WO2011114408A1 - 電力検出回路および電力検出方法 - Google Patents
電力検出回路および電力検出方法 Download PDFInfo
- Publication number
- WO2011114408A1 WO2011114408A1 PCT/JP2010/007286 JP2010007286W WO2011114408A1 WO 2011114408 A1 WO2011114408 A1 WO 2011114408A1 JP 2010007286 W JP2010007286 W JP 2010007286W WO 2011114408 A1 WO2011114408 A1 WO 2011114408A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- frequency
- detection circuit
- power detection
- band
- power
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
- H04B1/1027—Means associated with receiver for limiting or suppressing noise or interference assessing signal quality or detecting noise/interference for the received signal
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/16—Circuits
- H04B1/30—Circuits for homodyne or synchrodyne receivers
Definitions
- the present invention relates to a power detection circuit and a power detection method, and more particularly to a power detection circuit and a power detection method for detecting the power of a radio frequency signal.
- Non-patent document 1 discloses a technique related to a power detection circuit in relation to a technique for searching for a wireless vacant frequency (white space).
- FIG. 22 is a block diagram for explaining a power detection circuit according to the background art. As illustrated in FIG. 22, the power detection circuit according to the background art includes a mixer 101, a variable frequency oscillator 102, a low-pass filter 103, and an energy detection circuit 104.
- the variable frequency oscillator 102 outputs a carrier wave 106 having the same frequency as the reception frequency.
- the mixer 101 multiplies the reception signal 105 by the carrier wave 106 having the same frequency as the reception frequency output from the variable frequency oscillator 102, and outputs the in-phase component to the low-pass filter 103.
- the low pass filter 103 removes out-of-band signals from the signal output from the mixer 101.
- the energy detection circuit 104 detects power in the band of the low-pass filter 103.
- the frequency of the variable frequency oscillator 102 is set to an LO (Local Oscillator) frequency (local oscillation frequency: f LO ) that is the same frequency as the RF (radio) frequency (f RF ) signal to be detected.
- This method is generally called a zero IF method or a direct conversion method.
- the RF frequency signal is frequency-converted by the mixer 101 around the zero frequency (hereinafter referred to as DC around).
- the low-pass filter 103 removes the out-of-band signal
- the energy detection circuit 104 detects the power in the filter band.
- this detected power is equal to the power around the RF frequency (f RF ) filter band. Further, by changing the frequency of the variable frequency oscillator 102 and sweeping the LO frequency (f LO ), the power of the RF frequency (f RF ) can be detected over a wide band.
- the mixer 101 converts the frequency of the RF frequency signal (f RF ) around DC.
- f RF RF frequency signal
- 1 / f noise has the property that the noise increases as the frequency decreases.
- 1 / f noise increases.
- the 1 / f noise increases as the device size decreases as the CMOS process evolves.
- the frequency is converted to a frequency band around DC by the mixer 101, there is a problem that the power detection time becomes long. This is because the power detection time depends on the period of the detection signal. In particular, when the RF frequency band to be searched is wide, or when power is detected with high accuracy in a narrow filter band (that is, the frequency step is detected finely). The power detection time becomes longer. For this reason, the time required for frequency search becomes long.
- an object of the present invention is to provide a high-speed and high-sensitivity power detection circuit and a power detection method.
- a power detection circuit includes a variable frequency oscillator that oscillates a local oscillation frequency, a mixer that inputs the local oscillation frequency and a detection signal, and converts the detection signal using the local oscillation frequency, A complex bandpass filter that limits a frequency-converted detection signal band to a predetermined band, and an energy detection circuit that detects power of the predetermined band based on an output from the complex bandpass filter, and The local oscillation frequency is set so that a predetermined band of the frequency-converted detection signal is a frequency region with low 1 / f noise.
- the power detection method sets a local oscillation frequency, frequency-converts a detection signal using the local oscillation frequency, limits a band of the frequency-converted detection signal to a predetermined band, and converts the frequency conversion
- the present invention can provide a high-speed and high-sensitivity power detection circuit and power detection method.
- FIG. 1 is a block diagram showing a power detection circuit according to a first exemplary embodiment
- FIG. 3 is a block diagram showing an example of a variable frequency oscillator used in the power detection circuit according to the first exemplary embodiment
- FIG. 6 is a block diagram showing another example of the variable frequency oscillator used in the power detection circuit according to the first exemplary embodiment.
- 3 is a block diagram illustrating an example of an energy detection circuit used in the power detection circuit according to the first embodiment
- FIG. It is a block diagram which shows another example of the energy detection circuit used for the electric power detection circuit concerning Embodiment 1.
- FIG. FIG. 6 is a diagram illustrating an operation of the power detection circuit according to the first to third embodiments.
- FIG. 10 is a diagram for explaining the effect (speeding up) of the power detection circuit according to the first to sixth embodiments.
- the signal (comparative example) frequency-converted by the zero IF method is shown.
- or 6 is shown. It is a figure which shows the white space band of North America prescribed
- FIG. 3 is a block diagram showing a power detection circuit according to a second exemplary embodiment.
