JP2010193369A - Receiving system and receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for accurately acquiring a noise suppression original, with respect to a technique for suppressing by acquiring the noise suppression source signal. <P>SOLUTION: A receiving system 1 for receiving a radio signal including a desired signal is provided with: a CPU 30 for setting an acquisition frequency in accordance with a frequency of the radio wave in which the desired signal is included; a main antenna 32 for acquiring a reception signal by receiving the radio wave including the desired signal; a sub antenna 33 for acquiring a noise suppression source signal in accordance with the acquisition frequency set by the CPU 30; and a noise canceler 34 for suppressing noise in the reception signal obtained by the main antenna 32 based on the noise suppression source signal obtained by the sub antenna 33. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a technique for suppressing noise mixed in a desired signal with a noise suppression signal, and obtaining a noise suppression original signal that is a source of the noise suppression signal with high accuracy and efficiently extracting the desired signal. .

  The technology for receiving a desired signal using radio is configured to receive a transmitted radio wave with an antenna and extract the desired signal. For example, in a system for realizing terrestrial digital broadcasting, a television receiver used for viewing terrestrial digital broadcasting is provided with an antenna for receiving radio waves, and radio waves transmitted from broadcasting stations are received and received by the antennas. A technique for extracting a signal of a desired channel from radio waves is used.

  On the other hand, there is a problem that a noise signal different from a desired signal is mixed in the received signal acquired by the antenna. Therefore, techniques for removing the mixed noise signal are described in, for example, Patent Document 1 and Patent Document 2. In Patent Document 1 and Patent Document 2, first, a signal predicted to form noise is acquired as a noise suppression original signal, and the obtained noise suppression original signal is subjected to phase control and amplitude control to generate noise. Generate a suppression signal. And the technique which cancels the noise component in the said received signal with a noise suppression signal by synthesize | combining the produced | generated noise suppression signal with the received signal acquired by the antenna is described.

JP 2008-022294 A JP 2008-066684 A

  However, in the above technique, signal wiring and ground are used as noise sources, and for example, noise generated from inside the IC cannot be acquired as a noise suppression source signal. That is, there is a problem that noise sources that can be dealt with are limited. Further, when a ground is used as a noise source, adjustment (trial and error adjustment) is required to separate the ground signal and the ground signal of the noise canceller IC, and the merits of the noise canceller IC cannot be fully enjoyed. There is also a problem. In addition, when the ground signal is not sufficiently separated, the noise cancellation IC cannot sufficiently amplify the noise signal, and there is a problem that the noise cannot be suppressed.

  On the other hand, although a technique for receiving an original signal for noise suppression by an antenna has been proposed, a large antenna is required to receive a wide-band radio wave, so a noise signal originally used for auxiliary purposes is required. There is a problem that the receiving antenna becomes large. For example, in the UHF band, an antenna having a length of about 30 cm is required. There is also a problem that the noise signal receiving antenna acquires a noise signal (a signal that is not necessary for noise suppression).

  This invention is made | formed in view of the said subject, and it aims at providing the technique which acquires the original signal for noise suppression accurately in the technique which acquires the original signal for noise suppression and suppresses noise. .

  In order to solve the above problems, the invention of claim 1 is a receiving system for receiving a radio wave including a desired signal, and setting means for setting an acquisition frequency according to the frequency of the radio wave including the desired signal. A main antenna that receives a radio wave including the desired signal and acquires a received signal, a signal acquisition unit that acquires a noise suppression original signal according to an acquisition frequency set by the setting unit, and the signal acquisition Noise suppression means for suppressing noise of the received signal acquired by the main antenna based on the noise suppression original signal acquired by the means.

  Further, the invention of claim 2 is the receiving system according to the invention of claim 1, wherein the noise acquisition means receives radio waves in accordance with the acquisition frequency set by the setting means, and is a noise suppression original signal. It is the subantenna which acquires

  The invention of claim 3 is the receiving system according to the invention of claim 2, characterized in that the sub-antenna is arranged inside the receiving system.

