WO2006106967A1 - Dispositif suppresseur de bruit - Google Patents

Dispositif suppresseur de bruit Download PDF

Info

Publication number
WO2006106967A1
WO2006106967A1 PCT/JP2006/306937 JP2006306937W WO2006106967A1 WO 2006106967 A1 WO2006106967 A1 WO 2006106967A1 JP 2006306937 W JP2006306937 W JP 2006306937W WO 2006106967 A1 WO2006106967 A1 WO 2006106967A1
Authority
WO
WIPO (PCT)
Prior art keywords
interpolation
noise
signal
period
input signal
Prior art date
Application number
PCT/JP2006/306937
Other languages
English (en)
Japanese (ja)
Inventor
Hideyuki Kanno
Toru Ohashi
Original Assignee
Pioneer Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pioneer Corporation filed Critical Pioneer Corporation
Priority to JP2007511200A priority Critical patent/JP4174550B2/ja
Publication of WO2006106967A1 publication Critical patent/WO2006106967A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/08—Modifications for reducing interference; Modifications for reducing effects due to line faults ; Receiver end arrangements for detecting or overcoming line faults

Definitions

  • the present invention relates to a noise canceller that removes noise mixed in an input signal.
  • in-vehicle broadcast receivers mounted on automobiles are easily affected by external noise such as idling noise. Therefore, in general, processing such as detection and demodulation is not immediately performed on an intermediate frequency signal (IF signal) frequency-converted at the front end portion of the broadcast receiver, and external noise mixed in the intermediate frequency signal is eliminated by a noise canceller. After removal, the processing such as detection and demodulation is performed.
  • IF signal intermediate frequency signal
  • FIG. 1 (a) Conventionally, a noise canceller called a gate hold circuit shown in FIG. 1 (a) is generally known.
  • This noise canceller detects a noise mixing period of noise mixed in the input signal Sin and generates a gate signal GT, and interpolates the noise mixing period based on the gate signal GT.
  • the interpolation processing unit 2 is configured to perform interpolation processing for setting a period and removing noise in the input signal Sin.
  • the interpolation processing unit 2 gate-holds the signal component of the input signal Sin and outputs the held constant level as an interpolation signal. Further, after the interpolation processing unit 2 continuously outputs the interpolation signal in the interpolation period until the noise time detection unit 1 detects the end time t2 of the noise Nz, the signal is switched to the input signal Sin and output at the time t2.
  • the output signal Sout output from the interpolation processing unit 2 becomes the input signal Sin during the period other than the noise mixing period, and becomes a constant level interpolation signal during the noise mixing period (interpolation period). And when By using a series of synthesized waveforms, the noise Nz that is mixed into the input signal Sin is eliminated.
  • the noise canceller called the conventional gate hold circuit described above
  • the level of the interpolation signal in the interpolation period also increases.
  • the waveform of the output signal Sout changes steeply and at a large level discontinuously, and high-energy and high-frequency noise components are generated.
  • the present invention has been made in view of such a conventional problem, and provides a noise canceller that does not generate noise internally during interpolation processing for an input signal and that can simplify the circuit scale. With the goal.
  • the invention according to claim 1 is a noise canceller that removes and outputs noise that is mixed in the input signal via a storage unit that delays the input signal for a predetermined time.
  • Noise detection means for detecting noise mixed in the signal, and an interpolation period is set based on the detection result of the noise detection means, and the level of the signal component of the input signal immediately before the interpolation period is lower than a predetermined level.
  • the input signal is gate-held to generate an interpolation signal. If the signal level is determined to be greater than the predetermined level, the input signal is linearly approximated in the interpolation period to obtain an interpolation signal.
  • interpolation means for generating a signal and the interpolation means determine that the level is lower than a predetermined level
  • an interpolation signal by the gate hold is output during the interpolation period, and the level is lower than the predetermined level by the interpolation means.
  • switching means for outputting an interpolation signal based on the linear approximation during the interpolation period and outputting an input signal delayed by the storage means during a period other than the interpolation period when determined to be large It is characterized by.
  • the invention according to claim 2 is the noise canceller according to claim 1, wherein the interpolation period is longer than the delay time when the interpolation means determines that the level is greater than a predetermined level.
  • the interpolation period is set as a connection between a plurality of divided interpolation periods based on the delay time, and an interpolation signal by linear approximation that follows the change in the noise level is generated in each of the plurality of divided interpolation periods. It is characterized by that.
  • FIG. 1 is a diagram for explaining the configuration and function of a conventional noise canceller.