- FIG. 6 is a block diagram showing a power detection circuit according to a third exemplary embodiment.
- FIG. 6 is a diagram illustrating an example of an RSSI circuit used in a power detection circuit according to a third embodiment; 6 is a flowchart illustrating an operation of the power detection circuit according to the third and sixth embodiments.
- FIG. 6 is a block diagram showing a power detection circuit according to a fourth exemplary embodiment. It is a circuit diagram which shows an example of the band variable complex band pass filter used for the electric power detection circuit concerning this invention. It is a circuit diagram which shows another example of the band variable complex band pass filter used for the electric power detection circuit concerning this invention. It is a figure which shows operation
- FIG. 9 is a block diagram showing a power detection circuit according to a fifth exemplary embodiment.
- FIG. 10 is a block diagram illustrating a power detection circuit according to a sixth embodiment. 6 is a flowchart illustrating an operation of the power detection circuit according to the third and sixth embodiments. It is a block diagram which shows the electric power detection circuit concerning background art. It is a figure which shows operation
- FIG. 1 is a block diagram of a power detection circuit according to the first embodiment.
- the power detection circuit according to the present embodiment includes a mixer 1, a variable frequency oscillator 2, a complex bandpass filter 3, and an energy detection circuit 4.
- a detection signal (f RF ) 11 is input to the mixer 1 from the antenna.
- the variable frequency oscillator 2 oscillates a predetermined local oscillation frequency (f LO ).
- the mixer 1 multiplies the local oscillation frequency 12 output from the variable frequency oscillator 2 and the detection signal 11 to convert the frequency, and outputs the in-phase component to the complex bandpass filter 3.
- the complex bandpass filter 3 removes out-of-band signals from the signal output from the mixer 1.
- the energy detection circuit 4 detects the power in the band of the complex bandpass filter 3.
- FIG. 2 is a block diagram showing an example of the variable frequency oscillator 2 used in the power detection circuit according to the present embodiment.
- the variable frequency oscillator 2 shown in FIG. 2 includes a feedback loop of a crystal oscillator 21 that generates a reference frequency, a phase comparator 22, a charge pump circuit 23, a voltage controlled oscillator 24, and a frequency divider 25.
- the variable frequency oscillator 2 shown in FIG. 2 is a so-called PLL (Phase Locked Loop) circuit.
- the output frequency can be switched by switching the frequency division ratio of the frequency divider 25. Note that the output frequency can be similarly switched by arranging a variable frequency divider after the voltage controlled oscillator 24 or before the phase comparator 22.
- FIG. 3 is a block diagram showing another example of the variable frequency oscillator 2 used in the power detection circuit according to the present embodiment.
- the variable frequency oscillator 2 shown in FIG. 3 includes an accumulator 26, a memory 27, a DA converter 28, and a filter 29.
- the variable frequency oscillator shown in FIG. 3 is a so-called DDS (Direct Digital Synthesizer).
- the accumulator 26 has a function of accumulating and resetting numerical data.
- the cumulative data increment P is determined from the set frequency, and the numerical value of the output data increases for each clock CLK.
- the output of the accumulator 26 is delivered to the memory 27 as a read address. This data corresponds to the phase of the waveform to be finally output.
- the phase advance is slow and the waveform data is output to the DA converter 28 as a low frequency signal.
- the waveform data is read out in a jump and a high frequency signal is output. That is, the output frequency can be switched by switching the value of step P of the accumulator 26 or the operating frequency of the accumulator 26.
- FIG. 4 is a block diagram showing an example of the energy detection circuit 4.
- the energy detection circuit 4 includes a square detection means 41, an AD converter 42, a digital processing means 43, and a memory 44.
- the band of the signal input to the square detection means 41 is limited. Generally, energy can be detected at high speed by widening this band, whereas energy can be detected with high sensitivity by narrowing this band. That is, minute energy can be detected.
- the square detection means 41 energy is detected by, for example, analog calculation using an integrator or the like. Then, the analog output signal of the square detection means 41 is converted into a digital signal by the AD converter 42, and this digital signal is processed by the digital processing means 43, so that a control signal corresponding to the signal intensity can be generated. .
- This control signal is supplied to, for example, an analog processing unit. Also, by writing and storing the signal processing results in the digital processing means 43 in the memory 44, a plurality of energy detection results can be stored in a database. Therefore, a control signal can be generated according to a plurality of energy detection results by referring to this database.
- the reason for using such digital signal processing is that, when a recent miniaturized CMOS process is used, it has a high affinity with a digital circuit.
- FIG. 5 is a block diagram showing another example of the energy detection circuit 4.
- the energy detection circuit 4 shown in FIG. 5 includes an AD converter 42, digital processing means (fast Fourier transform) 45, and a memory 44.
- the AD converter 42 converts the analog output signal from the complex bandpass filter 3 into a digital signal.
- the digital processing means 45 generates a control signal corresponding to the signal from the AD converter 42. Also, by writing and storing the signal processing results in the digital processing means 45 in the memory 44, a plurality of energy detection results can be stored in a database.