  According to a fourth aspect of the present invention, there is provided a receiving system for receiving a radio wave including a desired signal, wherein a main antenna that receives the radio wave including the desired signal and converts it into a received signal; Based on the sub-antenna that receives the radio wave in the arranged state and acquires the original signal for noise suppression, and the original signal for noise suppression received by the sub-antenna, the noise of the received signal acquired by the main antenna Noise suppression means for suppressing.

  The invention according to claim 5 is the receiving system according to claim 3 or 4, wherein the main body includes a first connection portion therein, and the second connection portion is connected to the first connection portion of the main body. The module is configured to be detachably attached to the main body by connecting the second connection portion to the first connection portion, and the sub-antenna includes the second antenna. It is provided in the vicinity of the connecting portion.

  A sixth aspect of the invention is a receiving system according to any one of the first to fifth aspects of the present invention, and is configured as a portable system having portability.

  The invention according to claim 7 is the receiving system according to any one of claims 1 to 6, wherein the signal represents a digital terrestrial broadcast program from the received signal in which noise is suppressed by the noise suppressing means. Is further provided with a tuner for extracting the signal as the desired signal.

  The invention according to claim 8 is the receiving system according to any one of claims 1 to 7, wherein the main antenna can set the frequency of the received radio wave according to the desired signal. It is possible.

  The invention of claim 9 is a receiving method for receiving a radio wave including a desired signal, wherein (a) a step of setting an acquisition frequency according to a frequency of the radio wave including the desired signal; ) Receiving a radio wave including the desired signal and acquiring a received signal; (c) acquiring a noise suppression source signal according to the acquisition frequency set in the step (a); And (b) a step of suppressing noise of the received signal acquired in the step (b) based on the noise suppression original signal acquired in the step (c).

  The invention of claim 10 is the receiving method according to the invention of claim 9, wherein (e) a step of evaluating the received signal in which noise is suppressed in the step (d), and (f) the (e And (d) a step of controlling a noise suppression level in the step according to the evaluation in the step.

  The invention according to any one of claims 1 to 3 includes a setting unit that sets an acquisition frequency according to a frequency of a radio wave including a desired signal, a main antenna that receives a radio wave including the desired signal and acquires a reception signal; The signal acquisition means for acquiring the noise suppression original signal according to the acquisition frequency set by the setting means, and the received signal acquired by the main antenna based on the noise suppression original signal acquired by the signal acquisition means By providing the noise suppression means that suppresses noise, it is possible to suppress acquisition of a signal that is not necessary for noise suppression, and thus it is possible to efficiently suppress noise.

  According to the third aspect of the present invention, since the sub-antenna is arranged inside the receiving system, noise generated inside the receiving system can be acquired effectively.

  According to the fourth aspect of the present invention, a main antenna that receives a radio wave including a desired signal and converts it into a received signal, and receives the radio wave in a state of being placed inside the receiving system to obtain a noise suppression original signal. Noise generated inside the reception system by including a sub-antenna that suppresses noise of the received signal acquired by the main antenna based on the original signal for noise suppression received by the sub-antenna. Can be effectively suppressed.

  Since the invention according to claim 6 is configured as a portable system having portability, the effect is remarkable as compared with a stationary reception system.

  The invention described in claim 7 further includes a tuner that takes out a signal representing a digital terrestrial broadcast program as a desired signal from the received signal whose noise is suppressed by the noise suppressing means, so that a radio wave having a relatively narrow band can be obtained. As compared with a receiving system that only has to receive the signal, the effect is remarkable.

  In the invention according to claim 8, since the main antenna can set the frequency of the received radio wave according to the desired signal, it receives only the radio wave of the necessary frequency. Mixing noise is reduced.