  • FIG. 2 is a block diagram showing a configuration of a noise canceller according to the embodiment of the present invention.
  • FIG. 3 is a block diagram showing the configuration of the noise canceller according to the embodiment and a timing chart for explaining the operation.
  • FIG. 4 is a waveform diagram for explaining the operation of the noise canceller shown in FIG.
  • FIG. 5 is a block diagram showing a configuration of a noise canceller according to another embodiment.
  • FIG. 2 is a block diagram showing the configuration of the noise canceller of this embodiment.
  • the noise canceller 5 includes a storage unit 6, a noise period detection unit 7, an interpolation unit 8 and a selector unit 9.
  • the storage unit 6 is not included in the noise canceller 5; for example, a buffer memory or the like provided for temporarily storing a received signal or the like when a digital broadcast receiver or the like performs detection or demodulation. May be used.
  • the storage unit 6 buffers the input signal Sina, delays it by a predetermined delay time TD, and outputs the delayed input signal Sinb. Further, it has a function of outputting the buffered input signal Sina as a reference signal Sinnz in response to a request from the interpolation unit 8. [0017]
  • the noise period detection unit 7 detects the noise Nz mixed in the input signal Sina, and outputs a gate signal GT indicating the noise mixing period from the noise start time point to the end point of the noise Nz. .
  • the selector unit 9 is a switching unit that performs switching operation according to the switching control signal SW from the interpolation unit 8, and includes an input signal Sinb output from the storage unit 6 and an interpolation signal CA output from the interpolation unit 8. , CB is switched and output as output signal Sout.
  • the interpolation unit 8 detects a noise mixing period of the noise Nz mixed in the input signal Sina by the gate signal GT, and sets an interpolation period Tc corresponding to the noise mixing period.
  • the noise start time of noise Nz is expressed as ts and the end time is expressed as te
  • the start time of the interpolation period Tc is shifted by the delay time TD (ts + TD)
  • the end time of the interpolation period Tc is delayed.
  • Interpolation period Tc is set by setting the time (te + TD) shifted by time TD.
  • the interpolation unit 8 detects the noise start time ts by the gate signal GT, the interpolation unit 8 acquires the input signal Sina at the noise start time ts as the reference signal Sinnz, and sets the level of the reference signal Sinnz to a predetermined threshold value. Compare with THD.
  • the reference signal Sinnz is smaller than the threshold value THD, it is determined that the level of the input signal Sina is also small, the reference signal Sinnz compared with the threshold value THD is gated and held during the interpolation period Tc.
  • the held interpolation signal CA at a certain level is output as an output signal Sout through the selector unit 9.
  • the reference signal Sinnz is greater than the threshold value THD, it is determined that the level of the input signal Sina is also large, and the following processing is performed without performing gate hold. That is, the input signal Sina at the noise start point ts is acquired as the reference signal Sinnz (ts), and the input signal Sina at the end point te of the noise Nz is acquired as the reference signal Sinnz (te).
  • the rate of change of the interpolation period Tc ((Sinnz (te) -Sinnz (ts)) ZTc) with respect to the difference between Sinnz (ts) and Sinnz (te) (Sinnz (te) -Sinnz (ts)) is calculated.
  • an interpolation signal that changes at the rate of change (Sin nZ (te)-Sinnz (ts)) / Tc) with the level of the reference signal Sinnz (ts) as an initial value (i.e., an interpolation signal that approximates a straight line) CB is interpolated.
  • the output signal S out is output via the selector unit 9.
  • the interpolation unit 8 has a longer noise mixing period of the noise Nz than the delay time TD of the storage unit 6. Therefore, when both the above-described reference signals Sinnz (ts) and Sinnz (te) are not buffered in the storage unit 6, they are input to the storage unit 6 and buffered after the noise start time ts. The reference signal Sinnz (tp) corresponding to the noise at the time point tp is acquired.
  • the difference between the reference signal Sinnz (ts) at the noise start time point ts and the reference signal Sinnz (tp) at the intermediate time point tp (Sinn z (tp) – Sinnz (ts)) is calculated, and from the noise start time point ts
  • the period up to the midpoint tp is calculated as the divided interpolation period (tp—ts), and the rate of change of the divided interpolation period (tp—ts) with respect to the difference (Sinn Z (t P ) —Sin nz (ts)) ((Sinn Z (tp) —Sinnzfc)) Z (tp—ts)).
  • An interpolation signal that changes at the rate of change ((Sinnz (tp) —Sinnz (ts)) Z (tp-ts)) with the level of the reference signal Sinnz (ts) as an initial value (ie, an interpolation signal that is linearly approximated).
  • CB is output as an output signal Sout via the selector unit 9.
  • the interpolation unit 8 can obtain the reference signal Sinn Z
  • the difference between (tp) and the reference signal Sinna (te) at the end time te (Sinnz (te) — Sinnz (tp)) is calculated, and the period from halfway time tp to end time te is calculated as the second divided interpolation period.
