JP6823129B2 - Signal detection device, wireless communication device, wireless communication terminal and signal detection method - Google Patents

Description

Embodiments of the present invention relate to signal detection devices, wireless communication devices, wireless communication terminals, and signal detection methods.

In a wireless communication device that uses a frequency band such as an ISM (Industrial Scientific and Medical) band, radio communication may be disturbed by radio waves generated by an interference source such as a microwave oven or a medical device that uses the same frequency band. In order to avoid such interference, it is necessary to detect the signal by the radio wave from the interference source from the received radio signal and confirm the presence or absence of the interference source.

As a method of detecting a signal by radio waves from an interference source, there is a detection method using the periodicity of the operation of the interference source. For example, a microwave oven, which is one of the interference sources, is divided into a transformer type and an inverter type depending on its drive method. In either type, the magnetron in the microwave oven oscillates based on the cycle of the supplied AC power supply. Radio waves are emitted by alternately repeating and stopping. Therefore, the signal by the radio wave from the microwave oven has periodicity. Therefore, by detecting a signal having periodicity from the received radio signal, it is possible to detect the signal by the radio wave from the interference source.

However, in order to determine the periodicity of the signal, the signal must be received a plurality of times, and there is a problem that the time required for detection is long. In addition, in an inverter type microwave oven where switching is performed internally, the operation of the microwave oven may be temporarily stopped depending on the cooking content and situation, and it is difficult to accurately judge the periodicity of the signal. is there.

JP-A-2007-60625 JP-A-2002-111603

IEEE Std. 802.11ac (TM) -2013 IEEE Std. 802.11 (TM) -2012

An object of the present invention is to detect a signal due to radio waves from an interference source based on a change in signal level.

The signal detection device as the embodiment of the present invention calculates the first signal level indicating the signal level of the digital complex signal, calculates the first change amount indicating the temporal change amount of the first signal level, and determines. The statistics in the first period are calculated based on the first change amount in the first period, and the interference source is applied to the digital complex signal in the first period based on the statistics in the first period. It is provided with a processing unit that determines whether or not an interference source signal indicating a signal from a radio wave is included.

The block diagram which shows an example of the schematic structure of the wireless communication system which concerns on 1st Embodiment. The block diagram which shows an example of the schematic structure of the wireless processing part which concerns on 1st Embodiment. The block diagram which shows an example of the schematic structure of the signal detection part which concerns on 1st Embodiment. The figure which shows an example of the time series graph of the change amount calculated by the change amount calculation part. The figure explaining the determination by the signal determination unit. The figure which shows an example of the flowchart of the schematic processing in the signal detection apparatus which concerns on 1st Embodiment. The figure which shows an example of the flowchart of the signal determination processing in the signal determination unit which concerns on 1st Embodiment. The block diagram which shows an example of the schematic structure of the wireless communication system which concerns on 2nd Embodiment. The block diagram which shows an example of the schematic structure of the signal detection part which concerns on 2nd Embodiment. The figure which shows an example of the output by the change amount calculation unit which concerns on 2nd Embodiment. The figure which shows an example of the flowchart of the schematic processing in the signal detection apparatus which concerns on 2nd Embodiment. The block diagram which shows an example of the schematic structure of the signal detection apparatus which concerns on 3rd Embodiment. The block diagram which shows an example of the schematic structure of the occupied frequency band derivation part which concerns on 3rd Embodiment. The block diagram which shows an example of the schematic structure of the FFT processing part which concerns on 3rd Embodiment. The figure explaining the calculation method of the total number exceeding a threshold value. The figure explaining the output of the total number calculation part which concerns on 3rd Embodiment. The figure which shows an example of the flowchart of the schematic processing of the occupied frequency band derivation part which concerns on 3rd Embodiment. The figure which shows an example of the flowchart of the schematic processing of the total number calculation part which concerns on 3rd Embodiment. The figure explaining the output of the total number calculation part which concerns on 4th Embodiment. The block diagram which shows an example of the schematic structure of the occupied frequency band derivation part which concerns on 4th Embodiment. The figure explaining the calculation method of the weighting coefficient. The figure which shows an example of the flowchart of the schematic processing of the occupied frequency band derivation part which concerns on 4th Embodiment. The figure which shows an example of the flowchart of the schematic processing of the weighting coefficient calculation part which concerns on 4th Embodiment. Functional block diagram of the wireless communication device mounted on the terminal. The figure which shows the whole configuration example of a terminal. The figure which shows the hardware configuration example of a wireless LAN module. Perspective view of the terminal. The figure which shows the example which mounted the wireless communication device on the memory card.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. IEEE Std 802.11 ^TM- 2012 and IEEE Std 802.11ac ^TM- 2013, known as wireless LAN standards, are all incorporated herein by reference.

(First Embodiment)
FIG. 1 is a block diagram showing an example of a schematic configuration of a wireless communication system according to the first embodiment. At least the signal detection device 1 and the interference source 4 are present in the wireless communication system.

The signal detection device 1 includes an antenna 1A, a radio reception unit 11, a radio processing unit 12, and a signal detection unit 13. The signal detection device 1 detects a signal generated by radio waves from the interference source 4 from the received wireless signal. Hereinafter, the signal generated by the radio wave from the interference source 4 will be referred to as an interference source signal. The signal detection device 1 may output the presence / absence of the interference source 4 based on the detection result of the interference source signal. When the interference source signal is detected, the period during which the interference source signal is received, the transmission cycle of the interference source signal, and the like may be calculated and output.

The interference source 4 is a device that can become an interference source 4 of a wireless communication device that uses a high frequency band such as an ISM band by emitting radio waves. The high frequency band includes bands such as 2.4 GHz, 5 GHz, and 60 GHz. Hereinafter, an inverter type microwave oven is assumed as the interference source 4. The magnetron inside the inverter type microwave oven alternately oscillates and stops in synchronization with the cycle of the AC power supply that drives the microwave oven. The resulting interference source signal has a period synchronized with the period of the AC power supply. Hereinafter, the period during which the interference source signal is transmitted in synchronization with the cycle of the AC power source for driving the interference source 4 will be referred to as an interference source signal transmission period.

Further, in the assumption, the interference source signal transmission period includes a period in which the interference source signal is not transmitted due to switching performed inside the microwave oven. The cycle of the AC power supply that drives the microwave oven is 50 or 60 Hz, but the switching frequency is about 50 kHz, so the width (about μ seconds) is much shorter than the width of the interference source signal transmission period (about m seconds). The period during which the interference source signal is not transmitted is included in the interference source signal transmission period. As a result, the signal level of the interference source signal changes within the interference source signal transmission period.

The interference source 4 is a device that can be an interference source of a wireless communication device, such as an inverter type microwave oven, and the signal level of the interference source signal changes within the period of transmitting the interference source signal. All you need is. For example, a communication function jammer may be used.

The wireless communication system of the present embodiment may include a device that emits radio waves other than the interference source signal, but in the present embodiment, the interference source signal and the signal of the other radio waves do not interfere with each other. Imagine a case. Hereinafter, signals by other radio waves will be referred to as other signals.

Next, the internal configuration of the signal detection device 1 will be described. The wireless receiving unit 11 converts the wireless signal received via the antenna 1A into a baseband band signal (baseband signal) corresponding to the communication standard corresponding to the wireless communication system.

The radio processing unit 12 (digital complex signal generation unit) generates a digital complex signal (digital baseband signal) from the baseband signal converted by the radio reception unit 11. FIG. 2 is a block diagram showing an example of a schematic configuration of the wireless processing unit 12 according to the first embodiment. The radio processing unit 12 includes an ADC (Analog-to-Digital Controller) 121 unit, an AGC (Automatic Gain Control) 122 unit, a DC (Direct Current) offset correction unit 123, and an amplitude / phase correction unit 124. ..

The ADC unit 121 converts the analog signal input to the wireless processing unit 12 into a digital signal. The AGC unit 122 dynamically corrects the gain of the digital signal. The DC offset correction unit 123 corrects the leakage of the local oscillator related to the frequency conversion of the digital signal. The amplitude / phase correction unit 124 corrects the imbalance between the amplitude and the phase of the digital signal. As a result, a digital complex signal is obtained. The digital complex signal is composed of a digital I (In-phase) signal having the same phase as the received signal and a digital Q (Quad-phase) signal having a phase delayed by 90 °.

The signal detection unit 13 (processing unit) detects the interference source signal based on the digital complex signal generated by the radio processing unit 12. When the interference source signal is detected, the period during which the interference source signal is received, the period of the interference source signal, and the like may be calculated. FIG. 3 is a block diagram showing an example of a schematic configuration of the signal detection unit 13 according to the first embodiment. The signal detection unit 13 includes a signal level calculation unit 131, a change amount calculation unit 132, a statistic calculation unit 133, and a signal determination unit 134.

The signal level calculation unit 131 calculates the signal level (first signal level) of the digital complex signal input to the signal detection unit 13. It is assumed that the signal level includes a power value, an amplitude value, or an calculated value based on these. Further, the signal level may be represented by a true value, a log value, or the like.

Further, the signal level calculation unit 131 determines the signal level associated with each of the predetermined plurality of periods (second period). Hereinafter, the period is referred to as a block, and the signal level associated with the block is referred to as a block level. The block level is calculated based on the signal level of the digital complex signal within the block.

The block level may be any one of the signal levels of the digital complex signal included in the block, but it is preferably calculated based on a plurality of signal levels. For example, the signal level calculation unit 131 calculates two or more signal levels of digital complex signals in each block, calculates the sum or average value of the two or more signal levels, and sets the block level. As a result, the influence of noise and the like contained in the digital complex signal is reduced, and the smoothed block level is calculated.

It should be noted that adjacent blocks may have a period in which they overlap each other. In addition, there may be a gap between adjacent blocks. However, it is preferable that the length of each block is set so that the change in the signal level due to switching can be discriminated.

