JP2013201504A - Communication apparatus, received signal detection device, and received signal detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the moment of a received signal going high stably with high accuracy in a simple composition without relying on a change in environment.SOLUTION: An FM detection processing unit 40 converts the complex envelope signal of a received signal into an FM signal and then outputs it. An HPF unit 50 filters the high frequency component of the FM signal and then outputs a high frequency signal. A signal level determination unit 70 outputs a pseudo signal which is to be added to the high frequency signal according to the signal level of the complex envelope signal of the received signal. A pseudo signal addition unit 80 adds the pseudo signal and a value relating to the magnitude of the high frequency signal together to generate an added high frequency signal. A received signal detection processing unit 100 compares the magnitude of the added high frequency signal with a preset designated threshold and, on the basis of the comparison result, detects a rising edge of the received signal. The magnitude of the pseudo signal is set to be at least equal to or greater than the designated value of the received signal detection processing unit 100.

Description

  The present invention relates to a communication device, a reception signal detection device, and a reception signal detection method, and, for example, relates to a technique for detecting rising of a reception signal.

  In recent years, as a technique for detecting a rising edge of a received signal in a communication apparatus, a technique using a difference value between a low frequency component and a high frequency component of an FM signal after FM detection processing is known (for example, Patent Documents). 1). That is, in the technique described in Patent Document 1, first, the FM detection circuit converts the digital complex envelope signal of the received signal into an FM signal by FM detection processing. Next, a high pass filter (HPF) filters the high frequency component of the FM signal to obtain a high frequency signal. A low pass filter (LPF) filters the low frequency component of the FM signal to obtain a low frequency signal. Then, the rising edge detection processing circuit compares the difference value between the high frequency component and the low frequency component of the FM signal with a predetermined threshold value to detect the rising edge of the received signal.

  At this time, the FM detector circuit detects white noise of a relatively high signal level with a flat frequency characteristic when there is no signal, and a rising waveform and a speech waveform of a relatively low signal level when a signal arrives. In particular, in the rising waveform when a signal arrives, energy is concentrated on the low frequency side. In the technique described in Patent Document 1, the rising edge of the received signal is detected by utilizing the fact that the energy ratio of the low frequency component and the high frequency component of the FM signal differs between when there is no signal and when the signal arrives. doing.

  Patent Document 2 discloses a technique for detecting noise using only the high frequency components of the FM signal after the received signal is subjected to FM detection processing. That is, in the technique described in Patent Document 2, first, the HPF filters high frequency components from the FM signal output from the FM detection circuit. Next, the pulse detector detects and outputs a high frequency component of the FM signal that is equal to or higher than the predetermined threshold value as compared with the predetermined threshold value.

  Japanese Patent Application Laid-Open No. 2004-259542 discloses a technique for performing FM detection on a digital complex envelope signal of a received signal, extracting a feature vector waveform that is a frequency fluctuation waveform at the time of rising, and identifying a radio using this feature vector waveform Is described. In the technique described in Patent Document 3, first, a digital complex envelope signal outside a specific frequency band is excluded using a filter. Further, when extracting the feature vector waveform, an invalidation period in which the received signal energy is equal to or less than a predetermined threshold is specified. In the invalidation period, the radio device is identified using a feature vector having a value of 0 instead of the feature vector after FM detection.

  Further, as a reference technique, Patent Document 4 discloses a technique related to a press talk type radio receiver.

JP 2006-211241 A JP-A-1-109932 JP 2011-091712 A JP-A-6-29880

  However, the technique described in Patent Document 1 requires processing for filtering the high frequency component of the FM signal by HPF after FM detection processing, and processing for filtering the low frequency component of the FM signal by LPF. There was a problem that the scale of the wear would increase.

  In order to reduce the scale of hardware, it is also conceivable to apply the technique described in Patent Document 2 and perform rise detection using only the high frequency components of the FM signal. However, in this case, if the noise level at the time of no signal is small, the level difference between the power of the high frequency component of the FM signal is small between the time of no signal and the arrival of the signal, and detection of the rising of the received signal There was a problem that processing became unstable.

  In the technique described in Patent Document 3, a digital complex envelope signal outside a specific frequency band is excluded using a filter, but the high frequency component is not filtered by HPF.

  The present invention has been made in view of such circumstances, and an object thereof is to stably and accurately detect the rising edge of a received signal with a simple configuration without depending on environmental changes. It is to provide a technology that can be used.

  The communication apparatus according to the present invention includes an FM detection processing unit that converts a complex envelope signal of a received signal into an FM signal and outputs the FM signal, and a high-frequency component of the FM signal that is output by the FM detection processing unit by filtering the high frequency component. A high-pass filter unit that outputs a high-frequency signal, and a signal level that outputs a pseudo signal to be added to the high-frequency signal output by the high-pass filter unit according to the signal level of the complex envelope signal of the received signal A determination unit; a pseudo signal addition unit that generates an added high frequency signal by adding the pseudo signal output from the signal level determination unit and a value related to a magnitude of the high frequency signal; and The magnitude of the added high frequency signal generated by the signal adder is compared with a predetermined threshold value, and the rising edge of the received signal is determined based on the comparison result. And a reception signal detecting unit for output, the magnitude of the spurious signals is at least said predetermined threshold value or more.

  In addition, the received signal detection apparatus of the present invention includes an FM detection processing unit that converts a complex envelope signal of the received signal into an FM signal and outputs the FM signal, and a high frequency component of the FM signal output by the FM detection processing unit. A high-pass filter unit that filters and outputs a high-frequency signal, and a pseudo signal to be added to the high-frequency signal output by the high-pass filter unit according to the signal level of the complex envelope signal of the received signal A signal level determination unit that outputs, a pseudo signal addition unit that generates an added high frequency signal by adding the pseudo signal output by the signal level determination unit and a value related to the magnitude of the high frequency signal And the magnitude of the added high frequency signal generated by the pseudo signal adding unit and a predetermined threshold set in advance, and based on the comparison result, the received signal And a reception signal detecting unit for detecting a rising magnitude of the pseudo signal is at least the predetermined threshold value or more.

  The received signal detection method of the present invention includes a step of converting the complex envelope signal of the received signal into an FM signal and outputting the signal, a step of filtering the high frequency component of the FM signal and outputting a high frequency signal. Outputting a pseudo signal to be added to the high frequency signal according to the signal level of the complex envelope signal of the received signal, the pseudo signal, and a value relating to the magnitude of the high frequency signal. Adding, generating a summed high frequency signal, comparing the magnitude of the summed high frequency signal with a predetermined threshold value, and based on the comparison result, Detecting, and the magnitude of the pseudo signal is at least equal to or greater than the predetermined threshold.

  According to the present invention, it is possible to detect a rising edge of a received signal stably and accurately with a simple configuration without depending on environmental changes.