  • the entire interpolation period Tc corresponding to the noise mixing period is divided into a plurality of divided interpolation periods.
  • the noise Nz Interpolation is performed by generating an interpolated signal CB by linear approximation that tracks changes in the level.
  • the interpolation unit 8 detects noise mixed at the next intermediate time tn.
  • a reference signal Sin nz (tn) corresponding to is acquired.
  • the difference (Sinnz (tn)-Sinnz (tp)) between the reference signal Sinnz (tp) corresponding to the time point tp and the reference signal Sinnz (tn) corresponding to the intermediate time point tn is calculated, and the intermediate time point from the time point tp
  • the period up to tn is calculated as the divided interpolation period (tn—tp), and the change of the divided interpolation period (tn—tp) with respect to the difference (Sin nz (tn) —Simm (tp))
  • the ratio ((Sinnz (tn) ⁇ Sinnz (tp)) Z (tn ⁇ tp)) is calculated.
  • the interpolated signal CB is generated and output by linear approximation between the levels of the reference signals Sinnz (tp) and Sinnz (tn) at the midpoint tp, tn, and finally the reference signal corresponding to the noise end time te If Sinnz (te) can be obtained, the interpolation process is completed by performing the same process as the second interpolation described above.
  • the entire interpolation period Tc corresponding to the noise mixing period is divided into a plurality of divided interpolation periods, and in each divided interpolation period, Interpolation is performed by generating an interpolation signal CB by linear approximation that follows the change in the noise Nz level.
  • the interpolation unit 8 determines that the period other than the noise mixing period is based on the gate signal GT, the interpolation unit 8 performs switching control of the selector unit 9 to thereby control the input signal that is the delayed output of the storage unit 6.
  • the number Sinb is output via the selector unit 9.
  • the noise canceller 5 of the present embodiment mixes noise output from the storage unit 6 during a period in which no noise is mixed in the input signal Sina (a period other than the interpolation period Tc).
  • the interpolation signal CA is generated by gate hold and output during the interpolation period Tc.
  • the level of the input signal Sina is high, one or more straight lines Since the interpolation signal CB generated by approximation is output during the interpolation period Tc, noise can be removed.
  • the noise canceller 5 of the present embodiment is not a simple one in which noise is mixed and the input signal Sinb and the interpolation signal CA or CB are temporally synthesized to form the output signal Sout.
  • the signal is interpolated by the gate hold, and when the level of the input signal Sina is high, the interpolation is performed with the interpolation signal generated by linear approximation.
  • the interpolation signal CA Even if the input signal is switched to the input signal, it is possible to prevent internally generating a high-energy noise component, and when the amplitude of the input signal Sina is large, interpolation is performed with the interpolation signal CB by linear approximation. Therefore, it is possible to prevent noise components from being generated internally.
  • the noise canceller 5 of the embodiment described above may be realized by a force hardware configuration which is a so-called program configuration constituted by a microprocessor or a digital signal processor or the like.
  • a force hardware configuration which is a so-called program configuration constituted by a microprocessor or a digital signal processor or the like.
  • a digital circuit configuration can be used, or an analog circuit configuration can be used.
  • the reference signal Sinnz corresponding to the input signal is used for the determination, but the level of the input signal Sina may be determined by other methods.
  • Fig. 3 (a) is a block diagram showing the configuration of the noise canceller of this embodiment
  • Fig. 3 (b) is a timing chart for explaining the operation of the noise canceller
  • Fig. 4 is a waveform for explaining the operation of the noise canceller.
  • the noise canceller 5 is formed by a microprocessor (MPU) or a digital signal processor (DSP) that operates according to a computer program, and includes a storage unit 6 and a noise period detection unit. 7, a first interpolation processing unit 8a, a second interpolation processing unit 8b, a control unit 8c, and a selector unit 9.
  • the interpolation unit 8 shown in FIG. 3 includes a first interpolation processing unit 8a, a second interpolation processing unit 8b, and a control unit 8c.
  • the storage unit 6 is formed by a buffer memory or the like that outputs the input signal Sina after being delayed by a predetermined delay time TD by FIFO (first in first out) processing.
  • the input signal Sinb is supplied to the switching contact a of the selector unit 9.
  • the storage unit 6 outputs the input signal being processed by the FIFO addressed from the second interpolation processing unit 8b to the second interpolation processing unit 8b as a reference signal Sinnz, and also receives an address from the control unit 8c.
  • the designated input signal during FIFO processing is output to the control unit 8c as the reference signal Sinnz. That is, the storage unit 6 has a random access function.