- the bands of the complex bandpass filter 3 and the AD converter 42 are set to a wider band than the configuration of the energy detection circuit shown in FIG.
- a series of the input frequency and its intensity is calculated by fast Fourier transform in the digital processing means 45.
- the detection accuracy can be increased by increasing the number of points in the fast Fourier transform, the scale of the energy detection circuit 4 increases, and these are in a trade-off relationship.
- FIG. 6 is a diagram illustrating the operation of the power detection circuit according to the present embodiment.
- the frequency of the variable frequency oscillator 2 is set to the LO frequency (local oscillation frequency: f LO ) of the frequency (IF frequency: f IF ) shifted from the RF (radio) frequency signal (f RF ) to be detected.
- the IF frequency (f IF ) is about 1 MHz to several tens of MHz, and this method is called a low IF method.
- the RF frequency signal (f RF ) is frequency-converted around the IF frequency (f IF ) by the mixer 1.
- the complex bandpass filter 3 removes out-of-band signals including image signals, and the energy detection circuit 4 detects the power in the filter band (detection band).
- the image signal is a frequency signal having a pair relationship with the RF frequency (f RF ) with respect to the LO frequency (f LO ).
- the complex bandpass filter 3 removes the image signal by synthesizing I / Q signals (signals whose phases are shifted by 0 ° and 90 °).
- the frequency relationship is set so that the signal band to be detected does not enter the high 1 / f noise region.
- this detected power is equal to the power around the filter band at the RF frequency (f RF ).
- the frequency of the variable frequency oscillator 2 to sweep the LO frequency (f LO )
- FIGS. 7A and 7B are diagrams for explaining the effect (high speed) of the power detection circuit according to the present embodiment.
- FIG. 7A shows a signal subjected to frequency conversion by the zero IF method according to the background art as a comparative example.
- FIG. 7B shows a signal frequency-converted by the low IF method used in the power detection circuit according to the present embodiment.
- the signal to be detected is assumed to be a single sine wave.
- FIGS. 7A and 7B when these signals are compared, if the time required for power detection of the energy detection circuit is one period (t det_min ), the signal period of the low IF method (FIG. 7B) Shorter. That is, the detection time of the power detection circuit can be shortened.
- the IF frequency (f IF ) converted by the mixer can be set to a frequency region with a low 1 / f noise, so that power is detected with high sensitivity. Can do. That is, more minute power can be detected. Further, in the power detection circuit according to the present embodiment, the IF frequency (f IF ) converted by the mixer has a short cycle, and therefore, power can be detected at high speed (that is, in a short time).
- the power detection circuit described above can be used for cognitive radio such as IEEE 802.22 and IEEE ESCC 41 that use a vacant frequency of a television, for example.
- cognitive radio such as IEEE 802.22 and IEEE ESCC 41 that use a vacant frequency of a television, for example.
- cognitive radio such as IEEE 802.22 and IEEE ESCC 41 that use a vacant frequency of a television, for example.
- FIG. 8 use of a digital TV band ranging from about 50 MHz to 700 MHz is authorized in North America.
- this cognitive radio it is required to determine whether or not the frequency is used by detecting extremely small power called spectrum sensing.
- the detection accuracy is ⁇ 116 ⁇ dBm or less in a band of 6 MHz per channel.
- a two-step sensing method can be used. Specifically, in the first stage, energy detection (or blind detection) is performed that can be detected at high speed, although the detection sensitivity is slightly inferior. In the second stage, feature detection that can be detected with high accuracy is performed. Note that the latter feature detection is realized by, for example, a large-scale and long-time digital processing.
- FIG. 9 is a block diagram showing a power detection circuit according to the present embodiment.
- the power detection circuit according to the present embodiment includes a mixer 1, a variable frequency oscillator 2, an AD converter 5, a digital complex bandpass filter 6, and an energy detection circuit 4. That is, the power detection circuit according to the present embodiment includes an AD converter 5 and a digital complex bandpass filter 6 instead of the complex bandpass filter 3 according to the first embodiment. Since other than this is the same as that of the power detection circuit according to the first exemplary embodiment, redundant description is omitted.
- the frequency of the variable frequency oscillator 2 is set to the LO frequency (local oscillation frequency: f LO ) of the frequency (IF frequency: f IF ) shifted from the RF (radio) frequency signal (f RF ) to be detected.
- the IF frequency (f IF ) is about 1 MHz to several tens of MHz, and this method is called a low IF method.
- the RF frequency signal (f RF ) is frequency-converted around the IF frequency (f IF ) by the mixer 1.
- an out-of-band signal including an image signal is removed by the digital complex bandpass filter 6, and the power within the filter band (detection band) using the energy detection circuit 4. Is detected.
- the frequency relationship is set so that the signal band to be detected does not enter a high 1 / f noise region. Further, by changing the frequency of the variable frequency oscillator 2 to sweep the LO frequency (f LO ), it is possible to detect the power of the RF frequency (f RF ) over a wide band.
- the digital complex bandpass filter 6 can be used, so that a high performance, that is, a large-scale filter can be easily realized.
- the area and power of the filter can be reduced.
- FIG. 10 is a block diagram showing a power detection circuit according to the present embodiment.