For example, when the adjacent blocks do not have a period in which they overlap each other and there is no space between the adjacent blocks, the length of the blocks is preferably less than half the cycle of the switching frequency. For example, when the switching frequency is 50 kHz, the block length may be set to less than 10 μsec. Then, a block having a high block level and a block having a low block level are adjacent to each other. As a result, the amount of change calculated by the change amount calculation unit 132, which will be described later, becomes large.

In the above, the block level is calculated from the digital complex signal which is a time signal, but the block level may be calculated from the frequency signal. For example, after AD conversion by the ADC unit 121, time-frequency conversion such as short-time Fourier transform (STFT: Short-time Fourier Transform) is performed, and the block level is set based on the signal level of the sample (frequency signal) for each conversion cycle. It may be calculated. For example, the sum of the signal levels of the samples in the conversion cycle may be the block level.

The change amount calculation unit 132 calculates the temporal change amount (first change amount) of the block level calculated by the signal level calculation unit 131. FIG. 4 is a diagram showing an example of a time series graph of the amount of change calculated by the amount of change calculation unit 132. The amount of change over time shown on the vertical axis of FIG. 4 is obtained by the absolute value of the difference between the block levels of adjacent blocks when the second block level is represented by the log value. Further, the amount of change may be expressed as a ratio. The time-series graph of the amount of change includes an interference source signal reception period including the interference source signal, another signal reception period including other signals, and a noise reception period including noise. The length of the interference source signal reception period is the same as the length of the interference source signal transmission period.

Since noise and the like are smoothed when calculating the block level, the amount of change during the noise reception period does not become a very large value. Further, the amount of change in the other signal reception period does not become a very large value like the noise reception period except at the rising and falling edges of the signal. On the other hand, the amount of change in the interference source signal reception period becomes a large value in the entire interference source signal reception period due to the change in the block level due to switching.

In FIG. 4, the block levels of adjacent blocks are compared, but if the change in the block level can be recognized, the amount of change may be calculated using the blocks that are not adjacent to each other.

The statistic calculation unit 133 calculates the statistic in the period based on one or more change amounts calculated by the change amount calculation unit 132 within a predetermined period (first period). Hereinafter, the period will be referred to as a statistic definition section. It is assumed that there is one or more statistic definition sections. The statistic in the statistic definition section is calculated from, for example, the mean, variance, probability density function, or histogram of the amount of change in the statistic definition section.

When the block level changes rapidly, the mean, variance, probability density function, and histogram of the amount of change show large values or peculiar shapes. Therefore, by determining the statistic based on the mean, variance, probability density function, histogram, etc., the change can be recognized even if the block level changes abruptly. Further, model matching may be performed, the degree of matching with respect to a predetermined normative model may be calculated, and the degree of matching may be used as a statistic.

Further, the statistic may be the number of changes in the statistic definition interval that are larger than the threshold value for the change amount. Hereinafter, the threshold value will be referred to as a change amount threshold value. The value of the change amount threshold value may be calculated from the average, variance, probability density function, histogram, or the like of a part or all of the change amount in the statistic definition interval, or may be arbitrarily determined. The amount of change threshold used may be one or more. For example, if one change amount exceeds both the change amount threshold value due to the average and the change amount threshold value due to the variance, the statistic may be 2.

There are multiple possible methods for determining the statistic definition interval. For example, a predetermined period may be divided into a plurality of sections, and each divided section may be defined as a statistic definition section. It may also be determined based on the height of the signal level. For example, a period in which the signal level calculated by the signal level calculation unit 131 exceeds a predetermined threshold value may be defined as a statistic definition interval. Since it is unlikely that an interfering source signal will be present during periods of low signal level, by not defining a statistic definition interval during periods of low signal level, processing load and processing time will be reduced, and more accurate interfering source signals will be available. Detection is possible. When the statistic definition section is determined based on the height of the signal level, the statistic definition section is defined by the period of the interference source signal, that is, the width (msec) of the period of the AC power supply that drives the interference source 4. It shall be ignored for a short period of tens of microseconds when the interfering source signal due to switching is turned off.

Further, when a plurality of statistic definition sections are defined, adjacent statistic definition sections may have a period in which they overlap each other, or adjacent statistic definition sections may have an interval between them.

However, it is necessary to consider the length of the statistic definition section. For example, when the switching frequency is 50 kHz and the statistic definition interval is set to 20 μsec or more, the statistic definition interval includes a large amount of change indicating a rapid increase or decrease in the signal level due to switching on or off. As a result, even if there is a part where the amount of change does not have a very high value in the interference source signal reception period, or even if there is a part where the amount of change is suddenly high in the other signal reception period or the noise reception period, the influence thereof. Is reduced. As described above, the length of the statistic definition interval is preferably one cycle or more of switching.

In addition, when a certain period is divided into a plurality of sections and each divided section is used as a statistic definition section, the length of the statistic definition section is longer than the lower limit of the length of the statistic definition section. Shorter is preferable. If the statistic definition section overlaps both the interference source signal reception period and the other signal reception period, both the interference source signal and the other signal affect the statistic. Therefore, the interference source signal in the statistic definition section The detection accuracy may decrease. Also, when calculating the interference source signal reception period, the accuracy of the calculated interference source signal reception period becomes higher when the interference source signal reception period is calculated finely, that is, the shorter the length of the statistic definition section. The lower limit of the length of the statistic definition interval is determined by the definition of the block, for example, the length of the block. When the length of the statistic definition section is less than the lower limit, it becomes difficult to satisfy the condition that the length of the period during which the statistic exceeds the threshold value for the statistic is a predetermined time or more in the processing of the signal determination unit 134 described later. Because.

Further, for example, when the interference source 4 is operated by an AC power source having a commercial power frequency of 50 Hz, that is, when the period of the interference source signal is 20 msec, the length of the statistic definition section is 20 msec or more. The interference source signal of the second cycle is included, and the interference source signal reception period cannot be calculated accurately. Therefore, it is preferable that the length of the statistic definition interval is set to less than one cycle of the interference source signal.

The signal determination unit 134 determines whether or not the digital complex signal includes an interference source signal based on the statistic in the statistic definition section calculated by the statistic calculation unit 133. Specifically, if the length of the period during which the statistic exceeds the threshold value for the statistic is a predetermined time or longer, it is determined that the interference source signal is included in the period. Hereinafter, the threshold value will be referred to as a statistic threshold value. The value of the statistic threshold may be set arbitrarily.

FIG. 5 is a diagram illustrating determination by the signal determination unit 134. A statistic definition interval is defined for the output example shown in FIG. Example 1 of the statistic definition section shows an example in which a certain period is divided into a plurality of sections and each section is defined as a statistic definition section. Therefore, in Example 1, there is no period in which adjacent statistic definition sections overlap each other, and there is no interval between adjacent statistic definition sections.

Example 2 of the statistic definition section shows an example in which the statistic definition section is defined based on the signal level calculated by the signal level calculation unit 131. In Example 2, the statistic definition interval is not defined for the noise reception period with a low signal level, and the statistic definition interval corresponds to each of the two periods of the interference source signal reception period and the other signal reception period with a high signal level. Is stipulated. Therefore, in Example 2, there is an interval between adjacent statistic definition sections.

The signal determination unit 134 confirms whether the statistic exceeds the statistic threshold value in each statistic definition section. The black statistic definition section shown in FIG. 5 indicates the statistic definition section in which the statistic exceeds the statistic threshold, and the white statistic definition section indicates the statistic definition in which the statistic exceeds the statistic threshold. Indicates the section. Hereinafter, the statistic definition section in which the statistic exceeds the statistic threshold value will be referred to as a statistic excess statistic definition section. Then, the signal determination unit 134 compares the length of the threshold excess statistic definition section with the predetermined time.

When the length of the over-threshold statistic definition section is longer than the predetermined time, the signal determination unit 134 sets the over-threshold statistic definition section as the period during which the statistic exceeds the statistic threshold, and defines the over-threshold statistic. It is determined that the interference source signal exists in the section.

On the other hand, when the length of the threshold excess statistic definition section is shorter than the predetermined time, the sum of the lengths of the continuous threshold excess statistic definition sections is set as the period during which the statistic exceeds the statistic threshold, and the continuous threshold value If the total length of the excess statistic definition section exceeds the predetermined time, it is determined that the interference source signal exists in the continuous threshold excess statistic definition section. Here, as in Example 1 of FIG. 5, when the adjacent threshold excess statistic definition sections do not have a period in which they overlap each other and there is no interval between the adjacent threshold excess statistic definition sections, the threshold value is exceeded. It is defined that the statistic definition interval is continuous.
In this way, the signal detection device 1 detects the interference source signal.

Further, one or continuous threshold excess statistic definition interval substantially coincides with the interference source signal reception period. Therefore, the signal determination unit 134 can calculate the interference source signal reception period.

Further, the transmission cycle of the interference source signal can be calculated from the calculated first interference source signal reception period and the calculated second interference source signal reception period.

As described above, the signal detection device 1 of the present embodiment can detect the interference source signal if the signal determination unit 134 receives the interference source signal for a predetermined time or longer required for making a determination. On the other hand, in the detection method using the periodicity of the interference source signal, it is necessary to measure the rise of the interference source signal a plurality of times and determine that the signal is periodic. Therefore, the signal detection device 1 of the present embodiment is used. It takes time to detect.

For example, there is an inverter type microwave oven in which both the on time and the off time are T seconds, that is, the duty ratio is 50% by the AC power supply for driving the interference source 4, and the periodicity of the interference source signal is utilized. In the detection method, it is assumed that the periodicity can be determined by measuring the T seconds from the rise to the fall of the interference source signal three times. In this case, in the detection method using periodicity, it takes 5 T seconds to detect the interference source signal. On the other hand, in the present embodiment, the interference source signal can be detected by measuring once for T seconds from the rising edge to the falling edge of the interference source signal at the longest. Therefore, the time required for detecting the interference source signal is T seconds at the longest, and the detection time can be shortened to 1/5.

