JP2000013262A - Digital radio receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital radio receiver that eliminates efficiently a disturbing wave signal even when the disturbing wave signal is in existence in the vicinity of a desired wave signal. SOLUTION: The radio receiver has an RF section 2 that applies band pass filtering to a received signal (a) from a reception antenna 1, amplifies the resulting signal, and converts the signal into an intermediate frequency signal (b), a notch filter section 3 that eliminates only a desired wave signal in the intermediate frequency signal (b) outputted from the RF section 2 and outputs only a disturbing wave signal (c), a comparator section 4 that compares the intermediate frequency signal (b) outputted from the RF section 2 with the disturbing wave signal (c) as a reference signal to provide an output of a binary signal (d) and a data demodulation section 5 that demodulates the binary signal (d) outputted from the comparator section 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital radio receiver for high frequency reception for preventing deterioration of reception sensitivity.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a conventional digital radio receiver. In FIG. 6, 1 is a receiving antenna, 15 is a bandpass filter (BPF), 14 is a local oscillator, 11 is a frequency converter, 12 is an IF bandpass filter (IFBPF), 13 is a limiter amplifier, and 5 is a data demodulator. is there.

[0003] The operation of the digital radio receiving apparatus configured as described above will be described.

In this type of digital radio receiving apparatus, a radio wave is received by a receiving antenna 1, a received signal is output, and a BP signal is output.
The signal from the local oscillator 14 is multiplied by the received signal from the receiving antenna 1 by the frequency converter 11 via the F15 to convert the signal into an appropriate intermediate frequency band signal (intermediate frequency signal). That is, only the intermediate frequency signal) is extracted, amplified to a predetermined amplitude by the limiter amplifier 13, and then a demodulated signal is obtained by the data demodulator 5. In this case, unnecessary waves near the reception band are removed by the IFBPF 12, but in order to improve the anti-jamming characteristics, the IFBPF 1
2 needs to be a narrow band pass filter. In the above-described conventional configuration, the only way to remove an interference wave near the desired wave is to increase the Q of the narrow bandpass filter. The high Q of this narrow bandpass filter can be realized by digital processing.

[0005]

However, in the above-described conventional configuration, a high Q of a narrow band-pass filter can be realized by digital processing, but an A / D converter is required to perform digital processing. Become. In this case, considering the elimination of an interference wave having a power much stronger than a desired wave, the number of bits of the A / D converter must be increased. Was. Further, in the case of realization by analog processing, there is a problem that the Q of the filter that can be realized has a limit, and the anti-jamming performance is determined by the limit.

In this digital radio receiving apparatus, it is required that even if there is an interference signal near the desired signal, the interference signal is efficiently removed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital radio receiver capable of efficiently removing an interfering signal even when there is an interfering signal near a desired signal.

[0008]

SUMMARY OF THE INVENTION In order to solve this problem, a digital radio receiving apparatus according to the present invention comprises an RF section for band-pass amplifying a signal received from a receiving antenna and then converting the signal to an intermediate frequency signal; A notch filter section that removes only a desired signal from the intermediate frequency signals output from the section and outputs only an interference signal, and an intermediate frequency signal output from the RF section and an interference signal as a reference signal. There is provided a configuration having a comparator unit that performs binarization by comparison and a data demodulator that demodulates a binarized signal output from the comparator unit.

Thus, a digital radio receiving apparatus capable of efficiently removing an interfering signal even when there is an interfering signal near the desired signal can be obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A digital radio receiving apparatus according to a first aspect of the present invention converts a signal received from a receiving antenna into an intermediate frequency signal after amplifying the signal by band-passing.
An F section, a notch filter section that removes only a desired signal from the intermediate frequency signals output from the RF section and outputs only an interference signal, and an intermediate frequency signal output from the RF section and a reference signal. A comparator unit that compares the signal with an interfering wave signal and binarizes the signal;
And a data demodulator for demodulating the digitized signal. When the level of the interfering signal is high, the input of the intermediate frequency signal to the data demodulator is prevented.

