JP2009017018A - Pulse receiving device and pulse receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulse receiving device capable of reducing power consumption by a simple circuit configuration though a pulse signal can be decoded accurately in a radio-communication environment generating multipass propagation. <P>SOLUTION: Optimal decision timing at a receiving-signal level and a threshold in a pulse-signal section Tp are obtained by a synchronous-timing generating section 208, and a decision section 206 is informed of the decision timing and the threshold. The receiving-signal level is sampled at the decision timing in the pulse-signal section Tp by the decision section 206 and the sampled value is compared with the threshold to decide a value of the pulse signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pulse receiving apparatus and a pulse receiving method for receiving a pulse signal such as UWB (Ultra Wide Band) and determining the bit value.

  In the UWB wireless communication system, data is generally transmitted and received using an extremely wide frequency band of 500 MHz or higher, and the radiated power of a transmission signal is set to a noise level strength in the use frequency band. Wireless communication can be performed without interfering with other wireless devices using the same frequency band.

  As one of UWB wireless communication systems, there is an impulse UWB (UWB-IR) system in which ultra-short pulses of about several nsec are transmitted and received at regular intervals. This impulse UWB system can be realized with a simple circuit configuration as compared with multi-carrier technologies such as OFDM, and is expected to be used in communication applications such as sensor networks that require low power consumption.

  On the other hand, in an actual wireless communication environment, multipath propagation has an adverse effect. In this multipath propagation, radio wave signals are transmitted and received via a plurality of different propagation paths, there are path differences between the transmission paths, and there are delay propagation paths. When transmitting and receiving a pulse signal, if the signal component transmitted and received through this delay propagation path is significantly delayed, this signal component affects up to the next pulse signal section, causing intersymbol interference.

  The interference power component that causes this intersymbol interference is increased in proportion to the transmission power, unlike thermal noise at a substantially constant level, so even if the transmission power is increased, the S / N (signal to noise power ratio) is improved. This is a factor that causes errors that are difficult to reduce.

  Therefore, in a normal impulse communication system, the period of the pulse signal is increased to such an extent that intersymbol interference does not substantially occur in the assumed environment, that is, until the pulse signal component is not delayed in the next pulse signal section. Intersymbol interference is avoided. However, this countermeasure causes a reduction in communication speed. Therefore, it is desirable for the receiving apparatus to have a mechanism that is highly resistant to intersymbol interference caused by delayed signal components.

For example, in Patent Document 1, the characteristics of a propagation path are grasped at the start of communication, a template waveform corresponding to the propagation path is created, the correlation between the template waveform and the waveform of the received signal is obtained, and the received signal is decoded based on the correlation result. ing.
JP 2005-39392 A

  However, in order to decode the received signal using the template waveform as in Patent Document 1, the template waveform is stored, the waveform of the received signal is analyzed, and the correlation between the template waveform and the waveform of the received signal is calculated. This requires a complicated digital circuit, which increases the power consumption of the circuit.

  Accordingly, the present invention has been made to solve the above-described problems, and has a simple circuit configuration while being able to accurately decode a pulse signal in a wireless communication environment in which multipath propagation occurs. An object of the present invention is to provide a pulse receiving apparatus and a pulse receiving method capable of reducing power consumption.

  In order to solve the above-mentioned problem, the device of the present invention is a pulse receiving device that receives a pulse signal, and periodically samples the received signal level indicating bit 1 in the pulse signal section of bit 1 and Signal interval measuring means for periodically sampling the received signal level indicating bit 0 in the pulse signal interval, and each sampling value obtained by periodic sampling of the received signal level indicating bit 1 by the signal interval measuring means Bit 1 storing means for storing, bit 0 storing means for storing each sampling value obtained by periodic sampling of the received signal level indicating bit 0 by the signal interval measuring means, and each bit in the bit 1 storing means The sampling value and each sampling value in the bit 0 storing means are the same in the pulse signal section. The difference calculation means for obtaining the difference value between the sampling value of bit 1 and the sampling value of bit 0 for each same sampling timing, and the difference values obtained by the difference calculation means. Timing acquisition means for selecting the maximum value and setting the sampling timing at which the maximum value is obtained as the determination timing of the received signal level in the pulse signal section;

  The signal interval measuring means periodically performs sampling in each pulse signal interval of bits 1 and 0 included in the bit pattern when receiving a prescribed bit pattern.

  Further, the signal interval measuring means periodically samples the received signal level indicating bit 1 every time a pulse signal of bit 1 is received, and the bit 1 storage means sets bit 1 by the signal interval measuring means. Each time a sampling value obtained by periodic sampling of the received signal is input, an average sampling value is obtained and stored for each sampling timing.

  The signal interval measuring means periodically samples the received signal level indicating bit 0 every time a bit 0 pulse signal is received, and the bit 0 storage means sets bit 0 by the signal interval measuring means. Each time a sampling value obtained by periodic sampling of the received signal is input, an average sampling value is obtained and stored for each sampling timing.

  Furthermore, a reception start detecting means for detecting the start of reception of a frame made up of pulse signals and notifying the signal interval measuring means of the reception start of the pulse signals is provided.

  Further, the reception start of the data part included in the frame consisting of the pulse signal is detected, and the reception start of the data part is detected by the signal interval measurement means, the bit 1 storage means, the bit 0 storage means, the difference calculation means, Data start detection means for notifying the timing acquisition means is provided.

  Furthermore, the determination timing of the received signal level in the pulse signal section set by the timing acquisition means is notified, and the determination that is notified for each pulse signal section from the reception start time of the data part included in the frame composed of the pulse signal. Judgment means for judging the bit value of the pulse signal based on the received signal level of the timing is provided.

  The determination means samples the received signal level at the notified determination timing for each pulse signal section, holds the sampling value, and determines the bit value of the pulse signal from the held sampling value. .

  Further, the determination means periodically determines the bit value of the pulse signal based on the received signal level for each pulse signal section, and determines and determines the bit value at the notified determination timing.

  Further, the signal interval measuring means, the bit 1 storing means, the bit 0 storing means, the difference calculating means, and the timing acquiring means each receive a fixed number of frames consisting of pulse signals in the pulse signal interval. A series of operations for setting the reception signal level determination timing is performed.

  Furthermore, the bit 1 storage means and the bit 0 storage means once clear all the stored sampling values each time a certain number of frames made up of pulse signals are received, and then start storing the sampling values. is doing.

  The signal interval measuring means is activated when preamble information comprising a prescribed bit pattern included in the frame is received, and is deactivated when data information subsequent to the preamble information is received.

  Further, the signal section measuring means starts receiving a received signal when receiving preamble information composed of a prescribed bit pattern included in the frame, and inputs a received signal when receiving data information subsequent to the preamble information. Has stopped.