FIG. 6 is a diagram showing an example of a flowchart of schematic processing in the signal detection device 1 according to the first embodiment. This flow starts when the wireless receiving unit 11 receives the wireless signal. The radio receiving unit 11 converts the received radio signal into a baseband band signal (S101). The converted baseband band signal is input to the radio processing unit 12, and the radio processing unit 12 generates a digital complex signal from the baseband band signal (S102). The digital complex signal is input to the signal detection unit 13.

The signal level calculation unit 131 of the signal detection unit 13 calculates the block level in each block from the digital complex signal (S103). The change amount calculation unit 132 of the signal detection unit 13 compares the calculated block levels and calculates the change amount of the block level (S104). The statistic calculation unit 133 of the signal detection unit 13 calculates the statistic in the statistic definition section based on the calculated change amount and the change amount threshold value (S105). The signal determination unit 134 of the signal detection unit 13 performs signal determination processing and detects an interference source signal (S106).

FIG. 7 is a diagram showing an example of a flowchart of the signal determination process in the signal determination unit 134 according to the first embodiment. This flow is performed for each statistic definition interval and is repeated until all statistic definition intervals are processed. Further, the signal determination unit 134 holds a duration for measuring the time when the statistic exceeds the statistic threshold. The initial value of the duration is 0 (zero).

The signal determination unit 134 acquires information such as statistics from the statistic calculation unit 133 (S201). If the acquired statistic does not exceed the statistic threshold (NO in S202), the signal determination unit 134 initializes the duration (S203), that is, sets the duration value to 0, the flow ends, and then Move on to the processing of the statistic definition section of. If the statistic exceeds the statistic threshold (YES in S202), the signal determination unit 134 adds the length of the statistic definition section to the duration and updates the duration (S204). The signal determination unit 134 confirms whether the updated duration exceeds the predetermined time, and if it does not exceed the predetermined time (NO in S205), does nothing and the flow ends. If the statistic threshold is exceeded (YES in S205), it is determined that there is an interference source signal (S206). The above is the flow of signal determination processing.

When the signal determination unit 134 calculates the interference source signal reception period, the statistic definition section in which the statistic exceeds the threshold is recorded when the duration is updated, and the recorded statistic is recorded when the duration is initialized. Initialize the statistic definition interval. As a result, after the processing is completed for all the statistic definition sections, the statistic definition section as recorded becomes the interference source signal reception period.

As described above, the present embodiment calculates the amount of change in the signal level related to the received radio signal, and calculates the statistic in the statistic definition section. Then, based on the statistic, the presence / absence of the interference source signal, the interference source signal reception period, the transmission cycle of the interference source signal, and the like are calculated. If the judgment is made simply from the block level, it is difficult to distinguish the other signal from the interference source signal. However, if the judgment is made based on the statistic based on the amount of change in the block level as in the present embodiment, the other signals are used. The signal and the interference source signal can be distinguished, and the interference source signal can be detected.

(Second Embodiment)
In the first embodiment, it is assumed that there is no interference when the interference source signal is received, but in the present embodiment, it is assumed that there is interference, and the interference source signal is detected even if there is interference. The same points as in the described embodiments will be omitted.

FIG. 8 is a block diagram showing an example of a schematic configuration of a wireless communication system including the signal detection device 1 according to the second embodiment. The other radio device 5 emits another signal in the same channel or adjacent channel as the interference source signal, or in the monitoring frequency band of the signal detection device 1. The other signal is, for example, a wireless communication signal conforming to the wireless LAN standard. In addition, one or more other wireless devices 5 may exist in the wireless communication system.

FIG. 9 is a block diagram showing an example of a schematic configuration of the signal detection unit 13 according to the second embodiment. The signal detection unit 13 of the present embodiment further includes another signal removal unit 135.

The other signal removing unit 135 removes the change amount due to the other signal from the change amount calculated by the change amount calculation unit 132. FIG. 10 is a diagram showing an example of the output by the change amount calculation unit 132 according to the second embodiment. For example, it is assumed that the interference source 4 starts operating before the transmission of another signal from the other wireless device 5 is completed. In this case, the fall point of the other signal is included in the interference source signal reception period, it is difficult to distinguish between the other signal reception period and the interference source signal reception period, and the interference source signal reception period is calculated to be longer than the actual time. There is a risk of being interfered with. Therefore, the other signal removing unit 135 removes the other signal.

As described above, the amount of change calculated by the amount of change calculation unit 132 becomes a high value at both the rising and falling points of the other signal. Therefore, from the viewpoint of the amount of change, the other signal can be regarded as impulse noise for the interference source signal. Therefore, in order to remove impulse noise, the other signal removing unit 135 performs filter processing such as a median filter having an arbitrary number of taps, a load median filter, or a switching median filter on the amount of change. The number of taps on the filter is determined based on the number of blocks including the rising edge or the falling edge of the other signal to be removed.

For example, when adjacent blocks do not overlap each other and there is no space between adjacent blocks, the block level at the rising or falling edge of another signal gradually changes like a ramp function. , If the block length does not fall below the lower limit, it is included within at most two blocks. That is, the amount of change in the high value due to the rise or fall of another signal is at most two. In the median filter, when there are two changes in the high value, the median value becomes a low value and the change in the high value can be removed by comparing three or more with the change in the low value. Therefore, other signals can be removed by the median filter having 5 or more taps. In this way, other signals can be removed by removing the portion where the value having a high change amount becomes sparse in time.

Although a part of the interference source signal is also removed by the filter, there is no problem because there are many changes due to the interference source signal exceeding the change amount threshold value.

The statistic calculation unit 133 performs the same processing as in the first embodiment on the output of the other signal removal unit 135, that is, the amount of change that has been filtered. However, when the statistic definition section is determined based on the signal level calculated by the signal level calculation unit 131, for example, one statistic definition section is from the beginning of the other signal reception period to the end of the interference source signal reception period. May be said. Therefore, in the above case, the statistic calculation unit 133 shapes the statistic definition section.

The statistic calculation unit 133 determines the start and end of the statistic definition section after shaping. The start and end are selected from each time point in which the amount of change exceeds the amount of change threshold within the statistic definition section before shaping. Hereinafter, the time when the change amount exceeds the change amount threshold value in the statistic definition section before shaping is described as a section end candidate.

For example, among the section end candidates, the section end candidate with the earliest time is set as the start end of the statistic definition section after shaping. Then, it is confirmed whether or not a predetermined condition (first condition) is satisfied for the section end candidate that is the next earliest after the section end candidate as the start end, and it is determined whether or not the end is reached. If it does not end, check the section end candidate with the next earliest time. This is repeated to determine the termination.

One of the predetermined conditions is that the time of the next section end candidate of the target section end candidate exceeds the predetermined time from the time of the section end candidate. That is, if there is no time point when the change amount exceeds the change amount threshold value for a while after the target section end candidate, the section end candidate is determined to be the end. The other one of the predetermined conditions is that the time of the section end candidate is within a predetermined time from the time of the section end candidate set as the start end. This prevents the statistic definition interval from becoming too long. The predetermined time under each condition may be the same or different.

When the section end candidate remains after the end of the statistic definition section after shaping, the statistic calculation unit 133 repeats the same method to generate a new statistic definition section. In this way, the statistic definition interval is shaped. FIG. 10 shows a statistic definition section before shaping and a statistic definition section after shaping. The amount of change at the rising edge of the other signal shown in FIG. 10 has already been removed by the filtering process of the other signal removing unit 135. Therefore, the first section end candidate is the first time point in the interference source signal reception period when the amount of change exceeds the amount of change threshold. As a result, the statistic definition interval from which the extra period is excluded can be generated, and the interference source signal reception period can be calculated as in the first embodiment.

FIG. 11 is a diagram showing an example of a flowchart of schematic processing in the signal detection device 1 according to the second embodiment. The processing from S101 to S104 is the same as the schematic processing in the signal detection device 1 according to the first embodiment. After the process (S104) in which the change amount calculation unit 132 calculates the change amount at the block level, the other signal removal unit 135 removes the other signal from the change amount calculated by the change amount calculation unit 132 (S301). Then, the statistic calculation unit 133 calculates a section end candidate based on the amount of change from which other signals have been removed, and shapes the statistic definition section based on the section end candidate (S302). Subsequent processes (S105 and S106) are the same as in the first embodiment.

As described above, in the present embodiment, when another wireless device 5 that transmits another signal exists in the same wireless communication system as the interference source 4, the other signal is removed as impulse noise. This makes it possible to improve the resistance of signal detection to other signals.

(Third Embodiment)
The signal detection device 1 of the present embodiment derives the occupied frequency band of the interference source signal. FIG. 12 is a block diagram showing an example of a schematic configuration of the signal detection device 1 according to the third embodiment. The signal detection device 1 of the present embodiment further includes an occupied frequency band derivation unit 14. The same points as in the previous embodiment will be omitted. Although the signal detection unit 13 and the occupied frequency band derivation unit 14 are described separately for convenience, the signal detection unit 13 may include the occupied frequency band derivation unit 14.

The occupied frequency band derivation unit 14 interferes based on the digital complex signal generated by the radio processing unit 12 and the statistic definition section in which the interference source signal is detected by the signal detection unit 13, that is, the interference source signal reception period. Derivation of the occupied frequency band of the source signal. FIG. 13 is a block diagram showing an example of a schematic configuration of the occupied frequency band derivation unit 14 according to the third embodiment. The occupied frequency band derivation unit 14 includes an FFT (Fast Fourier Transform) processing unit 141, a level threshold value comparison unit 142, a total number calculation unit 143, and an occupied frequency band calculation unit 144.