According to a second aspect of the present invention, there is provided a digital radio receiving apparatus, comprising: an RF section for converting a reception signal from a reception antenna into an intermediate frequency signal after bandpass amplification, and an intermediate frequency signal output from the RF section; A notch filter unit that removes only the desired wave signal and outputs only the interference signal, and a delay unit that delays the intermediate frequency signal output from the RF unit by a predetermined time and outputs a delayed intermediate frequency signal,
A comparator for comparing the delayed intermediate frequency signal output from the delay unit with the interference signal as a reference signal to binarize the signal; and a data demodulator for demodulating the binary signal output from the comparator. And R
The intermediate frequency signal output from the F section has an effect of being delayed according to the delay amount of the notch filter section.

According to a third aspect of the present invention, in the digital radio receiving apparatus according to the second aspect, an interference wave detector for rectifying an interference wave signal output from the notch filter and converting the signal into a DC voltage, And an audiovisual display unit for displaying an interference wave when the DC voltage output from the wave detector is equal to or higher than a predetermined voltage, and when an interference wave signal of a predetermined level or higher is generated. This has the effect that notification by audiovisual display is performed.

According to a fourth aspect of the present invention, there is provided a digital radio receiving apparatus comprising: an RF section for converting a reception signal from a reception antenna into an intermediate frequency signal after bandpass amplification, and an intermediate frequency signal output from the RF section; A notch filter unit that removes only the desired wave signal and outputs only the interference signal, and a delay unit that delays the intermediate frequency signal output from the RF unit by a predetermined time and outputs a delayed intermediate frequency signal,
An interference wave detector that rectifies the interference wave signal output from the notch filter unit and converts it to a DC voltage, and a reference signal to the comparator unit only when the DC voltage output from the interference wave detector is equal to or higher than a predetermined voltage. A switch section to be input, a comparator section for comparing an intermediate frequency signal output from the delay section with an interference signal as a reference signal output from the switch section, and a binary section output from the comparator section And a data demodulator for demodulating the coded signal, and has an operation of performing an interference wave removing operation only when an interference wave is mixed.

According to a fifth aspect of the present invention, there is provided a digital radio receiving apparatus, comprising: an RF unit for converting a reception signal from a reception antenna into an intermediate frequency signal after bandpass amplification, and an intermediate frequency signal output from the RF unit. A notch filter unit that removes only the desired wave signal and outputs only the interference signal, a subtractor that subtracts the interference signal as a reference signal from the intermediate frequency signal output from the RF unit and binarizes the subtractor, A data demodulator that demodulates the binary signal output from the subtractor, and has an effect that the interference signal is removed in a subtraction operation of subtracting the interference signal from the intermediate frequency signal. .

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a block diagram showing a digital radio receiving apparatus according to Embodiment 1 of the present invention.

In FIG. 1, 1 is a receiving antenna, 2 is R
F section, 3 notch filter section, 4 comparator section, 5
Is a data demodulator.

The operation of the digital radio receiving apparatus thus configured will be described.

The reception antenna 1 receives a radio wave and outputs a reception signal a. The RF unit 2 receives the received signal a from the receiving antenna 1 and removes an interfering signal that is separated from the desired signal (not near the desired signal) by a wideband bandpass filter (not shown). The conversion is performed to convert the high frequency signal to an intermediate frequency signal and amplify the signal to a predetermined level. The output signal from the RF unit 2, that is, the intermediate frequency signal b is branched into two, and one of the output signals b is input to the notch filter unit 3 having the center frequency of the desired signal as a center frequency. Only the wave signal c is input to the comparator unit 4. The other output signal b from the RF unit 2 is directly input to the comparator unit 4, and the comparator unit 4 compares the output signal c of the notch filter unit 3 (that is, the interference signal) with the reference signal. At this time, since the reference signal c has the amplitude of the interference signal, when a high-level interference signal is generated, R
The output signal b of the F unit 2 cannot pass through the comparator unit 4, and when the output signal b is binarized by the comparator unit 4, the influence of the interference signal can be eliminated. The intermediate frequency signal d from which the interference signal has been removed is demodulated by the data demodulator 5. As described above, it is possible to eliminate the reception interference due to the interference wave signal near the desired wave signal.

