JP4603462B2 - Relay device - Google Patents

Description

  The present invention relates to a relay device, and more particularly to a relay device that relays a signal formed by a plurality of channels.

  In a broadcasting system such as a television broadcasting system, a signal is transmitted as an electromagnetic wave from a broadcasting station. The receiver receives a signal transmitted from the broadcast station, and acquires image information, audio information, and the like from the received signal. For signals transmitted by a broadcasting station, provisions such as transmission power and desired signal-to-interference wave ratio are established so that information of a predetermined quality can be obtained at a receiver existing in an area where the broadcasting station is a broadcasting area. . However, even if a broadcasting station transmits a signal that satisfies the regulations, if there are electromagnetic wave obstacles or the like in the broadcasting area, the electric field strength of the signal received by the receiver becomes insufficient, and the predetermined quality in the broadcasting area. There is a region where information on this is not available. Therefore, in order to reduce such quality degradation areas, a relay apparatus that receives a signal transmitted from a broadcasting station, amplifies and transmits the signal is installed in the broadcasting area.

  For example, the relay device receives an analog modulated signal formed by a plurality of channels by a receiving antenna, and outputs the received signal to a duplexer. The duplexer separates the received signal into channels. That is, the duplexer outputs a signal obtained by attenuating a signal in a frequency band other than the desired channel. The duplexer outputs a plurality of signals to a plurality of in-channel band amplification units. Each of the in-channel amplifying units amplifies a channel unit signal, and then converts it to an intermediate frequency band signal. In addition, after performing band limitation for attenuating a signal other than a desired channel, amplification is performed at an intermediate frequency, and the signal is again converted to a broadcast frequency band and then amplified. The amplified signals are output to the multiplexer. The multiplexer combines a plurality of signals. The signal synthesized by the multiplexer is transmitted as an electromagnetic wave via the transmission antenna.

Such a relay device separates a received signal into a plurality of channels, and individually performs band limitation and amplification on the frequency bands of the respective channels. This reduces as much as possible the interference wave caused by the intermodulation generated by the analog modulation signals of different channel frequency bands mutually affecting each other or the noise superimposed on the frequency band close to each channel frequency band. (For example, refer to Patent Document 1).
JP 2000-324036 A

  In recent years, digital television broadcasting that transmits information using a digitally modulated signal has been used, and an analog modulation signal and a digital modulation signal are mixed. Even in such a situation, the above-described relay device is used. In general, digital television broadcasting is composed of more channels than conventional television broadcasting. Therefore, in the above-described configuration, an in-channel amplifying unit corresponding to the number of channels is required, so that as the number of channels increases, the circuit becomes a large-scale configuration and the manufacturing cost increases. On the other hand, in general, the electric field strength of a signal received by the relay device differs for each channel. Therefore, if the amplification factor in the relay device is common to all channels, the electric field strength of the signal transmitted by the relay device also differs for each channel. As a result, even if a relay device is installed, it is difficult to obtain the effect of reducing the quality degradation area for all channels.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a relay device that relays signals formed by a plurality of channels while suppressing an increase in circuit scale.

In order to solve the above problems, a relay apparatus according to an aspect of the present invention should extract a reception unit that receives a signal including a plurality of frequency-multiplexed channels and a signal that should be received by the reception unit. A setting unit for setting at least two channels, a generation unit for generating frequency characteristics for extracting at least two channels set in the setting unit, and a signal received at the reception unit by the frequency characteristics generated at the generation unit A filter unit that extracts at least two channels, and a transmission unit that transmits at least two channels extracted by the filter unit as frequency-multiplexed signals. The generation unit measures the intensity for each of at least two channels and reduces the gain for the measured channel with a high intensity when generating a frequency characteristic that extracts at least two channels. intensities saw including a means for increasing the gain for small channels of generation unit is previously plural types retain the frequency characteristic for extracting a plurality of channels as the tap coefficients in the time domain, the setting unit Signal strength for each of at least two channels set in the setting unit and means for selecting a corresponding tap coefficient from the plurality of types of time-domain tap coefficients held according to the set at least two channels And a means for outputting the measured signal intensity while associating it with the channel number; Means for receiving the signal strength corresponding to each of the channels to be obtained, reducing the gain for the channel with a high signal strength, increasing the gain for the channel with a low signal strength, and the gain for the channel to be extracted as an amplification factor Means for amplifying the tap coefficient with the amplification factor corresponding to the channel, and means for synthesizing the amplified tap coefficient corresponding to each channel .
Another aspect of the present invention is also a relay device. The apparatus includes: a receiving unit that receives a signal including a plurality of frequency-multiplexed channels; a setting unit that sets at least two channels to be extracted from signals to be received by the receiving unit; and a setting unit A generating unit that generates a frequency characteristic for extracting at least two set channels; a filter unit that extracts at least two channels from a signal received at the receiving unit by the frequency characteristic generated by the generating unit; and a filter unit And a transmission unit that transmits at least two channels extracted in (2) as frequency-multiplexed signals. The generation unit measures the intensity for each of at least two channels and reduces the gain for the measured channel with a high intensity when generating a frequency characteristic that extracts at least two channels. And a means for increasing the gain for the low-intensity channel, wherein the generation unit generates at least two frequency characteristics such that each of the at least two channels is switched, and the intensity of the at least two channels. Means for switching and measuring, and means for stopping the measurement after measuring the intensity of at least two channels.

  According to this aspect, the frequency characteristic for extracting a desired channel is used for one filter unit, and the frequency characteristic reflecting the intensity of the channel unit is used. The difference in intensity between channels can be reduced.