  • the noise period detector 7 detects a noise Nz mixed in the input signal Sina, and indicates a noise start time ts when the signal component of the input signal Sina is switched to the noise Nz and an end time te of the noise Nz.
  • Supply signal GT to controller 8c Therefore, when the noise Nz is mixed for a long time, the gate signal GT indicating that the interval between the noise start time ts and the end time te is long, and the short time noise Nz are mixed.
  • the gate signal GT indicating that the interval between the noise start point ts and the end point te is short is supplied to the control unit 8c.
  • the control unit 8c Based on the gate signal GT, the control unit 8c detects the period from the noise start time ts to the end time te as the noise mixing period, and when the delay time TD has elapsed from the noise start time ts (ts + TD ) To the point (te + TD) from the end point te to the point when the delay time TD has elapsed (te + TD)
  • control unit 8c connects the selector unit 9 to the switching contact a by the switching control signal SW during the period other than the interpolation period Tc, thereby mixing the noise Nz that is a delayed output of the storage unit 6.
  • the uninput signal Sinb is output as the output signal Sout.
  • the control unit 8c detects the noise start time ts by the gate signal GT, the control unit 8c acquires the reference signal Sinnz corresponding to the input signal Sina at the noise start time ts, and the level (amplitude) of the reference signal Si nnz. ) Is smaller than a predetermined threshold value THD.
  • the threshold value THD is determined in advance in consideration of the amplitude of the input signal to be interpolated by the first interpolation processing unit 8a.
  • the control unit 8c determines that the level of the reference signal Sinnz is smaller than the threshold value THD, the time point (ts + TD) after the delay time TD elapses from the noise start time point ts, that is, the interpolation period Tc.
  • the selector unit 9 is connected to the switching contact b by the switching control signal SW, and at the same time, the interpolation processing signal CNT1 starts the interpolation processing to the first interpolation processing unit 8a, and the interpolation control signal CNT1
  • the interpolation signal CA generated by the first interpolation processing unit 8a is output as the output signal Sout until the end of the specified interpolation period Tc.
  • the selector unit 9 is connected to the switching contact c by the switching control signal SW at the start of the interpolation period Tc.
  • the interpolation control signal CNT2 causes the second interpolation processing unit 8b to start interpolation processing, and the second interpolation processing unit 8b generates it until the end of the interpolation period Tc specified by the interpolation control signal CNT2.
  • Interpolation signal CB is output as output signal Sout.
  • the control unit 8c controls the first and second interpolation processing units 8a and 8b and the selector unit 9, as shown in FIG. 3 (b), the input signal Sina and the output signal Sout
  • the input signal Sina in other words, the input signal Sinb
  • the input signal Sinb the input signal
  • the first interpolation processing unit 8a performs interpolation processing by gate hold in the interpolation period Tc (interpolation period Tea in FIG. 3B) according to the interpolation control signal CNT1 supplied from the control unit 8c. In other words, as described above, the control unit 8c determines that the level of the reference signal Sinnz is low and switches the level.
  • the first interpolation processing unit 8a gate-holds the reference signal Si nnz corresponding to the input signal Sina input at the start time (ts + TD) of the interpolation period Tc.
  • the held interpolation signal CA at a certain level is supplied to the switching contact b of the selector unit 9 during the above-described interpolation period Tea. Due to the powerful interpolation processing, the signal component of the input signal Sina at the noise start time ts is gate-held, and the interpolation signal CA of a certain level from which the noise Nz is removed is switched to the selector unit 9 within the interpolation period Tc. Output as output signal Sout via contact b.
  • the interpolation period Tc corresponding to the noise mixing period from the noise start time ts to the end time te is obtained.
  • the signal component Xs of the input signal Sina at the noise start time point ts is held, and a constant level interpolation signal CA is output as the output signal Sout until the end of the interpolation period Tc.
  • the noise Nz is replaced with the interpolation signal CA at a certain level, and the noise z can be removed.
  • the second interpolation processing unit 8b performs interpolation processing within the interpolation period Tc (interpolation period Tcb in FIG. 3B) according to the interpolation control signal CNT2 supplied from the control unit 8c.
  • the second interpolation processing unit 8b has a function of switching between basic interpolation processing and adaptive interpolation processing according to the length of the noise mixing period of the noise Nz.
  • This basic interpolation processing is performed when the noise mixing period from the noise start point ts force to the end point te is relatively short compared to the storage capacity of the storage unit 6.
  • the second interpolation processing unit 8b detects the noise start time ts based on the gate signal GT before the interpolation control signal CNT2 is supplied, and the input signal Si of the noise start time ts.