The FFT processing unit 141 Fourier transforms (FFT) the digital complex signal within the predetermined period (third period) into a frequency signal in each of the plurality of predetermined periods (third period). Then, the signal level (second signal level) of the frequency signal is calculated. The period may be the same as the block used by the signal level calculation unit 131, or may be changed. Hereinafter, the period will be referred to as a second block, and the signal level corresponding to the second block will be referred to as a second block level. Hereinafter, the block level calculated by the signal level calculation unit 131 will be referred to as a first block level, and the block related to the first block level will be referred to as a first block. Like the first block level, the second block level may be smoothed by averaging or summing. Also, i (i is an integer of 0 or more) describes th second block and _{t i.} Further, k (k is an integer of 0 or more) the frequency of the second frequency signal is described as _{f k,} in the second block _{t i,} describes a second block-level frequency signal of the frequency _{f k} and _{p ki.}

FIG. 14 is a block diagram showing an example of a schematic configuration of the FFT processing unit 141 according to the third embodiment. The FFT processing unit 141 includes an FFT pre-processing unit 1411, an FFT execution unit 1412, and an FFT post-processing unit 1413. The FFT preprocessing unit 1411 performs FFT preprocessing such as buffer processing and window function processing. The FFT execution unit 1412 performs FFT on the preprocessed digital complex signal. The FFT post-processing unit 1413 performs FFT post-processing such as power conversion, low-pass processing, and calculation of average, etc., and calculates the second block level.

The level threshold value comparison unit 142 receives the second block level calculated by the FFT processing unit 141, and compares the second block level with the threshold value for the second block level. Hereinafter, the threshold value will be referred to as a level threshold value. The value of the level threshold value may be arbitrarily determined.

The total number calculation unit 143 satisfies a predetermined condition (second condition) based on the comparison result of the level threshold value acquired from the level threshold value comparison unit 142 and the interference source signal reception period acquired from the signal detection unit 13. Calculate the total number of block levels. The predetermined condition is, for example, that the frequency signal related to the second block level is received within the interference source signal reception period, and the second block level exceeds the level threshold value. Hereinafter, the total number will be referred to as the total number exceeding the threshold value (first total number). Further, the total number of excess thresholds is calculated for each frequency of the frequency signal related to the second block level. Hereinafter, the total number of excess threshold values at the frequency f _k will be referred to as P _k .

FIG. 15 is a diagram illustrating a method of calculating the total number of excess threshold values. In the example shown in FIG. 15, a case where the second block level from t ₁ to t ₄ exists and the second block level is calculated for three frequency signals whose frequencies are f _ka , f _kb , and f _kc , respectively. Suppose. In this assumption, there are 12 second block levels. The total number calculation unit 143 confirms whether or not the 12 second block levels satisfy a predetermined condition. In the case of the above condition example, the total number calculation unit 143 confirms whether the second block from t ₁ to t ₄ is within the interference source signal reception period. For example, if the second blocks t ₁ to t ₃ are within the interference source signal reception period, but the second block t ₄ is outside the interference source signal reception period, the frequency signals in the second blocks t ₁ and t ₃ Is received during the interference source signal reception period. Therefore, the total number calculation unit 143 confirms the comparison result of the level threshold value with respect to the nine second block levels related to the second blocks t ₁ , t ₂ , and t ₃ . This is because the second block level within the period in which the interference source signal is received may be taken into consideration in calculating the occupied frequency band of the interference source signal.

For example, when two of the two block levels p _ka1 , p _ka2 , and p _{ka3 at} the frequency f _ka , which are circled p _ka1 and p _ka2 , exceed the level threshold value, the total number calculation unit 143 determines. The value of the total number of excess thresholds P _{ka at} the frequency f _ka is calculated as 2. The total number calculation unit 143 calculates the total number of excess thresholds P _kb and P _kk in the same manner. In this way, the total number calculation unit 143 calculates the total number of excess thresholds for each frequency of the frequency signal related to the second block level.

Further, the total number calculation unit 143 may perform an operation based on the total number exceeding the threshold value, and further calculate the calculated value by the operation. For example, the total number of exceeding the threshold value of each frequency may be divided by the total number of second block levels of each frequency within the interference source signal reception period, that is, the duty ratio may be calculated. In the example of FIG. 15, the total number of the second block-level _{f ka} interference sources in the signal reception _period, and _{p ka1,} and _{p ka2,} since it is three _{p ka3,} duty ratio of the frequency _{f ka} is P _ka / 3 = 2/3. Further, for example, the ratio of the total number of excess threshold values of each frequency to the largest total number of excess threshold values may be calculated. That is, P _ka / P _max may be calculated, where P _max is the total number of excess thresholds having the largest value for each frequency. In this way, the total number of excess thresholds may be normalized by the maximum value of the total number of excess thresholds.

In the above, the total number calculation unit 143 determines whether the second block is within the interference source signal reception period, but the level threshold comparison unit 142 acquires the interference source signal reception period from the signal detection unit 13. , It may be determined whether the second block is within the interference source signal reception period. Then, the comparison may not be performed for the second block outside the interference source signal reception period.

FIG. 16 is a diagram illustrating the output of the total number calculation unit 143 according to the third embodiment. FIG. 16A is a diagram showing an example of the signal level of the received radio signal. The whiter the color, the higher the signal level. The white part from 2.42 to 2.48 on the vertical axis indicates the signal level related to the interference source signal. FIG. 16B is an example of a graph showing the relationship between the frequency f _k and the total number of excess thresholds P _k . The vertical axis represents the frequency f _k , and the horizontal axis represents the total number of excess thresholds P _k . Corresponding to the signal level in FIG. 16 (A), the value of the total number of over-threshold values _Pk from the frequencies 2.42 to around 2.48 is shown large. A graph showing the duty ratio and the like is also shown in FIG. 16 (B).

The occupied frequency band calculation unit 144 calculates the frequency band occupied by the interference source signal based on the calculated value of the total number of excess thresholds or the total number of excess thresholds. Specifically, the frequency band in which the total number of excess thresholds or the calculated value thereof exceeds the total number of excess thresholds or the threshold value for the calculated value is defined as the frequency band of the interference source signal. Hereinafter, the threshold value will be referred to as a total threshold value. The calculated value of the total number of excess thresholds may be calculated by the occupied frequency band calculation unit 144. The dotted line shown in FIG. 16B means the total threshold value. The occupied frequency band calculation unit 144 uses the frequency band in which the graph exists on the right side of the dotted line as the frequency band of the interference source signal.

FIG. 17 is a diagram showing an example of a flowchart of the schematic processing of the occupied frequency band deriving unit 14 according to the third embodiment. The FFT processing unit 141 calculates the second block level from the digital complex signal (S401). The calculated second block level is sent to the level threshold comparison unit 142, and the level threshold comparison unit 142 compares the level threshold with the second block level (S402). The comparison result of the level threshold value is sent to the total number calculation unit 143.

The total number calculation unit 143 calculates the total number of excess threshold values or the calculated value thereof based on the comparison result of the level threshold value and the interference source signal reception period acquired from the signal detection unit 13 (S403). The detailed flow of the processing of S403 will be described later. The occupied frequency band calculation unit 144 compares the total number of excess thresholds obtained from the total number calculation unit 143 or the calculated value thereof with the total threshold value, and calculates the range of frequencies in which the total number of excess thresholds or the calculated value exceeds the total threshold value. Then, the range is set as the occupied frequency band of the interference source signal (S404). The above is the general processing flow of the occupied frequency band derivation unit 14.

FIG. 18 is a diagram showing an example of a flowchart of the schematic processing of the total number calculation unit 143 according to the third embodiment. This flow is performed for each second block and is repeated until all the second blocks are processed. The total number calculation unit 143 confirms whether the second block is within the interference source signal reception period (S501). If the second block is not within the interference source signal reception period (NO in S502), the flow ends and the process proceeds to the next second block. If it is within the interference source signal reception period (YES in S502), the comparison result of the level threshold value with respect to the second block level is confirmed for each frequency of the frequency signal in the second block (S503).

For example, in the case of the comparison result that the second block level p _kai of the frequency f _ka does not exceed the level threshold value (NO in S504), the second block level p _kbi of the next frequency f _kb is confirmed. In the case of the comparison result that the level threshold value is exceeded (YES in S504), 1 is added to the current total number of threshold value exceeding P _ka of the frequency f _ka (S505). By doing this for each frequency, the total number of excess thresholds for each frequency can be calculated. After this, the calculated value of the total number of excess thresholds of each frequency may be calculated based on the total number of excess thresholds of each frequency.

As described above, in the present embodiment, the frequency band occupied by the interference source signal can be derived based on the period during which the interference source signal calculated by the signal detection unit 13 is received and the signal level of the frequency signal. ..

(Fourth Embodiment)
In the present embodiment, it is assumed that another signal is transmitted from the other wireless device 5 within the interference source signal transmission period. In the case of the above assumption, in the third embodiment, the occupied frequency band of the derived interference source signal may include the occupied frequency band of another signal. Therefore, in the present embodiment, the occupied frequency band of other signals is not included.

FIG. 19 is a diagram illustrating the output of the total number calculation unit 143 according to the fourth embodiment. FIG. 19A is a diagram showing an example of the signal level of the received radio signal. The white part from 2.42 to 2.48 on the vertical axis indicates the signal level of the interference source signal. The white portion below 2.42 on the vertical axis indicates the signal level of another signal. The other signal in FIG. 19 is a WiFi (registered trademark) signal, and communication is performed on one channel from 2.401 to 2.423 GHz. The solid line graph of FIG. 19B is a graph of the total number of excess threshold values _Pk calculated according to the third embodiment. Since the total number of excess thresholds exceeds the total threshold even when the frequency is 2.42 or less due to the other signal, the occupied frequency band of the derived interference source signal includes the occupied frequency band of the other signal.

On the other hand, the broken line graph in FIG. 19B is a graph calculated according to the fourth embodiment. The graph of the broken line is a graph in which the total number of excess thresholds _{Pk is} weighted. The coefficients of the weighting for over-threshold total P _k, described as the weighting factor A _k. Also, the over-threshold total number weighted to as weighted threshold exceeded total _P'k. In the weighted-threshold value Total _P'k, the value of the part relating to the occupied frequency band of the other signal is low. Therefore, the occupied frequency band of the derived interference source signal does not include the occupied frequency band of other signals.