  Yet another embodiment of the present invention is also a relay device. The apparatus includes: a receiving unit that receives a signal including a plurality of frequency-multiplexed channels; a setting unit that sets at least two channels to be extracted from signals to be received by the receiving unit; and a setting unit A generating unit that generates a frequency characteristic for extracting at least two set channels, a filter unit that extracts at least two channels from a signal received by the receiving unit by the frequency characteristic generated by the generating unit, and a filter unit And a transmission unit that transmits at least two channels extracted in (2) as frequency-multiplexed signals. The generation unit holds in advance a plurality of types of frequency characteristics for extracting each of a plurality of channels as tap coefficients in the time domain, and the plurality of types of time stored in accordance with at least two channels set in the setting unit Means for selecting a corresponding tap coefficient from among the tap coefficients of the region, and means for generating a frequency characteristic for extracting at least two channels by combining the selected tap coefficients.

  According to this aspect, since the time domain tap coefficient is held in advance, the process of converting the frequency characteristic value into the time domain can be omitted, and an increase in the processing amount can be suppressed.

  Another aspect of the present invention is a receiving device. The apparatus includes: a receiving unit that receives a signal including a plurality of frequency-multiplexed channels; a setting unit that sets at least two channels to be extracted from signals to be received by the receiving unit; and a setting unit A generation unit that generates a frequency characteristic for extracting at least two set channels, and a filter unit that extracts at least two channels from a signal received by the reception unit based on the frequency characteristic generated by the generation unit. The generation unit measures the intensity for each of at least two channels and reduces the gain for the measured channel with a high intensity when generating a frequency characteristic that extracts at least two channels. And a means for increasing the gain for the low-intensity channel.

  Another embodiment of the present invention is also a receiving device. The apparatus includes: a receiving unit that receives a signal including a plurality of frequency-multiplexed channels; a setting unit that sets at least two channels to be extracted from signals to be received by the receiving unit; and a setting unit At least two filter units for extracting at least two channels separately from a signal received at the reception unit while having frequency characteristics for separately extracting at least two set channels, and at least two filter units For each of the extracted at least two channels, a measurement unit that measures the intensity, and a gain for each of the at least two channels is set based on the intensity measured in the measurement unit, and at least two channels are set according to the set gain. At least two channels extracted in the filter And a amplifier for respectively amplifying. The amplifying unit decreases the gain for the high-intensity channel measured in the measurement unit, and increases the gain for the low-intensity channel measured in the measurement unit.

  Yet another embodiment of the present invention is also a receiving device. The apparatus includes: a receiving unit that receives a signal including a plurality of frequency-multiplexed channels; a setting unit that sets at least two channels to be extracted from signals to be received by the receiving unit; and a setting unit A generation unit that generates a frequency characteristic for extracting at least two set channels, and a filter unit that extracts at least two channels from a signal received by the reception unit based on the frequency characteristic generated by the generation unit. The generation unit holds in advance a plurality of types of frequency characteristics for extracting each of a plurality of channels as tap coefficients in the time domain, and the plurality of types of time stored in accordance with at least two channels set in the setting unit Means for selecting a corresponding tap coefficient from among the tap coefficients of the region, and means for generating a frequency characteristic for extracting at least two channels by combining the selected tap coefficients.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, signals formed by a plurality of channels can be relayed while suppressing an increase in circuit scale.

  Before describing the present invention in detail, an outline will be described. An embodiment of the present invention relates to a relay apparatus that receives a signal including a plurality of frequency-multiplexed channels, amplifies the received signal, and transmits the amplified signal. The plurality of channels include signals that are compatible with digital television broadcasting and that are digitally modulated. Since digital television broadcasting includes many channels, the processing in the relay device is performed in units of channels, and if the processing in units of channels is performed by another circuit, the circuit scale increases. End up. Further, if the amplification factors for a plurality of channels are set to a uniform value, a difference in transmission power occurs between channels in a signal transmitted from the relay device. As a result, since there are channels with low transmission power, it is difficult to provide uniform quality for a plurality of channels. In the present embodiment, the following processing is executed in order to solve the above problems.

  The relay apparatus according to the present embodiment specifies in advance at least two channels to be relayed among a plurality of channels. In addition, a frequency characteristic that transmits at least two specified channels and attenuates the other channels is set for one filter. One filter extracts at least two channels from a plurality of received channels. In addition, the relay apparatus measures the reception intensity for each of the extracted at least two channels. When the relay apparatus derives the above-described frequency characteristic, the relay apparatus reflects the measured reception intensity of each channel. That is, the frequency characteristic is derived while increasing the amplification factor for a channel with low reception strength and decreasing the amplification factor for a channel with high reception strength. As a result, frequency characteristics with different amplification factors for each channel are derived. Finally, the relay apparatus combines at least two extracted channels and then transmits them.

  FIG. 1 shows a configuration of a relay device 100 according to an embodiment of the present invention. The relay device 100 includes a reception antenna 10, a reception filter 12, a reception amplification unit 14, a frequency converter 16, a frequency converter 22, a transmission amplification unit 24, a transmission filter 26, a transmission antenna 28, an A / D converter 40, a digital input An output filter 42, a D / A converter 44, a local oscillator 46, a channel input unit 48, a characteristic calculation unit 50, a characteristic synthesis unit 52, a normalized value calculation unit 56, and an electric field strength measurement unit 58 are included.

  The receiving antenna 10 receives a signal formed by a plurality of channels. The plurality of channels are frequency multiplexed. The plurality of channels includes a channel corresponding to digital television broadcasting and a channel corresponding to conventional analog television broadcasting. The reception antenna 10 outputs the received signal to the reception filter 12. The reception filter 12 attenuates the portion outside the band of the entire plurality of channels with respect to the signal received by the reception antenna 10. The reception amplification unit 14 amplifies the signal from the reception filter 12.