It is a figure which shows the structure of the communication apparatus in the 1st Embodiment of this invention. It is a figure which shows the signal characteristic at the time of the non-signal of the FM signal by which FM detection processing is carried out by the FM detection process part, and a signal arrival. It is a figure for demonstrating the effect by a signal level determination part and a pseudo signal addition part. It is a figure for demonstrating the effect by a signal level determination part and a pseudo signal addition part. It is a figure for demonstrating the effect by a signal level determination part and a pseudo signal addition part. It is a figure for demonstrating the effect by a signal level determination part and a pseudo signal addition part. It is a figure which shows the operation | movement flow of the communication apparatus in the 1st Embodiment of this invention. It is a figure for demonstrating the effect of the communication apparatus in the 1st Embodiment of this invention. It is a figure which shows the structure of the communication apparatus in the 2nd Embodiment of this invention. It is a figure which shows the operation | movement flow of the communication apparatus in the 2nd Embodiment of this invention.

<First Embodiment>
Communication apparatus 1000 according to the first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows the configuration of the communication apparatus 1000. The communication device 1000 is a device that transmits and receives intermittent signals, such as a Presstalk type communication device, and can detect the rising of a signal transmitted from a communication device on the other side of communication. .

  As shown in FIG. 1, the communication device 1000 includes an antenna unit 10, a receiving unit 20, an A / D (Analog Digital) analog unit 30, and a received signal detection device 500. The The received signal detection apparatus 500 includes an FM detection processing unit 40, a high-pass filter (hereinafter referred to as HPF) unit 50, a high-frequency signal level calculation unit 60, a signal level determination unit 70, and a pseudo signal addition unit 80. And a smoothing unit 90 and a received signal detection processing unit 100. The communication device 1000 corresponds to the communication device of the present invention. The reception signal detection device 500 corresponds to the reception signal detection device of the present invention.

  The antenna unit 10 is connected to the receiving unit 20 and corresponds to a predetermined radio signal (for example, specified by a frequency or the like).

  The receiving unit 20 receives a radio signal via the antenna unit 10 and performs predetermined reception processing (frequency conversion or the like) on the radio signal to generate a received signal (also referred to as an intermediate frequency signal). Then, the reception unit 20 outputs the reception signal to the A / D conversion unit 30.

  The A / D conversion unit 30 performs analog-to-digital conversion on the received signal, generates a digital complex envelope signal of the received signal, and outputs this to the received signal detection device 500. The digital complex envelope signal corresponds to the complex envelope signal of the present invention. Here, the general A / D conversion unit 30 cannot perform A / D conversion on a received signal that is equal to or lower than the minimum input level of the A / D conversion unit 30. The minimum input level of the A / D conversion unit 30 is a minimum value of a signal level at which the A / D conversion unit 30 can perform analog-digital conversion on a received signal (analog signal). For this reason, when the magnitude of the received signal is smaller than the minimum input level of the A / D converter 30, the A / D converter 30 outputs a digital complex envelope signal of the received signal at the signal level 0.

  The FM detection processing unit 40 converts the digital complex envelope signal of the reception signal input by the A / D conversion unit 30 into an FM signal and outputs the FM signal.

  The HPF unit 50 filters the high frequency component (for example, 30 to 40 kHz) of the FM signal output by the FM detection processing unit 40 and outputs a high frequency signal. In addition, 30-40 kHz is an example of the high frequency component of FM signal, Comprising: It is not limited to this. At this time, it is necessary to select a high frequency component so that a power difference is generated between no signal and signal arrival.

  The high frequency signal level calculation unit 60 includes a multiplier 61. The high frequency signal level calculation unit 60 calculates the high frequency signal level (for example, the power signal level) of the high frequency signal output from the HPF unit 50 as a high frequency signal level, and simulates the high frequency signal level. The signal is output to the signal adding unit 80. The high frequency signal level is a value related to the magnitude of the high frequency signal. Here, a value obtained by squaring the power of the high frequency signal is set as the high frequency signal level. However, the high frequency signal level may be a value related to the magnitude of the high frequency signal, and is not limited to a value obtained by squaring the power of the high frequency signal. For example, a value obtained by squaring the power of the high frequency signal and then performing a square root process on the square value may be used as the high frequency signal level. In this case, the output of the high frequency signal level calculation unit 60 is not the level of the power signal but the level of the envelope signal.

  The signal level determination unit 70 outputs a pseudo signal described below according to the signal level of the digital complex envelope signal of the reception signal output by the A / D conversion unit 30. That is, the pseudo signal is a signal generated in a pseudo manner to be added to the high frequency signal output from the HPF unit 50.

  A method for generating the pseudo signal is, for example, as follows. That is, after generating a uniformly distributed random number using a random number generation function of a computer program, Gaussian noise is acquired using a box Mueller method. Thereby, Gaussian noise can be generated as a pseudo signal of the present invention. Alternatively, a pseudo signal of a certain time may be generated in advance and stored in a memory (not shown) or the like, and the pseudo signal stored in the memory may be repeatedly used. This method is practical because it can eliminate the load generated during the process of generating the pseudo signal.

  The pseudo signal adding unit 80 adds the pseudo signal output from the signal level determining unit 70 and the high frequency signal level output from the high frequency signal level calculating unit 60 to generate an added high frequency signal. To do. Then, the pseudo signal adding unit 80 outputs the added high frequency signal to the smoothing unit 90.

  The smoothing unit 90 smoothes the added high frequency signal output from the pseudo signal adding unit 70 and outputs the smoothed added high frequency signal to the received signal detection processing unit 100.

  The received signal detection processing unit 100 compares the added high frequency signal output from the smoothing unit 90 with a predetermined threshold value set in advance. The received signal detection processing unit 100 detects the rising edge of the received signal based on the comparison result.

  Here, more specifically, the signal level determination unit 70 described above includes a case where the signal level of the digital complex envelope signal of the reception signal output from the A / D conversion unit 30 is 0, and a case where the signal level is other than 0. Then, different pseudo signals are output. That is, when the signal level of the digital complex envelope signal of the reception signal output from the A / D conversion unit 30 is 0, the signal level determination unit 70 is at least a predetermined threshold set by the reception signal detection processing unit 100 or more. Output a pseudo signal of magnitude. On the other hand, when the signal level of the digital complex envelope signal of the received signal is other than 0, the signal level determination unit 70 outputs a pseudo signal having a magnitude of 0.

  Next, signal characteristics at the time of no signal and signal arrival of the FM signal subjected to FM detection processing by the FM detection processing unit 40 will be described with reference to the drawings. FIG. 2 shows signal characteristics when the FM signal processed by the FM detection processing unit 40 has no signal and when the signal has arrived.

  As shown in FIG. 2, the vertical axis represents the high frequency signal level (dB) and the horizontal axis represents the frequency (Hz). In FIG. 2, the FM detection processing unit 40 performs FM detection processing on a digital complex envelope signal with a sampling frequency of 80 Hz, and illustrates the result of measuring the power spectrum in the high frequency range (30 to 40 kHz) of the FM signal. ing. In FIG. 2, a value obtained by squaring the power of the high frequency signal is shown as the high frequency signal level.