- the power detection circuit according to the present embodiment includes a mixer 1, a variable frequency oscillator 2, a complex bandpass filter 3, an RSSI circuit (Received Signal Strength Indicator) 7, an AD converter 5, a digital signal processor (DSP). ) 8 is provided.
- FIG. 11 is a diagram illustrating an example of the RSSI circuit 7.
- the detection signal (V IN ) is amplified by the amplifier group 71 cascade-connected in a plurality of stages.
- An output signal (V OUT ) is output from the last stage of the amplifier group 71.
- a rectifier 72 is connected between each stage, and a current (i n ) corresponding to the amplitude of the output of the amplifier is output from each rectifier 72. For example, a larger current flows as the amplitude is smaller. On the other hand, when the amplitude exceeds a certain level, current stops flowing.
- the RSSI circuit shown in FIG. 11 has a current-voltage conversion circuit 73 including a resistor R and a capacitor C in order to convert the current of each rectifier 72 into a voltage and smooth the fluctuation of the voltage.
- a current-voltage conversion circuit 73 including a resistor R and a capacitor C in order to convert the current of each rectifier 72 into a voltage and smooth the fluctuation of the voltage.
- Such an RSSI circuit outputs an output voltage (V RSSI ) in a logarithmic relationship with respect to the detection signal (V IN ).
- This output voltage (V RSSI ) is output to the AD converter 5. Therefore, a high sensitivity and a wide dynamic range can be obtained as compared with the linear power detection circuit.
- the low IF method applied in the power detection circuit according to the present embodiment has a higher input signal frequency than the zero IF method. Therefore, the AC coupling capacity for DC offset cancellation and the capacity of the current-voltage conversion circuit The area can be saved by reducing the value.
- the DC offset cancellation is a means for suppressing a decrease in dynamic range caused by a shift in the threshold value of the MOS transistor in the differential input stage of the amplifier.
- an RSSI circuit is used as the energy detection circuit 4 used in the power detection circuits of the first and second embodiments. The rest is the same as in the first and second embodiments.
- this RSSI circuit is also used during a receiving operation.
- the detection signal (V IN ) input to the RSSI circuit 7 is amplified by the amplifier group 71.
- the output voltage (V RSSI ) is converted into a digital signal by using the AD converter 5. This digital signal is demodulated using a digital signal processor (DSP) 8.
- DSP digital signal processor
- FIG. 12 is a flowchart showing the operation of the power detection circuit according to the present exemplary embodiment.
- VGA variable gain amplifier
- an amplifier with fine gain adjustment is provided for the RSSI output, it can be used as a VGA with high resolution over a wide range.
- the VGA can be switched by AGC (automatic gain control) according to the antenna input signal strength.
- AGC automatic gain control
- FIG. 13 is a block diagram showing a power detection circuit according to the present embodiment.
- the power detection circuit according to the present embodiment includes a mixer 1, a variable frequency oscillator 2, a band variable complex bandpass filter 9, and an energy detection circuit 4. That is, the power detection circuit according to the present embodiment includes a band variable complex bandpass filter 9 instead of the complex bandpass filter 3 according to the first embodiment. Since other than this is the same as that of the power detection circuit according to the first exemplary embodiment, redundant description is omitted.
- FIG. 14 is a circuit diagram showing an example of the band variable complex bandpass filter 9.
- a band variable complex bandpass filter 9 shown in FIG. 14 receives a first variable gm cell group 90 connected to a main path to which an I input signal of I / Q signals is input, and a Q input signal.
- the second variable gm cell group 91 connected to the main path, and the third variable gm cell group 91 connected between the main path of the first variable gm cell group 90 and the main path of the second variable gm cell group 91.
- a gm cell group 92, a first capacity group 93, and a second capacity group 94 are provided.
- each capacitor element constituting the first capacitor group 93 is connected to the gm cell of the first variable gm cell group 90 and the gm cell of the third variable gm cell group 92, and the other end is connected to the reference power source.
- One end of each capacitor element constituting the second capacitor group 94 is connected to the gm cell of the second variable gm cell group 91 and the gm cell of the third variable gm cell group 92, and the other end is connected to the reference power source.
- the gm cell can be realized by a linear region operation of a transistor, for example.
- the gm value of each gm cell in the first variable gm cell group 90 and the second variable gm cell group 91 can be adjusted by the f BW control signal.
- the gm value of each gm cell of the third variable gm cell group 92 can be adjusted by the f IF control signal.
- the band variable complex bandpass filter 9 shown in FIG. 14 adjusts the gm value of each gm cell of the first variable gm cell group 90 and the second variable gm cell group 91 to thereby adjust the filter band (f BW ) can be switched.
- the center frequency (that is, IF frequency (f IF )) of the filter can be switched by adjusting the gm value of each gm cell of the third variable gm cell group 92.
- FIG. 15 is a circuit diagram showing another example of the band-variable complex bandpass filter 9.
- the band-variable complex bandpass filter 9 shown in FIG. 15 includes a first gm cell group 95 connected to a main path to which an I input signal of I / Q signals is input, and a main to which a Q input signal is input.