The frequency converter 16 converts the broadcast frequency band signal from the reception amplification unit 14 into an intermediate frequency band signal and outputs the signal to the A / D converter 40. In addition to the signal of the broadcast frequency band from the reception amplification unit 14, the local oscillator signal L ₁ from the local oscillator 46 is also input to the frequency converter 16. Frequency converter 16 converts the signal of a broadcast frequency band to an intermediate frequency band signal by multiplying a local oscillator signal L ₁ to a signal of a broadcast frequency band.

Specifically, if the frequency of the local oscillator signal L ₁ is f _osc1 and the broadcast frequency band is a frequency band from the frequency f ₁ to the frequency f ₂ , the intermediate frequency band is from the frequency f ₁ −f _osc1 to the frequency f. The frequency band is up to ₂ −f _osc1 . Here, it is assumed that there is a relationship of f _osc1 <f ₁ <f ₂ . The processing by the frequency converter 16 generates an unnecessary image signal in the frequency band from the frequency f ₁ + f _osc1 to the frequency f ₂ + f _osc1, but this image signal is attenuated by the configuration _subsequent to the frequency converter 16. The The A / D converter 40 converts the intermediate frequency band signal into a digital signal and outputs the digital signal to the digital input / output filter 42.

  The channel input unit 48 sets at least two channels to be extracted from signals to be received. Here, at least two channels to be extracted correspond to channels to be relayed by the relay device 100. The channel input unit 48 has an interface for the user, and receives an instruction regarding a channel to be extracted from the user. For example, when a “channel number” is defined for each of a plurality of channels, the channel input unit 48 receives a channel number from the user.

  The characteristic calculation unit 50 generates a frequency characteristic that extracts at least two channels set in the channel input unit 48. The characteristic calculation unit 50 stores in advance frequency characteristics for extracting each of the plurality of channels. That is, frequency characteristics corresponding to a plurality of channel numbers are stored while associating channel numbers with frequency characteristics. Further, the characteristic calculator 50 selects a frequency characteristic corresponding to the channel number set in the channel input unit 48. Here, the characteristic calculation unit 50 stores in advance the frequency characteristics corresponding to each of the plurality of channels as time domain tap coefficients, and stores the plurality of types of time domain tap coefficients stored in accordance with the set at least two channels. Select the appropriate tap coefficient from

  The characteristic synthesizer 52 determines a frequency characteristic of a digital input / output filter 42 described later by synthesizing a plurality of frequency characteristics selected by the characteristic calculator 50. That is, the characteristic synthesis unit 52 determines the tap coefficient in the digital input / output filter 42 by synthesizing the tap coefficient selected by the characteristic calculation unit 50.

  Here, an outline of operations performed by the channel input unit 48, the characteristic calculation unit 50, and the characteristic synthesis unit 52 will be described. As described above, the channel input unit 48, the characteristic calculation unit 50, and the characteristic synthesis unit 52 determine the time domain tap coefficients of the channel input unit 48. Here, for the sake of simplicity, FIG. The frequency domain characteristics will be described using (a) to (f), and the description of the time domain characteristics will be described later. 2A to 2F show an outline of derivation of frequency characteristics by the characteristic calculation unit 50. FIG.

  The channel input unit 48, the characteristic calculation unit 50, and the characteristic synthesis unit 52 in FIG. 1 calculate the tap coefficient based on the input of the channel number of the broadcasting station whose broadcasting area is the area where the relay device 100 is installed. In FIG. 2A, the aforementioned “channel number” is indicated by the first channel 200 to the sixth channel 210. Here, as shown in FIG. 2A, the fifth channel 208 is assigned to the broadcasting station of the analog television broadcasting system, and the first channel 200 to the fourth channel 206 and the sixth channel 210 are the digital television. It is assumed that it is assigned to a broadcasting station of the John broadcasting system. Note that the third channel 204 is assigned to a broadcasting station of a digital television broadcasting system in which the area where the relay device 100 is installed is not a broadcasting area.

The channel input unit 48, the characteristic calculation unit 50, and the characteristic synthesis unit 52 calculate tap coefficients according to the following processes (1) to (10), and input them to the digital input / output filter 42 described later.
(1) Channel number of the broadcasting station of the digital television broadcasting system and channel number of the broadcasting station of the analog television broadcasting system are separately input to the channel input unit 48. However, it is assumed that the input channel number is assigned to a broadcasting station whose broadcasting area is the area where the relay device 100 is installed. In the example of FIG. 2A, the first channel 200, the second channel 202, the fourth channel 206, and the sixth channel 210 are input as channels of the digital television broadcasting system, and the fifth channel 208 is the analog television broadcasting system. Input as a channel. The channel input unit 48 outputs the input channel number to the characteristic calculation unit 50.

(2) The characteristic calculation unit 50 stores a channel frequency band corresponding to the channel number in advance, and calculates a broadcast frequency band based on the input channel number. From the calculated relationship between the predetermined intermediate frequency band as broadcast frequency bands to determine the frequency of the local oscillator signal L _1, local oscillator 46 sets the frequency of the local oscillator signal L ₁ to be output.
(3) The characteristic calculation unit 50 is input as the channel number of the digital television broadcast system or the channel number of the analog television broadcast system among the channel numbers of the channel frequency bands included in the calculated broadcast frequency band. It is recognized that the channel number that is not assigned is a channel number assigned to a broadcasting station that does not set the area where the relay apparatus 100 is installed as a broadcasting area. A function representing a band removal characteristic for attenuating a signal in the channel frequency band corresponding to the channel number is calculated and output to the characteristic combining unit 52. This function is assumed to be a function of frequency domain expression, and is hereinafter referred to as a band elimination characteristic function. In the example of FIG. 2A, it corresponds to the third channel 204, and the band elimination characteristic function is shown as in FIG.