  The invention according to claim 9 is set with a step of setting an acquisition frequency according to a frequency of a radio wave including a desired signal, a step of receiving a radio wave including the desired signal and acquiring a received signal. It is necessary for noise suppression by having a step of acquiring a noise suppression original signal according to the acquisition frequency and a step of suppressing noise of the acquired reception signal based on the acquired noise suppression original signal. Since acquisition of no signal can be suppressed, noise can be suppressed efficiently.

  The invention according to claim 10 includes: (e) evaluating the received signal in which noise is suppressed in the step (d); and (f) step (d) according to the evaluation in the step (e). In addition, since the so-called feedback control can be realized, the noise suppression effect can be enhanced.

It is a figure which shows the structure of the receiving system which concerns on this invention. It is a block diagram of a receiving system. 3 is a flowchart illustrating a reception method according to the present invention. 3 is a flowchart illustrating a reception method according to the present invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

<1. Embodiment>
FIG. 1 is a diagram showing a configuration of a receiving system 1 according to the present invention. FIG. 2 is a block diagram of the receiving system 1.

  In the following description, the receiving system 1 will be described as a system that receives terrestrial digital broadcasting. That is, in this embodiment, the desired signal is a signal that mainly represents one program in terrestrial digital broadcasting. However, the present invention is not limited to a system that receives radio waves of terrestrial digital broadcasting, and can be widely applied to systems that receive signals (desired signals) transmitted wirelessly.

  As shown in FIG. 1, the reception system 1 includes a main body 2 and a module 3 that is detachably attached to the main body 2, and receives a radio wave including a desired signal transmitted from a broadcasting station 9. It is configured as a system. In FIG. 1, only one broadcasting station 9 is illustrated, but the number of broadcasting stations 9 is not limited to this.

  The main body 2 includes an input unit 20 for an operator to input information, a display unit 21 that mainly displays an image, and an audio reproduction unit 22 that emits sound. In addition, a control unit 23 having a function of controlling each component of the receiving system 1 and a slot unit 24 for detachably attaching the module 3 are provided inside the main body unit 2.

  The input unit 20 is mainly configured by buttons and keys. The operator can input desired information to the receiving system 1 by operating the input unit 20. In particular, in the receiving system 1 in the present embodiment, channel information 28 (information for designating a program desired by the operator) is input from the input unit 20.

  Note that the input unit 20 is not limited to buttons and keys, and may include, for example, a joystick or a mouse that is externally connected to the main unit 2, or by touching the surface of the display unit 21. A touch panel for inputting information may be used. Further, the input information is not limited to the instruction information, and the main body unit 2 may include a microphone for inputting audio information and a camera for inputting image information as the input unit 20.

  The display unit 21 is configured as a general liquid crystal panel, and mainly plays video of a program in terrestrial digital broadcasting. In addition, although illustration is abbreviate | omitted, the display part 21 also contains the lamp | ramp, LED, etc. which display the operation condition of the receiving system 1, etc. That is, the display unit 21 is hardware having a function of visually providing some information to the operator in the receiving system 1.

  The audio reproduction unit 22 is a device that operates in accordance with a control signal from the control unit 23 and generates audio based on the audio signal. In particular, in the present embodiment, the audio reproduction unit 22 reproduces the audio of a program in terrestrial digital broadcasting. In the present embodiment, the sound reproducing unit 22 is described as a speaker built in the main body unit 2. However, for example, an earphone connected to the main body unit 2 through a plug may be adopted as the sound reproducing unit 22. These may be used together.

  As shown in FIG. 2, the control unit 23 is mainly composed of a CPU 25 that executes calculation of various data and a storage device 26 that stores various data such as a program 27 and channel information 28. Thereby, the control unit 23 has a function as a computer that operates by executing the program 27, and controls each component of the reception system 1.

  The slot part 24 is provided inside the main body part 2 and is physically and electrically connected to the interface part 37 of the module 3. As described above, by mounting the module 3 in the slot 24, data can be transmitted and received between the main body 2 and the module 3, and power can be supplied from the main body 2 to the module 3. It becomes.