  The signal interval measuring means, the bit 1 storing means, the bit 0 storing means, the difference calculating means, and the timing obtaining means are activated when receiving preamble information consisting of a prescribed bit pattern included in a frame. It is stopped when the data information following the preamble information is received.

  Further, the determination timing of the received signal level in the pulse signal section set by the timing acquisition means is notified, and the bit value of the pulse signal is determined for each pulse signal section based on the received signal level of the notified determination timing. A determination unit, wherein the timing acquisition unit selects a maximum value from among the difference values obtained by the difference calculation unit, and determines the received signal level in the pulse signal interval based on the sampling timing at which the maximum value is obtained. In addition to setting as a timing, an average value of the sampling value of bit 1 and the sampling value of bit 0 from which the difference value that has reached the maximum value is set as a threshold value, and the determination means determines the notified determination timing. The received signal level is compared with the threshold set by the timing acquisition means, And determining a bit value of the scan signal.

  The pulse signal is OOK modulated or PPM modulated.

  On the other hand, according to the method of the present invention, in the pulse receiving method for receiving a pulse signal, the received signal level indicating the bit 1 is periodically sampled in the pulse signal section of bit 1 and the bit signal is input in the pulse signal section of bit 0. A signal interval measuring step for periodically sampling a received signal level indicating 0, and a bit 1 storage for storing each sampling value obtained by periodic sampling of the received signal level indicating bit 1 in the signal interval measuring step A bit 0 storing step for storing each sampling value obtained by periodic sampling of the received signal level indicating bit 0 in the signal interval measuring step, and each sampling value stored in the bit 1 storing step And each sampling value stored in the bit 0 storing step is a pulse signal. A difference calculation step for obtaining a difference value between the sampling value of bit 1 and the sampling value of bit 0 for each same sampling timing, and each difference obtained in the difference calculation step. A timing acquisition step of selecting the maximum value from the values and setting the sampling timing at which the maximum value is obtained as the determination timing of the received signal level in the pulse signal section.

  The received signal sampled in the signal interval measuring step indicates preamble information composed of a prescribed bit pattern included in the frame.

  According to the pulse receiving apparatus of the present invention, the received signal level indicating the bit 1 is periodically sampled in the pulse signal interval of the bit 1 and the received signal level indicating the bit 0 is periodically changed in the pulse signal interval of the bit 0. Sampling is performed, and a difference value between the sampling value of bit 1 and the sampling value of bit 0 is obtained at the same sampling timing in the pulse signal section, and the maximum value is selected from the difference values of each sampling timing. The sampling timing at which the maximum value is obtained is set as the reception signal level determination timing in the pulse signal section. If the wireless communication environment for multipath propagation does not change abruptly within the frame period, even if the reception signal of bit 1 is repeated, the waveform of the reception signal hardly changes, and reception of bit 0 is similarly performed. Even if the signal is repeated, the waveform of the received signal hardly changes. Therefore, at the same sampling timing in the pulse signal section, the sampling value of bit 1 is constant, and similarly, the sampling value of bit 0 is also constant. Therefore, at the sampling timing (determination timing) in which the difference value between the bit 1 sampling value and the bit 0 sampling value is maximized as in the present invention, the change in the received signal level due to bits 1 and 0 is always the maximum. Thus, it can be considered that there is little intersymbol interference, and the sampling values of both can be identified accurately and easily. In other words, by using the determination timing required by the present invention, it is possible to accurately and easily identify the received signal level.

  In addition, if one determination timing in the pulse signal section is set and the reception signal level is determined in each pulse signal section, a special digital circuit is not required and an analog circuit with a simple configuration is applied. And power consumption can be kept low.

  For example, when a prescribed bit pattern is received, periodic sampling is performed in each pulse signal section of bits 1 and 0 included in the bit pattern. As a result, it is possible to distinguish the bit 1 pulse signal interval from the bit 0 pulse signal interval and perform the respective sampling. The prescribed bit pattern includes a repeating pattern of 1 and 0, a 1 and 0 pattern generated according to a prescribed random number sequence, and the like.

  Alternatively, an average sampling value may be obtained for each sampling timing each time a sampling value obtained by periodic sampling of the received signal level indicating bit 1 is input. The same can be applied to the reception signal indicating bit 0. In this case, the sampling values at the same sampling timing are averaged for each received signal, so that a more accurate sampling value can be obtained. As a result, the sampling value of bit 1 and the sampling value of bit 0 It is possible to accurately obtain the sampling timing (determination timing) that maximizes the difference value.

  Furthermore, since the start of reception of a frame consisting of a pulse signal is detected, sampling of the received signal level and processing subsequent to the sampling of the received signal level can be started from the point of detection of the start of reception, and the circuit is wasted. Therefore, the power consumption can be reduced.

  In addition, since the reception start of the data part included in the frame composed of the pulse signal is detected, the reception signal level is determined using the determination timing from the start time of the data part, and the transmission constituting the data part is performed. The signal can be demodulated. Further, from this point of time, the operation for obtaining the determination timing by the apparatus of the present invention can be stopped, and power consumption can be reduced by stopping this operation.

  For example, the bit value of the pulse signal is determined based on the reception signal level at the set determination timing for each pulse signal section from the reception start time of the data portion, and the transmission signal constituting the data portion is demodulated.

  More specifically, for each pulse signal section, the received signal level is sampled at a set determination timing, and this sampling value is held, and the bit value of the pulse signal is determined from the held sampling value, or The bit value of the pulse signal is obtained periodically based on the received signal level, and the bit value is determined and determined at the set determination timing.

  The operation for obtaining the determination timing by the apparatus of the present invention is performed every time a certain number of frames are received. This certain number may be singular or plural. If the number is singular, the determination timing is obtained for each frame using the preamble information of the frame, and if there is a plurality, the determination timing is obtained for each of a plurality of frames. In this case, it is necessary to once clear all sampling values stored in the bit 1 storage means and the bit 0 storage means every time a certain number of frames made up of pulse signals are received.

  Also, when receiving the preamble information of the frame, start the signal section measuring means or start inputting the received signal to the signal section measuring means, and when receiving the data information following this preamble information, the signal section It is preferable to stop the measuring means or stop the input of the received signal to the signal interval measuring means to avoid useless operation of the signal interval measuring means and reduce power consumption. Similarly, not only the signal interval measurement means but also the bit 1 storage means, bit 0 storage means, difference calculation means, and timing acquisition means are activated when the preamble information of the frame is received, and the data information following the preamble information It is preferable to stop at the time of receiving and reduce power consumption.

  In addition, the maximum value is selected from the difference values of each sampling timing, and the sampling timing at which the maximum value is obtained is not only set as the determination timing of the received signal level in the pulse signal section, but becomes the maximum value. The average value of the sampling value of bit 1 and the sampling value of bit 0 for which the difference value has been obtained is set as a threshold value. In this case, the bit value of the pulse signal is determined by comparing the received signal level at the set determination timing with the threshold value.