(4) The characteristic calculator 50 calculates a band removal characteristic function for attenuating the signal in the channel frequency band corresponding to the channel number of the analog television broadcasting system, and outputs the band removal characteristic function to the characteristic synthesizer 52. In the example of FIG. 2A, since the analog television broadcasting system corresponds to the fifth channel 208, the band elimination characteristic function is shown as in FIG.
(5) The characteristic calculation unit 50 searches for the channel frequency band to be extracted that is the lowest among the channel numbers of the digital television broadcasting system.
(6) The characteristic calculator 50 calculates a function representing a high-pass characteristic having the low frequency end of the channel frequency band corresponding to the searched channel number as a cutoff frequency, and outputs the function to the characteristic synthesizer 52. This function is assumed to be a function of frequency domain expression, and is hereinafter referred to as a high-pass characteristic function. In the example of FIG. 2 (a), the channel of the digital television broadcasting system having the lowest channel frequency band is the first channel 200, and the high-pass characteristic function is shown as in FIG. 2 (d). .

(7) The characteristic calculation unit 50 searches for the channel frequency band to be extracted that is the highest in the channel numbers of the digital television broadcasting system.
(8) The characteristic calculator 50 calculates a function representing a low-pass characteristic having the high frequency end of the channel frequency band corresponding to the searched channel number as a cutoff frequency, and outputs the function to the characteristic synthesizer 52. This function is assumed to be a function of frequency domain expression, and hereinafter referred to as a low-pass characteristic function. In the example of FIG. 2A, the channel of the digital television broadcasting system having the highest channel frequency band is the sixth channel 210, and the low-pass characteristic function is shown as in FIG.
(9) The characteristic synthesis unit 52 calculates a characteristic function obtained by multiplying the band elimination characteristic function, the high-pass characteristic function, and the low-pass characteristic function. In the example of FIG. 2A, the calculated characteristic function is shown as in FIG.
(10) The characteristic synthesizer 52 performs inverse Fourier transform on the characteristic function to calculate the characteristic function of time domain expression, calculates the tap coefficient by discretizing it, and outputs it to the digital input / output filter 42 described later To do.

  Returning to FIG. The digital input / output filter 42 extracts at least two channels from the signal from the A / D converter 40 based on the tap coefficient set by the characteristic synthesis unit 52. That is, the filter characteristics of the digital input / output filter 42 are determined by setting a tap coefficient in the digital input / output filter 42. In this embodiment, the tap coefficient is input from the characteristic synthesis unit 52. The digital input / output filter 42 is configured by an FIR (Finite Impulse Response) filter. The digital input / output filter 42 inputs an intermediate frequency band signal subjected to band limitation to the D / A converter 44.

  In addition, another operation | movement is added to the description mentioned above for the operation | movement of the characteristic calculation part 50 in a present Example. Before explaining the added operation, the problem with respect to the signal output from the digital input / output filter 42 according to the above explanation will be described with reference to FIGS. 3A to 3C show the problem of the frequency characteristic derived by the characteristic calculation unit 50. FIG. FIG. 3A shows a signal input to the digital input / output filter 42 as in FIG. The first channel 200, the third channel 204, the fourth channel 206, the sixth channel 210 to the eighth channel 214 are input as the channels of the above-mentioned digital television broadcasting system, and the second channel 202 and the fifth channel 208 are analog televisions. It is input as a channel of John broadcasting system. Note that the signal strengths of the first channel 200, the third channel 204, the fourth channel 206, and the sixth channel 210 to the eighth channel 214 are different due to the influence of fading or the like.

  FIG. 3B shows a frequency characteristic calculated by the characteristic calculation unit 50 and then synthesized by the characteristic synthesis unit 52. This corresponds to the frequency characteristic in the digital input / output filter 42. Note that FIG. 3B corresponds to FIG. FIG. 3C shows a signal output by the digital input / output filter 42. As shown in the figure, channels corresponding to the digital television broadcasting system are extracted. Further, the signal intensity for each extracted channel is different as in FIG. That is, the frequency characteristics set by FIG. 3B have a uniform amplification factor for the first channel 200, the third channel 204, the fourth channel 206, and the sixth channel 210 to the eighth channel 214. Therefore, the signal strength in FIG. 3A is reflected in the signal strength in FIG. As a result, since there are channels with low signal strength, it is difficult to provide uniform quality for a plurality of channels. In order to solve such a problem, the characteristic calculation unit 50 performs an additional operation.

  Returning to FIG. The electric field strength measuring unit 58 measures the signal strength for each of at least two channels from the digital input / output filter 42. Specifically, the electric field strength measuring unit 58 measures the signal strength within the channel band for each channel. That is, the electric field strength measuring unit 58 converts the time domain signal input from the digital input / output filter 42 into a frequency domain signal by discrete Fourier transform. Here, the signal in the frequency domain is shown as numerical data corresponding to the frequency value. Further, the electric field strength measurement unit 58 derives the signal strength of the channel by integrating the numerical data in units of channels. The electric field strength measurement unit 58 outputs the measured signal strength to the normalized value calculation unit 56 while associating it with the channel number. Further, the normalized value calculation unit 56 receives the signal strength corresponding to each channel to be extracted from the electric field strength measurement unit 58. When generating the frequency characteristics, the normalization value calculation unit 56 decreases the gain for a channel with a high signal strength and increases the gain for a channel with a low signal strength. For example, the normalized value calculation unit 56 derives a value corresponding to the reciprocal of the signal strength and sets it as the amplification factor in the channel corresponding to the signal strength. The characteristic calculation unit 50 generates a frequency characteristic that extracts at least two channels as described above while reflecting the gain derived by the normalized value calculation unit 56. Details will be described later.

