equipment, 122…First broadcast signal acquisition unit, 124…Second broadcast signal acquisition unit, 126…Level adjustment unit, 128…Hierarchical multiplexing unit, 130…Frame configuration unit, 132…Modulation unit, 134…Transmission unit, 212…Receiving unit, 214…Demodulation unit, 216…First decoding unit, 218…Second decoding unit, 222…Multiplex signal separation unit, 224…Noise estimation unit, 230…Reception processing unit, 232…Reception control unit, 234…Reception status processing unit, 236…Content processing unit, 240…Output unit, 250…Input unit

Claims

1. An injection level information acquisition unit that acquires injection level information indicating an injection level from a received signal that carries a data signal and a control signal; A processing unit that outputs notification information indicating transmission of a low power level signal and antenna level information indicating a reception state of the data signal; The low power level signal is multiplexed in a layer having a signal level lower than that of a high power level signal in the data signal, and the injection level is a level ratio between the high power level signal and the low power level signal A receiving device.

2. A noise estimation unit that estimates a carrier-to-noise ratio based on the data signal; The processing unit Outputs antenna level information based on a mixed noise level corresponding to the carrier-to-noise ratio The receiving device according to claim 1.

3. The processing unit Calculates an environmental noise level by subtracting the injection level from the mixed noise level in a linear region; Outputs antenna level information based on the environmental noise level The receiving device according to claim 2.

4. A noise estimation unit that estimates a carrier-to-noise ratio based on the control signal; The processing unit Outputs antenna level information based on an environmental noise level corresponding to the carrier-to-noise ratio The receiving device according to claim 1.

5. The processing unit Subtracts the injection level from the environmental noise level in a logarithmic region to determine antenna level information based on a signal level of the low power level signal The receiving device according to claim 3.

6. The processing unit Determines a reception state of a received signal based on the environmental noise level The receiving device according to claim 5.

7. The processing unit Creates a list indicating channels in which the environmental noise level is lower than a predetermined level for each channel of the received signal The receiving device according to claim 6.

8. A method performed by a receiving device, the method including: An injection level information acquisition step of acquiring injection level information indicating an injection level from a received signal that carries a data signal and a control signal; A processing step of outputting notification information indicating transmission of a low power level signal and antenna level information indicating a reception state of the data signal. The low-power layer signal is multiplexed into a layer having a signal level lower than that of the high-power layer signal in the data signal, and the injection level is the level ratio between the high-power layer signal and the low-power layer signal. Method. **Claim 9**: Control information regarding the low-power layer signal is included in auxiliary channel information, and the injection level information is obtained from the auxiliary channel information. The receiving apparatus according to claim 1. **Claim 10**: A control information acquisition unit that acquires control information from a received signal, an injection level information acquisition unit that acquires injection level information indicating an injection level that is the level ratio between a high-power layer signal and a low-power layer signal, a high-power layer signal acquisition unit that acquires the high-power layer signal from the received signal, and a low-power layer signal acquisition unit that acquires the low-power layer signal from the received signal, wherein control information regarding the low-power layer signal is included in auxiliary channel information, and the injection level information is obtained from the auxiliary channel information. Receiving apparatus. **Claim 11**: A method implemented by a receiving apparatus, including a control information acquisition step of acquiring control information from a received signal, an injection level information acquisition step of acquiring injection level information indicating an injection level that is the level ratio between a high-power layer signal and a low-power layer signal, a high-power layer signal acquisition step of acquiring the high-power layer signal from the received signal, and a low-power layer signal acquisition step of acquiring the low-power layer signal from the received signal, wherein control information regarding the low-power layer signal is included in auxiliary channel information, and the injection level information is obtained from the auxiliary channel information.

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