  Referring to FIG. 2, it can be seen that the high frequency signal level is high when there is no signal and low when the signal arrives. Therefore, using such signal characteristics, the moment when the high-frequency signal level falls below a predetermined threshold can be detected as the rising edge of the signal. In the example shown in FIG. 2, the measurement result in the high frequency range (30 to 40 kHz) is used, but the present invention is not limited to this. That is, a high frequency component may be selected so that a power difference occurs between no signal and signal arrival.

  Next, effects of the signal level determination unit 70 and the pseudo signal addition unit 80 will be described with reference to the drawings. 3-6 is a figure for demonstrating the effect by the signal level determination part 70 and the pseudo signal addition part 80. FIG. 3 and 4 show a case where the signal level determination unit 70 and the pseudo signal addition unit 80 are not provided. 5 and 6 show the case where the signal level determination unit 70 and the pseudo signal addition unit 80 are provided.

  First, the case where the signal level determination unit 70 and the pseudo signal addition unit 80 are not provided will be described with reference to FIGS.

  3A shows a state in which the signal level N of noise input to the A / D conversion unit 30 is higher than the minimum input level L of the A / D conversion unit 30. FIG. FIG. 3B shows the high frequency of the FM signal output from the high frequency signal level calculation unit 60 via the FM detection processing unit 40 and the HPF unit 50 when the relationship shown in FIG. Indicates the frequency signal level.

  As shown in FIG. 3A and FIG. 3B, when the signal level N of noise input to the A / D converter 30 is higher than the minimum input level L of the A / D converter 30, it is high. The local frequency signal level is higher when there is no signal than when the signal arrives. For this reason, if a threshold value is set between the signal level when there is no signal and when the signal arrives, the received signal detection processing unit 100 can detect the rising edge of the received signal.

  4A shows a state in which the signal level N of noise input to the A / D conversion unit 30 is lower than the minimum input level L of the A / D conversion unit 30. FIG. FIG. 4B shows the high frequency of the FM signal output from the high frequency signal level calculation unit 60 via the FM detection processing unit 40 and the HPF unit 50 when the relationship shown in FIG. Indicates the frequency signal level.

  As shown in FIGS. 4A and 4B, when the noise level N input to the A / D converter 30 is lower than the minimum input level L of the A / D converter 30, A / D The D conversion unit 30 cannot extract a noise signal. For this reason, the signal level of the digital complex envelope signal output from the A / D converter 30 is 0, and the high frequency signal level of the FM signal when there is no signal becomes unstable. In this case, as will be described later, the high-frequency signal level when there is no signal is generally 0, but when 0 is converted to a dB scale, it is −∞ (dB) and cannot be expressed in the figure. Therefore, in FIG. 4B, the signal level is shown as 0 (dB).

  Here, the fact that the high frequency signal level at the time of no signal becomes indefinite when the signal level of the digital complex envelope signal output from the A / D conversion unit 30 becomes 0 will be described in detail using equations. .

また、Ｓ（ｎ）の瞬時移相φ（ｎ）は、Ｑ（ｎ）をＩ（ｎ）で除算した値の逆正接であるので、（式２）のように表される。

また、瞬時移相φ（ｎ）の変化量ｅ_ＦＭ（ｎ）は、φ（ｎ）の一回微分値であり、（式３）のように表される。なお、ｅ_ＦＭ（ｎ）は、ＦＭ検波信号とも呼ばれる。

（式１）において、Ｓ（ｎ）＝０の場合、Ｉ（ｎ）＝Ｑ（ｎ）＝０となる。したがって、Ｓ（ｎ）＝０ときの瞬時移相φ（ｎ）は、０／０の逆正接となり、不定となる。この場合、ｅ_ＦＭ（ｎ）も不定となる。 The digital complex envelope signal S (n) is expressed as (Equation 1) where the in-phase component is I (n) and the complex component Q (n).

Further, since the instantaneous phase shift φ (n) of S (n) is an arctangent of a value obtained by dividing Q (n) by I (n), it is expressed as (Equation 2).

Further, the change amount e _FM (n) of the instantaneous phase shift φ (n) is a one-time differential value of φ (n) and is expressed as (Equation 3). Note that e _FM (n) is also called an FM detection signal.

In (Formula 1), when S (n) = 0, I (n) = Q (n) = 0. Therefore, the instantaneous phase shift φ (n) when S (n) = 0 is an arctangent of 0/0 and is indefinite. In this case, e _FM (n) is also undefined.

Thus, when the signal level of the digital complex envelope signal output from the A / D conversion unit 30 becomes S (n) = 0, the high frequency signal level at the time of no signal becomes unstable. When S (n) = 0, φ (n) = 0 is often obtained, and e _FM (n) = 0. Accordingly, in the following description, it is assumed that e _FM (n) = 0 is output when S (n) = 0. Although the case where φ (n) is indefinite will not be described in detail, it is clear that the received signal detection device 500 of the present invention does not operate normally.

  As described above, when the FM signal output by the FM detection processing unit 40 is 0, the high frequency signal level of the FM signal is also 0, and when converted to the dB scale, −∞ (dB). Here, as shown in FIG. 4B, the high frequency signal level is assumed to be 0 (dB). In FIG. 4B, the high-frequency signal level is lower when there is no signal than when the signal arrives, unlike in FIG. 3B.

  Therefore, when the signal level determination unit 70 and the pseudo signal addition unit 80 are not provided and the FM signal output by the FM detection processing unit 40 becomes 0, as described above, the high frequency range of the FM signal Since the frequency signal level is also treated as 0 (dB), the reception signal detection processing unit 100 erroneously recognizes the absence of a signal as the arrival of a signal, and the rising edge of the reception signal cannot be detected correctly.

  Next, a case where the signal level determination unit 70 and the pseudo noise addition unit 40 are provided will be described with reference to FIGS. 5 and 6.

  5A shows a state in which the level N of noise input to the A / D conversion unit 30 is higher than the minimum input level L of the A / D conversion unit 30. FIG. FIG. 5B shows an FM signal output from the high frequency signal level calculation unit 60 via the FM detection processing unit 40 and the HPF unit 50 when the relationship shown in FIG. The added high frequency signal obtained by adding the pseudo signal output by the signal level determination unit 70 to the high frequency signal level of FIG.

  As shown in FIG. 5A and FIG. 5B, when the signal level N of noise input to the A / D converter 30 is higher than the minimum input level L of the A / D converter 30, The local frequency signal level is higher when there is no signal than when the signal arrives.