  For example, the pulse signal is OOK modulated or PPM modulated, and the present invention can be applied to any modulation system.

  Further, the pulse receiving method of the present invention provides the same effects as the pulse receiving apparatus of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a first embodiment of a pulse receiving apparatus of the present invention. Moreover, FIG. 2 is explanatory drawing which shows typically the communication system to which the pulse receiver of this embodiment is applied.

  In the communication system of FIG. 2, each pulse signal P indicating a value of a plurality of bits B is sequentially communicated by a UWB (Ultra Wide Band) wireless communication method, and the pulse signal P is transmitted as a radio wave signal from the transmission device 2. The radio wave signal is received by the pulse receiver 1. Each column of bits B constitutes a frame. Therefore, the frame is transmitted / received from the transmitter 2 to the pulse receiver 1.

  The transmission apparatus 2 generates a pulse signal P having a pulse width Tw whose power is limited within a predetermined frequency mask at a certain period Tp. The pulse signal P is subjected to OOK modulation (on-off keying modulation) according to the value of each bit B. The OOK-modulated pulse signal P is transmitted as a radio signal. The transmission device 2 may have any configuration and is not specified by the present invention.

  When receiving the radio signal, the pulse receiving device 1 sequentially demodulates each pulse signal P from the high frequency reception input, and sequentially determines the value of each bit B from these pulse signals P.

  FIG. 3 shows the structure of a frame composed of a sequence of bits B. The frame P includes a preamble part p1 for synchronization detection, a header part p2 including frame information such as a transmission source, a reception destination, and a frame size, and a payload part p3 including communication information. The preamble part p1 includes a synchronization word and a data start word.

  As shown in FIG. 1, a pulse receiving apparatus 1 includes a receiving antenna 201, a band limiting filter 202 (bandpass filter, BPF), an LNA unit 203 (low noise amplifier), an AGC unit 204 (automatic gain control, automatic Gain Control), a detection unit 205, a determination unit 206, a CCA detection unit 207 (Clear Channel Assessment), a synchronization timing generation unit 208, and a data start word detection unit 209.

  In this pulse reception device 1, when a radio wave signal from the transmission device 2 is received by the reception antenna 201, a high frequency reception input corresponding to this radio wave signal is transmitted from the reception antenna 201 via the band limiting filter 202 and the LNA unit 203. It is added to the AGC unit 204.

  The AGC unit 204 controls its own amplification factor according to the high frequency reception input level, and amplifies and controls the high frequency reception input so that the high frequency reception input level becomes a constant value. The feedback input is received from the subsequent circuit, and the amplification factor is updated.

  The detection unit 205 detects the high frequency reception input from the AGC unit 204 and outputs, for example, an analog detection output corresponding to the envelope level of the high frequency reception input as a reception signal. The detection unit 205 may be not only asynchronous detection typified by envelope detection or diode detection, but also synchronous detection that requires carrier recovery. The received signal may be input to an integrator to smooth the thermal noise component. This received signal is added to the determination unit 206, the CCA detection unit 207, and the synchronization timing generation unit 208.

  In the case of performing synchronous detection, a carrier regeneration mechanism using a voltage controlled oscillator (VCO), a phase motive circuit (PLL), or the like is necessary. Here, such a carrier regeneration mechanism is included in the detection unit 205. Shall be.

  The CCA detection unit 207 receives an analog reception signal from the detection unit 205, detects a preamble part included in the frame from the reception signal, and notifies the synchronization timing generation unit 208 that the preamble part has been detected.

  Various methods have been proposed as a method of detecting the preamble part p1, and any method may be applied. For example, an analog received signal level is compared with a preset threshold value, a pulse signal is generated based on whether the received signal level exceeds the threshold value, and this pulse signal is detected as a preamble part.

  Here, the synchronization timing generation unit 208 may be stopped until the preamble portion p1 is detected, and the synchronization timing generation unit 208 may be activated in response to a notification that the preamble portion has been detected. Alternatively, input to the synchronization timing generation unit 208 may be prohibited until the preamble part is detected, and input to the synchronization timing generation unit 208 may be started in response to a notification that the preamble part has been detected. Until the preamble portion is detected, not only the synchronization timing generation unit 208 but also the determination unit 206, the synchronization timing generation unit 208, and the data start word detection unit 209 are stopped, and a notification to the effect that the preamble portion has been detected. In response, the units 206 to 209 may be activated. Thereby, in the period when frame communication is not performed, each part 206-209 is stopped and power consumption is reduced.

  When the synchronization timing generation unit 208 receives a notification from the CCA detection unit 207 that the preamble portion is detected, the synchronization timing generation unit 208 inputs an analog reception signal from the detection unit 205, and based on this reception signal, a pulse signal section (pulse signal) The optimum sampling timing of the received signal level in the period (which corresponds to one period Tp of P) is obtained, and the optimum sampling timing in this pulse signal section Tp is notified to the determination unit 206 as the determination timing.

  Further, the synchronization timing generation unit 208 obtains and sets a threshold value to be compared with the reception signal level based on the analog reception signal, and notifies the determination unit 206 of the threshold value.

  Upon receiving notification of the optimum sampling timing and threshold value in the pulse signal interval Tp, the determination unit 206 sets the optimum sampling timing as the determination timing of the received signal level in the pulse signal interval Tp, and for each pulse signal interval Tp, The analog reception signal level from the detection unit 205 is sampled at the determination timing, the sampling value is held, and the sampling value of the reception signal level at the determination timing is compared with a threshold value. , A binary signal indicating bit 1 is output, and if the sampling value is less than the threshold value, a binary signal indicating bit 0 is output.

  The binary signal output from the determination unit 206 is output to the data start word detection unit 209 and a circuit (not shown) after the next stage.

  When the data start word detection unit 209 receives the binary signal from the determination unit 206, the data start word detection unit 209 waits until the synchronization word of the preamble part p1 ends, detects the data start word following the synchronization word, and detects the data start word. Is detected, the synchronization timing generation unit 208 is notified of this data start word detection.

  The synchronization timing generation unit 208 repeatedly obtains the optimum sampling timing of the received signal level in the pulse signal interval Tp and the threshold value to be compared with the received signal level, and updates the sampling timing and the threshold value while improving the accuracy. When the determination unit 206 is notified and the notification that the data start word is detected is received, the synchronization word is ended, and the notification of the sampling timing and the threshold value is stopped.

  Therefore, the determination unit 206 is notified of the most accurate sampling timing and threshold when the synchronization word is completed, determines the most accurate sampling timing as the determination timing, and also determines the most accurate threshold. Thereafter, the determination unit 206 determines the received signal level using these highly accurate determination timings and thresholds until reception of one frame is completed, and outputs a binary signal indicating the header part p2 and the payload part p3. Generate and output sequentially.