- a second gm cell group 96 connected to the path, and a third variable gm cell group 97 connected between the main path of the first gm cell group 95 and the main path of the second gm cell group 96.
- a first variable capacitance group 98 and a second variable capacitance group 99 are examples of the band-variable complex bandpass filter 9.
- Each capacitor element constituting the first variable capacitor group 98 has one end connected to the gm cell of the first gm cell group 95 and the gm cell of the third variable gm cell group 97, and the other end connected to the reference power source.
- Each of the capacitive elements constituting the second variable capacitance group 99 has one end connected to the gm cell of the second gm cell group 96 and the gm cell of the third variable gm cell group 97, and the other end connected to the reference power source.
- the gm cell can be realized by a linear region operation of a transistor, for example. Further, the gm value of each gm cell of the third variable gm cell group 97 can be adjusted by the f IF control signal.
- the capacitances of the capacitive elements constituting the first variable capacitance group 98 and the capacitive elements constituting the second variable capacitance group 99 can be adjusted by the f BW control signal.
- the capacitance of each capacitive element can be easily and accurately adjusted by switching a plurality of binary-weighted capacitances connected in parallel with a switch.
- the band (f BW ) of the filter can be switched by adjusting the capacitance of each capacitive element of the first and second variable capacitance groups 98 and 99.
- the center frequency (that is, IF frequency (f IF )) of the filter can be switched by adjusting the gm value of the third variable gm cell group 97.
- 16A and 16B are diagrams illustrating the operation of the power detection circuit according to the present embodiment.
- the operation of the power detection circuit according to the present embodiment is largely different from the power detection circuit according to the first to third embodiments in that the band for detecting the power is switched.
- a band (f RF ) to be detected that is frequency-converted by the mixer 1 does not become a frequency range with high 1 / f noise. Then, the LO frequency (f LO ) of the variable frequency oscillator 2 is selected (FIG. 16A). Next, when power is detected in a wide band at the same RF frequency (f RF ), the band (f BW ) of the band variable complex bandpass filter 9 is widened, and the band to be detected (ie, f BW) that is frequency-converted by the mixer 1.
- FIGS. 17A and 17B are diagrams showing another operation of the power detection circuit according to the present exemplary embodiment.
- the operation of the power detection circuit shown in FIGS. 17A and 17B is performed by the variable frequency oscillator 2 so that the band to be detected that is frequency-converted by the mixer does not become a high 1 / f noise frequency range even if the filter band is changed.
- the operation is the same as that shown in FIGS. 16A and 16B in that the LO frequency (f LO ) is set.
- the operation of the power detection circuit shown in FIGS. 17A and 17B is performed while the ratio of the IF frequency (f IF ) to the filter band (f BW ) is kept constant, while the filter band (f BW ) and LO frequency (f The point of changing IF ) differs from the operation in the case of FIGS. 16A and 16B.
- Such an operation facilitates the adjusting means of the band variable complex bandpass filter 9.
- the gm of the first and second variable gm cell groups 90 and 91 and the gm of the third variable gm cell group 92 of the band variable complex bandpass filter shown in FIG. Each may be doubled.
- variable band complex bandpass filter 9 eliminates the need for a lookup table and complicated calculation processing.
- FIGS. 16 and 17 are diagrams showing another operation of the power detection circuit according to the present exemplary embodiment.
- the case of power detection in the narrow band shown in FIG. 18A and the case of power detection in the wide band shown in FIG. 18B are the same as those in FIGS. 16 and 17 described above.
- the LO frequency (f LO ) is set to be the same as the RF frequency (f RF ). (That is, zero IF) to detect power.
- the IF frequency increases with the detection band, so that the problem of increasing the power and area of the circuit after the band variable complex bandpass filter can be avoided.
- FIG. 19 is a block diagram showing a power detection circuit according to the present embodiment.
- the power detection circuit according to the present embodiment includes a mixer 1, a variable frequency oscillator 2, an AD converter 5, a digital band variable complex bandpass filter 10, and an energy detection circuit 4.
- the power detection circuit according to the present embodiment is a combination of the power detection circuit according to the second embodiment (see FIG. 9) and the power detection circuit according to the fourth embodiment (see FIG. 13).
- the power detection circuit according to the present embodiment is provided with an AD converter 5 that converts an analog signal into a digital signal after the mixer 1 like the power detection circuit according to the second embodiment. Further, after the AD converter 5, a complex bandpass filter with variable bandwidth is provided as in the power detection circuit according to the fourth embodiment. At this time, the band-variable band-pass filter 10 uses the digital band-variable complex band-pass filter 10 so as to correspond to the digital signal converted by the AD converter 5.
- FIG. 20 is a block diagram showing a power detection circuit according to the present embodiment.
- the power detection circuit according to the present embodiment includes a mixer 1, a variable frequency oscillator 2, a band variable complex bandpass filter 9, an RSSI circuit 7, an AD converter 5, and a digital signal processor (DSP) 8.
- the power detection circuit according to the present embodiment is a combination of the power detection circuit according to the third embodiment (see FIG. 10) and the power detection circuit according to the fourth embodiment (see FIG. 13).