  Here, when the level N of the noise input to the A / D conversion unit 30 is larger than the minimum input level L of the A / D conversion unit 30, as described above, the A / D conversion unit 30 converts the received signal into an analog signal. Since digital conversion is possible, the signal level of the digital complex envelope signal of the reception signal output by the A / D conversion unit 30 is other than zero. Since the FM detection processing unit 40 performs FM detection processing on the digital complex envelope signal of the received signal other than the signal level 0, the output of the FM detection processing unit 40 does not become zero. As described above, when the signal level of the digital complex envelope signal of the received signal is other than 0, the signal level determination unit 70 outputs a pseudo signal having a magnitude of 0. Therefore, the added high frequency signal is the same as the high frequency signal level of the FM signal output from the high frequency signal level calculation unit 70. As described above, when the signal level N of the noise input to the A / D conversion unit 30 is higher than the minimum input level L of the A / D conversion unit 30, the signal level determination unit 70 and the pseudo signal addition unit 80 are provided. The characteristics similar to those in the case where there is not (see FIG. 3A and FIG. 3B) are shown. For this reason, if a threshold value is set between the signal level when there is no signal and when the signal arrives, the rising edge of the received signal can be detected correctly.

  6A shows a state where the level N of noise input to the A / D conversion unit 30 is smaller than the minimum input level L of the A / D conversion unit 30. FIG. FIG. 6B shows an FM signal output from the high frequency signal level calculation unit 60 via the FM detection processing unit 40 and the HPF unit 50 when the relationship shown in FIG. The added high frequency signal obtained by adding the pseudo signal output by the signal level determination unit 70 to the high frequency signal level of FIG.

  Here, when the level N of the noise input to the A / D conversion unit 30 is smaller than the minimum input level L of the A / D conversion unit 30, the A / D conversion unit 30 converts the received signal from analog to digital. Therefore, the signal level of the digital complex envelope signal of the reception signal output from the A / D conversion unit 30 becomes zero. Then, the FM detection processing unit 40 performs FM detection processing on the digital complex envelope signal of the received signal with the signal level 0, so that the output of the FM detection processing unit 40 becomes zero. However, in the present invention, as described above, when the signal level of the digital complex envelope signal of the reception signal is 0, the signal level determination unit 70 is at least equal to or larger than a predetermined threshold set by the reception signal detection processing unit 100. The pseudo signal is output. Therefore, for the addition high frequency signal, a pseudo signal equal to or higher than a predetermined threshold set by the reception signal detection processing unit 100 is added to the high frequency signal level of the FM signal output from the high frequency signal level calculation unit 60. Signal. For this reason, the added high frequency signal is at least larger than a predetermined threshold set by the received signal detection processing unit 100. Thereby, as shown in FIG. 6A and FIG. 6B, the signal level N of noise input to the A / D converter 30 is smaller than the minimum input level L of the A / D converter 30. Even in this case, a pseudo signal that is equal to or higher than a predetermined threshold set by the received signal detection processing unit 100 is added to the high frequency signal level of the FM signal, which will be described with reference to FIGS. 4A and 4B. Unlike the case, it is not 0 (dB). Further, the added high frequency signal when there is no signal is higher than the added high frequency signal when the signal arrives. This is the same characteristic as in the state where the level N of noise input to the A / D conversion unit 30 is higher than the minimum input level L of the A / D conversion unit 30 (see FIG. 5B).

Thus, even when the level N of the noise input to the A / D conversion unit 30 is smaller than the minimum input level L of the A / D conversion unit 30, the signal level determination unit 70 and the pseudo signal addition unit 80 Is added to the high frequency signal level of the FM signal output from the high frequency signal level calculation unit 60 to add the pseudo signal equal to or higher than a predetermined threshold value. The level becomes higher than the level when the signal arrives. Therefore, the rising of the received signal can be detected by setting a threshold value between the signal level at the time of no signal and when the signal arrives.

  4 and 6 exemplify a case where the signal level of noise in the receiving unit 20 is always lower than the minimum input level of the A / D conversion unit 30 so that the technical contents of the present invention can be easily understood. Thus, the rising edge detection process of the received signal has been described. Actually, as the noise signal level decreases and approaches the minimum input level of the A / D converter 30, an abnormality is likely to occur in the rising detection process of the received signal. That is, as the noise signal level decreases, the proportion of time that falls below the minimum input level of the A / D conversion unit 30 increases. With this increase, the rate at which the high frequency signal level of the FM signal output from the high frequency signal calculation unit 60 via the FM detection processing unit 40 becomes 0 (dB) increases. For this reason, the signal level smoothed by the smoothing unit 90 (that is, the input of the received signal detection processing unit 100) becomes a small value, and the signal level approaches when the signal arrives.

  Next, the operation of the communication apparatus 1000 according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 7 shows an operation flow of the communication apparatus 1000.

  The signal received by the receiving unit 20 via the antenna unit 10 is converted into an intermediate frequency signal. Then, as shown in FIG. 7, the A / D conversion unit 30 performs A / D conversion on the intermediate frequency signal input from the reception unit 20 to obtain a digital complex envelope signal of the reception signal (a complex envelope signal of the reception signal). ) Is generated (S701). Then, the A / D converter 20 outputs the digital complex envelope signal of the received signal to the FM detection processor 40 and the signal level determiner 70.

  The FM detection processing unit 40 performs FM detection processing on the digital complex envelope signal to generate an FM signal (S702). Then, the FM detection processing unit 40 outputs the FM signal to the HPF unit 50.

  The HPF unit 50 filters only the high frequency component of the FM signal output from the FM detection processing unit 40 (FM detection processing), and uses this as a high frequency signal to generate a high frequency signal level calculation unit 60. (S703).

  In the high frequency signal level calculation unit 60, the multiplier 61 squares the high frequency signal (S704). Thereby, the high frequency signal level calculation unit 60 calculates a high frequency signal level indicating the magnitude of the high frequency signal. Then, the high frequency signal level calculating unit 60 outputs the high frequency signal level to the pseudo signal adding unit 80. The high frequency signal level may be a value related to the magnitude of the high frequency signal, and is not limited to the square value of the high frequency signal, as described above.

  The signal level determination unit 70 outputs different pseudo signals depending on whether the signal level of the digital complex envelope signal output by the A / D conversion unit 30 is 0 or not (S705). When the signal level of the digital complex envelope signal of the reception signal output by the A / D conversion unit 30 is 0, the signal level determination unit 70 is a fixed value (at least a predetermined threshold set by the reception signal detection processing unit 100) Is output (S705, Yes). On the other hand, when the signal level of the digital complex envelope signal is other than 0, the signal level determination unit 70 outputs a pseudo signal having a magnitude of 0 (No in S705).

  Then, the pseudo signal adding unit 80 adds the pseudo signal output from the signal level determining unit 70 and the high frequency signal level output from the high frequency signal level calculating unit 60 to obtain an added high frequency signal. Is generated (S706).

  That is, when the signal level of the digital complex envelope signal of the reception signal output by the A / D conversion unit 30 is 0, the pseudo signal addition unit 80 sets the high frequency signal level and a constant value (at least reception signal detection). A pseudo signal having a magnitude equal to or larger than a predetermined threshold set by the processing unit 100 is added to generate an added high frequency signal. When the signal level of the digital complex envelope signal of the received signal is 0, the high frequency signal level is also 0, so that the pseudo signal adding unit 80 outputs the same signal as the pseudo signal having a constant value as a result.

