WO2009147796A1

WO2009147796A1 - Broadcast reception device

Info

Publication number: WO2009147796A1
Application number: PCT/JP2009/002278
Authority: WO
Inventors: 稲垣善久; 江島直樹
Original assignee: パナソニック株式会社
Priority date: 2008-06-05
Filing date: 2009-05-25
Publication date: 2009-12-10
Also published as: JP2011166191A

Abstract

A broadcast reception device judges whether a noise cancel signal has an appropriate phase and an appropriate amplitude by using an evaluation value obtained by combining the bit error rate, the CN ratio, and the reception signal intensity parameter. Thus, it is possible to obtain a wide-range noise cancel effect and a highly accurate noise cancel effect in the vicinity of a boundary between a viewable range and an unviewable range.

Description

Broadcast receiver

The present invention relates to a broadcast receiving apparatus that receives broadcast waves.

Depending on the environment in which the broadcast receiving apparatus is installed, since the received broadcast signal is weak, it may be difficult to obtain a normal video / audio signal in the broadcast receiving apparatus. For example, in a weak electric field such as a fringe area, the broadcast signal is buried in noise from inside the broadcast receiving apparatus, and the broadcast signal cannot be extracted. The noise inside the broadcast receiving apparatus is, for example, noise from a back-end unit such as radiation from a substrate wiring, a clock generation component, or a DCDC converter. Therefore, when the reception state deteriorates, it is conceivable that the noise from the back-end unit is received by the noise sensor, and noise of the same cause that enters the antenna is removed based on the received noise.

A conventional example will be described with reference to FIG. As a conventional example, there is an interference wave removing device 711 described in Patent Document 1, for example. The antenna 709 is an antenna that also performs transmission and reception. A reception signal received by the antenna 709 is input to the duplexer 710. The received signal input to the duplexer 710 is input to the adder 712. Further, the transmission signal 716 is transmitted from the antenna 709 via the duplexer 710.

The noise 708 detected by the noise detection unit 707 is input to the phase adjustment unit 701 in the interference wave removing device 711. The input noise 708 is adjusted in phase, frequency band selection, delay, and gain according to the control signal from the control unit 705 in the phase adjustment unit 701, bandpass channel emulation filter 702, delay adjustment unit 703, and variable gain amplifier 704. Is done. The adjusted noise is input to the adder 712 as a noise cancellation signal. The adder 712 calculates the signal input from the duplexer 710 and the noise cancellation signal input from the variable gain amplifier 704 to attenuate the noise component. The signal 714 output from the adder 712 is supplied to a broadcast receiving device (not shown). On the other hand, an output signal 716 from a transmitter (not shown) is input to the duplexer 710.

In addition, the signal 714 attenuated by the noise component by the adder 712 is input to the power detection unit 706. The power detection unit 706 detects the power of the noise component of the input signal and transmits the result to the control unit 705. The control unit 705 controls the phase adjustment unit 701, the bandpass channel emulation filter 702, and the delay adjustment unit 703 so that the power of the noise component of the signal is minimized by the power detection unit 706 (for example, FIG. 3).

However, it is determined whether the phase and amplitude settings of the noise cancellation signal are appropriate based on the strength of the predetermined signal after noise cancellation. Therefore, an important point for the user as to whether or not viewing is possible is not used as a criterion and is not appropriate.

On the other hand, it is conceivable to use a parameter called a bit error rate (BER) at the time of decoding in the broadcast receiving apparatus. The bit error rate is one of the effective parameters for determining whether or not viewing is possible because the bit error rate greatly changes near the boundary between viewing and non-viewing. However, on the other hand, there is little change except near the boundary between viewable and unviewable, and it is difficult to control the noise cancellation signal at the bit error rate outside the boundary.

On the other hand, it is also conceivable to use parameters such as a CN ratio (Carrier to Noise Ratio) of received signals and a received signal strength parameter (AGC) in the broadcast receiving apparatus. These change not only in the vicinity of the boundary between viewing and non-viewing but also in a wide area including other areas. However, since the change near the boundary between viewable and unviewable is gentle, it is difficult to perform high-precision control using only these parameters in the region.

