JP4645342B2 - Radio receiving apparatus and radio receiving method - Google Patents

Description

  The present invention relates to a radio reception apparatus and a radio reception method for receiving radio signals for ultra-wideband communication.

  In recent years, attention has been paid to an ultra wide band (UWB) communication system that performs ultra-wideband communication using a pulse signal sequence composed of pulse signals synchronized with a predetermined cycle timing as one of high-speed wireless transmission systems. Yes. In one aspect of UWB communication, communication is performed without using a carrier wave and using a pulse signal sequence made up of extremely fine pulse signals such as a pulse width of 1 nsec or less (see, for example, Patent Document 1).

  FIG. 11 is a block diagram showing a UWB communication radio receiving apparatus 100 according to the background art. A radio reception apparatus 100 shown in FIG. 11 includes an antenna 101 that receives a UWB communication signal transmitted from a radio transmission apparatus using UWB communication, an amplifier 102 that amplifies the UWB communication signal received by the antenna 101, and its radio transmission. A decoder source 103 that generates a decode control signal corresponding to the same known PN (Pseudorandom Noise) code used to generate the UWB communication signal in the device; and substantially equivalent to each pulse of the received signal An adjustable time base 104 that generates a periodic timing signal including a pulse train of a template signal having a waveform, and a decoding signal that temporally matches a known PN code of the wireless transmission device based on the decoding control signal and the periodic timing signal Decode time modulator 105, received signal amplified by amplifier 102 and deco A correlator 106 that generates a correlation voltage by taking a correlation with the received signal, a low-pass filter 107 that feeds back the correlation voltage to the adjustable time base 104, and a demodulator that recovers received data by removing subcarriers from the correlation voltage. Device 108.

  Then, the correlator 106 demodulates the received signal by obtaining a correlation between the received signal amplified by the amplifier 102 and the decoded signal temporally matching the known PN code of the wireless transmission device. Can be done.

  The wireless reception device 100 configured as described above receives the pulse signal transmitted on the time axis in synchronization with a predetermined cycle timing and the reception timing on the wireless reception device 100 side. It is necessary to perform pulse synchronization to synchronize.

  FIG. 12 is an explanatory diagram for explaining a method of achieving pulse synchronization according to the background art. First, as shown in FIG. 12, the communication signal of UWB communication includes a pulse P100 (preamble) for establishing pulse synchronization at a constant period, for example, 200 nsec. On the other hand, the wireless reception device 100 receives a UWB communication signal only during a predetermined period, for example, a 10 nsec window period, and gradually sets the timing of the window period, for example, 10 nsec, until a pulse P100 is received within the window period. The timing of the pulse P100 is searched while shifting. When the pulse P100 is received within the window period, the pulse synchronization is performed by acquiring the timing of the window period as the synchronization timing.

At the time of data reception, the correlation is obtained by the correlator 106 between the received signal amplified by the amplifier 102 and the known PN code of the wireless transmission device in the window period synchronized with the synchronization timing. The receiver 108 demodulates the received signal.
Japanese National Patent Publication No. 10-508725

  By the way, in the radio receiving apparatus 100 as described above, since signal processing is performed on a very fine pulse signal received using the antenna 101, it is necessary to increase the power amplification factor of the amplifier 102. There was an inconvenience that electric power was large.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a wireless reception device and a wireless reception method that can reduce power consumption in an amplification unit of a reception signal.

  In order to achieve the above-described object, a radio receiving apparatus according to the first means of the present invention includes a receiving unit that receives a signal for radio communication that includes pulses arranged at a predetermined period and accommodates predetermined data. An amplification unit that amplifies the signal received by the reception unit, an integration unit that integrates the signal amplified by the amplification unit in a window period that is a part of the period, and the reception unit. A synchronization unit that synchronizes the timing of the pulse and the timing of the window period in the received signal, a demodulation unit that demodulates the signal for wireless communication based on the integral value, and acquires the data, and the timing of the pulse And a control unit that causes the amplifying unit to perform the amplifying operation in a synchronous window period that is a window period synchronized with the control unit.