  With the above configuration, the main unit 2 (reception system 1) is configured as a portable terminal device having a function as a general computer. In addition, as such a portable terminal device, a notebook personal computer, a portable game machine, a mobile phone, etc. can be considered, but of course, it is not limited to this.

  In a portable system such as the reception system 1, the direction in which the radio wave is transmitted (relative positional relationship between the reception system 1 and the broadcast station 9) changes from time to time. Therefore, for example, the conventional method of relatively suppressing noise by giving directivity to the main antenna 32 and directing the main antenna 32 in the direction in which the radio wave from the broadcasting station 9 is most strongly received is a stationary type. It is not effective compared with the system.

  In recent years, noise generated by devices tends to increase. However, since a portable system needs to be designed to be a portable size, the main body 2 is a noise source. However, it is difficult to install the main antenna 32 at a position far from the noise source (main body 2).

  That is, compared to a stationary system, a portable system such as the receiving system 1 has a unique situation that it is difficult to suppress noise by a conventional method.

  The module 3 includes a CPU 30, a storage device 31, a main antenna 32, a sub antenna 33, a noise canceller 34, a tuner 35, an OFDM demodulator 36, and an interface unit 37.

  The CPU 30 controls each component of the module 3 by executing the program 38 and performs data communication with the CPU 25 of the main body unit 2 through the interface unit 37 and the slot unit 24.

  When the channel information 28 is newly input in the main body 2, the CPU 30 acquires the input channel information 28 from the control unit 23 and obtains a desired signal (channel information) indicated by the channel information 28. The frequency information 39 is updated so that the frequency of the radio wave including the signal of the program of the channel indicated by 28 is included. From the time when the receiving system 1 is turned on until the first channel information 28 is input, the frequency information 39 stores an initial value (for example, the frequency corresponding to the last viewed channel). And

  Further, the CPU 30 has a function of setting and controlling the reception frequency of the main antenna 32, the tuning frequency of the tuner 35, and the acquisition frequency of the sub antenna 33 according to the frequency information 39.

  The reception frequency is a parameter for controlling the main antenna 32, which is a tunable antenna, and the CPU 30 sets the main antenna 32 so that the frequency of the radio wave received by the main antenna 32 becomes the set reception frequency. Control. The acquisition frequency is a parameter for controlling the sub-antenna 33, which is a tunable antenna, and the CPU 30 sets the sub-antenna 33 so that the frequency of the radio wave received by the sub-antenna 33 becomes the set reception frequency. Control. Further, the tuning frequency is a control parameter of the tuner 35, and the CPU 30 controls the tuner 35 so as to extract a radio wave signal of the tuning frequency from a signal (received signal) input to the tuner 35.

  Further, the CPU 30 has a function of controlling the noise canceller 34 according to the suppression parameter 40 while changing (adjusting) the suppression parameter 40 according to an evaluation value (described later) calculated by the OFDM demodulator 36. . The suppression parameter 40 is a parameter for controlling the noise suppression level in the noise canceller 34. The suppression parameter 40 includes a parameter for determining a signal level (amplification factor) and a parameter for determining a phase difference between the noise suppression original signal (input signal) and the noise suppression signal (output signal).

  The storage device 31 is a device that stores various data such as the program 38 executed by the CPU 30, the frequency information 39, and the suppression parameter 40. A part or all of the program 38 stored in the storage device 31 may be loaded into the main body unit 2 and executed by the CPU 25 of the control unit 23.

  The main antenna 32 has a function of receiving a radio wave including a desired signal and acquiring a received signal. The reception signal acquired by the main antenna 32 is combined with an output signal (noise suppression signal) from the noise canceller 34 to be a reception signal in which noise is suppressed and then input to the tuner 35.