US Patent Application Publication No. 2007/0060059

The broadcast receiving apparatus of the present invention is a broadcast receiving apparatus that receives a broadcast wave, and includes an antenna unit, a noise sensor unit, a cancel signal generating unit, an adding unit, a tuner unit, a signal demodulating unit, and a signal generating unit. And a control unit.

The antenna unit receives broadcast waves. The noise sensor unit detects noise inside the broadcast receiving apparatus. The cancel signal generation unit receives the noise supplied from the noise sensor unit, adjusts at least one of the phase or amplitude of the noise, and generates a cancel signal. The adding unit adds the signal from the antenna unit and the cancel signal. The tuner unit receives the signal from the addition unit and outputs the signal of the selected channel. The signal demodulator demodulates the channel signal and outputs a state signal indicating the state of the channel signal output from the tuner unit. The cancel signal generation control unit controls the cancel signal generation unit according to the state signal.

With such a configuration, it is possible to provide a broadcast receiving device having a more suitable determination criterion for a noise cancellation signal.

Further, the status signal may be an evaluation value that combines a bit error rate, a CN ratio, and a received signal strength parameter.

FIG. 1 is a block diagram showing a configuration of a broadcast receiving apparatus according to Embodiment 1 of the present invention. FIG. 2 is a conceptual diagram showing the relationship between the electric field strength of the broadcast signal received by the broadcast receiving apparatus according to Embodiment 2 of the present invention and the changing point of each state signal. FIG. 3 is a conceptual diagram showing the relationship between the electric field strength of the broadcast signal received by the broadcast receiving apparatus according to Embodiment 3 of the present invention and the changing point of each state signal. FIG. 4 is a diagram showing a time relationship required for reading each status signal of the broadcast receiving apparatus in Embodiment 4 of the present invention. FIG. 5 is a block diagram showing a configuration of a broadcast receiving apparatus according to Embodiment 5 of the present invention. FIG. 6 is a block diagram showing a configuration of another example of a broadcast receiving apparatus according to Embodiment 5 of the present invention. FIG. 7 is a diagram showing the relationship between the amplitude instruction signal / phase instruction signal output from the cancel signal generation control unit in the first to fifth embodiments of the present invention. FIG. 8 is a configuration diagram of an interference wave removing device in a conventional example.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a broadcast receiving apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, a broadcast receiving apparatus that receives broadcast waves includes an antenna unit 101, a noise sensor unit 106, a cancel signal generation unit 107, an addition unit 102, a tuner unit 103, a signal demodulation unit 104, and a cancel signal generation control unit 108. And.

The antenna unit 101 receives radio waves of digital broadcasting emitted from a broadcasting station. The antenna unit 101 supplies a reception signal to one input terminal of the addition unit 102. The noise sensor unit 106 detects noise inside the broadcast receiving apparatus that is radiated from the back-end unit 109 and causes deterioration in reception sensitivity between weak electricity. Then, the noise sensor unit 106 supplies noise to the cancel signal generation unit 107. The cancel signal generation unit 107 receives the noise supplied from the noise sensor unit 106, adjusts at least one of the phase or amplitude of the noise, and generates a cancel signal. Then, the cancel signal generation unit 107 supplies a cancel signal to the other input terminal of the addition unit 102.

The addition unit 102 adds the reception signal from the antenna unit 101 and the cancellation signal from the cancellation signal generation unit 107 to remove noise inside the broadcast receiving apparatus. Then, the adding unit 102 inputs a signal from which noise inside the broadcast receiving apparatus is removed to the tuner unit 103.

The tuner unit 103 extracts the signal 111 of the channel selected by the user from the signal from the addition unit 102 and inputs it to the signal demodulation unit 104. The signal demodulator 104 demodulates the channel signal 111 output from the tuner unit 103 to generate a digital signal (TS: transport stream). Then, the signal demodulation unit 104 inputs a signal related to video and audio processing to the video / audio generation unit 105.