- the power detection circuit according to the present embodiment replaces the complex bandpass filter 3 used in the power detection circuit according to the third embodiment with the band variable complex bandpass filter 9 used in the fourth embodiment. ing.
- FIG. 21 is a flowchart showing the operation of the power detection circuit according to the present exemplary embodiment.
- an empty frequency search is performed using the RSSI circuit 7 as an energy detection circuit (step S21).
- a vacant frequency is found, it is set to the same LO frequency (f LO ) as that RF frequency (f RF ) (step S22).
- the amplifier group 71 of the RSSI circuit 7 is set to the same LO frequency (f LO ) as that RF frequency (f RF ) (step S22).
- the amplifier group 71 of the RSSI circuit 7 is started with zero IF (step S23).
- the reception frequency is set to the same LO frequency (f LO ) as that of the vacant RF frequency (f RF ) (that is, set to zero IF). It is.
- the influence of the interference wave of the image signal frequency can be reduced as compared with the case of receiving with the low IF described in FIG.
- the low IF method is weaker against the strong interference wave of the image signal frequency than the zero IF method.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Circuits Of Receivers In General (AREA)
- Superheterodyne Receivers (AREA)
Abstract
Description
以下、図面を参照して本発明の実施の形態について説明する。
図1は実施の形態1にかかる電力検出回路を示すブロック図である。本実施の形態にかかる電力検出回路は、ミキサー1、可変周波数発振器2、複素バンドパスフィルタ3、およびエネルギー検出回路4を備える。ミキサー1にはアンテナから検出信号(fRF)11が入力される。可変周波数発振器2は、所定の局部発振周波数(fLO)を発振する。ミキサー1は、可変周波数発振器2から出力された局部発振周波数12と検出信号11との乗算を行ない周波数変換し、同相成分を複素バンドパスフィルタ3へ出力する。複素バンドパスフィルタ3は、ミキサー1から出力された信号から帯域外信号を除去する。エネルギー検出回路4は複素バンドパスフィルタ3の帯域内の電力を検出する。
次に、本発明の実施の形態2にかかる電力検出回路について説明する。図9は本実施の形態にかかる電力検出回路を示すブロック図である。本実施の形態にかかる電力検出回路は、ミキサー1、可変周波数発振器2、AD変換器5、デジタル複素バンドパスフィルタ6、およびエネルギー検出回路4を備える。つまり、本実施の形態にかかる電力検出回路では、実施の形態1にかかる複素バンドパスフィルタ3の代わりにAD変換器5とデジタル複素バンドパスフィルタ6を備えている。これ以外は実施の形態1にかかる電力検出回路と同様であるので、重複した説明は省略する。
次に、本発明の実施の形態3にかかる電力検出回路について説明する。図10は本実施の形態にかかる電力検出回路を示すブロック図である。本実施の形態にかかる電力検出回路は、ミキサー1、可変周波数発振器2、複素バンドパスフィルタ3、RSSI回路(Received Signal Strength Indicator:受信強度表示回路)7、AD変換器5、デジタル信号プロセッサ(DSP)8を備える。
次に、本発明の実施の形態4にかかる電力検出回路について説明する。図13は本実施の形態にかかる電力検出回路を示すブロック図である。本実施の形態にかかる電力検出回路は、ミキサー1、可変周波数発振器2、帯域可変複素バンドパスフィルタ9、およびエネルギー検出回路4を備える。つまり、本実施の形態にかかる電力検出回路では、実施の形態1にかかる複素バンドパスフィルタ3の代わりに帯域可変複素バンドパスフィルタ9を備えている。これ以外は実施の形態1にかかる電力検出回路と同様であるので、重複した説明は省略する。
次に、本発明の実施の形態5にかかる電力検出回路について説明する。図19は本実施の形態にかかる電力検出回路を示すブロック図である。本実施の形態にかかる電力検出回路は、ミキサー1、可変周波数発振器2、AD変換器5、デジタル帯域可変複素バンドパスフィルタ10、およびエネルギー検出回路4を備える。本実施の形態にかかる電力検出回路は、実施の形態2にかかる電力検出回路(図9参照)と実施の形態4にかかる電力検出回路(図13参照)を組み合わせたものである。
次に、本発明の実施の形態6にかかる電力検出回路について説明する。図20は本実施の形態にかかる電力検出回路を示すブロック図である。本実施の形態にかかる電力検出回路は、ミキサー1、可変周波数発振器2、帯域可変複素バンドパスフィルタ9、RSSI回路7、AD変換器5、およびデジタル信号プロセッサ(DSP)8を備える。本実施の形態にかかる電力検出回路は、実施の形態3にかかる電力検出回路(図10参照)と実施の形態4にかかる電力検出回路(図13参照)を組み合わせたものである。
2 可変周波数発振器
3 複素バンドパスフィルタ
4 エネルギー検出回路
5 AD変換器
6 デジタル複素バンドパスフィルタ
7 RSSI回路
8 デジタル信号プロセッサ
9 帯域可変複素バンドパスフィルタ
10 デジタル帯域可変複素バンドパスフィルタ
Claims (10)
- 局部発振周波数を発振する可変周波数発振器と、
前記局部発振周波数と検出信号とを入力し、前記局部発振周波数を用いて前記検出信号を周波数変換するミキサーと、
前記周波数変換された検出信号の帯域を所定の帯域に制限する複素バンドパスフィルタと、
前記複素バンドパスフィルタからの出力に基づき、前記所定の帯域の電力を検出するエネルギー検出回路と、を備え、
前記局部発振周波数は、前記周波数変換された検出信号の所定の帯域が1/fノイズの低い周波数領域となるように設定される、
電力検出回路。 - 前記可変周波数発振器は前記局部発振周波数をスイープする、請求項1に記載の電力検出回路。