  On the other hand, when the signal level of the digital complex envelope signal is other than 0, the pseudo signal adding unit 80 adds the high frequency signal level and the pseudo signal of size 0 to generate an added high frequency signal. To do. Then, the pseudo signal adding unit 80 outputs the added high frequency signal to the smoothing unit 90. As a result, the pseudo signal adding unit 80 outputs the same signal as the high frequency signal level.

  The smoothing unit 90 smoothes (smoothing processing) the added high frequency signal output from the pseudo signal adding unit 80 (S707). Then, the smoothing unit 90 outputs the smoothed addition high frequency signal to the received signal detection processing unit 100.

  The reception signal detection processing unit 100 detects the rising edge of the reception signal in S708 and S709 as described below.

  First, the received signal detection processing unit 100 compares the added high-frequency signal after smoothing with a predetermined threshold set in advance for the previous sample (S708). If the added high-frequency signal after smoothing is equal to or greater than a predetermined threshold value for the previous sample (S708, Yes), the received signal detection processing unit 100 adds the smoothed sample for the currently received sample. The high frequency signal is compared with a predetermined threshold (S709). On the other hand, for the previous sample, if the added high-frequency signal after smoothing is not equal to or greater than the predetermined threshold (No in S708), the processing after S701 is performed again.

  When the high frequency signal level after smoothing is equal to or lower than a predetermined threshold for the sample received at the current time (S709, Yes), the received signal detection processing unit 100 externally detects that the rising edge of the received signal has been detected. A circuit (not shown) is notified (S710). At the same time, the received signal detection apparatus 500 records the added high frequency signal after smoothing in a memory (not shown) for the sample received at the present time. Note that the memory used at this time may be an external circuit of the reception signal detection apparatus 500. On the other hand, for the sample received at the current time, if the summed high frequency signal after smoothing is not less than or equal to the predetermined threshold value (No in S709), the processing after S701 is performed again.

  In this way, the received signal detection processing unit 100, with respect to the sample received at the present time, when the summed high frequency signal after smoothing is equal to or greater than a predetermined threshold (Yes in S708) for the previous sample. When the added high frequency signal after smoothing is equal to or lower than the predetermined threshold (S709, Yes), the moment is detected as the rising edge of the received signal.

  And the communication apparatus 1000 repeatedly performs the process of the above S701-S710 for every sample of a digital complex envelope signal.

  As described above, the communication apparatus 1000 according to the first embodiment of the present invention includes the FM detection processing unit 40, the HPF unit 50, the signal level determination unit 70, the pseudo signal addition unit 80, and the reception signal detection processing unit. 100. The FM detection processing unit 40 converts the complex envelope signal of the received signal into an FM signal and outputs it. The HPF unit 50 filters the high frequency component of the FM signal output by the FM detection processing unit 40 and outputs a high frequency signal. The signal level determination unit 70 outputs a pseudo signal to be added to the high frequency signal output from the HPF unit 50 according to the signal level of the digital complex envelope signal of the received signal. The pseudo signal adding unit 80 adds the pseudo signal output from the signal level determining unit 70 and a value related to the magnitude of the high frequency signal to generate an added high frequency signal. The reception signal detection processing unit 100 compares the magnitude of the added high frequency signal generated by the pseudo signal addition unit 80 with a predetermined threshold value set in advance, and determines the rising edge of the reception signal based on the comparison result. To detect. The magnitude of the pseudo signal is at least a predetermined threshold value.

  As described above, in the communication apparatus 1000 according to the first embodiment of the present invention, the FM detection processing unit 40 performs FM detection processing on the digital complex envelope signal of the received signal. The HPF unit 50 filters the high frequency component of the FM signal generated by the FM detection processing unit 40 and outputs this as a high frequency signal.

  Here, in the FM detection processing unit 40, for example, if the signal level of the input signal becomes small due to the influence of fading or the like, the input signal cannot be detected, and the signal level of the FM signal that is the output signal may become unstable depending on circumstances. It becomes 0. Such a phenomenon becomes remarkable particularly when there is no signal. That is, when the signal level of the digital complex envelope signal of the received signal is 0, the FM detection processing unit 40 performs FM detection processing on the digital complex envelope signal of the received signal of signal level 0. The output of the processing unit 40 is 0 or indefinite, and the output of the high frequency signal output by the HPF unit 50 is also 0 or indefinite.

  Therefore, in the present invention, by providing the signal level determination unit 70 and the pseudo signal addition unit 80, when the signal level of the digital complex envelope signal of the reception signal is 0, the signal input to the reception signal detection processing unit 100 is The reception signal detection processing unit 100 is configured to be surely larger than a predetermined threshold set in advance in order to detect the rising edge of the reception signal. That is, when the signal level of the digital complex envelope signal of the received signal is 0, the signal level determination unit 70 outputs a pseudo signal having a magnitude equal to or larger than a predetermined threshold set by at least the received signal detection processing unit 100. Next, the pseudo signal adding unit 80 adds the pseudo signal output by the signal level determining unit 70 to the value (high frequency signal level) related to the magnitude of the high frequency signal output from the HPF unit 50. , Generating a summed high frequency signal. Since the added high frequency signal is a signal obtained by adding the pseudo signal to the high frequency signal level, the added high frequency signal is at least larger than a predetermined threshold set by the reception signal detection processing unit 100. For this reason, the added high frequency signal input to the received signal detection processing unit 100 does not become indefinite or 0 (dB) even when the received signal becomes no signal. Therefore, the received signal detection processing unit 100 can detect the rising edge of the received signal by using the added high-frequency signal having a certain magnitude or more and comparing it with a predetermined threshold.

  As a result, as a first effect, according to the communication apparatus 1000 in the first embodiment of the present invention, the rising edge of the received signal can be stabilized with a simple configuration without depending on environmental changes such as fading. And can be detected accurately. In the present invention, since the FM detection processing is performed without using the envelope information in the FM detection processing unit 40, it is hardly affected by fading. In addition, an SN (Signal Noise) ratio improvement effect also acts as a characteristic property by FM detection processing.

  As a second effect, according to the communication apparatus 1000 in the first embodiment of the present invention, unlike the technique described in Patent Document 1, it is not necessary to provide both HPF and LPF, and the hardware scale Can be easy. That is, the first effect can be obtained with a simpler configuration as compared with the technique described in Patent Document 1. In particular, since a member that performs processing such as filtering on the low frequency region of the received signal is not required, the hardware scale can be reduced. Further, for example, even when processing such as filtering is performed by software on a computer, it is not necessary to perform processing on the low frequency region of the received signal, so the amount of calculation is reduced. Thereby, compared with the case where the technique described in Patent Document 1 is used, the rising detection process of the received signal can be realized using an inexpensive computer having a simpler configuration. In the present invention, a signal level determination unit 70 and a pseudo signal addition unit 80 are added as compared with the technique described in Patent Document 1. However, the processing load of the signal level determination unit 70 and the pseudo signal addition unit 80 is significantly lower than the processing load of the LPF described in Patent Document 1. This is because the signal level determination unit 70 and the pseudo signal addition unit 80 only perform one determination process and one addition process for one sample input signal, whereas the filter process using LPF or the like This is because it is necessary to perform multiple multiplications and additions for one sample of the input signal.