  Further, in the above-described wireless reception device, the wireless communication device can be used for the wireless communication based on the integration value obtained by the integration unit in the synchronization window period and the integration value obtained by the integration unit in a period excluding the synchronization window period. A threshold value generating unit that generates a threshold value for discriminating between a signal and noise and further causes the amplification unit to perform the amplification operation in a period excluding the synchronization window period until the threshold value is generated, The demodulator performs the demodulation by determining the value of the data according to whether or not an integral value obtained by the integrator in the synchronization window period exceeds a threshold generated by the threshold generator. It is characterized by.

  Further, in the above-described wireless reception device, the threshold generation unit includes a high-pass filter that acquires the frequency component of the pulse from the integration value obtained by the integration unit during the synchronization window period, and a signal obtained by the high-pass filter. An effective value calculating unit that calculates an effective value of the average value, and an average processing unit that averages the integrated value obtained by the integrating unit in a period excluding the synchronization window period, and an average value obtained by the average processing unit, The threshold value is generated by adding a reference value obtained by multiplying an effective value calculated by the effective value calculation unit by a predetermined set value.

  Further, in the above-described wireless reception device, the threshold value generation unit is configured so that the average value obtained by the average processing unit and the high-pass filter and the effective value calculation unit in the synchronization window period after the threshold value is generated. The threshold value is updated with a new threshold value obtained by adding a reference value obtained by multiplying the obtained new effective value by a predetermined set value.

  Further, in the above-described wireless reception device, the control unit causes the amplification unit to perform the amplification operation in a predetermined synchronization window period of the plurality of synchronization window periods in a plurality of cycles, and the integration is performed in the synchronization window period. A difference between a first value that is a value corresponding to the integration value obtained by the integration unit and a second value that is a value corresponding to the integration value obtained by the integration unit in a window period excluding the synchronous window period The ratio is increased / decreased according to the increase / decrease, and the amplification section is caused to perform the amplification operation in a period excluding the synchronization window period until the difference is calculated.

  Further, in the above-described wireless reception device, the control unit may include a third value that is a value corresponding to an integration value obtained by the integration unit in the synchronization window period after the difference is calculated, and the second value. The ratio is repeatedly increased and decreased in accordance with the increase or decrease of the difference from the value.

  Further, in the above-described wireless reception device, the signal for wireless communication includes a plurality of communication frames containing the same data, and the control unit synchronizes with the threshold generated by the threshold generating unit. When the ratio of the integral values obtained by the integration unit in the window period is equal to or greater than a preset setting value, at least one communication frame of the plurality of communication frames is transmitted by the demodulation unit in the wireless communication signal. After being demodulated, the amplification operation of the amplification unit in the synchronization window period is stopped.

  Further, in the above-described wireless reception device, the synchronization unit includes a value corresponding to an integration value obtained by the integration unit in the synchronization window period and an integration obtained by the integration unit in a window period excluding the synchronization window period. A time width of the synchronization window period is set based on a value corresponding to the value.

  And the wireless reception method according to the second means of the present invention comprises a step of receiving a signal for wireless communication in which pulses are arranged at a predetermined cycle and accommodating predetermined data, and the received signal is Amplifying a signal by an amplifying unit; integrating the amplified signal in a window period which is a part of the period; timing of the pulse in the received signal; and the window period In the synchronization window period, which is a window period synchronized with the timing of the pulse, the step of synchronizing the timing of the above, the step of demodulating the signal for wireless communication based on the integral value and acquiring the data And a step of causing the amplification section to perform the amplification operation.