FIG. 20 is a block diagram showing an example of a schematic configuration of the occupied frequency band derivation unit 14 according to the fourth embodiment. The occupied frequency band derivation unit 14 of the present embodiment further includes a parameter calculation unit 145, a parameter threshold value comparison unit 146, and a weight coefficient calculation unit 147.

The parameter calculation unit 145 calculates a parameter for calculating the weighting coefficient based on the second block level calculated by the FFT processing unit 141. The expected parameter proposals are shown below.

(Proposed parameter 1)
In this proposal, the amount of change at the second block level (the amount of change) is used as a parameter. When the second block level is represented by a log value, the amount of change in the second block level is the absolute value of the difference between the second block levels of the same frequency among the adjacent second blocks. When the second block level is represented by a true value, it is the ratio between the second block levels. When calculating the ratio, the second block level related to the slower second block is not substituted into the denominator, but the larger or smaller second block level is substituted into the denominator. Hereinafter, the case where the second block level is represented by the log value will be described. The absolute value of the difference, and wherein the second block-level difference value, the second block t _i, the second block-level difference value of the frequency signal of the frequency f _k to as d _ki. That is, the second block-level difference value _{d ki} is an absolute value of the difference between the second block-level _{p ki} in the second block _{t i,} the second block-level _{p ki-1} in the second block _{t i-1} , D _ki = | p _ki- p _k-i |. The initial value d _k1 (i = 1) of the second block level difference value may be an arbitrary value such as 0 (zero).

Due to switching, the second block level related to the interference source signal changes drastically, but the second block level related to other signals by the wireless communication device adapted to the standard such as wireless LAN does not change so drastically. Therefore, it is expected that the second block level difference value of the occupied frequency band of the interference source signal is large and the second block level difference value of the occupied frequency band of the other signal is small. Therefore, by calculating the weighting coefficient based on the second block level difference value, the total number of weighted threshold values exceeded becomes a value in which the influence of other signals is suppressed.

(Proposed parameter 2)
In this proposal, the calculated value based on the second block level and the second block level difference value related to the second block level is used as a parameter. The calculated value, and wherein the second block-level calculation value, the second block t _i, describes a second block-level calculation value of the frequency signal of the frequency f _k and c _ki. The second block level calculated value may be calculated by addition, subtraction, integration, division or a combination thereof of the second block level and the second block level difference value, and the calculation method may be arbitrarily determined. For example, it is expressed as c _ki = p _ki × d _ki .

The parameter threshold value comparison unit 146 compares the parameter calculated by the parameter calculation unit 145 with the threshold value for the parameter. The threshold value is referred to as a parameter threshold value. The parameter threshold value may be arbitrarily set according to the parameter.

The weighting coefficient calculation unit 147 calculates the weighting coefficient based on a predetermined calculation method. The calculation method of the weighting coefficient is shown below.

(Calculation method 1)
In this method, as in the processing of the total number calculation unit 143, the weight coefficient calculation unit 147 is based on the parameter threshold comparison result acquired from the parameter threshold comparison unit 146 and the interference source signal reception period acquired from the signal determination unit 134. , The total number of parameters (second total number) satisfying a predetermined condition (third condition) is calculated for each frequency of the frequency signal related to the parameter, and the total number for each calculated frequency is used as a weighting coefficient for each frequency. .. The predetermined condition is, for example, that the frequency signal related to the parameter is received within the interference source signal reception period, and the parameter exceeds the parameter threshold value. Further, the calculated values such as the duty ratio and the normalized value related to the total number may be used as the weighting coefficient.

FIG. 21 is a diagram illustrating a method of calculating the weight coefficient. FIG. 21 shows a second block level, a second block level difference value, and a second block level calculated value for each second block from t ₁ to t ₄ at a frequency f _k . The second block from t ₁ to t ₃ is within the interference source signal reception period. Further, the circle in FIG. 21 means that the value surrounded by the circle exceeds the level threshold value or the parameter threshold value.

If the parameter is a second block-level difference value, the total number of the second block-level difference value exceeds the parameter threshold because it is 2, the weighting factor A _k at frequency f _k by the calculation method 1 is 2. When the duty ratio is used as the calculated value, the weighting coefficient _Ak is 2/3. If the parameter is a second block-level calculation value, since the total number of the second block-level calculation value exceeds the parameter threshold is 1, the weighting factor A _k at frequency f _k by the calculation method 1 is one. When the duty ratio is used as the calculated value, the weighting coefficient _Ak is 1/3.

(Calculation method 2)
In this method, the weighting coefficient calculation unit 147 further acquires the level threshold value comparison result from the level threshold value comparison unit 142, and based on the level threshold value comparison result, the parameter threshold value comparison result, and the interference source signal reception period. Calculate the weighting factor. It is assumed that the comparison result of the parameter threshold value and the comparison result of the level threshold value are represented by logical values, and are represented by 1 when the threshold value is exceeded and 0 when the threshold value is not exceeded.

The weighting coefficient calculation unit 147 performs a logical operation on each of the frequency signals received within the interference source signal reception period, using the second block level generated based on the frequency signal and the comparison result of the parameters. The logical operation may be arbitrarily defined such as AND, OR, and XOR. Then, the weighting coefficient for each frequency is calculated based on the logical operation result of the frequency signals having the same frequency. For example, among all the logical operation results of frequency signals having the same frequency at f _k , the total number of logical operation results of 1 is calculated. The total number of the calculated frequency f _k is a weighting factor A _k of the frequency f _k. The sum of the logical operation results of the frequency signals having the same frequency may be calculated. Further, the calculated values such as the duty ratio and the normalized value of the total number may be used as the weighting coefficient.

For example, in FIG. 21, the circled portion exceeds the level threshold value or the parameter threshold value, and the value of the comparison result is 1. Further, the logical operation of the calculation method 2 is a logical product. When the second block level difference value is a parameter, p _k1 · d _k1 is 1, but p _k2 · d _k2 and p _k3 · d _k3 are 0. Therefore, among all the logical operation results of the frequency signals having the same frequency at f _k1 , the total number of logical operation results of 1 is 1. Accordingly, the weighting factor _{A k} at frequency _{f k} by the calculation method 2 is 1, when using a duty ratio as the calculated value, a 1/3. Even when the second block level operation value is a parameter, p _k1 and c _k1 are 1, but p _k2 and c _k2 and p _k3 and c _k3 are 0. Therefore, the weighting coefficient at the frequency f _k according to the calculation method 2 _{Ak is} also 1, and 1/3 when the duty ratio is used as the calculated value. Further, after calculating the weighting coefficient of each frequency, the weighting coefficient of each frequency may be normalized by the value of the largest weighting coefficient or the like.

In the above, the weighting coefficient calculation unit 147 has acquired the level threshold comparison result from the level threshold comparison unit 142, but it may be acquired from the parameter threshold comparison unit 146. In that case, the parameter threshold value comparison unit 146 acquires the second block level from the parameter calculation unit 145 or the like, compares the second block level with the level threshold value, and calculates the comparison result.

The total number calculation unit 143 calculates the total number of excess thresholds of each frequency as in the third embodiment, and sets the weighting coefficient of each frequency acquired by the weighting coefficient calculation unit 147 and the total number of excess thresholds of each frequency at the same frequency. Multiply each other. As a result, the total number of weighted threshold excesses for each frequency is calculated.

FIG. 22 is a diagram showing an example of a flowchart of the schematic processing of the occupied frequency band deriving unit 14 according to the fourth embodiment. The processes from S401 to S403 are the same as those in the third embodiment. On the other hand, in the present embodiment, after the processing of S401, the processing of S601 to S603 is performed in parallel with the processing of S402 and S403.

The parameter calculation unit 145 calculates the designated parameter based on the second block level calculated by the FFT processing unit 141 (S601). The calculated parameter is sent to the parameter threshold value comparison unit 146, and the parameter threshold value comparison unit 146 compares the parameter threshold value with the parameter (S602). The comparison result of the parameter threshold value is sent to the weighting coefficient calculation unit 147.

The weighting coefficient calculation unit 147 calculates the weighting coefficient of each frequency based on the comparison result of the parameter threshold value and the interference source signal reception period acquired from the signal detection unit 13 (S603). The detailed flow of the processing of S603 will be described later. The calculated weighting coefficient of each frequency is sent to the total number calculation unit 143. The total number calculation unit 143 multiplies the total number of excess thresholds or duty ratio of each frequency calculated in the process of S403 by the acquired weighting coefficient of each frequency for each frequency (S604). The occupied frequency band calculation unit 144 compares the total number of weighted threshold excesses or duty ratios of each frequency acquired from the total number calculation unit 143 with the total threshold value, and derives the occupied frequency band (S605). The above is the general processing flow of the occupied frequency band derivation unit 14.

FIG. 23 is a diagram showing an example of a flowchart of the schematic processing of the weighting coefficient calculation unit 147 according to the fourth embodiment. This flow is a flow when the weighting coefficient is calculated by the logical operation of the calculation method 2. This flow is performed for each level threshold comparison result or parameter threshold comparison result, and is repeated until all the comparison results are processed.

The weighting coefficient calculation unit 147 confirms whether the second block related to the comparison result is within the interference source signal reception period (S701). If the second block is not within the interference source signal reception period (NO in S702), the flow ends and the process proceeds to the next comparison result processing. If the second block is within the interference source signal reception period (YES in S702), the comparison result of the level threshold value and the comparison result of the parameter threshold value in the second block are logically operated for each frequency (S703). The logical operation result is added to the current weighting coefficient of the frequency (S704). By performing the processing of S703 and S704 for each frequency, the sum of the logical operation results of each frequency can be obtained and used as the weighting coefficient of each frequency. After calculating the sum of the logical operation results of each frequency, the duty ratio may be calculated and used as the weighting coefficient.