  As described above, when the first effect and the second effect are summarized, according to the communication apparatus 1000 in the first embodiment of the present invention, for example, rising of a received signal without depending on environmental changes such as fading. Can be detected stably and accurately with a simple configuration.

  In addition, the communication device 1000 according to the first embodiment of the present invention may further include an A / D conversion unit 30. The A / D converter 30 performs analog-digital conversion on the received signal and outputs a digital complex envelope signal of the received signal. In particular, when the magnitude of the received signal is smaller than the minimum input level of the A / D converter 30, the A / D converter 30 outputs a digital complex envelope signal of the received signal at the signal level 0. Further, when the signal level of the digital complex envelope signal of the reception signal output from the A / D conversion unit 30 is 0, the signal level determination unit 70 is at least a predetermined threshold set in advance by the reception signal detection processing unit 100 A pseudo signal having the above magnitude is output. On the other hand, when the signal level of the digital complex envelope signal of the reception signal output by the A / D conversion unit 30 is other than 0, a pseudo signal having a magnitude of 0 is output. Note that the minimum input level of the A / D conversion unit 30 is the minimum value of the signal level at which the A / D conversion unit 30 can perform analog-digital conversion on the received signal (analog signal) as described above. The minimum input level of the A / D conversion unit 30 is a value at the time of an analog signal before analog-digital conversion.

  Thus, when the magnitude of the received signal is smaller than the minimum input level L of the A / D converter 30, the A / D converter 30 outputs a digital complex envelope signal of the received signal at the signal level 0. At this time, as described above, the FM detection processing unit 40 performs the FM detection processing on the digital complex envelope signal of the received signal at the signal level 0, so the output of the FM detection processing unit 40 is 0 or indefinite. The output of the high frequency signal output by the HPF unit 50 is also 0 or indefinite. Therefore, in the present invention, when the signal level of the digital complex envelope signal of the reception signal output from the A / D conversion unit 30 is 0, the signal level determination unit 70 is preset by at least the reception signal detection processing unit 100. In addition, a pseudo signal having a magnitude larger than a predetermined threshold value is output. As a result, the added high frequency signal output from the pseudo signal adding unit 80 is a signal obtained by adding the pseudo signal to the high frequency signal level, so that at least the predetermined signal set by the received signal detection processing unit 100 It becomes the magnitude | size beyond the threshold value. For this reason, the added high frequency signal input to the received signal detection processing unit 100 does not become indefinite or zero even when the received signal becomes no signal. On the other hand, when the signal level of the digital complex envelope signal of the reception signal output by the A / D conversion unit 30 is other than 0, the signal level determination unit 70 outputs a pseudo signal having a magnitude of 0. Thereby, the added high frequency signal output from the pseudo signal adding unit 80 becomes the same as the high frequency signal level. As described above, even if the magnitude of the received signal is smaller than the minimum input level L of the A / D converter 30, a pseudo signal having a magnitude equal to or larger than a predetermined threshold set in advance by the received signal detection processor 100 is obtained. By adding the signal to the high-frequency signal level, the level of the added high-frequency signal becomes higher when no signal is present than when the signal arrives. Thereby, if a threshold value is set between the signal level at the time of no signal and the arrival of the signal, the rising edge of the received signal can be detected. As a result, the rising edge of the received signal can be detected more stably and more accurately with a simple configuration without depending on environmental changes.

  As a further effect, according to the communication apparatus 1000 in the first embodiment of the present invention, the cost for adjusting the signal level of the reception signal between the reception unit 20 and the A / D conversion unit 30 can be reduced. . In the present invention, since the pseudo signal adding unit 80 adds the pseudo signal to the signal output from the FM detection processing unit 40, the minimum input level of the A / D conversion unit 30 is set to the received signal of the receiving unit 20. This is because there is no need to adjust in accordance with the signal level of the medium noise. In particular, since the signal level of noise output by the receiving unit 20 is easily affected by aging and temperature changes, the minimum input level of the A / D conversion unit 30 is set to the noise level in the received signal of the receiving unit 20. It is very difficult to adjust appropriately according to the signal level. In the present invention, as described above, the pseudo signal adding unit 80 is equal to or higher than a predetermined threshold so that the reception signal detection processing unit 100 can detect the rising edge of the reception signal in the signal output from the FM detection processing unit 40. Such a problem can be solved because the pseudo signals are added.

  Moreover, according to the communication apparatus 1000 in the 1st Embodiment of this invention, an effective dynamic range can be expanded. FIG. 8 is a diagram for explaining the effect of the communication apparatus 1000. FIG. 8A is a diagram illustrating a dynamic range when the signal level determination unit 70 and the pseudo signal addition unit 80 are not provided. On the other hand, FIG. 8B is a diagram illustrating a dynamic range when the signal level determination unit 70 and the pseudo signal addition unit 80 are provided.

  As shown in FIGS. 8A and 8B, the A / D converter 30 is set with a minimum input level L and a maximum input level H. Note that the minimum input level L of the A / D conversion unit 30 is the minimum value of the signal level at which the A / D conversion unit 30 can perform analog-digital conversion on the received signal (analog signal) as described above. The maximum input level H of the A / D conversion unit 30 is the maximum value of the signal level at which the A / D conversion unit 30 can perform analog-digital conversion on the received signal (analog signal). N represents the noise component of the digital complex envelope signal generated by the A / D conversion unit 30 as described above.

  As shown in FIG. 8A, in the case where the signal level determination unit 70 and the pseudo signal addition unit 80 are not provided, in order to prevent a signal of level 0 from being input to the reception signal detection processing unit 100, noise N It is necessary to set the minimum input level L of the A / D conversion unit 30 in accordance with the minimum value of the signal level. For this reason, as shown in FIG. 8A, the effective dynamic range DL1 is limited and narrowed.

  On the other hand, when the signal level determination unit 70 and the pseudo signal addition unit 80 are provided, even if a level 0 signal is output from the A / D conversion unit 30, the pseudo signal addition unit 80 does not change the FM detection processing unit. A pseudo signal having a magnitude equal to or larger than a predetermined threshold preset by the reception signal detection processing unit 100 is added to the output of 40, and an added high frequency signal is output. Therefore, the added high frequency signal is a signal obtained by adding the pseudo signal to the high frequency signal level, and therefore, the added high frequency signal is at least larger than a predetermined threshold set by the reception signal detection processing unit 100. Therefore, as shown in FIG. 8B, the minimum input level L of the A / D converter 30 can be set to a level smaller than the minimum value of the signal level of the noise N. Thereby, as shown in FIG. 8B, the effective dynamic range DL2 can be widened (DL2> DL1).