  The main antenna 32 in the present embodiment is configured as a tunable antenna capable of setting (changing) the frequency (reception frequency) of a received radio wave. For example, a tunable antenna having a structure in which a variable capacitance element is connected to an antenna portion formed of a chip or a pattern is known. In such a tunable antenna, the receivable frequency can be changed by controlling the variable capacitance element with an external voltage. However, the structure of the main antenna 32 is not limited to this.

  In the present embodiment, as described above, the reception frequency of the main antenna 32 is set by the CPU 30 in accordance with the frequency information 39 determined based on the channel information 28. In this way, by controlling the frequency (reception frequency) of the radio wave received by the main antenna 32 according to the channel that the operator wants to view, it is possible to receive only the radio wave of the frequency necessary for viewing. . Therefore, noise mixed in the received signal is reduced as compared with the case where the received signal is acquired while receiving radio waves in all bands.

  In the terrestrial digital broadcast receiving system 1, when radio waves of all bands used for terrestrial digital broadcast are received simultaneously, the band of the received radio waves is wide (430 to 730 [MHz]), so noise mixed in the received signal is generated. Increase. Even when a desired signal is extracted from the received signal by the tuner 35 described later, noises at frequencies other than the frequency corresponding to the desired signal cannot be completely removed (detailed principles are not described).

  On the other hand, an operator who is a viewer of digital terrestrial broadcasting does not need information on all channels at the same time. That is, the receiving system 1 only needs to be able to receive a sufficient amount of radio waves instantaneously to reproduce a program that the operator wants to watch.

  Therefore, when the main antenna 32 is configured as a tunable antenna, the reception system 1 that receives digital terrestrial broadcasting must continuously receive a relatively wide band of radio waves. This is particularly effective for a system that needs to receive only a relatively narrow band of radio waves. However, the main antenna 32 is not limited to a tunable antenna.

  The sub-antenna 33 has a function as a signal acquisition unit that acquires a noise suppression original signal input to the noise canceller 34. The noise suppression original signal acquired by the sub-antenna 33 is input to the noise canceller 34.

  In the present embodiment, if a signal approximate to the noise signal mixed in the reception signal of the main antenna 32 can be acquired as the noise suppression source signal, the noise suppression effect by the noise canceller 34 is enhanced.

  As shown in FIG. 2, in the present embodiment, the sub antenna 33 is provided in the vicinity of the interface unit 37. Therefore, the sub-antenna 33 is disposed inside the main body 2 in a state where the module 3 is mounted on the main body 2 (a state where the reception system 1 operates).

  In a portable system like the receiving system 1, it is difficult to dispose the main antenna 32 at a position far from the main body 2. As described above, when the main antenna 32 is disposed in the vicinity of the noise source, noise generated from the main body 2 (device) is strongly mixed into the received signal.

  However, since the sub-antenna 33 in the present embodiment is disposed inside the main body 2, the sub-antenna 33 receives radio waves (not noise) from the broadcasting station 9 as compared with the case where it is exposed to the outside. While suppressing, since the noise which generate | occur | produces inside the main-body part 2 can be acquired effectively, the noise suppression effect improves.

  Further, the noise canceller 34 performs adjustment by AGC (Auto Gain Control) so that the signal to be amplified is not saturated. That is, since the amplification factor is determined according to the signal with the largest level, if a signal with a large level exists in a band that is not necessary for noise suppression, the signal in the band necessary for noise suppression is not sufficiently amplified, and noise The problem that the suppression effect falls occurs.

  However, the sub-antenna 33 in the present embodiment is configured as a tunable antenna like the main antenna 32, and receives radio waves according to the acquisition frequency set by the CPU 30, and acquires a noise suppression original signal. To do. That is, since it is configured not to receive radio waves in a band that is not necessary for noise suppression (band other than the acquisition frequency), a signal necessary for noise suppression can be sufficiently amplified, and the noise suppression effect by the noise canceller 34 can be obtained. Will improve.