The video / audio generation unit 105 calculates the signal from the signal demodulation unit 104 so that it can be reproduced as video and audio, and outputs a video / audio signal. For example, output video / audio signals include composite signal, REC656 signal format, and MPEG-2 AAC (Advanced Audio Coding) and MPEG-2 AAC + SBR (Spectral Band Replication) as video output formats.

Further, the signal demodulator 104 is a state signal indicating the state of the signal 111 output from the tuner unit 103. The bit error rate in the broadcast receiver, the CN ratio of the received signal in the broadcast receiver, and the reception in the broadcast receiver. Output signal strength parameters. Then, the signal demodulation unit 104 inputs these output parameters to the cancel signal generation control unit 108.

Note that the bit error rate in the broadcast receiving apparatus is a parameter obtained by counting the bit errors detected when the signal demodulation unit 104 performs error correction processing. As described above, in digital broadcasting, the signal demodulation unit 104 normally performs error correction processing when demodulating the input signal 111.

Also, the CN ratio of the received signal in the broadcast receiving apparatus is a ratio between the carrier power of the channel signal 111 selected by the tuner unit 103 and the noise power accompanying the channel signal.

And the received signal strength parameter in the broadcast receiving apparatus is, for example, a parameter related to automatic gain control. That is, the signal demodulator 104 compares the level of the input signal 111 with a predetermined reference level. Then, the signal demodulation unit 104 feeds back the comparison result to the tuner unit 103 as the control signal 112. Based on the control signal 112, the tuner unit 103 adjusts the level of the signal 111 of the output channel to be constant. As described above, the control signal 112 may be used as the received signal strength parameter, for example. Thus, in the present embodiment, the received signal strength parameter is a parameter related to the input level of the signal selected by tuner unit 103.

The cancel signal generation control unit 108 uses the evaluation value obtained by combining the state signal of the bit error rate, the CN ratio of the received signal, and the received signal strength parameter input from the signal demodulating unit 104, and the cancel signal generating unit 107. The control signal 112 is adjusted and output by determining whether the phase and amplitude settings of the cancel signal generated in step S1 are appropriate. That is, the cancel signal generation control unit 108 controls the cancel signal generation unit 107 according to the state signal. Here, if the bit error rate is BER, the CN ratio of the received signal is CN, and the received signal strength parameter is AGC, the evaluation value may be defined by the following equation, for example.

Evaluation value = 16 × LOG (1 / BER) + 4 × CN + AGC (1)
In Equation (1), the evaluation value is weighted so that the bit error rate coefficient is larger than the CN ratio or the received signal strength parameter. Therefore, in the broadcast receiving apparatus of the present embodiment, the evaluation value has a large amount of change in the vicinity of the sensitivity point that is a branching point of whether or not the evaluation value can be viewed by weighting the coefficient of the bit error rate. For this reason, the cancel signal generation control unit 108 can output the control signal 112 with high viewability. In addition, the cancel signal generation control unit 108 uses not only the bit error rate but also the CN ratio and the received signal strength parameter, so that a noise canceling effect can be achieved even in an electric field strength region where the bit error rate does not change. Possible settings are possible. For this reason, the broadcast receiving apparatus can improve tolerance to noise.

In this way, the broadcast receiving apparatus according to the present embodiment can be provided with a more suitable determination criterion for a cancel signal for noise.

In addition, the broadcast receiving apparatus according to the present embodiment realizes not only higher-precision noise cancellation control near the boundary between viewing and non-viewing but also higher-precision noise cancellation control in other areas. Is possible.

In addition to the bit error rate, CN ratio, and received signal strength parameter, MER (Modulation Error Ratio) may be used. Note that the MER is one of indexes indicating reception quality in a digital modulation scheme such as a QAM modulation scheme. In other words, the MER is the difference between the power of the demodulated signal at each reference point (constellation point) and the noise power that is the difference between the reference point and the demodulated signal in the IQ plane when the demodulated signal is represented by a complex number. It is obtained from the ratio. The signal demodulator 104 can calculate and output the MER.