As described above, according to the present embodiment, the RF unit 2 for converting the reception signal a from the reception antenna 1 into an intermediate frequency signal b after bandpass-amplifying the signal and the RF unit 2
Notch filter section 3 which removes only the desired wave signal from intermediate frequency signal b output from and outputs only the interference signal, intermediate frequency signal b output from RF section 2 and the interference wave as the reference signal A comparator unit 4 that compares the signal c with the signal c and binarizes the signal c;
With the provision of the data demodulator 5 for demodulating the digitized signal, the input of the intermediate frequency signal to the data demodulator 5 can be prevented when the level of the interfering signal is high. Can be generated.

(Embodiment 2) FIG. 2 is a block diagram showing a digital radio receiving apparatus according to Embodiment 2 of the present invention.

In FIG. 2, the receiving antenna 1, RF unit 2, notch filter unit 3, comparator unit 4, and data demodulator 5 are the same as those in FIG. 6 is a delay unit.

The operation of the digital radio receiving apparatus thus configured will be described.

As shown in FIG. 2, a delay section 6 is interposed between the RF section 2 and the comparator section 4. Normally, a delay occurs in the notch filter unit 3, and when there is no delay unit 6, a time difference occurs in the signal input to the comparator unit 4, and the demodulation performance deteriorates. Therefore, by inserting the delay unit 6 between the RF unit 2 and the comparator unit 4, the same time delay as in the notch filter unit 3 is performed. Thereby, the effect of the delay in the notch filter unit 3 can be eliminated. The comparator unit 4 performs a comparison between the signal (delayed intermediate frequency signal) e from the delay unit 6 and the reference signal c, using the signal (disturbing wave signal) c from the notch filter unit 3 as a reference signal, and binarizes the signal. The binary signal d is demodulated by the data demodulator 5. As described above, the influence of the delay of the notch filter unit 3 can be suppressed, and the reception interference of the interference wave signal due to the vicinity of the desired signal can be eliminated.

As described above, according to the present embodiment, the RF unit 2 for converting the reception signal a from the reception antenna 1 into an intermediate frequency signal b after bandpass-amplifying it and the RF unit 2
A notch filter unit 3 that removes only a desired wave signal from the intermediate frequency signal b output from the unit and outputs only an interference signal c, and delays the intermediate frequency signal b output from the RF unit 2 by a predetermined time. A delay unit 6 that outputs a delayed intermediate frequency signal e by using the delay intermediate frequency signal e output from the delay unit 6 and an interference wave signal c as a reference signal.
By providing a comparator unit 4 for converting the value into a value and a data demodulator 5 for demodulating the binary signal d output from the comparator unit 4, the intermediate frequency signal b output from the RF unit 2 is notch-filtered. Since the delay can be made in accordance with the delay amount of the section 3, the interference wave signal can be reliably removed.

(Embodiment 3) FIG. 3 is a block diagram showing a digital radio receiving apparatus according to Embodiment 3 of the present invention.

In FIG. 3, the receiving antenna 1, RF unit 2, notch filter unit 3, comparator unit 4, data demodulator 5, and delay unit 6 are the same as those in FIG. I do. 7 is an interference wave detector, and 8 is an audiovisual display unit.

The operation of the digital radio receiving apparatus thus configured will be described.