  • na is acquired as a reference signal Sinnz, and the level of the reference signal Sinnz (hereinafter referred to as “initial level X s”) is held.
  • the noise end time te is detected based on the gate signal GT within the preparation period TPR in which the noise start time ts force is also shorter than the delay time TD, and the input signal Sina of the noise end time te is detected.
  • the reference signal Sinnz corresponding to is acquired, and the level of the reference signal Sinnz (hereinafter referred to as “final level Xe” t) is held.
  • interpolation is performed by calculating the rate of change a of the noise mixing period (te-ts) with respect to the difference between the initial level Xs and the final level Xe. Prepare for interpolation before the control signal CNT2 is supplied.
  • the second interpolation processing unit 8b Is equivalent to the following equation (2) to obtain the rate of change oc.
  • the second interpolation processing unit 8b is configured to start the interpolation period Tc (ts + TD ) Is set to the initial level Xs, and as shown in the following equation (3), an interpolation signal CB whose level changes according to the change rate ⁇ is generated as time t passes, and the interpolation period Tc is Output until the end point (te + TD).
  • the second interpolation processing unit 8b performs the basic interpolation processing, instead of the noise Nz, one linearly approximated interpolation signal CB is output as the output signal Sout via the selector unit 9. Therefore, the noise Nz can be removed.
  • the interpolation period Tc corresponding to the noise mixing period from the noise start time ts to the end time te is obtained.
  • the noise N z is interpolated by the interpolation signal CB that linearly approximates the signal component Xs of the input signal Sina at the noise start time ts and the signal component Xe of the input signal Sina at the end time te of the interpolation period Tc.
  • the signal CB is replaced, and the noise Nz can be removed.
  • the basic interpolation processing is performed when a relatively short time noise Nz is mixed.
  • the noise Nz that continues from the noise start time ts to the end time te is shorter than the delay time TD of the storage unit 6, the power noise for which the basic interpolation processing based on the above equations (1) to (3) is performed.
  • the final level Xe of the input signal Sina at the noise end time te cannot be obtained as the reference signal Sinnz.
  • the rate of change ⁇ shown in Equation (1) cannot be calculated, and basic interpolation processing based on Equations (1) to (3) above cannot be performed.
  • the second interpolation processing unit 8b retains only the above-mentioned initial level Xs in the preparation period TPR after starting the basic interpolation processing, and the final input signal Sina at the noise end time te. If it is determined that the level Xe cannot be acquired as the reference signal Sinnz, the shift to the interpolation processing based on the above equations (1) to (3) is stopped, and the adaptive interpolation processing is performed.
  • the storage unit 6 is accessed within the preparation period TPR, and the noise Nz stored in the storage unit 6 is temporally stored after the noise start time ts.
  • a reference signal Sinnz having is obtained.
  • any reference signal Sinnz having a noise Nz stored in the storage unit 6 in time after the noise start time point ts may be used, but the second interpolation processing unit 8b of the present embodiment stores the reference signal Sinnz.
  • the reference signal Sinnz having the latest noise Nz stored in the part 6 is obtained.
  • the level of the reference signal Sinnz having the latest noise Nz (ie, the level of the noise Nz) is detected and set to the intermediate level Xp, and the reference signal Sin nz having the latest noise Nz is stored. Based on the address information, the latest noise Nz is input signal Sina.
  • the noise intermediate time tp actually mixed in is detected and the time after the delay time TD elapses from the noise start time ts (ts + TD) to the time after the delay time TD elapses from the noise intermediate time tp (tp + TD) The period until is the first interpolation period Tel.
  • the interpolation control signal CNT2 is supplied by calculating the change rate ⁇ of the first interpolation period Tel with respect to the difference between the initial level Xs and the intermediate level Xp. Prepare for interpolation before starting.
  • the second interpolation processing unit 8b Therefore, the rate of change ⁇ is obtained by performing an equivalent operation to the following equation (5).
  • the second interpolation processing unit 8b is configured to start the interpolation period Tc (ts + TD ) Is set to the initial level Xs, and as shown in the following equation (6), an interpolated signal CB whose level changes according to the rate of change j8 is generated as time t passes, and the above-mentioned time point ( (ts + TD) force is also output within the first interpolation period Tel, which is the period up to the time (tp + TD).
  • the second interpolation processing unit 8b receives the above-described interpolation signal CB within the period of the first interpolation period Tcl. In parallel with the generation, determine whether the noise end point te can be detected from the gate signal GT. If it is determined that it has been detected, the convergence interpolation processing described below is performed. If it is determined that it cannot be detected, extended interpolation processing is performed.