- 前記電力検出回路は、更に前記ミキサーから出力される前記周波数変換された検出信号をデジタル信号に変換するAD変換器を備え、
前記複素バンドパスフィルタは、前記デジタル信号に変換された検出信号の帯域を所定の帯域に制限するデジタル複素バンドパスフィルタである、請求項1または2に記載の電力検出回路。 - 前記エネルギー検出回路はRSSI回路で構成される、請求項1または2に記載の電力検出回路。
- 前記RSSI回路は、
複数段に従属接続された複数のアンプと、
前記複数のアンプの各段の間に接続された複数の整流器と、
前記複数の整流器から出力される電流を電圧に変換する電流電圧変換回路と、
を備える、請求項4に記載の電力検出回路。 - 前記RSSI回路は、前記複数段に従属接続された複数のアンプの出力段数を切り替えることで受信時に可変ゲインアンプとして用いられる、請求項5に記載の電力検出回路。
- 前記複素バンドパスフィルタの前記所定の帯域が可変である、請求項1乃至6のいずれか一項に記載の電力検出回路。
- 前記バンドパスフィルタの前記所定の帯域を変化させる際に、前記複素バンドパスフィルタの前記所定の帯域と前記複素バンドパスフィルタの中心周波数との比を一定とする、請求項7に記載の電力検出回路。
- 前記バンドパスフィルタの前記所定の帯域が1/fノイズの高い周波数領域よりも広い場合、前記局部発振周波数は前記周波数変換された検出信号の中心の周波数がDCとなるように設定される、請求項7に記載の電力検出回路。
- 局部発振周波数を設定し、
前記局部発振周波数を用いて検出信号を周波数変換し、
前記周波数変換された検出信号の帯域を所定の帯域に制限し、
前記周波数変換された検出信号の所定の帯域の電力を検出し、
前記局部発振周波数を設定する際に、前記周波数変換された検出信号の所定の帯域が1/fノイズの低い周波数領域となるように前記局部発振周波数を設定する、
電力検出方法。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012505323A JP5682619B2 (ja) | 2010-03-17 | 2010-12-15 | 電力検出回路および電力検出方法 |
US13/579,871 US9148184B2 (en) | 2010-03-17 | 2010-12-15 | Power detection circuit and power detection method |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2010-060294 | 2010-03-17 | ||
JP2010060294 | 2010-03-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011114408A1 true WO2011114408A1 (ja) | 2011-09-22 |
Family
ID=44648541
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2010/007286 WO2011114408A1 (ja) | 2010-03-17 | 2010-12-15 | 電力検出回路および電力検出方法 |
Country Status (3)
Country | Link |
---|---|
US (1) | US9148184B2 (ja) |
JP (1) | JP5682619B2 (ja) |
WO (1) | WO2011114408A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20150144079A (ko) * | 2014-06-16 | 2015-12-24 | (주)엑스엠더블유 | 광대역 멀티밴드 주파수 상향 변환기 |
US10536311B2 (en) | 2017-11-15 | 2020-01-14 | Asahi Kasei Microdevices Corporation | Direct conversion receiver |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3090489B1 (en) * | 2014-01-03 | 2019-04-24 | Telefonaktiebolaget LM Ericsson (publ) | Method for adjusting lo frequencies in receiver and associated receiver |
JP6655896B2 (ja) * | 2014-10-08 | 2020-03-04 | 日本電波工業株式会社 | 周波数シンセサイザ |
US10952250B2 (en) * | 2017-02-07 | 2021-03-16 | Intel IP Corporation | Receiver and a method for detecting channel occupancy of a radio channel |
CN107528641A (zh) * | 2017-09-06 | 2017-12-29 | 国网宁夏电力公司电力科学研究院 | 一种电力公司采集终端的信号功率检测方法 |
JP7383274B2 (ja) | 2019-08-23 | 2023-11-20 | 学校法人新潟工科大学 | 荷重計測装置及び荷重警報システム |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0998141A (ja) * | 1995-10-03 | 1997-04-08 | Matsushita Electric Ind Co Ltd | 電力検出回路 |
JP2007006026A (ja) * | 2005-06-22 | 2007-01-11 | Sharp Corp | Rssi回路、半導体集積回路および通信装置 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5937341A (en) * | 1996-09-13 | 1999-08-10 | University Of Washington | Simplified high frequency tuner and tuning method |
US6968167B1 (en) * | 1999-10-21 | 2005-11-22 | Broadcom Corporation | Adaptive radio transceiver with calibration |
JP4284089B2 (ja) | 2003-02-28 | 2009-06-24 | 株式会社日立国際電気 | 受信機 |
JP4098052B2 (ja) | 2002-10-01 | 2008-06-11 | 株式会社日立国際電気 | 直接検波回路 |
JP3964346B2 (ja) | 2003-04-14 | 2007-08-22 | シャープ株式会社 | Fm信号受信器およびそれを用いる無線通信装置 |
US20080051053A1 (en) * | 2006-08-24 | 2008-02-28 | Orest Fedan | Dynamic, low if, image interference avoidance receiver |
JP4901679B2 (ja) | 2007-10-02 | 2012-03-21 | 株式会社東芝 | 無線送受信装置及び無線送信方法 |