  In the wireless reception device and the wireless reception method configured as described above, a signal for wireless communication that accommodates data is received by the reception unit, the signal received by the reception unit is amplified by the amplification unit, and is amplified by the amplification unit. The signal is integrated by an integrating unit during a synchronous window period synchronized with the pulse timing in a part of the period of the pulse, and the signal for wireless communication is demodulated by the demodulating unit based on the integrated value. Is acquired. Then, since the amplification operation in the amplifying unit is executed by the control unit in the synchronization window period, the power consumption for signal amplification in the period other than the synchronization window period is reduced, so that the power consumption in the amplification unit of the received signal is reduced. Can be reduced.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

(First embodiment)
FIG. 1 is a block diagram showing an example of the configuration of the wireless reception device 1 according to the first embodiment of the present invention. 1 is a known UWB wireless transmission device, and radiates a UWB wireless signal from an antenna 12. FIG. 2 is an explanatory diagram illustrating an example of a wireless signal transmitted by the wireless transmission device 11. In order to improve communication reliability, the wireless transmission device 11 repeats the same communication frame A containing the same data a plurality of times, for example, three times, from the antenna 12 as shown in FIG. Transmit as a radio signal.

  FIG. 2B is an explanatory diagram illustrating an example of details of the communication frame A. The communication frame A is modulated by an on / off keying method that represents data “1” and “0” depending on the presence or absence of a short pulse signal P, for example, and a pulse that synchronizes the communication frame A and the reception timing on the wireless reception device 1 side. It consists of a pulse synchronization pulse train A1 for performing synchronization and a data part A2 for communication purposes. For example, as shown in FIG. 2C, the pulse synchronization pulse train A1 is configured such that a pulse P having a pulse width of 2 to 3 nsec continues for a time required for pulse synchronization processing at a constant period Trep. ing. A signal pattern A3 indicating the end of the pulse synchronization pulse train A1 is provided at the end of the pulse synchronization pulse train A1.

  For example, the data portion A2 represents “1” when N pulses P continue (period Trep × N period pulse P continues), and “0” when there is no period Trep × N period pulse P. Is meant to represent.

  1 includes an antenna 2 (receiver) that receives a communication frame A, an amplifier 3 (amplifier) that amplifies the received signal, a detector 4 that detects the received signal, and an integrator 5 (integrator). ), An AD converter 6, a control unit 7, a window signal generation unit 8, and a signal detection unit 9. The antenna 2 receives a UWB radio signal, for example, the radio signal shown in FIG. 2 radiated from the antenna 12 in the radio transmitter 11 and outputs the radio signal to the amplifier 3.

  The amplifier 3 is an amplifier that amplifies the signal received by the antenna 2 and outputs the amplified signal to the detector 4. The amplifier 3 has a control terminal for controlling the amplification factor, and the window signal Swin output from the window signal generation unit 8 is The signal is input to the control terminal. The amplifier 3 increases the power consumption when the amplification factor is increased using the control terminal, and the power consumption decreases when the amplification factor is decreased (amplification operation is stopped).

  As the amplifier 3, for example, a low noise amplifier (LNA) such as BGA622 manufactured by Infineon Technologies can be used. For example, in the case of BGA622, when the amplification factor at a frequency of 3 to 4 GHz is set to 12 to 13 dB, the current consumption becomes 6 mA. When the amplification operation is stopped and the amplification factor at a frequency of 3 to 4 GHz is set to -17 dB, the consumption current is When the amplification operation is stopped, the current consumption can be reduced to 1/20.

  The detector 4 detects the output signal of the amplifier 3 by, for example, envelope detection or peak detection. Further, the signal S 1 obtained by detection by the detector 4 is output to the integrator 5. The integrator 5 integrates the signal S1 output from the detector 4 in the integration interval corresponding to the window signal Swin from the window signal generator 8, and outputs the integrated signal to the AD converter 6. The AD converter 6 converts the integration signal output from the integrator 5 into a digital value, and outputs the digitally converted integration value SD to the control unit 7 and the signal detection unit 9.

  The control unit 7 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a ROM (Read Only Memory) in which a predetermined control program is recorded, and a RAM (Random Access Memory) in which data is temporarily recorded. And a peripheral circuit and the like, and by executing a control program stored in the ROM, it functions as a synchronization unit 71 that performs pulse synchronization processing and sets the synchronization timing in the window signal generation unit 8.