  In response to the detection of the data start word by the data start word detection unit 209, not only the synchronization timing generation unit 208 is stopped, but also the CCA detection unit 207 and the data start word detection unit 209 itself are stopped and consumed. The power may be reduced.

  By the way, when multipath propagation occurs in an actual wireless communication environment, radio signal is transmitted / received via a plurality of different propagation paths, and the signal component of the delay propagation path among these propagation paths is greatly delayed, The delayed signal component may affect the next pulse signal interval Tp, causing intersymbol interference.

  For example, as shown in FIG. 4A, the synchronization word of the preamble part p1 is a pattern in which bit B (bit 1) having a value “1” and bit B (bit 0) having a value “0” are repeated. When this bit pattern is OOK-modulated, one pulse signal P is allocated only when bit 1 is set as shown in FIG. Here, the pulse signal P is allocated to the first pulse signal section Tp, the pulse signal P is not allocated to the next pulse signal section Tp, and the pulse signal P is allocated to the third pulse signal section Tp. The pulse signal P is assigned only to the first pulse signal section Tp.

  If transmission / reception of the pulse signal P does not cause multipath propagation and transmission / reception of the pulse signal is performed normally, the detection unit 205 of the pulse receiver 1 receives a signal as a reception signal shown in FIG. ) Is output, the determination unit 206 demodulates the pulse signal P, and the bit 1 and the even-numbered pulse signal section of the odd-numbered pulse signal section Tp as shown in FIG. The synchronization word of the preamble part p1 consisting of bit 0 of Tp is generated and output.

  However, when multipath propagation occurs during transmission / reception of the pulse signal P, the signal component (radio wave signal component) of the pulse signal P transmitted via the delay propagation path is delayed, and the received signal output from the detection unit 205 ( The waveform of the pulse signal P) is deformed. For example, as shown in FIG. 4C, the waveform of the received signal is deformed, and the signal component is delayed until the next pulse signal period Tp of bit 0.

  Therefore, even though the pulse signal P is assigned only to the odd-numbered pulse signal section Tp, the signal component also extends to the even-numbered pulse signal section Tp. If the level of the signal component of the even-numbered pulse signal section Tp is high, the determination unit 206 generates bit 1 of the even-numbered pulse signal section Tp, and a bit error occurs in the synchronization word of the preamble section p1. To do.

  Therefore, in the present embodiment, the synchronization timing generation unit 208 obtains the optimum determination timing and threshold of the received signal level in the pulse signal section Tp, notifies the determination unit 206 of these determination timing and threshold, and the determination unit 206 The received signal level is sampled at the determination timing in the pulse signal interval Tp, and the value of the pulse signal P is determined by comparing the sampled value with a threshold value so that no bit error caused by multipath propagation occurs. I have to.

  Next, the processing of the synchronization timing generation unit 208, that is, the processing for obtaining the reception signal level determination timing and threshold value in the pulse signal section Tp will be described in detail.

  FIG. 5 is a block diagram illustrating a configuration of the synchronization timing generation unit 208. As shown in FIG. 5, the synchronization timing generation unit 208 includes an AD conversion unit 501, a reception level acquisition unit 502, a bit 1 information storage unit 503, a bit 0 information storage unit 504, a difference value calculation unit 505, and a timing selection unit 506. It is prepared for.

  First, the pulse receiver 1 generates a synchronization signal that is synchronized with the pulse signal P, that is, a synchronization signal that is synchronized with the pulse signal section Tp of FIG. 4, based on the received signal that is the detection output of the detection unit 205. The signal is added to the determination unit 206, the CCA detection unit 207, the synchronization timing generation unit 208, and the data start word detection unit 209. As a result, synchronization processing between the units 206 to 209 can be performed.

  When the reception signal from the detection unit 205 is input, the AD conversion unit 501 sequentially samples the reception signal level at a predetermined sampling period for each pulse signal interval Tp, and sets each sampling value of the reception signal level in the pulse signal interval Tp. Output one by one.

  For example, if the received signal level changes as indicated by the solid line A in the pulse signal section Tp of bit 1 as shown in FIG. 6, the received signal level is sampled at the sampling period ts, and 16 sampling values V1k (k = 1 to 16) are output one by one. If the received signal level changes as indicated by the solid line B in the pulse signal section Tp of bit 0, the received signal level is sampled at the sampling period ts, and 16 sampling values V0k (k = 1 to 16) are obtained. Output one by one.

  The AD converter 501 outputs a plurality of bits indicating the sampling value, but the number of bits is about 3 to 4 bits.

  The reception level acquisition unit 502 inputs 16 sampling values V1k (k = 1 to 16) or 16 sampling values V0k (k = 1 to 16) for each pulse signal section Tp, and bits the 16 sampling values V1k. 1 information storage section 503 and 16 sampling values V0k are stored in bit 0 information storage section 504.

  For example, the pulse signal P of bit 1 is allocated to the first pulse signal section Tp of the preamble part p1, the pulse signal P of bit 0 is allocated to the next pulse signal section Tp. If the pulse signal P of bit 0 is repeated, the odd-numbered pulse signal interval Tp is set as the pulse signal interval Tp of bit 1, and the 16 sampling values V1k in the pulse signal interval Tp of bit 1 are stored in the bit 1 information storage unit. The even-numbered pulse signal section Tp is stored as the bit 0 pulse signal section Tp, and the 16 sampling values V0k in the bit 0 pulse signal section Tp are stored in the bit 0 information storage section 504.

  Alternatively, the 16 sampling values obtained in the first pulse signal interval Tp are compared with the 16 sampling values obtained in the next pulse signal interval Tp, and the pulse signal with the larger average value or integrated value of the sampling values is compared. The interval Tp is the pulse signal interval Tp of bit 1 and 16 sampling values V1k in the pulse signal interval Tp of bit 1 are stored in the bit 1 information storage unit 503, and the average value or integral value of the sampling values is smaller. The pulse signal section Tp is set as the pulse signal section Tp of bit 0, and 16 sampling values V0k in the pulse signal section Tp of bit 0 are stored in the bit 0 information storage unit 504, and thereafter, 1 and 0 of the synchronization word are repeated. According to the order, 16 sampling values V1k and 16 sampling values V0k are set to bit 1 for each pulse signal section Tp. Allocation is alternately performed between the information storage unit 503 and the bit 0 information storage unit 504.

  Further, the bit 1 information storage unit 503 and the bit 0 information storage unit 504 have the same configuration, and the difference value calculation unit 505 in the next stage has a relative difference between the sampling values in the storage units 503 and 504 of both. Since only the value is obtained, the first stored 16 sampling values V1k in the pulse signal section Tp of bit 1 is the bit 1 information storage unit 503, the other is the bit 0 information storage unit 504, and thereafter the pulse The 16 sampling values V1k and the 16 sampling values V0k may be alternately distributed to the bit 1 information storage unit 503 and the bit 0 information storage unit 504 for each signal interval Tp.