  • the convergence interpolation process is performed when the second interpolation processing unit 8b detects the noise end point te from the gate signal GT within the period of the first interpolation period Tel.
  • the second interpolation processing unit 8b determines that the noise end point te has been detected, accesses the storage unit 6, and refers to the noise end point te already stored in the storage unit 6 within the first complement period Tel. Get the level (final level) Xe of the signal Sinnz. Then, the period from the previously determined noise intermediate time tp after the delay time TD (tp + TD) to the time after the noise end time te to the time after the delay time TD (te + TD) 2 Interpolation period Tc2. Further, as expressed by the following equation (7), the change rate ⁇ of the second interpolation period Tc2 with respect to the difference between the intermediate level Xp and the final level Xe is calculated.
  • the second interpolation processing unit 8b continues to set the second interpolation period Tc2, and sets the initial value at the start time (tp + TD) of the second interpolation period Tc2 to an intermediate value.
  • the interpolation signal CB whose level changes according to the rate of change ⁇ is generated as the time t passes and is output within the period of the second interpolation Tc2.
  • the second interpolation processing unit 8b sets the first interpolation period Tel and the second interpolation period Tc2 and performs adaptive interpolation processing, as shown in Fig. 4 (d)
  • the first interpolation period Tel In the second interpolation period Tc2 interpolation is performed using the interpolation signal CB1.
  • the interpolation signals CB1 and CB2 are interpolated with continuity, so noise is generated internally. thing The long-term noise Nz mixed in the input signal Sina can be removed.
  • the entire interpolation period Tc corresponding to the noise mixing period is divided into a first interpolation period Tel and a second interpolation period Tc2, and the interpolation by the interpolation signal CB1 is performed in the first interpolation period Tel.
  • the second interpolation period Tc2 convergence interpolation is performed and interpolation is performed using the interpolation signal CB2, so even if noise Nz is mixed for a long time compared to the storage capacity of the storage unit 6, the noise Nz Can be removed.
  • the extended interpolation process is performed when the second interpolation processing unit 8b cannot detect the noise end point te from the gate signal GT within the period of the first interpolation period Tel. If the second interpolation processing unit 8b determines that the noise end point te cannot be detected,
  • the reference signal Sinnz corresponding to the latest input signal Sina having the noise Nz is acquired, the level of the reference signal Sinnz is detected and set to the second intermediate level Xn, and the reference signal Sinnz having the latest noise Nz is obtained.
  • the latest noise Nz detects the noise intermediate time tn actually mixed in the input signal Sina, and the time after the delay time TD has elapsed from the noise start time ts
  • the period from (ts + TD) to the time (tp + TD) after the delay time TD elapses from the noise intermediate time tn is defined as the second interpolation period Tc2.
  • the second interpolation processing unit 8b performs the same process as the above-described convergence interpolation process,
  • the third interpolation period Tc3 is set after the second interpolation period Tc2, and the interpolation signal CB3 is generated and output until the end of the third interpolation period Tc3, and the adaptive interpolation process is completed.
  • the above-described extended interpolation process is further repeated until the noise end point te can be detected from the gate signal GT. Thereafter, the convergence interpolation process is performed to complete the adaptive interpolation process.
  • the second interpolation processing unit 8b performs the extended interpolation process, it is possible to remove the noise Nz mixed for a longer time. That is, the entire interpolation period Tc corresponding to the noise mixing period is time-divided into a number of interpolation periods such as the first interpolation period Tcl, the second interpolation period Tc2, the third interpolation period Tc3, etc. Interpolation that follows noise in multiple interpolation periods is performed, and then convergent interpolation processing is performed in the last interpolation period, so even if noise Nz is mixed for a long time compared to the storage capacity of the storage unit 6, Noise Nz can be removed.
  • the input signal is output as the output signal Sout during a period in which no noise is mixed in the input signal Sina, and the predetermined threshold THD is output.
  • the first interpolation processing unit 8a outputs the interpolation signal CA generated by performing the gate hold as the output signal Sout, and from the predetermined threshold THD.
  • the second interpolation processing unit 8b performs basic interpolation processing and adaptive interpolation processing, so that the interpolation signal CB by one or more linear approximations is used as the output signal Sout. Since it is output, noise can be removed.