  As described above, according to the communication apparatus 1000 in the first embodiment of the present invention, the effective dynamic range can be expanded by providing the signal level determination unit 70 and the pseudo signal addition unit 80.

  The communication apparatus 1000 according to the first embodiment of the present invention further includes a high frequency signal level calculation unit 60. The high frequency signal level calculator 60 calculates a high frequency signal level that is a value related to the magnitude of the high frequency signal output from the HPF 50. The pseudo signal adding unit 80 adds the high frequency signal level calculated by the high frequency signal level calculating unit 60 and the pseudo signal to generate the added high frequency signal.

  Thereby, the high frequency signal level calculation part 60 outputs the high frequency signal level which is a natural number as a value regarding the magnitude | size of a high frequency signal. Therefore, the received signal detection processing unit 100 can easily set a predetermined threshold value using a natural number. In addition, since the configuration of the high frequency signal level calculation unit 60 can be set in accordance with a predetermined threshold value set in advance, the degree of design freedom can be increased.

  The communication apparatus 1000 according to the first embodiment of the present invention further includes a smoothing unit 90. The smoothing unit 90 smoothes the added high frequency signal generated by the pseudo signal adding unit 80. The received signal detection processing unit 100 compares the added high frequency signal smoothed by the smoothing unit 90 with a predetermined threshold value, and detects the rising edge of the received signal based on the comparison result. As a result, the rising edge of the received signal can be detected using the received signal detection processing unit 100 after eliminating the extraneous signal level.

<Second Embodiment>
A communication apparatus 1000A according to the second embodiment of the present invention will be described with reference to the drawings.

  FIG. 9 shows the configuration of the communication apparatus 1000A. As shown in FIG. 9, the communication device 1000A includes a received signal detection processing device 500A. The reception signal detection processing device 500A includes an FM detection processing unit 40, an HPF unit 50, a signal level determination unit 70, a pseudo signal addition unit 80, and a reception signal detection processing unit 100. In FIG. 9, components equivalent to the components shown in FIG. 1 are denoted by the same symbols as those shown in FIG.

  Here, FIG. 1 and FIG. 9 are compared. In FIG. 1, the communication apparatus 1000 includes an antenna unit 10, a reception unit 20, an A / D conversion unit 30, a high frequency signal level calculation unit 60, and a smoothing unit 90. In FIG. 9, the communication apparatus 1000A is different in that it does not have these configurations.

  The FM detection processing unit 40 converts the digital complex envelope signal of the reception signal input to the reception signal detection device 500A into an FM signal and outputs the FM signal. The digital complex envelope signal corresponds to the complex envelope signal of the present invention.

  The HPF unit 50 filters the high frequency component of the FM signal output by the FM detection processing unit 40 and outputs a high frequency signal.

  The signal level determination unit 70 outputs a pseudo signal according to the signal level of the digital complex envelope signal of the reception signal input to the reception signal detection device 500A. The pseudo signal is a signal generated in a pseudo manner to be added to the high frequency signal output from the HPF unit 50.

  The pseudo signal adding unit 80 adds the pseudo signal output from the signal level determining unit 70 and the value related to the magnitude of the high frequency signal output from the HPF unit 50 to generate an added high frequency signal. .

  The received signal detection processing unit 100 compares the magnitude of the added high frequency signal generated by the pseudo signal adding unit 80 with a predetermined threshold value set in advance. The received signal detection processing unit 100 detects the rising edge of the received signal based on the comparison result.

  The magnitude of the aforementioned pseudo signal is set to at least a predetermined threshold value preset in the reception signal detection processing unit 100.

  Next, the operation of the communication apparatus 1000A according to the second embodiment of the present invention will be described with reference to the drawings. FIG. 10 shows an operation flow of the communication apparatus 1000A. In FIG. 10, S902, S903, S905, S906, S908 to S910 correspond to S702, S703, S705, S706, and S708 to S710 in FIG.

  First, the FM detection processing unit 40 performs FM detection processing on the digital complex envelope signal of the reception signal input to the reception signal detection device 500A to generate an FM signal (S902). Then, the FM detection processing unit 40 outputs the FM signal to the HPF unit 50.

  The HPF unit 50 filters only the high frequency component of the FM signal output by the FM detection processing unit 40 (FM detection processing), and outputs this as a high frequency signal to the pseudo signal adding unit 80. (S903).

  The signal level determination unit 70 outputs different pseudo signals depending on whether the signal level of the digital complex envelope signal input to the received signal detection device 500A is 0 or not (S905). That is, when the signal level of the digital complex envelope signal input to the reception signal detection device 500A is 0, the signal level determination unit 70 determines a certain value (at least greater than a predetermined threshold set by the reception signal detection processing unit 100). )) Is output (S905, Yes). On the other hand, when the signal level of the digital complex envelope signal is other than 0, the signal level determination unit 70 outputs a pseudo signal having a magnitude of 0 (No in S905).

  Next, the pseudo signal adding unit 80 adds the pseudo signal output from the signal level determining unit 70 and the value related to the magnitude of the high frequency signal output from the HPF unit 50 to obtain an added high frequency signal. Is generated (S906). That is, when the signal level of the digital complex envelope signal input to the reception signal detection device 500A is 0, the pseudo signal addition unit 80 sets a value related to the magnitude of the high frequency signal and a constant value (at least reception signal detection). A pseudo signal having a magnitude equal to or larger than a predetermined threshold set by the processing unit 100 is added to generate an added high frequency signal. On the other hand, when the signal level of the digital complex envelope signal is other than 0, the pseudo signal adding unit 80 adds the value related to the magnitude of the high frequency signal and the pseudo signal having the magnitude 0, and adds the high frequency Generate a frequency signal. Then, the pseudo signal adding unit 80 outputs the added high frequency signal to the received signal detection processing unit 100.

  The reception signal detection processing unit 100 detects the rising edge of the reception signal in S908 and S909 as described below.

  First, the received signal detection processing unit 100 compares the added high frequency signal with a predetermined threshold value for the previous sample (S908). When the added high frequency signal is equal to or greater than a predetermined threshold for the previous sample (S908, Yes), the received signal detection processing unit 100 determines the added high frequency signal and the predetermined frequency for the sample received at the present time. The threshold value is compared (S909). On the other hand, if the added high-frequency signal is not equal to or greater than the predetermined threshold value for the previous sample (S908, No), the processing from S902 is performed again.

  When the high frequency signal level is equal to or lower than a predetermined threshold for the sample received at the current time (S909, Yes), the received signal detection processing unit 100 detects that the rising edge of the received signal has been detected by an external circuit (not shown). ) (S910). At the same time, the received signal detection apparatus 500 records the added high frequency signal in a memory (not shown) for the sample received at the current time. Note that the memory used at this time may be an external circuit of the reception signal detection device 500A. On the other hand, if the added high frequency signal is not less than or equal to the predetermined threshold value for the sample received at the current time (No in S909), the processing from S902 is performed again.