  The noise canceller 34 suppresses the noise of the reception signal acquired by the main antenna 32 based on the original signal for noise suppression acquired by the sub antenna 33. The principle of the noise canceller 34 is not described in detail because conventional techniques can be used as appropriate. However, the noise canceller 34 amplifies the noise suppression original signal according to the suppression parameter 40 and shifts its phase (mostly). A noise suppression signal is generated by simply inverting the phase, and the generated noise suppression signal is combined with the reception signal acquired by the main antenna 32. Thereby, the noise signal mixed in the received signal is canceled by the noise suppression signal, and the noise of the received signal is suppressed.

  The interface unit 37 is connected to the slot unit 24 by being inserted into the slot unit 24 of the main body unit 2 as described above. Thus, the module 3 has a structure that is detachably attached to the main body 2. As shown in FIG. 1, the receiving system 1 is configured as a portable system that is portable even when the module 3 is mounted on the main body 2.

  The above is the description of the structure and function of the receiving system 1. Next, a reception method for receiving radio waves of digital terrestrial broadcasting using the reception system 1 will be described.

  3 and 4 are flowcharts showing a receiving method according to the present invention. Note that “SET” in the following description is a flag indicating whether or not the channel has been changed, and it is assumed that “1” is stored as an initial value at the start of the processing shown in FIG. In the initial state, it is assumed that the noise canceller 34 is controlled by the CPU 30 according to the initial value of the suppression parameter 40.

  When the module 3 is mounted on the main body 2 and the power of the receiving system 1 is turned on, the CPU 30 newly inputs the channel information 28 in the main body 2, and the updated channel information 28 is transmitted from the control unit 23. It is determined whether or not (step S11). That is, in the receiving system 1, every time the operator operates the input unit 20 of the main unit 2 and inputs an instruction to change the channel of terrestrial digital broadcasting, it is determined Yes in step S11.

  When it is determined Yes in step S11, the CPU 30 sets the value of SET to “1” (step S12), and updates the frequency information 39 stored in the storage device 31 according to the transmitted channel information 28. (Step S13). More specifically, the frequency of the radio wave corresponding to the channel indicated in the channel information 28 is set as new frequency information 39.

  On the other hand, when it determines with No in step S11, CPU30 skips step S12, S13. Therefore, in this case, the frequency information 39 is not updated.

  Next, the CPU 30 determines whether or not the value of SET is “0” (step S14). If the value of SET is “0” (No in step S14), the processing of steps S15 to S18 is skipped.

  If the SET value is “1” in step S14, the CPU 30 determines Yes in step S14, and sets the SET value to “0” (step S15).

  When step S15 is executed, the CPU 30 sets a tuning frequency according to the frequency information 39 and controls the tuner 35 (step S16). As a result, the signal that the tuner 35 subsequently extracts from the received signal is a radio wave signal having the frequency indicated in the frequency information 39 at this time. Since the frequency information 39 stores the frequency corresponding to the channel to be viewed, the signal taken out by the tuner 35 is the signal of the channel to be viewed.

  Further, the CPU 30 sets a reception frequency according to the frequency information 39 and controls the main antenna 32 (step S17). Thereby, the frequency of the radio wave received by the main antenna 32 thereafter becomes the radio wave of the frequency indicated in the frequency information 39 at this time, and becomes the radio wave of the channel to be viewed.

  Further, the CPU 30 sets an acquisition frequency according to the frequency information 39 and controls the sub antenna 33 (step S18). Thereby, the frequency of the radio wave received by the sub-antenna 33 thereafter becomes the radio wave of the frequency indicated in the frequency information 39 at this time, and the radio wave of the same frequency as the radio wave of the viewing channel.

  By executing steps S16 to S18, the control of the tuner 35, the main antenna 32, and the sub antenna 33 by the CPU 30 is completed. As a result, reception of radio waves of the reception frequency by the main antenna 32 is started thereafter, and acquisition of reception signals by the main antenna 32 is started (step S19). In addition, reception of radio waves of the acquisition frequency by the sub antenna 33 is started, and acquisition of the noise suppression original signal by the sub antenna 33 is started (step S21).