As described above, in the present embodiment, the second block level difference value or the second block level operation value is calculated as a parameter, the weighting coefficient is calculated based on the parameter, and the total number of weighted threshold excesses based on the weighting coefficient is calculated. To do. Then, by obtaining the occupied frequency band of the interference source signal based on the total number of weighted threshold values exceeded, it is possible to prevent the occupied frequency band of the other signal from being included even when another signal exists.

(Fifth Embodiment)
The signal detection device 1 of the embodiment described so far may be realized by a wireless communication terminal or the like having the function of the signal detection device 1. For example, when the wireless communication terminal incorporating the signal detection device 1 detects an interference source signal, the wireless communication may be stopped for a certain period of time. Further, the cycle of the interference source signal may be calculated from the interference source signal reception period, and the timing of wireless communication may be controlled based on the cycle. As a result, it is possible to avoid a situation in which the wireless signal transmitted from the wireless communication terminal is interfered with by the interference source signal.

The wireless communication terminal may also be referred to as a terminal, a wireless terminal, or a station (STA). Further, the access point, which is the base station of the wireless communication terminal, is also a form of the terminal because it has the function of the terminal except that it has the relay function. Therefore, unless otherwise specified in the following description, it is assumed that the terminal includes an access point. The terminal performs wireless communication according to an arbitrary wireless communication method. As an example, each terminal performs communication conforming to the IEEE802.11 standard. The wireless communication system of the present embodiment assumes a wireless LAN of the IEEE802.11 standard, but is not limited to this.

FIG. 24 is a functional block diagram of a wireless communication device mounted on the terminal. The wireless communication device 2 includes at least one antenna 1A, a control unit 201, a transmission unit 202, a reception unit 203, and a buffer 204.

The control unit 201 corresponds to a device or baseband integrated circuit that controls communication, and the transmission unit 202 and the reception unit 203 correspond to a device that transmits and receives frames or an RF integrated circuit. All or part of the processing of the control unit 201 and the processing of the digital area of the transmission unit 202 and the reception unit 203 may be performed by software (program) running on a processor such as a CPU, or by hardware. It may be done by both these software and hardware. The terminal may include a processor that performs all or part of the processing of the control unit 201, the transmission unit 202, and the reception unit 203.

The buffer 204 is a storage unit for passing a frame, data, or the like between the upper layer and the control unit 201. The buffer 204 may be a volatile memory such as DRAM or a non-volatile memory such as NAND or MRAM.

The upper layer generates a frame to be transmitted to another device on the network such as another terminal or server and stores it in the buffer 204, or controls the frame or its payload received from the other terminal or device. It receives from 201 via buffer 204. The upper layer may perform communication processing higher than the MAC layer, such as TCP / IP and UDP / IP. Further, TCP / IP and UDP / IP may be processed by the control unit 201, and the upper layer may be processed by an application layer higher than this. The operation of the upper layer may be performed by processing software (program) by a processor such as a CPU, may be performed by hardware, or may be performed by both software and hardware.

The control unit 201 mainly processes the MAC layer. The control unit 201 controls communication with other terminals by transmitting and receiving frames to and from other terminals via the transmission unit 202 and the reception unit 203. Further, the control unit 201 may include a clock generation unit that generates a clock, and may manage the internal time by using the clock generated by the clock generation unit. The control unit 201 may output the clock created by the clock generation unit to the outside. Alternatively, the control unit 201 may generate an external clock generation unit, receive a clock input, and use the clock to manage the internal time.

As an example, the control unit 201 receives a beacon frame, grasps the BSS (Basic Service Set) attribute and synchronization information of another terminal, and then makes an association request to the other terminal to perform the association process. As a result, a wireless link is established with the other terminal by exchanging necessary information such as each other's abilities and attributes (which may include ability information as to whether or not DL-MU-MIMO can be implemented). If necessary, an authentication process may be performed with the access point in advance.

By periodically checking the buffer 204, the control unit 201 grasps the state of the buffer 204, such as whether or not there is data to be uplink-transmitted. Alternatively, the control unit 201 confirms the state of the buffer 204 by an external trigger such as the buffer 204. After confirming the existence of data to be transmitted to another terminal, the control unit 201 acquires an access right (transmission right) to the wireless medium based on CSMA / CA or the like, and then a frame containing the data (more specifically, a physical header). (Physical packet to which is added) may be transmitted via the transmission unit 202 and the antenna 1A. The access right may be acquired by transmitting an RTS frame to the access point and receiving the CTS frame.

The radio processing unit 12, the signal detection unit 13, and the occupied frequency band derivation unit 14 of the signal detection device 1 may be realized by the control unit 201 or may be realized by an upper layer. When realized by the control unit 201, the control unit 201 generates a digital complex signal from the radio signal received by the reception unit 203, calculates the block level from the digital complex signal, and calculates the amount of change in the block level. Then, the statistic of the change amount is calculated, and the interference source signal from the interference source 4 in the statistic definition section is detected based on the statistic. Further, the control unit 201 controls the transmission of the radio signal of the transmission unit 202. For example, when the control unit 201 detects an interference source signal, the control unit 201 may stop the processing of the transmission unit 202 until a certain period of time has elapsed. Alternatively, in the period in which the interference source signal is detected, that is, in the period in which the period of the interference source signal is estimated based on the calculated interference source signal reception period and the interference source signal is predicted to be transmitted, the transmission unit 202 The process may be stopped.

The transmission unit 202 performs DA conversion, filter processing for extracting desired band components, frequency conversion (up-conversion), and the like on the frame input from the control unit 201, and amplifies the signal obtained by these with a preamplifier. Emit as radio waves into space from one or more antennas. When a plurality of antennas are provided, the same signal may be transmitted from the antennas at the same time. Alternatively, it is possible to control the directivity of transmission by using a plurality of antennas.

The signal received by the antenna 1A is processed by the receiving unit 203. The received signal is amplified by a low noise amplifier (LNA) in the receiving unit 203, frequency-converted (down-converted), and a desired band component is extracted by file telling processing. The extracted signal may be further converted into a digital signal by AD conversion and output to the control unit 201. Therefore, the wireless receiving unit 11 and the wireless processing unit 12 of the signal detection device 1 may be realized by the receiving unit 203. The control unit 201 performs demodulation, error correction / decoding, and processing of physical headers, and acquires frames such as data frames (including frames received by DL-MU-MIMO). If the receiving address of the MAC header of the frame matches the MAC address of the local terminal, the frame is processed as a frame addressed to the local terminal. If they do not match, the frame is discarded.

The control unit 201 performs a CRC inspection of the received frame (in the case of an aggregation frame, a CRC inspection is performed for each of a plurality of data frames in the aggregation frame). The control unit 201 transmits a delivery confirmation response frame via the transmission unit 202 after a certain period of time such as SIFS (Short InterFrame Space) from the completion of frame reception.

When the control unit 201 receives the propagation path estimation frame from the access point, the control unit 201 changes the amplitude and phase based on the reception signal of the predetermined field included in the propagation path estimation frame and the known signal grasped in advance. calculate. Then, a report frame including propagation path information representing the calculated amplitude and phase fluctuation is generated and transmitted to the access point.

When the control unit 201 receives the frame requesting the quality measurement of the propagation path from the access point, the control unit 201 acquires the quality information of the propagation path by the measurement and transmits the frame including the quality information. For example, the quality of the propagation path is measured and quality information is acquired by using a known signal included in the physical header of the frame. Examples of quality information include, but are not limited to, SNR (Signal to Nose Ratio) or RSSI (Received Signal Strength Indicator). Alternatively, the above-mentioned report frame may include quality information together with propagation path information. Further, when the access point transmits a frame for soliciting terminals having a desire for DL-MU-MIMO transmission by broadcasting or multicast, and transmits a frame including a notification that the access point has the desire as a response, the response is made. Quality information may be included in the frame. Further, the control unit 201 may voluntarily transmit a frame including quality information of the propagation path. A frame containing quality information of the propagation path may be transmitted by a method other than that described here.

When the control unit 201 transmits a frame such as a data frame to another terminal, the control unit 201 receives the delivery confirmation response frame transmitted from the other terminal via the reception unit 203 after a certain period of time such as SIFS from the completion of transmission. .. The control unit 201 determines whether or not the data frames (in the case of aggregation frames, the aggregated individual data frames) have been successfully transmitted.

The control unit 201 may access and read the information to be notified to another terminal, the information notified from the other terminal, or a storage device for storing both of them. The storage device may be an internal memory or an external memory, and may be a volatile memory or a non-volatile memory. In addition to the memory, the storage device may be an SSD, a hard disk, or the like.

The above-mentioned separation of the processing of the control unit 201 and the transmission unit 202 is an example, and a form different from the above-mentioned form is also possible. For example, the digital domain processing and the DA conversion may be performed by the control unit 201, and the processing after the DA conversion may be performed by the transmission unit 202. Similarly, for the processing of the control unit 201 and the reception unit 203, the processing before the AD conversion (processing of the wireless reception unit 11) is performed by the reception unit 203, and the processing in the digital region including the processing after the AD conversion is performed. , The control unit 201 may perform the operation.

As an example, the baseband integrated circuit according to the present embodiment corresponds to a portion that performs digital region processing and DA conversion at the time of transmission and a portion that performs processing after AD conversion at the time of reception, and the RF integrated circuit It corresponds to the part that performs the processing after the DA conversion at the time of transmission and the part that performs the processing before the AD conversion at the time of reception. The wireless communication integrated circuit according to the present embodiment includes at least a baseband integrated circuit among the baseband integrated circuit and the RF integrated circuit. Processing between blocks or processing between a baseband integrated circuit and an RF integrated circuit may be separated by a method other than that described here.