JP4941560B2 (ja) * | 2007-10-03 | 2012-05-30 | 富士通株式会社 | Zero−IF方式により直交周波数分割多重された信号を受信する受信機及び受信方法 |
JP2009273021A (ja) | 2008-05-09 | 2009-11-19 | Nec Electronics Corp | 周波数ホッピングを有する無線通信装置と受信方法 |
CN101621810B (zh) * | 2008-07-04 | 2013-04-10 | 博通集成电路(上海)有限公司 | 接收信号强度指示探测器和校准接收信号强度指示的方法 |
-
2010
- 2010-12-15 WO PCT/JP2010/007286 patent/WO2011114408A1/ja active Application Filing
- 2010-12-15 US US13/579,871 patent/US9148184B2/en active Active
- 2010-12-15 JP JP2012505323A patent/JP5682619B2/ja active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0998141A (ja) * | 1995-10-03 | 1997-04-08 | Matsushita Electric Ind Co Ltd | 電力検出回路 |
JP2007006026A (ja) * | 2005-06-22 | 2007-01-11 | Sharp Corp | Rssi回路、半導体集積回路および通信装置 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20150144079A (ko) * | 2014-06-16 | 2015-12-24 | (주)엑스엠더블유 | 광대역 멀티밴드 주파수 상향 변환기 |
KR101693467B1 (ko) * | 2014-06-16 | 2017-01-17 | (주)엑스엠더블유 | 광대역 멀티밴드 주파수 상향 변환기 |
US10536311B2 (en) | 2017-11-15 | 2020-01-14 | Asahi Kasei Microdevices Corporation | Direct conversion receiver |
Also Published As
Publication number | Publication date |
---|---|
US20120313680A1 (en) | 2012-12-13 |
US9148184B2 (en) | 2015-09-29 |
JP5682619B2 (ja) | 2015-03-11 |
JPWO2011114408A1 (ja) | 2013-06-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5682619B2 (ja) | 電力検出回路および電力検出方法 | |
JP5922177B2 (ja) | 局部発振器信号のためのデューティサイクル調整 | |
US8130053B2 (en) | Tank tuning for band pass filter used in radio communications | |
JP4566228B2 (ja) | 送受信機 | |
US7477881B2 (en) | Intermediate frequency receiver with improved image rejection ratio | |
US7873342B2 (en) | Low IF receiver of rejecting image signal and image signal rejection method | |
US8594601B2 (en) | Receiver with on-demand linearity | |
KR101136246B1 (ko) | 무선 수신기를 동조시키기 위한 시스템 및 방법 | |
US8417204B2 (en) | Method and system for on-demand signal notching in a receiver | |
JPWO2011074193A1 (ja) | 自動利得制御装置及び電子機器 | |
KR20150086886A (ko) | 채널 선택도가 개선된 초재생 수신기 및 초재생 수신 방법 | |
US20120307947A1 (en) | Signal processing circuit, wireless communication device, and signal processing method | |
US6686861B1 (en) | Slice circuit capable of accurate conversion of an analog signal to a digital signal | |
JP2010252174A (ja) | 受信装置およびチューナ | |
US20090022208A1 (en) | Method and system for rapidly detecting the presence of interferers in bluetooth frequency hopping | |
JP2006020238A (ja) | 無線受信装置 | |
US9143313B2 (en) | Frequency sweep signal generator, frequency component analysis apparatus, radio apparatus, and frequency sweep signal generating method | |
JP2010021826A (ja) | 半導体集積回路 | |
US11012085B1 (en) | Scheme for mitigating clock harmonic interference and desensitization in RF channels | |
JP2019009497A (ja) | 半導体装置及びその方法 | |
JP2008160554A (ja) | フィルタ装置およびそれを有する送受信機 | |
Chen et al. | Design of an L1 band low noise single-chip GPS receiver in 0.18 μ m CMOS technology | |
JP2020202521A (ja) | 無線受信装置及びそれを備えた照明装置 | |
JP2002152298A (ja) | 復調装置及び復調方法 | |
US20110286557A1 (en) | Receiving apparatus |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 10847826 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13579871 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012505323 Country of ref document: JP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 10847826 Country of ref document: EP Kind code of ref document: A1 |