(Embodiment 2)
The configuration of the broadcast receiving apparatus in the second embodiment of the present invention is the same as that of FIG. 1 described in the first embodiment. Therefore, the description about the structure of the broadcast receiving apparatus in this Embodiment is abbreviate | omitted. FIG. 2 is a conceptual diagram showing the relationship between the field intensity of the broadcast wave received by the broadcast receiving apparatus according to Embodiment 2 of the present invention and the change point of each state signal. In FIG. 2, the horizontal axis represents the electric field strength of the broadcast wave input to the antenna unit 101. The vertical axis represents the bit error rate, CN ratio, and received signal strength parameter.

The broadcast receiving apparatus according to Embodiment 1 generates a cancel signal for noise inside the broadcast receiving apparatus using an evaluation value that combines a state signal of a bit error rate, a CN ratio of the received signal, and a received signal strength parameter. did. The broadcast receiving apparatus according to the second embodiment uses only the state signal that changes for each fixed range of the electric field strength in the evaluation value that combines the state signal of the bit error rate, the CN ratio of the received signal, and the received signal strength parameter. Is used. An example of the operation of the broadcast receiving apparatus in this embodiment will be described with reference to FIG.

A range 210 shown in FIG. 2 indicates a range of electric field strength where the bit error rate (shown as BER) changes. A range 212 indicates a range of electric field strength where the CN ratio changes. A range 214 indicates a range of electric field strength in which the received signal strength parameter changes.

Range 301 shows from the change start point of the CN ratio to the change start point of the received signal strength parameter as the electric field strength increases. A range 302 indicates from the change start point of the received signal strength parameter to the change start point of the bit error rate. A range 303 indicates from the bit error rate change start point to the bit error rate change end point. A range 304 indicates from the bit error rate change end point to the CN ratio change end point. A range 305 indicates from the change end point of the CN ratio to the change end point of the received signal strength parameter.

In range 301, only the CN ratio changes. Therefore, the evaluation value is an expression using only the CN ratio, for example,
Evaluation value = CN (2)
Is used. Here, in the present embodiment as well as in the first embodiment, the bit error rate is BER, the CN ratio of the received signal in the broadcast receiving apparatus is CN, and the received signal strength parameter is AGC.

In range 302, since the received signal strength parameter and the CN ratio change, an expression and an evaluation value using the received signal strength parameter and the CN ratio are, for example,
Evaluation value = 4 × CN + AGC (3)
Is used.

In range 303, the bit error rate, the received signal strength parameter, and the CN ratio change. Therefore, the evaluation value uses an equation using the bit error rate, the received signal strength parameter, and the CN ratio, for example, the equation (1). In the range 304, the CN ratio and the received signal strength parameter change. Therefore, the evaluation value uses the expression (3) using the CN ratio and the received signal strength parameter as in the range 302. In range 305, only the received signal strength parameter changes. Therefore, the evaluation value is an expression using only the received signal strength parameter, for example,
Evaluation value = AGC (4)
Is used.

Thus, the cancel signal generation control unit 108 of the broadcast receiving apparatus in the present embodiment controls the cancel signal generation unit 107 according to the evaluation value for each fixed range of the electric field strength. As a result, the broadcast receiving apparatus has a more preferable criterion for determining a cancel signal for noise.

Also, the broadcast receiving apparatus in the present embodiment does not acquire and calculate a state signal with a small change amount. Therefore, the broadcast receiving apparatus can shorten the processing time, and can obtain the appropriate control signal 112 quickly. That is, the broadcast receiving apparatus in the present embodiment uses all the status signals of the bit error rate, the CN ratio of the received signal, and the received signal strength parameter at the same time by using the most effective and minimum status signal. Compared to the case, the convergence time can be shortened.

The broadcast receiving apparatus may use MER as an evaluation value in addition to the bit error rate, the CN ratio of the received signal, and the received signal strength parameter. In the above example, discontinuity of the evaluation value occurs when the range is crossed, but a differential value of the evaluation value may be used so that discontinuity does not occur. In addition, when the range is crossed so that discontinuity does not occur, an offset value may be added to or subtracted from the evaluation value.