  The bit 1 information storage unit 503 inputs 16 sampling values V1k (k = 1 to 16) for each pulse signal interval Tp of bit 1, and each time the same sampling timing (k value is the same). Each sampling value V1k is averaged, and this average value is stored as the sampling value V1k. That is, the average value of the sampling values V11 is set as the sampling value V11, the average value of the sampling values V12 is set as the sampling value V12,..., And the average value of the sampling values V116 is set as the sampling value V116.

  Similarly, the bit 0 information storage unit 504 inputs 16 sampling values V0k for each pulse signal interval Tp of bit 0, and each sampling value V0k at the same sampling timing (the value of k is the same) each time. Are averaged, and this average value is stored as the sampling value V0k.

  The difference value calculation unit 505 associates each sampling value V1k in the bit 1 information storage unit 503 with each sampling value V0k in the bit 0 information storage unit 504 at the same sampling timing in the pulse signal section Tp, and the same At each sampling timing, a difference value Vdk between the sampling value V1k of bit 1 and the sampling value V0k of bit 0 is obtained. That is, a difference value Vd1 between the sampling value V11 and the sampling value V01 is obtained, a difference value Vd2 between the sampling value V12 and the sampling value V02 is obtained,..., And a difference value Vd16 between the sampling value V116 and the sampling value V016 is obtained.

  Then, the difference value calculation unit 505 notifies the timing selection unit 506 of the 16 difference values Vd1 to Vd16. The timing selection unit 506 obtains the maximum value from the 16 difference values Vd1 to Vd16, and notifies the determination unit 206 of the sampling timing at which the maximum value is obtained. In addition, the timing selection unit 506 calculates an average value of the sampling value of bit 1 and the sampling value of bit 0 at this sampling timing, and notifies the determination unit 206 of this average value as a threshold value.

  Upon receiving the notification of the sampling timing at which the maximum value is obtained and the threshold value, the determination unit 206 sets this sampling timing as the determination timing of the received signal level in the pulse signal interval Tp, and the determination timing for each pulse signal interval Tp. The analog reception signal level from the detection unit 205 is sampled, and the sampling value at this determination timing is compared with a threshold value. If the sampling value is equal to or greater than the threshold value, a binary signal indicating bit 1 is output. If is less than the threshold, a binary signal indicating bit 0 is output.

  If the wireless communication environment for multipath propagation does not change abruptly, the waveform of the received signal of bit 1 that is repeatedly transmitted and received hardly changes, and the waveform of the received signal of bit 0 hardly changes. Therefore, in any pulse signal interval Tp, the sampling value of bit 1 becomes substantially constant at the same sampling timing, and similarly, the sampling value of bit 0 becomes substantially constant. For this reason, in any pulse signal interval Tp, at the sampling timing (determination timing) when the difference value Vdk between the sampling value V1k of bit 1 and the sampling value V0k of bit 0 is maximized, the received signal by bits 1 and 0 is received. It is considered that the level change becomes the maximum and the influence of intersymbol interference is small, so that bits 1 and 0 can be identified accurately and easily. In addition, an average value of the sampling value of bit 1 and the sampling value of bit 0 at this sampling timing is set as a threshold value, and the sampling value of the determination timing is compared with the threshold value for each pulse signal interval Tp, and the sampling value Since the determination is performed, the received signal level can be identified accurately and easily.

  The bit 1 information storage unit 503 averages the sampling values V1k at the same sampling timing (k values are the same) and stores the average value. Similarly, the bit 0 information storage unit 504 also stores the same value. Each sampling value V0k at the sampling timing (k value is the same) is averaged, and this average value is stored. Therefore, even if there are variations in the waveforms of the received signals of bits 1 and 0 that are repeatedly transmitted and received, the sampling values V1k and the sampling values V0k corresponding to the average waveform of the received signals of bits 1 and 0 are obtained. In other words, the accuracy of these values V1k and V0k is improved at the end of the preamble part p1. Accordingly, the accuracy of the difference value Vdk and the maximum value is improved, the accuracy of the determination timing is also improved, and the discrimination of the received signal level by the determination unit 206 is further improved.

  When the data start word detection unit 209 detects the data start word, the synchronization timing generation unit 208 is stopped, so that the determination unit 206 determines the highly accurate sampling timing obtained at the end of the preamble part p1. As a result, the determination unit 206 performs demodulation of the header part p2 and the payload part p3 with high accuracy, thereby reducing code errors.

  When the synchronization timing generation unit 208 is stopped in response to detection of the data start word, all sampling values in the bit 1 information storage unit 503 and the bit 0 information storage unit 504 are cleared, and the next frame At the time of reception, the sampling value is stored in the bit 1 information storage unit 503 and the bit 0 information storage unit 504 again. Thereby, the determination timing and the threshold are reset for each frame.

  In such a pulse receiver 1, not only can the received signal be accurately demodulated, regardless of the wireless communication environment of multipath propagation, but also the determination unit 206 can be configured with an analog circuit, so that power consumption Can be reduced. On the other hand, the conventional method of storing the template waveform, analyzing the waveform of the received signal, and obtaining the correlation between the template waveform and the waveform of the received signal requires a digital circuit, and this circuit scale Becomes larger and power consumption increases.

  Next, a second embodiment of the pulse receiving apparatus of the present invention will be described. The pulse receiving apparatus of the present embodiment has substantially the same configuration as the apparatus of FIG. 2, but demodulates the pulse signal PPM modulated while the apparatus of FIG. 2 demodulates the pulse signal P modulated by OOK. Therefore, instead of the synchronization timing generation unit 208, a synchronization timing generation unit 208A as shown in FIG. 7 is applied.

  Accordingly, in FIG. 1, a transmission device 2 transmits a PPM-modulated pulse signal as a radio wave signal, and a pulse reception device 1 receives the radio signal and receives each PPM-modulated pulse signal P from its high-frequency reception input. Are sequentially demodulated, and the value of each bit B is sequentially determined from these pulse signals P.

  In the pulse receiving apparatus 1 of the present embodiment, the high frequency reception input is passed through the band limiting filter 202, the LNA unit 203, and the AGC unit 204, and the high frequency reception input is added to the detection unit 205, as in the case of OOK modulation. Then, an analog reception signal is obtained as a detection output of the detection unit 205. The analog reception signal is added to the determination unit 206, the CCA detection unit 207, and the synchronization timing generation unit 208A.

  The CCA detection unit 207 receives the analog reception signal from the detection unit 205, detects the preamble part p1 included in the frame from the reception signal, and notifies the synchronization timing generation unit 208A and the like that the preamble part p1 has been detected. Notice.