(Sixth Embodiment)
FIG. 25 shows an example of the overall configuration of the terminal. This configuration example is an example, and the present embodiment is not limited thereto. The terminal includes one or more antennas 247 (1 to n: n is an integer of 1 or more), a wireless LAN module 248, and a host system 249. The wireless LAN module 248 corresponds to the wireless communication device according to the fifth embodiment. The wireless LAN module 248 includes a host interface, which is connected to the host system 249. In addition to being connected to the host system 249 via a connection cable, it may be directly connected to the host system 249. Further, the wireless LAN module 248 can be mounted on the board by solder or the like and connected to the host system 249 via the wiring of the board. The host system 249 uses the wireless LAN module 248 and the antennas 247 (1 to n) to communicate with an external device according to an arbitrary communication protocol. The communication protocol may include TCP / IP and a higher layer protocol. Alternatively, TCP / IP may be mounted on the wireless LAN module 248, and the host system 249 may execute only the protocol of the upper layer. In this case, the configuration of the host system 249 can be simplified. This terminal is, for example, a mobile terminal, TV, digital camera, wearable device, tablet, smartphone, game device, network storage device, monitor, digital audio player, Web camera, video camera, project, navigation system, external adapter, internal It may be an adapter, a set-top box, a gateway, a printer server, a mobile access point, a router, an enterprise / service provider access point, a portable device, a handheld device, or the like.

FIG. 26 shows a hardware configuration example of the wireless LAN module. This configuration can be applied when the wireless communication device is mounted on either a non-access point terminal or an access point, and can be applied as an example of a specific configuration of the wireless communication device shown in FIG. 24. The signal processing device can also be realized by this configuration. The number of antennas 247 may be one or two or more. In this case, a plurality of sets of transmission system (216, 222-225), reception system (232-235), PLL242, crystal oscillator (reference signal source) 243, and switch 245 are arranged corresponding to each antenna, and each set is arranged. May be connected to the baseband circuit 212, respectively. The PLL 242, the crystal oscillator 243, or both correspond to the oscillator according to this embodiment.

The wireless LAN module (wireless communication device) is a baseband IC (Integrated).
It includes a Circuit) 211, an RF (Radio Frequency) IC 221 and a balun 225, a switch 245, and an antenna 247.

The baseband IC (control circuit) 211 includes a baseband circuit 212, a memory 213, a host interface 214, a CPU 215, a DAC (Digital to Analog Converter) 216, and an ADC (Analog to Digital Converter) 217. .. The baseband IC (control circuit) 211 processes the control unit 201 of the wireless communication device shown in FIG. 24.

The baseband IC211 and RF IC221 may be formed on the same substrate. Further, the baseband IC211 and the RF IC221 may be composed of one chip. DAC216 and / or ADC217 may be located at the RF IC 221 or at another IC. Further, the memory 213 and / or the CPU 215 may be arranged in an IC different from the baseband IC.

The memory 213 stores data used for baseband processing (for example, block level) and data to be transferred to and from the host system. Further, the memory 213 stores information notified to the terminal or the base station, information notified from the terminal or the base station, or both of them. Further, the memory 213 may store a program necessary for executing the CPU 215 and may be used as a work area when the CPU 215 executes the program. The memory 213 may be a volatile memory such as SRAM or DRAM, or a non-volatile memory such as NAND or MRAM.

The host interface 214 is an interface for connecting to the host system. The interface may be anything such as UART, SPI, SDIO, USB, PCI Express® and the like.

The CPU 215 is a processor that controls the baseband circuit 212 by executing a program. The baseband circuit 212 mainly processes the MAC layer and the physical layer. Therefore, the baseband circuit 212, the CPU 215, or both of them correspond to the control unit 201 of the wireless communication device. Further, the signal detection unit 13 and the occupied frequency band derivation unit 14 of the signal detection device 1 are realized.

At least one of the baseband circuit 212 and the CPU 215 includes a clock generation unit that generates a clock, and the internal time may be managed by the clock generated by the clock generation unit.

The baseband circuit 212 performs addition, coding, encryption, modulation processing, etc. of a physical header on the frame to be transmitted as processing of the physical layer, for example, two types of digital baseband signals (hereinafter, digital I signal and digital Q). Signal) is generated. Therefore, the baseband circuit 212 realizes the radio processing unit 12 of the signal detection device 1.

The DAC 216 DA-converts the signal input from the baseband circuit 212. More specifically, the DAC 216 converts the digital I signal into an analog I signal and the digital Q signal into an analog Q signal. In addition, there may be a case where the signal of one system is transmitted as it is without quadrature modulation. When a plurality of antennas are provided and transmission signals of one system or a plurality of systems are distributed and transmitted by the number of antennas, a number of DACs or the like corresponding to the number of antennas may be provided.

The RF IC (radio frequency communication circuit) 211 processes the transmission unit 202 and the reception unit 203 of the wireless communication device shown in FIG. 24. The RF IC 221 is, for example, an RF analog IC, a high frequency IC, or both of them. The RF IC 221 includes a filter 222, a mixer 223, a preamplifier (PA) 224, a PLL (Phase Locked Loop) 242, an LNA, a balun 235, a mixer 233, and a filter 232. Some of these elements may be located on baseband IC211 or another IC. The filters 222 and 232 may be a band pass filter or a low pass filter.

The filter 222 extracts a signal in a desired band from each of the analog I signal and the analog Q signal input from the DAC 216. The PLL 242 uses the oscillation signal input from the crystal oscillator 243, and divides or multiplies the oscillation signal, or both, to generate a signal having a constant frequency synchronized with the phase of the input signal. The PLL 242 includes a VCO (Voltage Controlled Oscillator), and obtains a signal having a constant frequency by performing feedback control using the VCO based on an oscillation signal input from the crystal oscillator 243. The generated constant frequency signal is input to the mixer 223 and the mixer 233. The PLL 242 corresponds to an example of an oscillator that generates a signal having a constant frequency.

The mixer 223 up-converts the analog I signal and the analog Q signal that have passed through the filter 222 to a radio frequency by using a signal having a constant frequency supplied from the PLL 242. The preamplifier (PA) amplifies the radio frequency analog I and Q signals generated by the mixer 223 to the desired output power. The balun 225 is a converter for converting a balanced signal (differential signal) into an unbalanced signal (single-ended signal). The RF IC 221 handles balanced signals, but since the unbalanced signals are handled from the output of the RF IC 221 to the antenna 247, the balun 225 performs these signal conversions.

The switch 245 is connected to the transmitting side balun 225 at the time of transmission, and is connected to the receiving side balun 234 or RF IC 221 at the time of receiving. The control of the switch 245 may be performed by the baseband IC211 or the RF IC221, or there may be another circuit for controlling the switch 245, and the switch 245 may be controlled from the circuit.

The analog I signal and analog Q signal of the radio frequency amplified by the preamplifier 224 are balanced-unbalanced converted by the balun 225, and then radiated as radio waves from the antenna 247 into space.

The antenna 247 may be a chip antenna, an antenna formed by wiring on a printed circuit board, or an antenna formed by using a linear conductor element.

The LNA 234 in the RF IC 221 amplifies the signal received from the antenna 247 via the switch 245 to a level that can be demodulated while keeping noise low. Balun 235 performs an unbalanced-balanced conversion of the signal amplified by LNA234. The mixer 233 down-converts the received signal converted into the balanced signal by the balun 235 to the baseband using the signal of a constant frequency input from the PLL 242. More specifically, the mixer 233 has means for generating carriers that are 90 ° out of phase with each other based on the constant frequency signal input from the PLL 242, and the received signals converted by the balun 235 are 90 ° to each other. It is orthogonally demodulated by the out-of-phase carriers to generate an I (In-phase) signal having the same phase as the received signal and a Q (Quad-phase) signal having a phase delayed by 90 °. The filter 232 extracts a signal of a desired frequency component from these I signal and Q signal. The I signal and Q signal extracted by the filter 232 are output from the RF IC 221 after the gain is adjusted.

The ADC 217 in the baseband IC 211 AD-converts the input signal from the RF IC 221. More specifically, the ADC 217 converts the I signal into a digital I signal and the Q signal into a digital Q signal. In some cases, only one system of signals may be received without orthogonal demodulation.

When a plurality of antennas are provided, the number of ADCs may be provided according to the number of antennas. Based on the digital I signal and the digital Q signal, the baseband circuit 212 performs physical layer processing such as demodulation processing, error correction code processing, and physical header processing to obtain a frame. The baseband circuit 212 processes the MAC layer on the frame. If the baseband circuit 212 implements TCP / IP, the baseband circuit 212 can also be configured to perform TCP / IP processing.

(7th Embodiment)
27 (A) and 27 (B) are perspective views of the terminal according to the present embodiment, respectively. The wireless terminal of FIG. 16A is a notebook PC 301, and the wireless terminal of FIG. 16B is a mobile terminal 321. The notebook PC 301 and the mobile terminal 321 are equipped with wireless communication devices 305 and 315, respectively. As the wireless communication devices 305 and 315, the wireless communication device mounted on the wireless terminal described above, the wireless communication device mounted on the access point (base station), or both of them can be used. The wireless terminal equipped with the wireless communication device is not limited to a notebook PC or a mobile terminal. For example, TVs, digital cameras, wearable devices, tablets, smartphones, game devices, network storage devices, monitors, digital audio players, web cameras, camcorders, projects, navigation systems, external adapters, internal adapters, set-top boxes, gateways, etc. It can also be installed in printer servers, mobile access points, routers, enterprise / service provider access points, portable devices, handheld devices, and the like.

Further, the wireless communication device mounted on the wireless terminal, the access point, or both of them can also be mounted on the memory card. FIG. 28 shows an example in which the wireless communication device is mounted on a memory card. The memory card 331 includes a wireless communication device 355 and a memory card main body 332. The memory card 331 utilizes the wireless communication device 335 for wireless communication with an external device (wireless terminal and / or access point, etc.). In FIG. 28, the description of other elements (for example, memory, etc.) in the memory card 331 is omitted.