In addition, the above-mentioned range division may hold a storage table and read a predetermined division. In addition, the above-described range division may be obtained from the bit error rate, the CN ratio of the received signal, and the amount of change in the received signal strength parameter as appropriate.

(Embodiment 3)
The configuration of the broadcast receiving apparatus in the third embodiment of the present invention is the same as that in FIG. 1 described in the first embodiment. Therefore, the description about the structure of the broadcast receiving apparatus in this Embodiment is abbreviate | omitted. FIG. 3 is a conceptual diagram showing the relationship between the field intensity of the broadcast wave received by the broadcast receiving apparatus according to Embodiment 3 of the present invention and the change point of each state signal. In FIG. 3, the horizontal axis represents the electric field strength of the broadcast wave input to the antenna unit 101. The vertical axis represents the bit error rate, CN ratio, and received signal strength parameter.

The broadcast receiving apparatus according to Embodiment 1 generates a cancel signal for noise inside the broadcast receiving apparatus using an evaluation value that combines a state signal of a bit error rate, a CN ratio of the received signal, and a received signal strength parameter. did. The broadcast receiving apparatus according to the third embodiment has a state signal having a large amount of change for each fixed range of electric field strength in an evaluation value obtained by combining state signals of a bit error rate, a CN ratio of a received signal, and a received signal strength parameter. Use only. An example of the operation of the broadcast receiving apparatus in the present embodiment will be described with reference to FIG.

The range 401 indicates the range of electric field strength where the CN ratio changes most in comparison with the other two according to the change in electric field strength. A range 402 indicates a range of electric field strength where the bit error rate changes most compared to the other two. A range 403 indicates a range of electric field strength where the received signal strength parameter changes most compared to the other two. A range 404 indicates a range of electric field strength where the CN ratio changes most compared to the other two in a region where the electric field strength is strong.

In the range 401, the CN ratio changes most according to the change in the electric field strength. Therefore, the evaluation value uses, for example, Expression (2). In the range 402, the bit error rate changes most according to the change in the electric field strength. Therefore, the evaluation value is, for example,
Evaluation value = BER (5)
Is used. In range 403, the received signal strength parameter changes most according to the change in electric field strength. Therefore, the evaluation value uses, for example, Expression (4). In the range 404, the CN ratio changes most according to the change in the electric field strength. Therefore, the evaluation value uses Expression (2) as in the range 401.

In this way, the cancel signal generation control unit 108 of the broadcast receiving apparatus according to the present embodiment uses any one of the bit error rate, the CN ratio, and the received signal strength parameter for each predetermined range of the electric field strength. The cancel signal generation unit 107 is controlled in accordance with the evaluation value based on the state signal that changes most with respect to the change of. As a result, the broadcast receiving apparatus has a more preferable criterion for determining a cancel signal for noise.

Also, the broadcast receiving apparatus in the present embodiment does not calculate a state signal with little change. Therefore, the broadcast receiving apparatus can shorten the calculation time and can obtain the appropriate control signal 112 quickly. That is, by using the most effective and minimum status signal, the convergence time is shortened compared to the case where all the status signals of the bit error rate, the CN ratio of the received signal, and the received signal strength parameter are used simultaneously. It becomes possible.

The broadcast receiving apparatus may use MER as an evaluation value in addition to the bit error rate, the CN ratio of the received signal, and the received signal strength parameter. Moreover, when straddling the range of electric field strength so that discontinuity does not occur, an offset value may be added to or subtracted from the evaluation value.

In addition, the above-described field intensity range classification may be stored in a storage table and read out in advance. By holding the final setting value for each channel and reading it at the time of channel selection, the setting search position becomes more appropriate, and the convergence time can be shortened.

Also, the above-described field intensity range classification may always be obtained from the bit error rate, the CN ratio of the received signal, and the amount of change in the received signal strength parameter.