  A signal output from the digital input / output filter 42 by the operation as described above will be described with reference to FIGS. 4A to 4C correspond to FIGS. 3A to 3C, respectively. FIG. 4A is the same as FIG. FIG. 4B shows the frequency characteristic calculated by the characteristic calculation unit 50 and then synthesized by the characteristic synthesis unit 52, as in FIG. 3B. As described above, based on the signal strength measured by the electric field strength measurement unit 58, the characteristic calculation unit 50 derives the frequency characteristic while changing the amplification factor for each channel. Therefore, a small amplification factor is derived for a channel having a high received signal strength, such as the first channel 200 and the seventh channel 212 in FIG. In addition, a large amplification factor is derived for a channel whose received signal strength is small, such as the third channel 204 and the sixth channel 210 in FIG. FIG. 4C shows a signal output by the digital input / output filter 42. As shown in the figure, the signal intensity for each extracted channel is an equivalent value.

Returning to FIG. The D / A converter 44 converts the input signal into an analog signal and inputs the analog signal to the frequency converter 22. The frequency converter 22 converts the intermediate frequency band signal into a broadcast frequency band signal and inputs the signal to the transmission amplification unit 24. The frequency converter 22 multiplies the intermediate frequency band signal by the local oscillator signal L ₁ to convert the intermediate frequency band signal into a broadcast frequency band signal. If the broadcast frequency band of the signal converted by the frequency converter 22 and the broadcast frequency band of the signal input at the receiving antenna 10 are equal, a sneak wave is generated between them. Therefore, the relay apparatus 100 may be provided with a wraparound canceller (not shown). Here, since the wraparound canceller is realized by a known technique, description thereof is omitted.

  The transmission amplifier 24 amplifies the signal in the broadcast frequency band and inputs it to the transmission filter 26. The transmission filter 26 attenuates the image signal included outside the broadcast frequency band of the input signal, the harmonic component signal due to the nonlinearity of the transmission amplifier 24, and the like, and inputs the attenuated signal to the transmission antenna 28. The transmission antenna 28 transmits the input signal as an electromagnetic wave. That is, at least two channels extracted by the digital input / output filter 42 are transmitted as a frequency multiplexed signal.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it is realized by a program having a communication function loaded in the memory. Describes functional blocks realized by collaboration. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  FIG. 5 shows a configuration of the characteristic calculation unit 50. The characteristic calculator 50 includes a first memory 60a, a second memory 60b, a third memory 60c, a fourth memory 60d, a fifth memory 60e, a sixth memory 60f, a seventh memory 60g, and an eighth memory, which are collectively referred to as the memory 60. 60h, first switch 62a, second switch 62b, third switch 62c, fourth switch 62d, fifth switch 62e, sixth switch 62f, seventh switch 62g, eighth switch 62h, amplifying unit First amplifying section 64a, second amplifying section 64b, third amplifying section 64c, fourth amplifying section 64d, fifth amplifying section 64e, sixth amplifying section 64f, seventh amplifying section 64g, and eighth amplifying section. Part 64h is included.

  The memory 60 stores a time domain waveform corresponding to a frequency characteristic for extracting each channel. Here, the first memory 60a stores a time-domain waveform corresponding to the frequency characteristics for extracting the first channel 200 of FIG. The same applies to the memories 60 other than the first memory 60a, and one memory 60 stores a time-domain waveform corresponding to the frequency domain for extracting one channel. FIGS. 6A to 6H show waveforms stored in the memory 60. FIG. On the left side of FIGS. 6A to 6H, frequency characteristics for extracting each channel are shown. Here, FIG. 6A corresponds to the first channel 200, and FIGS. 6B to 6H also correspond to the second channel 202 to the eighth channel 214, respectively. 6A to 6H, on the right side, a time domain waveform corresponding to the frequency characteristic on the left side is shown. These are stored in the memory 60, respectively.

  Returning to FIG. When information about a channel to be extracted is input from the channel input unit 48, the switch 62 turns on the corresponding channel. In the example of FIG. 4A, since the first channel 200, the third channel 204, the fourth channel 206, the sixth channel 210, the seventh channel 212, and the eighth channel 214 are selected, the first switch 62a, The third switch 62c, the fourth switch 62d, the sixth switch 62f, the seventh switch 62g, and the eighth switch 62h are turned on. The remaining switches 62 are turned off.

  The amplification unit 64 receives the amplification factor from the normalized value calculation unit 56 and amplifies the waveform from the switch 62 by the received amplification factor. As described above, since the amplification factor from the normalized value calculation unit 56 generally has different values in units of channels, the amplification unit 64 outputs waveforms having different amplitudes in units of channels. The characteristic synthesis unit 52 receives the waveform amplified by the amplification unit 64 and synthesizes the received waveform to generate a tap coefficient. Note that the synthesis in the characteristic synthesis unit 52 is executed in units of each value of the normalization time. The characteristic synthesis unit 52 outputs the generated tap coefficient to the digital input / output filter 42. The digital input / output filter 42 sets the accepted tap coefficient.