In FIG. 3, the interference signal c output from the notch filter section 3 is branched into two, one of the interference signals c is input to a comparator section 4 and the other interference signal c
Is input to the interference wave detector 7. The output signal f of the interference wave detector 7 is input to the audiovisual display unit 8. The signal that is not removed by the notch filter unit 3 is the interference signal c near the desired wave. If there is any signal on the output side of the notch filter unit 3, it can be determined that the interference signal c is mixed. .
Therefore, the output signal of the notch filter unit 3 (interference signal)
c is rectified by the interference wave detector 7 and converted into a DC voltage. When the DC voltage output from the interference wave detector 7 is equal to or more than a predetermined voltage, the audiovisual display unit 8 displays the interference wave mixing and notifies the user or the like. The comparator unit 4 performs binarization by comparing the output signal e from the delay unit 6 with the reference signal c, using the interfering wave signal c from the notch filter unit 3 as a reference signal, and binarizes the binarized signal d. The data is demodulated by the data demodulator 5. As described above, the display of the interference wave is displayed to notify the user or the like, and the reception interference due to the interference wave near the desired signal can be eliminated.

As described above, according to the present embodiment, the interference wave detector 7 that rectifies the interference wave signal c output from the notch filter unit 3 and converts it into a DC voltage,
And an audio-visual display unit 8 for displaying an interfering wave when the DC voltage output from the unit is equal to or higher than a predetermined voltage. , It is possible to clearly know the state of the usage environment.

(Embodiment 4) FIG. 4 is a block diagram showing a digital radio receiving apparatus according to Embodiment 4 of the present invention.

In FIG. 4, the receiving antenna 1, RF unit 2, notch filter unit 3, comparator unit 4, data demodulator 5, delay unit 6, and interference wave detector 7 are the same as those in FIG. And the description is omitted. 9 is a switch unit.

The operation of the digital radio receiving apparatus thus configured will be described.

In FIG. 4, the output signal (disturbing wave signal) c of the notch filter section 3 is branched into two, one of which is inputted to the disturbing wave detector 7 and the other is inputted to the switch section 9. The output signal (DC voltage) f of the interference wave detector 7 is input to the switch unit 9, and the output signal (interference signal) c ′ of the switch unit 9 is input to the comparator unit 4. The signal that is not removed by the notch filter section 3 is the interference signal c near the desired signal, and if there is any signal on the output side of the notch filter section 3, it is determined that the interference signal c is mixed. can do. Therefore, the output signal (disturbance wave signal) c of the notch filter unit 3 is rectified by the disturbance wave detector 7 and converted into a DC voltage f. When the DC voltage f becomes equal to or higher than a predetermined voltage, the switch unit 9 is turned on, and connects the output side of the notch filter unit 3 and the input side of the comparator unit 4. DC voltage f
Is less than the predetermined voltage, the switch unit 9 is in the OFF state. In the OFF state, the output side of the switch section 9 is connected to the ground through a high resistor, and the output side of the switch section 9 (that is, the input side of the comparator section 4) is at the ground level. The comparator unit 4 performs a binarization by comparing the delayed intermediate frequency signal e output from the delay unit 6 with the reference signal c ′ using the interference signal c ′ output from the switch unit 9 as a reference signal, The binary signal d is demodulated by the data demodulator 5. As described above, the interference signal is removed only when the interference signal is mixed, and the reception interference due to the interference signal near the desired signal can be eliminated.

As described above, according to the present embodiment, the switch unit 9 for inputting the reference signal c 'to the comparator unit 4 only when the DC voltage output from the interference wave detector 7 is equal to or higher than the predetermined voltage. And the comparator unit 4 that compares the intermediate frequency signal e output from the delay unit 6 with the interference signal c ′ as a reference signal output from the switch unit 9 and binarizes the signal. Since the operation of removing the interference signal can be performed only when the interference signal is mixed, the operation of the comparator unit 4 can be ensured.

(Embodiment 5) FIG.5 is a block diagram showing a digital radio receiving apparatus according to Embodiment 5 of the present invention.

In FIG. 5, the receiving antenna 1, the RF section 2, the notch filter section 3, and the data demodulator 5 are the same as those in FIG. 10
Is a subtractor.

The operation of the digital radio receiving apparatus thus configured will be described.