(Embodiment 4)
The configuration of the broadcast receiving apparatus according to the fourth embodiment of the present invention is the same as that of FIG. 1 described in the first embodiment. Therefore, the description about the structure of the broadcast receiving apparatus in this Embodiment is abbreviate | omitted. FIG. 4 is a diagram showing a time relationship required for reading each status signal of the broadcast receiving apparatus in Embodiment 4 of the present invention. That is, when the cancel signal generation control unit 108 of the broadcast receiving apparatus requests the signal demodulation unit 104 to simultaneously read out the bit error rate, the CN ratio of the received signal, and the received signal strength parameter, the time required to read out each parameter. Represents. In FIG. 4, a period 601 is a period from when the received signal strength parameter is determined until the bit error rate is determined. A period 602 is a period until the bit error rate is determined after the CN ratio is determined.

For example, in the present embodiment, after the cancel signal generation control unit 108 outputs the control signal 112, the cancel signal generation control unit 108 transmits the bit error rate, the CN ratio, and the received signal strength parameter simultaneously from the signal demodulation unit 104. I can't get it. This is because the response time differs for each state signal as shown in FIG. In order of increasing response time, the received signal strength parameter, CN ratio, and bit error rate.

In order to obtain a set value roughly, first after canceling a new channel, the cancel signal generation control unit 108 uses a received signal strength parameter with a quick response time as an evaluation value. That is, the cancel signal generation control unit 108 first controls the cancel signal generation unit 107 based on the received signal strength parameter. This makes it possible to shorten the period 601 compared to waiting for the output of the CN ratio and the bit error rate. Next, the cancellation signal generation control unit 108 performs adjustment using the received signal strength parameter and the CN ratio as evaluation values. That is, the cancellation signal generation control unit 108 secondly controls the cancellation signal generation unit 107 based on the received signal strength parameter and the CN ratio. This makes it possible to shorten the period 602 as compared with waiting for the output of the bit error rate. Finally, fine adjustment is performed using the received signal strength parameter, CN ratio, and bit error rate as evaluation values. That is, thirdly, the cancel signal generation control unit 108 controls the cancel signal generation unit 107 based on the received signal strength parameter, the CN ratio, and the bit error rate.

In this way, the cancel signal generation control unit 108 of the broadcast receiving apparatus in this embodiment first controls the cancel signal generation unit 107 based on the received signal strength parameter, and secondly, the received signal strength parameter and the CN The cancel signal generation unit 107 is controlled based on the ratio, and thirdly, the cancel signal generation unit 107 is controlled based on the received signal strength parameter, the CN ratio, and the bit error rate. As a result, the broadcast receiving apparatus has a more preferable criterion for determining a cancel signal for noise.

In addition, the broadcast receiving apparatus in the present embodiment can shorten the convergence time compared to the broadcast receiving apparatus in the above-described embodiment.

(Embodiment 5)
FIG. 5 is a block diagram showing a configuration of a broadcast receiving apparatus according to Embodiment 5 of the present invention. In FIG. 5, the same reference numerals are given to the same components as those in the block diagram of the first embodiment shown in FIG. 1, and the detailed description thereof will be omitted.

This embodiment is different from the first embodiment in that a storage unit 201 connected to the cancel signal generation control unit 108 is provided. The cancel signal generation control unit 108 records the final set value of each state signal in the storage unit 201 for each channel when the viewing of the broadcast receiving apparatus ends or when the currently viewed channel is changed. . Then, when the broadcast receiving apparatus is activated or when a new channel is set, the final setting value of each corresponding state signal is read from the storage unit 201.

As described above, the status signal of the broadcast receiving apparatus in the present embodiment is a bit error rate, a CN ratio, and a received signal strength parameter. Furthermore, the broadcast receiving apparatus includes a storage unit 201 that records a bit error rate, a CN ratio, and a received signal strength parameter for each channel. Then, the status signal stored in the storage unit 201 is read when the broadcast receiving apparatus is activated or when a new channel is set. Further, the cancel signal generation control unit 108 starts control of the cancel signal generation unit 107 based on the read state signal. With such a configuration, since the read status signal is a final value after the previous channel selection, it is substantially the same as the convergence value when the broadcast receiving device is activated or when a new channel is set. It is assumed that Therefore, the broadcast receiving apparatus can shorten the convergence time of noise cancellation.