  • the noise canceller 5 of the present embodiment is not simply switched by the first and second interpolation processing units 8a and 8b, and the first signal is input when the amplitude of the input signal Sina is smaller than the threshold value THD.
  • the second interpolation processing unit 8b performs interpolation processing.
  • the level of the interpolation signal CA generated by the first interpolation processing unit 8a also decreases, and at the end of the noise mixing period (in other words, Even when the interpolation signal CA is switched to the input signal at the end of the interpolation period Tc, it is possible to prevent the high energy noise component from being generated internally.
  • interpolation processing can be performed even if the storage capacity of the storage unit 6 is limited.
  • FIG. 5 is a block diagram showing the configuration of the noise canceller of this embodiment, and the same or corresponding parts as those in FIG.
  • the noise canceller 5 of this embodiment inputs a baseband signal detected by the front end FE provided in the FM receiver as an input signal Sina and applies external noise such as idling noise.
  • the output signal Sout which is the baseband signal after noise removal, is output to the demodulator.
  • the high-frequency received signal (RF received signal) generated at the receiving antenna ANT and the local frequency signal of the tuning frequency are mixed and subjected to frequency conversion to convert the intermediate frequency signal (IF signal) is generated, and the intermediate frequency signal is band-limited and amplified to an amplitude level that allows signal processing, thereby generating a baseband signal as a desired signal component.
  • the baseband signal is supplied to the noise period detection unit 7 and the storage unit 6 as the input signal Sina.
  • the noise period detector 7 includes a high-pass filter 7a, a smoothing circuit 7b, and a comparator 7c.
  • the filter 7a passes the external noise mixed in the input signal Sina, and the smoothing circuit 7b By smoothing, a smooth noise component is generated, and the comparator 7a having hysteresis compares the level of the smooth noise component with a predetermined comparison voltage, and the level of the smooth noise component is larger than the comparison voltage.
  • the period is detected as a noise mixing period, and the gate signal GT is supplied to the control unit 8c and the second interpolation processing unit 8b.
  • the storage unit 6 buffers the input signal Sina and outputs an input signal Sinb that is delayed by a predetermined delay time TD.
  • the first and second interpolation processing units 8a and 8b and the selector unit 9 have the same functions as the first and second interpolation processing units 8a and 8b and the selector unit 9 shown in FIG. Yes.
  • the control unit 8c has basically the same function as the control unit 8c shown in FIG. However, instead of comparing the input signal Sina with the threshold value THD and determining the amplitude of the input signal Sina, the reception sensitivity signal CN indicating the reception sensitivity (CZN) output from the front end FE is input and the reception is performed.
  • the sensitivity signal CN is compared with a predetermined threshold value THD.
  • the control unit 8c detects that the noise Nz is mixed based on the gate signal GT. If the reception sensitivity signal CN is smaller than the threshold value THD, the control unit 8c determines that the amplitude of the input signal Sina is small and performs the first interpolation process.
  • the reception sensitivity signal CN is larger than the threshold value THD, it is determined that the amplitude of the input signal Sina is large, and the second interpolation processing unit 8b performs the interpolation process.
  • the control unit 8c performs switching control of the selector unit 9 and the first and second interpolation processing units 8a and 8b.
  • the switching control By performing the switching control, the noise Nz mixed in the input signal Sina that is a baseband signal is removed, and the output signal Sout after the noise removal is supplied to a demodulator or the like.
  • the noise canceller 5 of the present embodiment when no noise is mixed in the baseband signal, the baseband signal is output as an output signal Sout to a demodulator or the like, and when the noise is mixed. Since the interpolation signal CA or CB generated by the first interpolation processing unit 8a or the second interpolation processing unit 8b is output as an output signal Sout to a demodulator or the like, noise can be removed. [0098] Furthermore, when the reception sensitivity is smaller than the threshold value THD, the first interpolation processing unit 8a performs an interpolation process for a baseband signal having a small amplitude, thereby preventing a high-energy noise component from being generated internally.
  • the second interpolation processing unit 8b When the reception sensitivity is greater than the threshold value THD, switching from the first interpolation processing unit 8a to the second interpolation processing unit 8b can prevent the above-described high-energy noise component from being generated internally. Furthermore, when long-term noise is mixed, the second interpolation processing unit 8b performs basic interpolation processing and adaptive interpolation processing, so that even if the storage capacity of the storage unit 6 is limited, the interpolation processing is performed. Makes it possible to do.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Noise Elimination (AREA)