  In this way, the received signal detection processing unit 100 adds the high frequency for the sample received at the present time when the added high frequency signal is equal to or higher than the predetermined threshold value for the previous sample (S908, Yes). When the frequency signal is equal to or lower than the predetermined threshold (S909, Yes), the moment is detected as the rising edge of the received signal.

  And the communication apparatus 1000 repeatedly performs the process of the above S902-S910 for every sample of a digital complex envelope signal.

  As described above, the communication apparatus 1000A according to the first embodiment of the present invention includes the FM detection processing unit 40, the HPF unit 50, the signal level determination unit 70, the pseudo signal addition unit 80, and the reception signal detection processing unit. 100. The FM detection processing unit 40 converts the complex envelope signal of the received signal into an FM signal and outputs it. The HPF unit 50 filters the high frequency component of the FM signal output by the FM detection processing unit 40 and outputs a high frequency signal. The signal level determination unit 70 outputs a pseudo signal to be added to the high frequency signal output from the HPF unit 50 according to the signal level of the complex envelope signal of the received signal. The pseudo signal adding unit 80 adds the pseudo signal output from the signal level determining unit 70 and a value related to the magnitude of the high frequency signal to generate an added high frequency signal. The reception signal detection processing unit 100 compares the magnitude of the added high frequency signal generated by the pseudo signal addition unit 80 with a predetermined threshold value set in advance, and determines the rising edge of the reception signal based on the comparison result. To detect. The magnitude of the pseudo signal is at least a predetermined threshold value.

  Thereby, there exists an effect similar to the communication apparatus 1000 in the 1st Embodiment of this invention mentioned above.

  The present invention has been described above based on the embodiment. The embodiment is an exemplification, and various modifications, increases / decreases, and combinations may be added to the above-described embodiments without departing from the gist of the present invention. It will be understood by those skilled in the art that modifications to which these changes, increases / decreases, and combinations are also within the scope of the present invention.

  In the description of the above-described embodiment (particularly, description of FIGS. 7 and 10), it has been described that each process is repeatedly executed for each sample of the digital complex envelope signal. However, each process may be repeatedly executed for each of a plurality of samples of the digital complex envelope signal.

  In the description of the above-described embodiment (particularly, FIG. 7 and FIG. 10), the received signal detection processing unit 100 has the magnitude of the high frequency signal (high frequency signal level) for the previous sample. The rising edge of the received signal is detected when the magnitude of the high frequency signal (high frequency signal level) is equal to or lower than the predetermined threshold for the sample received at the present time as well as when it is equal to or higher than the predetermined threshold. However, on the contrary, for the previous sample, the magnitude of the high-frequency signal (high-frequency signal level) is equal to or lower than a predetermined threshold, and the high-frequency signal is received for the sample received at the present time. The received signal detection processing unit 100 may be provided with a detection function of detecting that the received signal is instantaneous when the magnitude (high frequency signal level) is equal to or greater than a predetermined threshold.

DESCRIPTION OF SYMBOLS 10 Antenna part 20 Reception part 30 A / D conversion part 40 FM detection process part 50 HPF part 60 High frequency signal level calculation part 70 Signal level determination part 80 Pseudo signal addition part 90 Smoothing part 100 Received signal detection process part 500, 500A Received signal detection device 1000, 1000A Communication device

Claims (7)

An FM detection processing unit that converts a complex envelope signal of the received signal into an FM signal and outputs the FM signal;
A high-pass filter unit that filters a high-frequency component of the FM signal output by the FM detection processing unit and outputs a high-frequency signal;
A signal level determination unit that outputs a pseudo signal to be added to the high-frequency signal output by the high-pass filter unit according to the signal level of the complex envelope signal of the reception signal;
A pseudo signal adding unit that adds the pseudo signal output by the signal level determination unit and a value related to the magnitude of the high frequency signal to generate an added high frequency signal;
A received signal detection process for comparing the magnitude of the added high frequency signal generated by the pseudo signal adder with a predetermined threshold value and detecting the rising edge of the received signal based on the comparison result With
A communication device in which the magnitude of the pseudo signal is at least equal to or greater than the predetermined threshold. An A / D converter that performs analog-digital conversion on the received signal and outputs a complex envelope signal of the received signal,
The A / D converter is
When the magnitude of the received signal is smaller than the minimum input level of the A / D converter, the complex envelope signal of the received signal at the signal level 0 is output,
The signal level determination unit
When the signal level of the complex envelope signal of the received signal is 0, the pseudo signal having a magnitude of at least the predetermined threshold is output,
The communication apparatus according to claim 1, wherein the pseudo signal having a magnitude of 0 is output when a signal level of the complex envelope signal of the received signal is other than zero. A high-frequency signal level calculating unit that calculates a high-frequency signal level that is a value related to the magnitude of the high-frequency signal output by the high-pass filter;
The communication device according to claim 1, wherein the pseudo signal adding unit adds the high frequency signal level and the pseudo signal to generate the added high frequency signal. A smoothing unit for smoothing the added high frequency signal generated by the pseudo signal adding unit;
The received signal detection processing unit compares the added high-frequency signal smoothed by the smoothing unit with the predetermined threshold value, and detects a rising edge of the received signal based on the comparison result. 3. The communication device according to 3.   The communication apparatus according to claim 1, wherein the reception signal detection processing unit compares the magnitude of the added high frequency signal with the predetermined threshold and detects the disappearance of the reception signal based on the comparison result. . An FM detection processing unit that converts a complex envelope signal of the received signal into an FM signal and outputs the FM signal;
A high-pass filter unit that filters a high-frequency component of the FM signal output by the FM detection processing unit and outputs a high-frequency signal;
A signal level determination unit that outputs a pseudo signal to be added to the high-frequency signal output by the high-pass filter unit according to the signal level of the complex envelope signal of the reception signal;
A pseudo signal adding unit that adds the pseudo signal output by the signal level determination unit and a value related to the magnitude of the high frequency signal to generate an added high frequency signal;
A received signal detection process for comparing the magnitude of the added high frequency signal generated by the pseudo signal adding unit with a predetermined threshold value and detecting the rising edge of the received signal based on the comparison result With
The received signal detection device wherein the magnitude of the pseudo signal is at least equal to or greater than the predetermined threshold. Converting the complex envelope signal of the received signal into an FM signal and outputting it;
Filtering the high frequency component of the FM signal to output a high frequency signal;
Outputting a pseudo signal for addition to the high frequency signal according to the signal level of the complex envelope signal of the received signal;
Adding the pseudo signal and a value related to the magnitude of the high frequency signal to generate an added high frequency signal;
Comparing the magnitude of the added high frequency signal and a predetermined threshold set in advance, and detecting the rising edge of the received signal based on the comparison result,
The received signal detection method wherein the magnitude of the pseudo signal is at least equal to or greater than the predetermined threshold.

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