  When the synchronization timing generation unit 208A receives the notification of the detection of the preamble portion from the CCA detection unit 207, the synchronization timing generation unit 208A inputs an analog reception signal from the detection unit 205, and based on this reception signal, for each bit 1 and 0, The optimum sampling timing of the received signal level is obtained, and the determination unit 206 is notified of these sampling timings.

  In addition, the synchronization timing generation unit 208A obtains and sets thresholds to be compared with the received signal level based on the analog reception signal for each of bits 1 and 0, and notifies the determination unit 206 of these threshold values.

  Upon receiving the received signal level sampling timing and threshold notification for each bit 1 and 0, the determination unit 206 sets these sampling timings as the respective determination timings, and at each determination timing for each pulse signal interval Tp. The analog reception signal level is sampled, the sampling values of these determination timings are compared with the respective threshold values, and a binary signal indicating bits 1 and 0 is generated and output.

  The binary signal output from the determination unit 206 is output to the data start word detection unit 209 and a circuit (not shown) after the next stage.

  When the data start word detection unit 209 receives the binary signal from the determination unit 206, the data start word detection unit 209 waits until the synchronization word of the preamble part p1 ends, detects the data start word following the synchronization word, and detects the data start word. Is detected, the synchronization timing generation unit 208A is notified of this data start word detection.

  When the synchronization timing generation unit 208A receives the notification that the data start word is detected, the synchronization word is terminated, and therefore, the synchronization timing generation unit 208A stops obtaining and notifying the sampling timing and threshold for each bit 1 and 0.

  When the synchronization word ends, the determination unit 206 is notified of the most accurate sampling timing and threshold for each of bits 1 and 0, determines these sampling timings as respective determination timings, and also determines the highly accurate threshold. To do. Thereafter, the determination unit 206 determines the received signal level using these determination timings and thresholds, and sequentially generates and outputs a binary signal indicating the header part p2 and the payload part p3.

  For example, as shown in FIG. 8A, when the preamble part p1 has a pattern in which bit 1 and bit 0 are repeated, when this bit pattern is PPM modulated, as shown in FIG. 8B. In the pulse signal interval Tp of bit 1, one pulse signal P is immediately allocated at the start time of the interval Tp, and in the pulse signal interval Tp of bit 0, one pulse signal P is time ΔT from the start time of the interval Tp. Allocated only late.

  If the transmission / reception of the pulse signal P does not cause multipath propagation and the transmission / reception of the pulse signal is performed normally, the detection unit 205 of the pulse receiver 1 performs the operation as shown in FIG. The pulse signal P is output, the pulse signal P is demodulated by the determination unit 206, and a preamble part p1 having a bit pattern as shown in FIG. 8A is generated and output.

  However, when multipath propagation occurs, the signal component (radio wave signal component) of the pulse signal P transmitted through the delay propagation path is delayed and output from the detector 205 as shown in FIG. 8C, for example. The waveform of the received signal (pulse signal P) is deformed.

  In the pulse signal section Tp of bit 1 shown in FIG. 8C, the signal component is also present at the timing delayed by the time ΔT even though one pulse signal P is immediately allocated at the start time of the section Tp. If the level of this signal component is high, a determination error of bits 1 and 0 occurs.

  Therefore, in the present embodiment, the synchronization timing generation unit 208A obtains the optimum determination timing and threshold of the received signal level for each bit 1 and 0, notifies the determination unit 206 of these determination timing and threshold, and determines the determination unit 206. Thus, the analog reception signal level is sampled at each determination timing for each of bits 1 and 0, and the value of the pulse signal P is determined by comparing the sampling values of these determination timings with the respective threshold values.

  Next, the process of the synchronization timing generation unit 208A, that is, the process for obtaining the reception signal level determination timing and threshold value in the pulse signal section Tp will be described in detail.

  As shown in FIG. 7, the synchronization timing generation unit 208A includes an AD conversion unit 501, a reception level acquisition unit 502, a bit 1 information storage unit 503, a bit 0 information storage unit 504, a bit 1 difference value calculation unit 801, and a bit 0 difference value. A calculation unit 803, a bit 1 timing selection unit 802, and a bit 0 timing selection unit 804 are provided. Note that, in FIG. 7, the same reference numerals are given to portions that perform the same functions as those of the apparatus of FIG.

  First, in the pulse receiving device 1, a synchronization signal that is synchronized with the pulse signal P is generated based on the received signal that is a detection output of the detection unit 205, and this synchronization signal is generated by the determination unit 206, the CCA detection unit 207, and the synchronization timing generation In addition to the unit 208A and the data start word detection unit 209, synchronization between these units is enabled.

  When the reception signal from the detection unit 205 is input, the AD conversion unit 501 sequentially samples the reception signal level at a predetermined sampling period for each pulse signal interval Tp, and sets each sampling value of the reception signal level in the pulse signal interval Tp. Output one by one.

  For example, as shown in FIG. 9, the received signal level indicated by the solid line A is sampled at the sampling period ts in the pulse signal interval Tp of bit 1, and 16 sampling values V1k (k = 1 to 16) are output one by one. Further, the received signal level indicated by the solid line B is sampled at the sampling period ts in the pulse signal section Tp of bit 0, and 16 sampling values V0k (k = 1 to 16) are output one by one.

  The reception level acquisition unit 502 inputs 16 sampling values V1k (k = 1 to 16) or 16 sampling values V0k (k = 1 to 16) for each pulse signal section Tp, and bits the 16 sampling values V1k. 1 information storage unit 503 and 16 sampling values V0k are stored in bit 0 information storage unit 504.

  For example, the pulse signal P of bit 1 is allocated to the first pulse signal section Tp of the preamble part p1, the pulse signal P of bit 0 is allocated to the next pulse signal section Tp. If the pulse signal P of bit 0 is repeated, the odd-numbered pulse signal interval Tp is set as the pulse signal interval Tp of bit 1, and the 16 sampling values V1k in the pulse signal interval Tp of bit 1 are stored in the bit 1 information storage unit. The even-numbered pulse signal section Tp is stored as the bit 0 pulse signal section Tp, and the 16 sampling values V0k in the bit 0 pulse signal section Tp are stored in the bit 0 information storage section 504.

  The bit 1 information storage unit 503 inputs 16 sampling values V1k (k = 1 to 16) for each pulse signal interval Tp of bit 1, and each time the same sampling timing (k value is the same). Each sampling value V1k is averaged, and this average value is stored as the sampling value V1k.

  Similarly, the bit 0 information storage unit 504 inputs 16 sampling values V0k for each pulse signal interval Tp of bit 0, and each sampling value V0k at the same sampling timing (the value of k is the same) each time. Are averaged, and this average value is stored as the sampling value V0k.