(8th Embodiment)
In the present embodiment, in addition to the configuration of the wireless communication device (the wireless communication device of the base station, the wireless communication device of the wireless terminal, or both) according to the above-described embodiment, the bus, the processor unit, and the external interface unit are provided. Be prepared. The processor unit and the external interface unit are connected to an external memory (buffer) via a bus. The firmware runs in the processor section. By including the firmware in the wireless communication device in this way, it is possible to easily change the function of the wireless communication device by rewriting the firmware. The processor unit on which the firmware operates may be a control unit or a processor that performs processing of the control unit according to the present embodiment, or may be another processor that performs processing related to function expansion or modification of the processing. Good. The base station and / or wireless terminal according to the present embodiment may include a processor unit on which the firmware operates. Alternatively, the processor unit may be provided with an integrated circuit in a wireless communication device mounted on a base station or an integrated circuit in a wireless communication device mounted on a wireless terminal.

(9th embodiment)
In this embodiment, in addition to the configuration of the wireless communication device (the wireless communication device of the base station, the wireless communication device of the wireless terminal, or both) according to the above-described embodiment, a clock generation unit is provided. The clock generator generates a clock and outputs the clock from the output terminal to the outside of the wireless communication device. In this way, the clock generated inside the wireless communication device is output to the outside, and the host side is operated by the clock output to the outside, so that the host side and the wireless communication device side can be operated in synchronization with each other. It will be possible.

(10th Embodiment)
In this embodiment, in addition to the configuration of the wireless communication device (wireless communication device of the base station or wireless communication device of the wireless terminal) according to the above-described embodiment, a power supply unit, a power supply control unit, and a wireless power supply unit are included. The power supply control unit is connected to the power supply unit and the wireless power supply unit, and controls to select the power supply to be supplied to the wireless communication device. In this way, by providing the wireless communication device with a power source, it is possible to perform a power consumption reduction operation in which the power source is controlled.

(11th Embodiment)
The present embodiment includes a SIM card in addition to the configuration of the wireless communication device according to the above-described embodiment. The SIM card is connected to, for example, a control unit in a wireless communication device. In this way, by providing the SIM card in the wireless communication device, it is possible to easily perform the authentication process.

(12th Embodiment)
In this embodiment, in addition to the configuration of the wireless communication device according to the above-described embodiment, a moving image compression / decompression unit is included. The moving image compression / decompression section is connected to the bus. As described above, by providing the moving image compression / decompression unit in the wireless communication device, it is possible to easily transmit the compressed moving image and decompress the received compressed moving image.

(13th Embodiment)
The present embodiment includes an LED unit in addition to the configuration of the wireless communication device (the wireless communication device of the base station, the wireless communication device of the wireless terminal, or both) according to the above-described embodiment. The LED unit is connected to the transmission unit 202, the reception unit 203, the control unit 201, or a plurality of these. By providing the LED unit in the wireless communication device in this way, it is possible to easily notify the user of the operating state of the wireless communication device.

(14th Embodiment)
In this embodiment, in addition to the configuration of the wireless communication device (the wireless communication device of the base station, the wireless communication device of the wireless terminal, or both of them) according to the above-described embodiment, the vibrator unit is included. The vibrator unit is connected to, for example, a control unit in a wireless communication device. By providing the vibrator unit in the wireless communication device in this way, it is possible to easily notify the user of the operating state of the wireless communication device.

(15th Embodiment)
The present embodiment includes a display in addition to the configuration of the wireless communication device (base station wireless communication device, wireless terminal wireless communication device, or both) according to the above-described embodiment. The display may be connected to the control unit of the wireless communication device via a bus (not shown). By providing the display in this way and displaying the operating state of the wireless communication device on the display, it is possible to easily notify the user of the operating state of the wireless communication device.

The frame described in each embodiment may refer to an IEEE802.11 standard or a compliant standard such as Null Data Packet, which is called a packet.

The terms used in this embodiment should be broadly interpreted. For example, the term "processor" may include general purpose processors, central processing units (CPUs), microprocessors, digital signal processors (DSPs), controllers, microcontrollers, state machines, and the like. In some circumstances, "processor" may refer to application-specific integrated circuits, field programmable gate arrays (FPGAs), programmable logic circuits (PLDs), and the like. "Processor" may refer to a combination of processing devices such as multiple microprocessors, a combination of DSPs and microprocessors, and one or more microprocessors that work with a DSP core.

As another example, the term "memory" may include any electronic component capable of storing electronic information. "Memory" includes random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable PROM (EEPROM), and non-volatile. It may refer to random access memory (NVRAM), flash memory, magnetic or optical data storage, which can be read by a processor. If the processor reads and writes information to the memory, or both, then the memory can be said to communicate electrically with the processor. The memory may be integrated into the processor, again which can be said to be in electrical communication with the processor.

The present invention is not limited to the above embodiment as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.

1 Signal detection device 1A Antenna 11 Wireless reception unit 12 Wireless processing unit 121 ADC unit 122 AGC unit 123 DC offset correction unit 124 Amplitude / phase correction unit 13 Signal detection unit 131 Signal level calculation unit 132 Change amount calculation unit 133 Statistics calculation unit 134 Signal judgment unit 135 Other signal removal unit 14 Occupied frequency band derivation unit 141 FFT processing unit 1411 FFT preprocessing unit 1412 FFT execution unit 1413 FFT post-processing unit 142 Level threshold comparison unit 143 Total number calculation unit 144 Occupied frequency band calculation unit 145 Parameters Calculation unit 146 Parameter threshold comparison unit 147 Weight coefficient calculation unit 2, 305, 315, 355 Wireless communication device 201 Control unit 202 Transmission unit 203 Reception unit 204 Buffer 211 Baseband IC
212 Baseband Circuit 213 Memory 214 Host Interface 215 CPU
216 DAC
217 ADC
221 RF IC
222, 232 Filter 223, 233 Mixer 224, 234 Amplifier 225, 235 Balun 242 PLL
243 Crystal Oscillator 245 Switch 247 Antenna 248 Wireless LAN Module 249 Host System 301 Notebook PC
321 Mobile terminal 331 Memory card 332 Memory card body 4 Interference source 5 Other wireless devices

Claims (6)

Calculate the first signal level, which indicates the signal level of the digital complex signal,
The first change amount indicating the time change amount of the first signal level is calculated.
Based on the first change amount within the predetermined first period, the statistic in the first period is calculated.
Based on the statistic in the first period, the digital complex signal in the first period includes a processing unit for determining whether or not an interference source signal indicating a signal due to a radio wave from an interference source is included.
The statistic in the first period is the number of the first change amounts in the first change amount, which is larger than the change amount threshold value indicating the threshold value for the first change amount.
The processing unit
Performs filter processing on the first variation,
The statistic in the first period is calculated based on the first change amount in the first period after the filtering process is performed.
Signal detection that shapes the first period based on the time point at which the first change amount in the first period exceeds the change amount threshold value and the predetermined first condition is satisfied. apparatus. Calculate the first signal level, which indicates the signal level of the digital complex signal,
The first change amount indicating the time change amount of the first signal level is calculated.
Based on the first change amount within the predetermined first period, the statistic in the first period is calculated.
Based on the statistic in the first period, the digital complex signal in the first period includes a processing unit for determining whether or not an interference source signal indicating a signal due to a radio wave from an interference source is included.
The statistic in the first period is
Of the first change amounts in the first period, the number of the first change amounts is larger than the change amount threshold value indicating the threshold value for the first change amount, or
It is calculated from the mean, variance, probability density function, or histogram of the first change amount within the first period.
The processing unit
In each of the plurality of predetermined third periods, the digital complex signal within the third period is Fourier transformed into a frequency signal, and a second signal level indicating the signal level of the frequency signal is calculated.
The second signal level is compared with the level threshold value indicating the threshold value for the second signal level.
Based on the comparison result relating to the level threshold value and the interference source signal reception period indicating the period in which the digital complex signal is determined to contain the interference source signal by the determination, the predetermined second condition is satisfied. The first total number indicating the total number of the second signal levels is calculated for each frequency of the frequency signal related to the second signal level.
A signal detection device that calculates a frequency band occupied by the interference source signal based on the first total number or a calculated value based on the first total number. The second condition is that the frequency signal related to the second signal level is received within the interference source signal reception period, and the second signal level exceeds the level threshold value. 2. The signal detection device according to 2. The processing unit
As a parameter for calculating the weighting coefficient for multiplying the total number of the second signal levels, it is based on the second change amount or the second change amount indicating the change amount of the second signal level in the third period. Calculate the calculated value,
The parameter is compared with the parameter threshold indicating the threshold for the parameter.
Based on the comparison result related to the parameter threshold value and the interference source signal reception period, a second total number indicating the total number of the parameters satisfying a predetermined third condition is calculated for each frequency of the frequency signal related to the parameter. ,
Based on the second total number or the calculated value based on the second total number, the weighting coefficient for each frequency of the frequency signal is calculated.
The signal detection device according to claim 2 or 3, wherein the frequency band occupied by the interference source signal is calculated based on the weighting coefficient and the first total number or the calculated value based on the first total number. The signal detection device according to claim 4, wherein the third condition is that the frequency signal related to the parameter is received within the interference source signal reception period, and the parameter exceeds the parameter threshold value. .. The processing unit
As a parameter for calculating the weighting coefficient for multiplying the total number of the second signal levels, it is based on the second change amount or the second change amount indicating the change amount of the second signal level in the third period. Calculate the calculated value,
The parameter is compared with the parameter threshold indicating the threshold for the parameter.
Based on the comparison result related to the level threshold value, the comparison result related to the parameter threshold value, and the interference source signal reception period, the second signal level and the second signal level related to the frequency signal received within the interference source signal reception period. Perform a logical operation using the comparison results of the above parameters.
Based on the result of the logical operation of the frequency signal having the same frequency, the weighting coefficient for each frequency of the frequency signal is calculated.
The signal detection device according to claim 2 or 3, wherein the frequency band occupied by the interference source signal is calculated based on the weighting coefficient and the first total number or the calculated value based on the first total number.