  The operation of the relay device 100 configured as above will be described. The channel input unit 48 receives a channel to be extracted in advance. The characteristic calculator 50 and the characteristic synthesizer 52 generate tap coefficients according to the channel to be extracted. The tap coefficient is set in the digital input / output filter 42. The digital input / output filter 42 inputs a signal received via the receiving antenna 10 and extracts a desired channel from the received signal. The extracted channel signal is transmitted. Here, the electric field strength measurement unit 58 measures the signal strength for each of the extracted channels, and the normalized value calculation unit 56 derives the amplification factor for each channel according to the signal strength. The characteristic calculator 50 and the characteristic synthesizer 52 reflect the amplification factor for each channel when generating the tap coefficients.

  According to the embodiment of the present invention, for one digital input / output filter, a frequency characteristic that extracts a desired channel and a frequency characteristic that reflects the signal strength of each channel is used. The difference in signal strength between channels can be reduced while suppressing an increase in circuit scale. Further, since the channel to be extracted can be set by the user, the channel to be extracted can be easily changed as necessary. In addition, since the signal strength measurement result is reflected in the tap coefficient, it is possible to execute control according to the actual reception status. Further, since control according to the actual reception situation is executed, it is possible to follow fluctuations in the propagation path. In addition, since the difference in signal strength between channels can be reduced, the quality degradation area can be reduced for all channels. In addition, since the time domain tap coefficient is stored in advance, the process of converting the frequency characteristic value into the time domain can be omitted, and an increase in the processing amount can be suppressed.

  In addition, by utilizing the fact that the influence of the intermodulation signal generated in the adjacent channel frequency band is due to the digital modulation signal is smaller than that due to the analog modulation signal, One input / output filter. In addition, the influence of the interference wave generated by the noise superimposed on the frequency band close to each channel frequency band, such as the interference wave generated in the adjacent channel frequency band at the time of frequency conversion, is also due to the analog modulation signal Compared to a digital modulation signal, the digital input / output filter can be integrated into one. This is a signal in which a large amount of power is concentrated in a narrow frequency band while an analog modulation signal is a signal in which power is distributed with a uniform density in a channel frequency band. It is because. That is, if the signals have the same power, the lower the power density in the frequency domain, the smaller the influence on the adjacent channel frequency band.

(Modification 1)
The modification 1 of this invention is related with the relay apparatus by which the tap coefficient which adjusted the gain for every channel is used like an Example. However, in the embodiment, adjustment of the amplification factor is executed by feedback processing, whereas in Modification 1, adjustment of the amplification factor is executed by feedforward processing.

  FIG. 7 shows a configuration of the relay device 100 according to the first modification of the present invention. The components included in the relay device 100 of FIG. 7 are the same as the components included in the relay device 100 of FIG. The electric field strength measurement unit 58 receives not the signal from the digital input / output filter 42 but the signal from the A / D converter 40. The electric field strength measurement unit 58 measures the signal strength for each of at least two channels included in the signal from the digital input / output filter 42. The signal intensity is measured in the same manner as in the example. The normalized value calculation unit 56 derives amplification factors corresponding to at least two channels as described above based on the signal strength from the electric field strength measurement unit 58. Further, the characteristic calculation unit 50 generates a frequency characteristic that extracts at least two channels as described above while reflecting the gain derived by the normalized value calculation unit 56.

  The operation of the relay device 100 configured as above will be described. The channel input unit 48 receives a channel to be extracted in advance. The characteristic calculator 50 and the characteristic synthesizer 52 generate tap coefficients according to the channel to be extracted. Here, the electric field strength measurement unit 58 measures the signal strength for each of the channels included in the received signal, and the normalized value calculation unit 56 derives the amplification factor for each channel according to the signal strength. To do. The characteristic calculator 50 and the characteristic synthesizer 52 reflect the amplification factor for each channel when generating the tap coefficients. The tap coefficient is set in the digital input / output filter 42. The digital input / output filter 42 inputs a signal received via the receiving antenna 10 and extracts a desired channel from the received signal. The extracted channel signal is transmitted.

  According to the first modification of the present invention, the frequency characteristic that extracts a desired channel and reflects the signal strength of each channel is used for one digital input / output filter. The difference in signal strength between channels can be reduced while suppressing an increase in circuit scale. Further, since the channel to be extracted can be set by the user, the channel to be extracted can be easily changed as necessary. In addition, since the signal strength measurement result is reflected in the tap coefficient, it is possible to execute control according to the actual reception status. Further, since control according to the actual reception situation is executed, it is possible to follow fluctuations in the propagation path. Further, since the amplification factor is controlled by feedforward control, it is possible to follow even if the propagation path changes to some extent. Since the difference in signal strength between channels can be reduced, quality degradation areas can be reduced for all channels. In addition, since the time domain tap coefficient is stored in advance, the process of converting the frequency characteristic value into the time domain can be omitted, and an increase in the processing amount can be suppressed.

(Modification 2)
Similarly to the embodiment, the second modification of the present invention also relates to a relay device using a tap coefficient whose gain is adjusted for each channel. In the embodiment, signal strengths for a plurality of channels are measured in parallel. However, in the second modification, after measuring the signal strength for one channel, the signal strength for another channel is measured.

  FIG. 8 shows a configuration of a relay device 100 according to a modification of the present invention. In the relay device 100 of FIG. 8, a switch 70 is added to the relay device 100 of FIG. The other configuration of relay apparatus 100 in FIG. 8 is the same as that of relay apparatus 100 in FIG. Note that the relay device 100 according to the second embodiment adjusts the amplification factor when not performing the relay operation but performing the reception operation in the preceding stage.