In this embodiment, the storage unit 201 is connected to the cancel signal generation control unit 108. However, as illustrated in FIG. 6, the storage unit 201 may be connected to the cancel signal generation unit 107. Then, the cancel signal generation unit 107 may record the final setting value of each state signal in the storage unit 201 and read it out. In addition to the bit error rate, CN ratio, and received signal strength parameter, MER may be used as the status signal.

(Embodiment 6)
The configuration of the broadcast receiving apparatus according to the sixth embodiment of the present invention is the same as that of FIG. 1 described in the first embodiment or FIG. 5 and FIG. 6 described in the fifth embodiment. In the first to fifth embodiments of the present invention, the control signal 112 that indicates the amplitude and phase of the cancel signal output from the cancel signal generation control unit 108 is an amplitude instruction signal and a phase instruction signal. It is.

An example of how to obtain the two types of control signals 112 described above will be described with reference to FIG. The amplitude instruction signal is represented by r and the phase instruction signal is represented by θ. J (r, θ) represents an evaluation value when the amplitude instruction signal is r and the phase instruction signal is θ. J (r + δr, θ) represents an evaluation value when the minimum amplitude instruction unit δr is added to the amplitude instruction signal r. J (r−δr, θ) represents an evaluation value when the minimum amplitude instruction unit δr is subtracted from the amplitude instruction signal r. The same applies to the phase instruction signal θ. That is, J (r, θ + δθ) represents an evaluation value when the minimum phase indicating unit δθ is added to the phase indicating signal θ. J (r, θ−δθ) represents an evaluation value when the minimum phase indicating unit δθ is subtracted from the phase indicating signal θ.

First, J (r, θ) based on the current amplitude instruction signal r and phase instruction signal θ is obtained. Then, the amplitude instruction signal r is changed to obtain J (r + δr, θ) and J (r−δr, θ). Further, the phase instruction signal θ is changed to obtain J (r, θ + δθ) and J (r, θ−δθ). Among the obtained five evaluation values, the amplitude instruction signal value and the phase instruction signal value when the evaluation value J is the highest are set as the new amplitude instruction signal r and phase instruction signal θ. This is repeated, and the value with the highest evaluation value for the current r and θ is set as the optimum instruction signal.

When J (r + δr, θ) has a higher value than J (r−δθ, θ) and J (r, θ + δθ) has a higher value than J (r, θ−δθ), If J (r + δr, θ + δθ) is the highest, it may be determined as an evaluation value. Accordingly, in this case, r + δr and θ + δθ are set as a new amplitude instruction signal r and phase instruction signal θ, respectively.

Similarly, J (r + δr, θ) has a higher value than J (r−δθ, θ), and J (r, θ−δθ) has a higher value than J (r, θ + δθ). , J (r + δr, θ−δθ) may be judged as the evaluation value when it is the highest. Therefore, in this case, r + δr and θ−δθ are set as a new amplitude instruction signal r and phase instruction signal θ, respectively.

Further, when J (r−δθ, θ) has a higher value than J (r + δr, θ) and J (r, θ + δθ) has a higher value than J (r, θ−δθ), If J (r−δr, θ + δθ) is the highest, the evaluation value may be determined. Therefore, in this case, r−δr and θ + δθ are set as a new amplitude instruction signal r and phase instruction signal θ, respectively.

Furthermore, J (r−δθ, θ) has a higher value than J (r + δr, θ), and J (r, θ−δθ) has a higher value than J (r, θ + δθ). , J (r−δr, θ−δθ) may be determined to be the highest evaluation value. Therefore, in this case, r−δr and θ−δθ are set as new amplitude instruction signal r and phase instruction signal θ, respectively.

In this way, the step for obtaining the evaluation value J required twice is sufficient, and the convergence time can be shortened.

The invention according to the present invention is useful for a receiving apparatus that receives a broadcast wave or the like using noise cancellation.