  The bit 1 difference value calculation unit 801 associates each sampling value V1k in the bit 1 information storage unit 503 with each sampling value V0k in the bit 0 information storage unit 504 at the same sampling timing in the pulse signal section Tp, At every same sampling timing, a difference value V1dk (= V1k−V0k) obtained by subtracting the sampling value V0k of bit 0 from the sampling value V1k of bit 1 is obtained. That is, V11−V01 = V1d1 is obtained, V12−V02 = V1d2 is obtained,..., V116−V016 = V1d16 is obtained.

  Then, the bit 1 timing selection unit 802 obtains the maximum value from the 16 difference values V1d1 to V1d16 obtained by the bit 1 difference value calculation unit 801, and sends the sampling timing at which the maximum value is obtained to the determination unit 206. Notice. Also, the bit 1 timing selection unit 802 obtains an average value of the sampling value of bit 1 and the sampling value of bit 0 at this sampling timing, and notifies the determination unit 206 of this average value as a threshold value Sh1.

  Also, the bit 0 difference value calculation unit 803 associates each sampling value V1k in the bit 1 information storage unit 503 and each sampling value V0k in the bit 0 information storage unit 504 with the same sampling timing in the pulse signal section Tp. The difference value V0dk (= V0k−V1k) obtained by subtracting the sampling value V1k of bit 1 from the sampling value V0k of bit 0 is obtained at the same sampling timing. That is, V01-V11 = V0d1, V02-V12 = V0d2,..., V016-V116 = V0d16 are obtained.

  Then, the bit 0 timing selection unit 804 obtains the maximum value from the 16 difference values V0d1 to V0d16 obtained by the bit 0 difference value calculation unit 803, and determines the sampling timing at which the maximum value is obtained to the determination unit 206. Notice. The bit 0 timing selection unit 804 obtains an average value of the sampling value of bit 1 and the sampling value of bit 0 at this sampling timing, and notifies the determination unit 206 of this average value as a threshold value Sh0.

  The determination unit 206 sets the sampling timing and threshold value Sh1 from the bit 1 timing selection unit 802 as the determination timing Ts1 and threshold value Sh1 for the determination of bit 1, and the sampling timing and threshold value Sh0 from the bit 0 timing selection unit 804. Are set as determination timing Ts0 and threshold value Sh0 for determination of bit 0.

  Then, the determination unit 206 samples the analog reception signal level from the detection unit 205 at the determination timings Ts1 and Ts0 for each pulse signal interval Tp, and uses the sampling values of the determination timings Ts1 and Ts0 as the respective threshold values. Compared with Sh1 and Sh0, if the sampling value at the determination timing Ts1 is equal to or greater than the threshold value Sh1, a binary signal indicating bit 1 is output, and if the sampling value at the determination timing Ts0 is equal to or greater than the threshold value Sh0, bit 0 is set. The binary signal shown is output.

  It should be noted that in the same pulse signal section Tp, it is considered impossible to demodulate the received signal in a wireless communication environment in which the received signal level at each of the determination timings Ts1 and Ts0 is equal to or higher than the threshold values Sh1 and Sh0.

  The sampling timing at which the difference value V1dk for bit 1 is maximized is set as the determination timing Ts1, and the sampling timing at which the difference value V0dk for bit 0 is maximized is set as the determination timing Ts0. Since the determination of bits 1 and 0 is performed using the received signal level at each determination timing Ts1 and Ts0 every time, the influence of intersymbol interference is avoided and the determination of the bit value is performed accurately and easily. Can do. Further, since the average value of the sampling value of bit 1 and the sampling value of bit 0 is used as a threshold value at any determination timing, the reception signal level can be identified accurately and easily.

  The bit 1 information storage unit 503 averages each sampling value V1k and stores this average value. Similarly, the bit 0 information storage unit 504 averages each sampling value V0k and stores this average value. Therefore, in the last part of the preamble part p1, the accuracy of these values V1k and V0k is improved, the accuracy of the difference values V1dk, V0dk and the maximum value is also improved, and furthermore, the respective determination timings Ts1, Ts0. Is improved, and the discrimination of the received signal level by the determination unit 206 is improved.

  Then, after the data start word is detected by the data start word detection unit 209 and the synchronization timing generation unit 208A is stopped, the determination unit 206 sets the highly accurate sampling timing obtained at the end of the preamble part p1. As a result, the determination unit 206 performs demodulation of the header part p2 and the payload part p3 with high accuracy, thereby reducing code errors.

  Further, in each of the above embodiments, the determination timing and threshold value of the received signal level in the pulse signal section are obtained and set for each frame. However, once the determination timing and threshold value are set for one frame, several successive steps are performed. For such a frame, the determination timing and threshold value may be used, and the determination timing and threshold value may be updated when the next frame is received thereafter. That is, the determination timing and the threshold value are obtained and updated for every certain number of frames.

  Further, the determination unit 206 samples the reception signal level at the determination timing, holds the sampling value, and determines the bit value of the pulse signal from the held sampling value. It is also possible to periodically determine the bit value of the signal, determine the bit value at the determination timing, and perform the determination.

  Also, instead of storing or clearing the sampling value V1k and sampling value V0k in the bit 1 information storage unit 503 and the bit 0 information storage unit 504 for each frame, the synchronization word is generated for a certain number of frames. The sampling value V1k and the sampling value V0k are continuously written in the bit 1 information storage unit 503 and the bit 0 information storage unit 504, and the average value of the sampling value V1k and the average value of the sampling value V0k are obtained, A threshold may be set. In this case, the sampling values in the bit 1 information storage unit 503 and the bit 0 information storage unit 504 are stored or cleared for every fixed number of frames.

It is a block diagram which shows 1st Embodiment of the pulse receiver of this invention. It is explanatory drawing which shows typically the communication system to which the pulse receiver of FIG. 1 is applied. It is a figure which shows the structure of the flame | frame transmitted / received by the communication system of FIG. (A) is a diagram illustrating a bit string, (b) is a diagram illustrating a normal pulse signal (reception signal) that has been subjected to OOK modulation, and (c) is a reception that has been deformed under the influence of multipath propagation. It is a figure which shows a signal waveform. It is a block diagram which shows the structure of the synchronous timing generation part in the pulse receiver of FIG. It is a figure which illustrates the waveform of the received signal by which OOK modulation | alteration was carried out. It is a block diagram which shows the structure of the synchronous timing generation part in 2nd Embodiment of the pulse receiver of this invention. (A) is a diagram illustrating a bit string, (b) is a diagram illustrating a normal pulse signal (received signal) that has been PPM modulated, and (c) is a reception that has been deformed under the influence of multipath propagation. It is a figure which shows a signal waveform. It is a figure which illustrates the waveform of the received signal by which PPM modulation was carried out.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulse receiver 2 Transmitter 201 Receiving antenna 202 Band-limiting filter (band pass filter, BPF)
203 LNA (Low Noise Amplifier)
204 AGC (Automatic Gain Control)
205 Detection unit 206 Determination unit 207 CCA detection unit (Clear Channel Assessment)
208, 208A Synchronization timing generation unit 209 Data start word detection unit 501 AD conversion unit 502 Reception level acquisition unit 503 Bit 1 information storage unit 504 Bit 0 information storage unit 505 Difference value calculation unit 506 Timing selection unit 801 Bit 1 difference value calculation unit 802 Bit 1 timing selection unit 803 Bit 0 difference value calculation unit 804 Bit 0 timing selection unit