  The noise suppression original signal acquired by the sub-antenna 33 is input to the noise canceller 34, and the noise canceller 34 generates a noise suppression signal according to the input noise suppression original signal and the suppression parameter 40 (step S22). Furthermore, the noise suppression signal output from the noise canceller 34 is combined with the reception signal acquired by the main antenna 32, and noise is suppressed (step S23).

  The received signal in which noise is suppressed is input to the tuner 35, and a signal (desired signal) of a channel to be viewed is taken out by the tuner 35 (step S24) and demodulated into digital data by the OFDM demodulator 36 (step S25). . At this time, the OFDM demodulator 36 measures the bit error rate (BER) of the demodulated digital data and the carrier noise ratio (CNR) of the received signal input to the tuner 35, and uses these as evaluation values (step S26). .

  The demodulated digital data and the evaluation value obtained by the calculation are transmitted from the OFDM demodulator 36 to the CPU 30. The digital data is transmitted toward the main body 2 and reproduced on the display unit 21 and the audio reproduction unit 22. Thus, a digital terrestrial broadcast program is provided to the operator of the reception system 1.

  On the other hand, whether or not the evaluation value is appropriate is determined by the CPU 30 (step S27). Only when the evaluation value is not appropriate, the CPU 30 controls the noise canceller 34 by changing the suppression parameter 40 (step S28). Thus, the noise suppression level can be controlled by evaluating the noise suppression by the noise canceller 34 and changing the suppression parameter 40 for the noise canceller 34 accordingly.

  For example, when a portable system is in a moving state, the reception state changes constantly. For this reason, when the radio wave level of terrestrial digital broadcasting is low and the noise of the main body 2 is relatively large, it is necessary to cancel strongly. On the other hand, if the reception state is good and the radio wave of the terrestrial digital broadcasting is sufficiently strong compared to the noise of the main unit 2, the cancellation is weakened (or turned off). In addition, when the module 3 is connected to the main body 2 as shown in FIG. 2, the suppression parameter 40 may not be adjusted in advance depending on the combination of the main body 2 and the module 3. However, the receiving system 1 can realize appropriate noise suppression according to the situation by such feedback control. Of the suppression parameters 40, the change according to the evaluation value is not limited to the amplification factor, and the phase difference can also be changed.

  Next, it is determined whether or not to end the viewing (step S29). When the viewing ends, the process ends. If the viewing is not terminated (No in step S29), the process returns to step S12 and continues.

  As described above, the reception system 1 that receives a radio wave including a desired signal includes a CPU 30 that sets an acquisition frequency according to the frequency of the radio wave that includes the desired signal, and noise according to the acquisition frequency set by the CPU 30. A sub-antenna 33 that acquires the original signal for suppression, and a noise canceller 34 that suppresses noise of the received signal acquired by the main antenna 32 based on the original signal for noise suppression acquired by the sub-antenna 33 are provided. Thereby, since it can suppress acquiring the signal which is not required for noise suppression as a noise suppression original signal, noise can be suppressed efficiently.

  In addition, since the main antenna 32 and the sub-antenna 33 are configured as tunable antennas, the apparatus can be reduced in size. Therefore, in the receiving system 1 configured as a portable system having portability, the portability is improved. This is particularly effective.

<2. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made.

  For example, the steps described above are merely examples, and the contents and order thereof may be changed as appropriate as long as the same effects can be obtained. For example, the processes of steps S16 to S18 may be executed in any order.

  Further, a part or all of the functions described as being realized by the CPU 25 or the CPU 30 operating according to the program 27 or the program 38 may be realized by a dedicated logic circuit, or realized by hardware such as the noise canceller 34. Then, you may comprise so that a part or all of the function demonstrated may be implement | achieved by software processing.