  The characteristic calculator 50 and the characteristic synthesizer 52 generate at least two frequency characteristics that extract each of at least two channels. That is, the output is performed while changing the tap coefficient that transmits each channel. The digital input / output filter 42 is set while switching tap coefficients from the characteristic synthesis unit 52. As a result, the digital input / output filter 42 outputs a signal corresponding to one channel, and after a predetermined period, outputs a signal corresponding to another channel.

  The electric field strength measurement unit 58 performs measurement while switching the signal strength of at least two channels. The electric field strength measurement unit 58 receives information about the channel corresponding to the currently measured signal from the channel input unit 48. Since a known technique is used for the measurement in the electric field strength measurement unit 58, the description is omitted here. The electric field strength measurement unit 58 outputs the measurement result to the normalized value calculation unit 56. The normalized value calculation unit 56, the characteristic calculation unit 50, and the characteristic synthesis unit 52 determine the tap coefficient as in the embodiment. The electric field strength measuring unit 58 stops the measurement when measuring the signal strength of at least two channels. In addition, when the measurement is stopped, the electric field intensity measurement unit 58 switches the switch 70 from OFF to ON. Thereafter, the relay device 100 performs a relay operation.

  The operation of the relay device 100 configured as above will be described. The channel input unit 48 receives a channel to be extracted in advance. In the reception operation mode, the characteristic calculation unit 50 and the characteristic synthesis unit 52 generate a tap coefficient according to one of the channels to be extracted. The tap coefficient is set in the digital input / output filter 42. The digital input / output filter 42 receives a signal received via the receiving antenna 10 and extracts one channel from the received signal. Here, the electric field strength measuring unit 58 measures the signal strength for each of one channel. In addition, the characteristic calculation unit 50, the characteristic synthesis unit 52, the digital input / output filter 42, and the electric field strength measurement unit 58 measure the signal strength in the same manner for other channels. The normalized value calculation unit 56 derives an amplification factor for each channel according to the signal strength.

  In the relay operation mode, the characteristic calculator 50 and the characteristic synthesizer 52 generate tap coefficients according to the channels to be extracted. The characteristic calculator 50 and the characteristic synthesizer 52 reflect the amplification factor for each channel when generating the tap coefficients. The tap coefficient is set in the digital input / output filter 42. The digital input / output filter 42 inputs a signal received via the receiving antenna 10 and extracts a desired channel from the received signal. The extracted channel signal is transmitted.

  According to the second modification of the present invention, since the intensity of one channel is measured at a predetermined moment, the instantaneous processing amount can be reduced. Moreover, since it is only necessary to measure the intensity of one channel, an increase in circuit scale can be suppressed.

(Modification 3)
The third modification of the present invention relates to a relay apparatus that adjusts the amplification factor for each channel, as in the embodiment. In the embodiment, one digital input / output filter is provided, and a tap coefficient whose amplification factor is adjusted for each channel is used. However, in the third modification example, a digital input / output filter is provided so as to correspond to each of the plurality of channels, and a fixed tap coefficient is used for each digital input / output filter. In the third modification, the amplitude is adjusted in units of channels for signals output from a plurality of digital input / output filters. With the above processing, the third modification reduces the processing amount of the electric field strength measurement unit.

  FIG. 9 shows a configuration of the relay device 100 according to the third modification of the present invention. The repeater 100 includes a first digital input / output filter 42a, a second digital input / output filter 42b, a third digital input / output filter 42c, a fourth digital input / output filter 42d, an eighth digital input, which are collectively referred to as a digital input / output filter 42. The output filter 42h includes a first amplifying unit 64a, a second amplifying unit 64b, a third amplifying unit 64c, a fourth amplifying unit 64d, an eighth amplifying unit 64h, and a synthesizing unit 72. The other components are the same as those of the relay device 100 in FIG.

  The channel input unit 48 sets at least two channels to be extracted from signals to be received by the receiving unit. As described above, the channel input unit 48 has an interface for the user, and receives an instruction regarding a channel to be extracted from the user. The characteristic calculation unit 50 selects a channel number set in the channel input unit 48 from a plurality of channel numbers. The characteristic combining unit 52 instructs the digital input / output filter 42 corresponding to the channel number selected by the characteristic calculating unit 50 to operate. For example, when the first channel 200 in FIG. 4 is selected, the characteristic synthesis unit 52 instructs the first digital input / output filter 42a to operate.

  The plurality of digital input / output filters 42 store in advance the frequency characteristics for extracting the channels corresponding to each. That is, one digital input / output filter 42 extracts one channel. Of the plurality of digital input / output filters 42, the one selected by the characteristic synthesizer 52 operates, and the other filters stop operating. The digital input / output filter 42 separately extracts at least two channels from the signal from the A / D converter 40.

  The electric field strength measuring unit 58 and the normalized value calculating unit 56 operate in the same manner as in the embodiment, and the normalized value calculating unit 56 derives the amplification factor for each channel. As described above, the normalization value calculation unit 56 decreases the amplification factor for the high-intensity channel and increases the amplification factor for the low-intensity channel. The amplification unit 64 sets the amplification factor derived by the normalized value calculation unit 56 and for each of at least two channels. The amplifying unit 64 amplifies at least two channels extracted by the digital input / output filter 42 according to the set amplification factor. The synthesizer 72 synthesizes at least two channels amplified by the amplifier 64 and generates a frequency-multiplexed signal.