DESCRIPTION OF SYMBOLS 101 Antenna part 102 Adder part 103 Tuner part 104 Signal demodulator part 105 Video / audio generation part 106 Noise sensor part 107 Cancel signal generation part 108 Cancel signal generation control part 109 Back end part 112 Control signal 201 Storage part J Evaluation value r Amplitude instruction signal θ Phase indication signal δr Minimum amplitude indication unit δθ Minimum phase indication unit

Claims

A broadcast receiver for receiving broadcast waves,
An antenna unit for receiving the radio wave of the broadcast wave;
A noise sensor unit for detecting noise inside the broadcast receiving device;
Input noise supplied from the noise sensor unit, adjust at least one of the phase or amplitude of the noise, and generate a cancellation signal;
An addition unit for adding the signal from the antenna unit and the cancellation signal;
A tuner unit that inputs a signal from the adder unit and outputs a signal of a selected channel;
A signal demodulator that demodulates the signal of the channel and outputs a state signal indicating the state of the signal of the channel output from the tuner unit;
A broadcast receiving apparatus comprising: a cancellation signal generation control unit that controls the cancellation signal generation unit according to the state signal.
The broadcast receiving apparatus according to claim 1, wherein the status signal is an evaluation value obtained by combining a bit error rate, a CN ratio, and a received signal strength parameter.
The broadcast receiving apparatus according to claim 2, wherein the cancel signal generation control unit controls the cancel signal generation unit according to the evaluation value for each predetermined range of electric field strength.
The cancellation signal generation control unit is configured to change the electric field strength most in response to a change in the electric field strength at any one of the bit error rate, the CN ratio, and the received signal strength parameter for each predetermined range of electric field strength. The broadcast receiving apparatus according to claim 2, wherein the cancel signal generation unit is controlled according to the evaluation value based on a signal.
The cancellation signal generation control unit first controls the cancellation signal generation unit based on the reception signal strength parameter, and secondly controls the cancellation signal generation unit based on the reception signal strength parameter and the CN ratio, Thirdly, the broadcast receiving apparatus according to claim 2, wherein the cancel signal generating unit is controlled based on the received signal strength parameter, the CN ratio, and the bit error rate.
A storage unit for recording the status signal for each channel;
When starting the broadcast receiving device or setting a new channel, the status signal stored from the storage unit is read,
The broadcast receiving apparatus according to claim 2, wherein the cancel signal generation control unit starts control of the cancel signal generation unit based on the state signal.
The cancel signal generation control unit sets the amplitude instruction signal of the control signal generated to control the cancel signal generation unit as r and the phase instruction signal as θ,
When the evaluation value is J (r, θ), the minimum amplitude indicating unit of the amplitude indicating signal is δr, and the minimum phase indicating unit δθ of the phase indicating signal is
J (r, θ), J (r + δr, θ), J (r−δr, θ), J (r, θ + δθ), J (r, θ−δθ), where the evaluation value J is the highest The broadcast receiving apparatus according to claim 2, wherein the amplitude instruction signal and the phase instruction signal are set as new amplitude instruction signals and phase instruction signals.
The cancel signal generation control unit
When J (r + δr, θ) has a higher value than J (r−δθ, θ) and J (r, θ + δθ) has a higher value than J (r, θ−δθ),
r + δr and θ + δθ are set as new amplitude instruction signal and phase instruction signal, respectively.
Alternatively, when J (r + δr, θ) has a higher value than J (r−δθ, θ) and J (r, θ−δθ) has a higher value than J (r, θ + δθ),
r + δr and θ−δθ are respectively set as new amplitude indication signal and phase indication signal,
Alternatively, when J (r−δθ, θ) has a higher value than J (r + δr, θ) and J (r, θ + δθ) has a higher value than J (r, θ−δθ),
r−δr and θ + δθ are set as new amplitude instruction signal and phase instruction signal, respectively.
Alternatively, when J (r−δθ, θ) has a higher value than J (r + δr, θ) and J (r, θ−δθ) has a higher value than J (r, θ + δθ),
The broadcast receiving apparatus according to claim 7, wherein r-δr and θ-δθ are set as a new amplitude instruction signal and phase instruction signal, respectively.