  Further, the relative positional relationship between the main body 2 and the sub-antenna 33 is fixed during the operation of the receiving system 1. Therefore, the sub-antenna 33 may be provided with directivity to selectively receive a signal from a noise source that generates particularly large noise inside the main body 2. Thereby, the sub antenna 33 can acquire noise more efficiently.

  Further, the signal acquisition means is limited to the tunable antenna (sub antenna 33) as long as the frequency of the noise suppression original signal to be acquired can be selected (restricted) according to the acquisition frequency set by the CPU 30. is not.

  Moreover, although the receiving system 1 in the said embodiment employ | adopted the structure which can attach or detach the module 3 to the main-body part 2, an integrated device may be sufficient.

  Further, the reception system 1 in the above embodiment has been described as a portable system in which the effects of the present invention are significant. However, the present invention is not limited to a portable system, and has an excellent effect that noise can be suppressed even in a stationary system.

DESCRIPTION OF SYMBOLS 1 Reception system 2 Main-body part 20 Input part 21 Display part 22 Audio | voice reproduction | regeneration part 23 Control part 24 Slot part 25 CPU
26 storage device 27 program 28 channel information 3 module 30 CPU
31 storage device 32 main antenna 33 sub antenna 34 noise canceller 35 tuner 36 OFDM demodulator 37 interface unit 38 program 39 frequency information 40 suppression parameter 9 broadcast station

Claims (10)

A receiving system for receiving radio waves including a desired signal,
Setting means for setting an acquisition frequency according to the frequency of the radio wave including the desired signal;
A main antenna for receiving a radio wave including the desired signal and obtaining a received signal;
Signal acquisition means for acquiring an original signal for noise suppression according to the acquisition frequency set by the setting means;
Based on the noise suppression original signal acquired by the signal acquisition means, noise suppression means for suppressing noise of the reception signal acquired by the main antenna;
A receiving system comprising: The receiving system according to claim 1,
The reception system according to claim 1, wherein the noise acquisition unit is a sub-antenna that receives a radio wave according to the acquisition frequency set by the setting unit and acquires a noise suppression original signal. The receiving system according to claim 2,
The receiving system, wherein the sub-antenna is arranged inside the receiving system. A receiving system for receiving radio waves including a desired signal,
A main antenna that receives a radio wave including the desired signal and converts it into a received signal;
A sub-antenna that receives radio waves in a state of being arranged inside the receiving system and obtains a noise-suppressing original signal;
Based on the original signal for noise suppression received by the sub-antenna, noise suppression means for suppressing noise of the received signal acquired by the main antenna;
A receiving system comprising: The receiving system according to claim 3 or 4,
A main body having a first connection portion therein;
A module comprising a second connection connected to the first connection of the body;
With
The module has a structure that is detachably attached to the main body by connecting the second connection portion to the first connection portion.
The receiving system, wherein the sub-antenna is provided in the vicinity of the second connecting portion. A receiving system according to any one of claims 1 to 5,
A receiving system configured as a portable system having portability. A receiving system according to any one of claims 1 to 6,
A receiving system, further comprising: a tuner that extracts a signal representing a digital terrestrial broadcast program as the desired signal from the received signal whose noise is suppressed by the noise suppressing means. A receiving system according to any one of claims 1 to 7,
The receiving system according to claim 1, wherein the main antenna can set a frequency of a radio wave to be received according to the desired signal. A reception method for receiving radio waves including a desired signal,
(a) setting an acquisition frequency according to a frequency of a radio wave including the desired signal;
(b) receiving a radio wave including the desired signal to obtain a received signal;
(c) acquiring a noise suppression source signal according to the acquisition frequency set in the step (a);
(d) based on the noise suppression original signal acquired in the step (c), the step of suppressing the noise of the received signal acquired in the step (b),
A receiving method comprising: The reception method according to claim 9, comprising:
(e) evaluating the received signal in which noise is suppressed in the step (d),
(f) according to the evaluation in the step (e), the step of controlling the noise suppression level in the step (d),
The receiving method further comprising:

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