Abstract

L’invention concerne un dispositif suppresseur de bruit comprenant une section d’interpolation (8) qui définit une période d’interpolation Tc pour traiter la suppression du bruit, en détectant une période pendant laquelle on mélange du bruit dans un signal d’entrée Sina. Si l’on décide que le niveau de composante de signal du signal d’entrée Sina est faible, un signal d’interpolation CA est créé par une porte maintenant le signal d’entrée Sina dans la période d’interpolation Tc et généré par le biais d’une section de sélection (9). Si l’on décide que le niveau de composante de signal du signal d’entrée Sina est élevé, la période allant jusqu’au terme du mélange de bruit est divisée en une pluralité de périodes auxiliaires sur la base d’une temporisation TD, et l’on crée un signal d’interpolation CB en réalisant une approximation linéaire sur le signal d’entrée Sina dans chaque période d’interpolation divisée, avant de le générer par le biais de la section de sélection (9).
PCT/JP2006/306937 2005-03-31 2006-03-31 Dispositif suppresseur de bruit WO2006106967A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007511200A JP4174550B2 (ja) 2005-03-31 2006-03-31 ノイズキャンセラ及びノイズ除去方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2005101832 2005-03-31
JP2005-101832 2005-03-31

Publications (1)

Publication Number Publication Date
WO2006106967A1 true WO2006106967A1 (fr) 2006-10-12

Family

ID=37073517

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2006/306937 WO2006106967A1 (fr) 2005-03-31 2006-03-31 Dispositif suppresseur de bruit

Country Status (2)

Country Link
JP (1) JP4174550B2 (fr)
WO (1) WO2006106967A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001237725A (ja) * 2000-02-23 2001-08-31 Mitsubishi Electric Corp 雑音除去装置
JP2004056173A (ja) * 2002-07-16 2004-02-19 Mitsubishi Electric Corp ノイズ抑圧装置

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001237725A (ja) * 2000-02-23 2001-08-31 Mitsubishi Electric Corp 雑音除去装置
JP2004056173A (ja) * 2002-07-16 2004-02-19 Mitsubishi Electric Corp ノイズ抑圧装置

Also Published As

Publication number Publication date
JPWO2006106967A1 (ja) 2008-09-25
JP4174550B2 (ja) 2008-11-05

Similar Documents

Publication Publication Date Title
US7880721B2 (en) Wave receiving device and method of determining wave reception
JP2011188467A (ja) 放送受信装置及び、放送受信装置の雑音有無判断方法
JP2005210261A (ja) 無線通信システムおよび高周波ｉｃ
WO2006106967A1 (fr) Dispositif suppresseur de bruit
JP3586267B2 (ja) 自動利得制御回路
JP3567928B2 (ja) ノイズ抑圧装置
JP4170381B2 (ja) ノイズキャンセラ
WO2006098324A1 (fr) Dispositif d'annulation de bruit
JP3641497B2 (ja) マルチプレクス信号から点火ノイズを消去する回路装置
US20040108906A1 (en) Noise eliminator
JP3358221B2 (ja) アンテナ切換え装置
JP5402496B2 (ja) 受信回路、信号伝送回路、集積回路、及び信号伝送方法
US6657482B2 (en) Digital filter
JPS6332295B2 (fr)
JP3833094B2 (ja) 電圧レベル検知回路および電圧レベル検知方法
US10171191B2 (en) Broadcast receiving apparatus and broadcast receiving method
JPS585042A (ja) ダイバ−シテイ受信装置
JPH0354922A (ja) スケルチ信号発生回路
JP2538627B2 (ja) ゴ―スト除去装置
JP2009267833A (ja) 音声信号処理回路
JP2000022566A (ja) ノイズ低減回路
JPH07115568A (ja) 車載用テレビジョン装置
JPH0583591A (ja) フレームタイミング検出回路
JPH06232711A (ja) Ｆ／ｖ変換平均化回路
JPH02260876A (ja) 波形等化装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2007511200

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: RU

122 Ep: pct application non-entry in european phase

Ref document number: 06730885

Country of ref document: EP

Kind code of ref document: A1