As shown in FIG. 5, the receiving antenna 1 receives a radio wave and outputs a received signal a. The RF unit 2 receives the received signal a from the receiving antenna 1 and removes an interfering wave separated from the desired signal (not near the desired signal) by a wideband band-pass filter (not shown). To convert the high-frequency signal into an intermediate frequency signal and amplify the signal to a predetermined level. The output signal from the RF unit 2, that is, the intermediate frequency signal b is branched into two, and one of the output signals b is input to the notch filter unit 3 having the center frequency of the desired signal as a center frequency. Only the wave signal c is input to the subtractor 10. The other output signal b from the RF unit 2 is directly input to the subtractor 10, and the subtractor 10 converts the output signal (intermediate frequency signal) b of the RF unit 2 to the output signal (interference signal) c of the notch filter unit 3. Is subtracted to obtain a binary signal g. The binary signal g from which the interference wave signal c has been removed is demodulated by the data demodulator 5.
As described above, it is possible to eliminate the reception interference caused by the interference signal c near the desired signal.

As described above, according to the present embodiment, the RF
The interference signal c is subtracted from the intermediate frequency signal b by including the subtractor 10 that subtracts and binarizes the interference signal c as the reference signal from the intermediate frequency signal b output from the unit 2. Since the interference signal c can be removed by performing the subtraction operation, a reception error when the interference signal c is mixed can be efficiently prevented.

[0040]

As described above, according to the digital radio receiving apparatus according to the first aspect of the present invention, an RF unit that amplifies a signal received from a receiving antenna by band-passing and then converts the signal into an intermediate frequency signal; A notch filter section that removes only the desired signal from the intermediate frequency signals output from the RF section and outputs only the interference signal; an intermediate frequency signal output from the RF section and an interference signal as the reference signal; And a data demodulator for demodulating the binarized signal output from the comparator unit, so that the data demodulator for the intermediate frequency signal when the level of the interference signal is large. Therefore, an advantageous effect that a binarized signal from which an interference wave signal is removed can be generated can be obtained.

According to the second aspect of the present invention, the RF unit converts the received signal from the receiving antenna into an intermediate frequency signal after bandpass-amplifying the signal and the intermediate frequency signal output from the RF unit. A notch filter section that removes only the desired signal and outputs only the interference signal, a delay section that delays the intermediate frequency signal output from the RF section by a predetermined time and outputs a delayed intermediate frequency signal, By having a comparator unit that compares the output delayed intermediate frequency signal with the interference signal as a reference signal and binarizes the data, and a data demodulator that demodulates the binary signal output from the comparator unit, Since the intermediate frequency signal output from the RF unit can be delayed according to the delay amount of the notch filter unit, the interference signal can be reliably removed. Interest effect can be obtained.

According to the invention of claim 3, according to claim 2,
In the invention described in the above, the interference wave detector that rectifies the interference wave signal output from the notch filter unit and converts it to a DC voltage, and the interference is performed when the DC voltage output from the interference wave By having the audiovisual display unit for displaying the wave mixing, when an interference wave signal of a predetermined level or more is generated, it is possible to notify by audiovisual display, so that the state of the use environment can be clearly known. The advantageous effect described above can be obtained.

According to the fourth aspect of the present invention, the RF unit converts the reception signal from the reception antenna into an intermediate frequency signal after bandpass-amplifying the signal and the intermediate frequency signal out of the intermediate frequency signal output from the RF unit. A notch filter section that removes only a desired signal and outputs only an interference signal, a delay section that delays an intermediate frequency signal output from the RF section by a predetermined time and outputs a delayed intermediate frequency signal, and a notch filter section Wave detector that rectifies the disturbance wave signal output from the converter and converts it into a DC voltage, and a switch that inputs a reference signal to the comparator unit only when the DC voltage output from the disturbance wave detector is equal to or higher than a predetermined voltage A comparator section for comparing the intermediate frequency signal output from the delay section with an interference signal as a reference signal output from the switch section to binarize the signal; And a data demodulator that demodulates the binary signal output from the data section, the operation of removing the interference signal can be performed only when the interference signal is mixed. Has an advantageous effect that can be ensured.