Claims (18)

In a pulse receiving device that receives a pulse signal,
A signal interval measuring means for periodically sampling the received signal level indicating bit 1 in the pulse signal interval of bit 1 and periodically sampling the received signal level indicating bit 0 in the pulse signal interval of bit 0;
Bit 1 storage means for storing each sampling value obtained by periodic sampling of the received signal level indicating bit 1 by the signal section measuring means;
Bit 0 storage means for storing each sampling value obtained by periodic sampling of the received signal level indicating bit 0 by the signal section measuring means;
Each sampling value in the bit 1 storage means and each sampling value in the bit 0 storage means are made to correspond to each other at the same sampling timing in the pulse signal section, and the sampling value of bit 1 and the bit are set at the same sampling timing. A difference calculating means for obtaining a difference value from a sampling value of 0;
A timing acquisition unit that selects a maximum value from the difference values obtained by the difference calculation unit and sets a sampling timing at which the maximum value is obtained as a determination timing of a received signal level in a pulse signal section; A pulse receiving device.   2. The pulse according to claim 1, wherein the signal section measurement unit performs periodic sampling in each pulse signal section of bits 1 and 0 included in the bit pattern when receiving a prescribed bit pattern. 3. Receiver device. The signal section measuring means periodically samples the received signal level indicating bit 1 every time a pulse signal of bit 1 is received,
The bit 1 storage means obtains and stores an average sampling value for each sampling timing every time each sampling value obtained by periodic sampling of the received signal indicating bit 1 by the signal section measuring means is input. The pulse receiver according to claim 1, wherein: The signal interval measuring means periodically samples the received signal level indicating bit 0 every time a pulse signal of bit 0 is received,
The bit 0 storage means obtains and stores an average sampling value for each sampling timing every time each sampling value obtained by periodic sampling of the received signal indicating bit 0 by the signal section measuring means is input. The pulse receiver according to claim 1, wherein:   2. The pulse receiving apparatus according to claim 1, further comprising a reception start detecting unit that detects a reception start of a frame composed of a pulse signal and notifies the signal interval measuring unit of the reception start of the pulse signal. The frame consisting of the pulse signal includes a data part demodulated as information,
Data start detection that detects the reception start of the data part and notifies the reception start of the data part to the signal interval measurement means, the bit 1 storage means, the bit 0 storage means, the difference calculation means, and the timing acquisition means The pulse receiving device according to claim 1, further comprising: means.   The determination timing of the received signal level in the pulse signal section set by the timing acquisition means is notified, and the determination timing notified for each pulse signal section from the reception start time of the data part included in the frame consisting of the pulse signal. 2. The pulse receiving apparatus according to claim 1, further comprising a determining unit that determines a bit value of the pulse signal based on the received signal level.   The determination means samples the received signal level at the notified determination timing for each pulse signal section, holds the sampling value, and determines the bit value of the pulse signal from the held sampling value. The pulse receiver according to claim 7.   The determination unit is characterized by periodically determining a bit value of a pulse signal based on a received signal level for each pulse signal section, and determining and determining the bit value at a notified determination timing. Item 8. The pulse receiving device according to Item 7.   The signal interval measurement means, the bit 1 storage means, the bit 0 storage means, the difference calculation means, and the timing acquisition means each receive a received signal in a pulse signal interval every time a certain number of frames consisting of pulse signals are received. The pulse receiving apparatus according to claim 1, wherein a series of operations for setting a level determination timing is performed.   Each time the bit 1 storage means and the bit 0 storage means receive a certain number of frames of pulse signals, all the stored sampling values are once cleared and storage of the sampling values is started. The pulse receiver according to claim 10.   11. The signal section measuring means is activated when receiving preamble information composed of a prescribed bit pattern included in a frame, and is stopped when receiving data information subsequent to the preamble information. The pulse receiving device described in 1.   The signal section measuring means starts receiving a received signal when receiving preamble information including a prescribed bit pattern included in a frame, and stops receiving a received signal when receiving data information subsequent to the preamble information. The pulse receiving device according to claim 10.   The signal interval measurement means, the bit 1 storage means, the bit 0 storage means, the difference calculation means, and the timing acquisition means are activated upon reception of preamble information consisting of a prescribed bit pattern included in a frame, The pulse receiving device according to claim 10, wherein the pulse receiving device is stopped when data information subsequent to the preamble information is received. Determination means for receiving the determination timing of the received signal level in the pulse signal section set by the timing acquisition means and determining the bit value of the pulse signal for each pulse signal section based on the received signal level of the notified determination timing With
The timing acquisition means selects the maximum value from the difference values obtained by the difference calculation means, sets the sampling timing at which the maximum value is obtained as the determination timing of the received signal level in the pulse signal section, and The average value of the sampling value of bit 1 and the sampling value of bit 0 for which the maximum difference value is obtained is set as a threshold value.
2. The pulse reception according to claim 1, wherein the determination unit determines the bit value of the pulse signal by comparing the received signal level at the notified determination timing with a threshold set by the timing acquisition unit. apparatus.   The pulse receiving apparatus according to claim 1, wherein the pulse signal is subjected to OOK modulation or PPM modulation. In a pulse receiving method for receiving a pulse signal,
A signal interval measuring step of periodically sampling the received signal level indicating the bit 1 in the pulse signal interval of the bit 1 and periodically sampling the received signal level indicating the bit 0 in the pulse signal interval of the bit 0;
A bit 1 storing step for storing each sampling value obtained by periodic sampling of the received signal level indicating bit 1 in the signal interval measuring step;
A bit 0 storage step of storing each sampling value obtained by periodic sampling of the received signal level indicating bit 0 in the signal interval measurement step;
Each sampling value stored in the bit 1 storing step and each sampling value stored in the bit 0 storing step are made to correspond to each other at the same sampling timing in the pulse signal section, and for each same sampling timing, the bit 1 A difference calculation step for obtaining a difference value between the sampling value and the sampling value of bit 0;
A timing acquisition step of selecting a maximum value from each difference value obtained in the difference calculation step and setting a sampling timing at which the maximum value is obtained as a determination timing of a received signal level in a pulse signal section. A pulse receiving method characterized by the above.   The pulse reception method according to claim 17, wherein the reception signal sampled in the signal interval measurement step indicates preamble information including a predetermined bit pattern included in a frame.

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