  According to the third modification of the present invention, since the value corresponding to the channel to be extracted is used as it is among the frequency characteristics held in advance for a plurality of digital input / output filters, the processing can be simplified. Moreover, since the processing can be simplified, an increase in circuit scale can be suppressed. Moreover, since the amplification factor reflecting the intensity of each channel is used, the difference in signal intensity between channels can be reduced.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the embodiment of the present invention, the characteristic calculator 50 and the characteristic synthesizer 52 derive the tap coefficient of the digital input / output filter 42 while using the amplification factor derived by the normalized value calculator 56. However, the present invention is not limited to this. For example, the characteristic calculation unit 50 and the characteristic synthesis unit 52 may derive the tap coefficient of the digital input / output filter 42 without using the amplification factor derived by the normalized value calculation unit 56. . That is, the channel input unit 48 sets at least two channels to be extracted from the signals to be received, and the characteristic calculation unit 50 and the characteristic synthesis unit 52 extract frequency characteristics that extract at least two set channels. Is generated. Here, the characteristic calculation unit 50 holds a plurality of types of frequency characteristics for extracting each of a plurality of channels as time domain tap coefficients in advance, and corresponds to at least two channels set in the channel input unit 48. The corresponding tap coefficient is selected from the plurality of types of time domain tap coefficients held. Further, the characteristic combining unit 52 generates a frequency characteristic that extracts at least two channels by combining the selected tap coefficients. The digital input / output filter 42 extracts at least two channels from the received signal according to the generated frequency characteristic. The transmission amplifier 24 transmits the extracted at least two channels as a frequency-multiplexed signal. According to this modification, since the time domain tap coefficient is stored in advance, the process of converting the frequency characteristic value into the time domain can be omitted, and an increase in the processing amount can be suppressed. That is, it is sufficient if the digital input / output filter 42 can be integrated.

  In the embodiment of the present invention and the first to third modifications, the relay device 100 is described. However, the present invention is not limited to this. For example, the present invention may be applied to a receiving apparatus. The configuration of the receiving apparatus corresponds to the relay apparatus 100 according to the embodiment and the first to third modifications, in which functions related to transmission are omitted. According to this modification, a plurality of channels can be received with substantially uniform quality in a receiving apparatus including a plurality of tuners.

It is a figure which shows the structure of the relay apparatus based on the Example of this invention. 2A to 2F are diagrams showing an outline of derivation of frequency characteristics by the characteristic calculation unit of FIG. FIGS. 3A to 3C are diagrams showing a problem of frequency characteristics derived by the characteristic calculation unit of FIG. 4A to 4C are diagrams showing an input signal spectrum to the digital input / output filter, a frequency characteristic derived by the characteristic calculation unit in FIG. 1, and an output signal spectrum of the digital input / output filter, respectively. It is a figure which shows the structure of the characteristic calculation part of FIG. FIGS. 6A to 6H are diagrams showing waveforms stored in the memory of FIG. It is a figure which shows the structure of the relay apparatus which concerns on the modification 1 of this invention. It is a figure which shows the structure of the relay apparatus which concerns on the modification 2 of this invention. It is a figure which shows the structure of the relay apparatus which concerns on the modification 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Reception antenna, 12 Reception filter, 14 Reception amplification part, 16 Frequency converter, 22 Frequency converter, 24 Transmission amplification part, 26 Transmission filter, 28 Transmission antenna, 40 A / D converter, 42 Digital input / output filter, 44 D / A converter, 46 local oscillator, 48 channel input unit, 50 characteristic calculation unit, 52 characteristic synthesis unit, 56 normalized value calculation unit, 58 electric field strength measurement unit, 100 relay device.

Claims (2)

A receiver for receiving a signal including a plurality of frequency-multiplexed channels;
A setting unit for setting at least two channels to be extracted from signals to be received by the receiving unit;
A generating unit that generates a frequency characteristic for extracting at least two channels set in the setting unit;
A filter unit that extracts at least two channels from the signal received by the receiving unit according to the frequency characteristics generated by the generating unit;
A transmission unit that transmits at least two channels extracted in the filter unit as a frequency-multiplexed signal;
The generation unit reduces the gain for the channel having a large measured intensity when generating the frequency characteristic for extracting the intensity for each of at least two channels and the frequency characteristic for extracting at least two channels, look including a means for increasing the gain for the measured intensity of small channels,
The generation unit holds a plurality of types of frequency characteristics for extracting each of a plurality of channels as time domain tap coefficients in advance, and holds the plurality of types according to at least two channels set in the setting unit The signal strength is measured for each of at least two channels set in the setting unit and the means for selecting the corresponding tap coefficient from the time domain tap coefficients, and the measured signal strength corresponds to the channel number. Output means, receiving signal strength corresponding to each channel to be extracted, reducing gain for a channel with high signal strength, increasing gain for a channel with low signal strength, and Tap with gain corresponding to each channel with gain as gain Means for amplifying the number of relay apparatus characterized by comprising: means for combining the tap coefficients amplified corresponding to each channel. A receiver for receiving a signal including a plurality of frequency-multiplexed channels;
A setting unit for setting at least two channels to be extracted from signals to be received by the receiving unit;
A generating unit that generates a frequency characteristic for extracting at least two channels set in the setting unit;
A filter unit that extracts at least two channels from the signal received by the receiving unit according to the frequency characteristics generated by the generating unit;
A transmission unit that transmits at least two channels extracted in the filter unit as a frequency-multiplexed signal;
The generation unit reduces the gain for the channel having a large measured intensity when generating the frequency characteristic for extracting the intensity for each of at least two channels and the frequency characteristic for extracting at least two channels, Means for increasing the gain for a measured low intensity channel,
The generating unit generates at least two frequency characteristics such as extracting each of at least two channels, and measures at least two channel strengths, and measures at least two channel intensities. And a means for stopping the measurement after the measurement.

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