According to the fifth aspect of the present invention, the RF section converts the received signal from the receiving antenna into an intermediate frequency signal after bandpass amplification, and the intermediate frequency signal among the intermediate frequency signals output from the RF section. A notch filter section for removing only the desired signal and outputting only the interference signal, a subtractor for subtracting the interference signal as a reference signal from the intermediate frequency signal output from the RF section to binarize the signal, And a data demodulator that demodulates the binarized signal output from the device, it is possible to remove the interference signal by performing a subtraction operation of subtracting the interference signal from the intermediate frequency signal.
An advantageous effect is obtained in that a reception error at the time of mixing of an interference wave signal can be efficiently prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a digital wireless receiver according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a digital wireless receiver according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a digital wireless receiver according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a digital radio receiving apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a digital wireless receiver according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a conventional digital wireless receiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving antenna 2 RF part 3 Notch filter part 4 Comparator part 5 Data demodulator 6 Delay part 7 Interference wave detector 8 Audiovisual display part 9 Switch part 10 Subtractor

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 5K004 AA01 BA02 BB06 BD00 5K020 AA08 DD01 EE01 EE04 EE05 HH13 KK04 KK07 NN01 NN02 5K052 BB02 CC06 DD04 EE12 FF33 GG02 GG19 GG26 GG31 GG32 GG33 GG42 GG42

Claims (5)

[Claims] An RF unit for bandpassing and amplifying a reception signal from a reception antenna and then converting the signal into an intermediate frequency signal;
A notch filter section that removes only a desired wave signal from the intermediate frequency signals output from the RF section and outputs only an interference wave signal; and an intermediate frequency signal output from the RF section and the interference as a reference signal. A digital radio receiving apparatus, comprising: a comparator section for comparing a wave signal to binarize the signal; and a data demodulator for demodulating the binarized signal output from the comparator section. 2. An RF unit for band-passing and amplifying a reception signal from a reception antenna and converting the signal to an intermediate frequency signal.
A notch filter section that removes only the desired wave signal from the intermediate frequency signals output from the RF section and outputs only the interference signal, and delays the intermediate frequency signal output from the RF section by a predetermined time. A delay unit that outputs a delayed intermediate frequency signal, a comparator unit that compares the delayed intermediate frequency signal output from the delay unit with the interfering wave signal as a reference signal to binarize the signal, And a data demodulator for demodulating the binarized signal. 3. An interference wave detector for rectifying an interference wave signal output from the notch filter and converting the signal into a DC voltage.
3. The digital radio receiving apparatus according to claim 2, further comprising: an audiovisual display unit that displays an interference wave when the DC voltage output from the interference wave detector is equal to or higher than a predetermined voltage. 4. An RF unit for band-passing and amplifying a reception signal from a reception antenna and then converting the signal into an intermediate frequency signal.
A notch filter section that removes only the desired wave signal from the intermediate frequency signals output from the RF section and outputs only the interference signal, and delays the intermediate frequency signal output from the RF section by a predetermined time. A delay unit that outputs a delayed intermediate frequency signal, an interference wave detector that rectifies an interference wave signal output from the notch filter unit and converts it to a DC voltage, and a DC voltage output from the interference wave detector is a predetermined value. A switch unit for inputting the interference signal as a reference signal to the comparator unit only when the voltage is equal to or higher than a voltage, and comparing an intermediate frequency signal output from the delay unit with the reference signal output from the switch unit. Comprising: a comparator unit for performing binarization and a data demodulator for demodulating a binary signal output from the comparator unit; Line receiver. 5. An RF section for bandpassing and amplifying a reception signal from a reception antenna and then converting the signal into an intermediate frequency signal.
A notch filter section that removes only a desired wave signal from the intermediate frequency signal output from the RF section and outputs only an interference signal, and the interference as a reference signal from the intermediate frequency signal output from the RF section. A digital radio receiving apparatus comprising: a subtractor that subtracts a wave signal to binarize the wave signal; and a data demodulator that demodulates a binarized signal output from the subtractor.