  The window signal generation unit 8 generates a window signal Swin indicating a window period during which the amplifier 3 performs an amplification operation or the integrator 5 performs an integration operation according to a control signal from the control unit 7. Output to 5.

  FIG. 3 is a block diagram illustrating an example of the configuration of the signal detection unit 9. The signal detection unit 9 shown in FIG. 3 is based on the integration value obtained by the integration unit 5 in the synchronization window period synchronized with the received pulse and the integration value obtained by the integrator 5 in the period excluding the synchronization window period. A threshold value generation unit 91 that generates a threshold value Sth for discriminating between a signal for wireless communication and noise, and an integration value SD obtained by the integrator 5 during the synchronization window period is the threshold value Sth generated by the threshold value generation unit 91. And a demodulator 92 that outputs the received data Sout obtained by performing demodulation by determining the value of the data depending on whether or not the value exceeds.

  The threshold value generation unit 91 removes a change caused by the presence or absence of the pulse P at the time of pulse synchronization and a change caused according to the data value stored in the data part A2 from the integrated value SD obtained by the integrator 5. The high-pass filter 93 that passes the frequency component of the pulse P, the effective value calculator 94 that calculates the effective value of the signal obtained by the high-pass filter 93, the average processor 95 that averages the integral value SD, and the average processor An arithmetic unit 96 that generates a threshold value Sth by adding a value obtained by multiplying the average value obtained in 95 by the effective value calculated by the effective value calculation unit 94 by 3; The effective value calculation unit 94, the average processing unit 95, and the calculation unit 96 are configured using, for example, a CPU (Central Processing Unit), and by executing a predetermined calculation program, the effective value calculation unit 94, the average process The unit 95 and the calculation unit 96 function.

  Next, the operation of the wireless reception device 1 configured as described above will be described. First, a signal radiated from the antenna 12 of the transmission device 11, for example, the communication frame A is received by the antenna 2, amplified by the amplifier 3, and detected by the detector 4 by, for example, envelope detection or peak detection. Further, the signal detected by the detector 4 is integrated by the integrator 5, and the integrated value SD obtained by digitally converting the integrated voltage by the AD converter 6 is output to the control unit 7 and the signal detection unit 9. The

  Then, the synchronization unit 71 in the control unit 7 performs a pulse synchronization process. FIG. 4 is a signal waveform diagram for explaining the operation of the synchronization unit 71. First, in response to a control signal from the synchronization unit 71, a window signal Swin having a pulse width Ton and a period Trep is output from the window signal generation unit 8 to the amplifier 3 and the integrator 5 at a phase timing of φ1. Then, during the pulse width Ton in which the window signal Swin is at the high level, the amplification operation by the amplifier 3 and the integration operation by the integrator 5 are performed, and the integration value SD output from the AD converter 6 is the synchronization unit 71. Is stored as the integral value SD1 at the phase timing of φ1.

  Further, the synchronization unit 71 outputs a control signal indicating that the phase timing of the window signal Swin is shifted to the timing of φ2 shifted by the pulse width Ton to the window signal generation unit 8, and from the window signal generation unit 8 at the phase timing of φ2. The window signal Swin is output to the amplifier 3 and the integrator 5. Then, the integrated value SD output from the AD converter 6 is stored as the integrated value SD2 at the phase timing of φ2 by the synchronizing unit 71 by the same operation as described above.

  As described above, the integration values SD obtained at the respective phase timings when the phase timing of the window signal Swin is moved from φ1 to φn by the synchronization unit 71 as the integration values SD1 to SDn at the phase timings of φ1 to φn. Remembered.

Then, the synchronization unit 71, the difference between the integrated value _{SD x-1} with the integral value SD _x, the second largest value of the integrated value SD _x having the maximum value among the integrated values SD1~SDn is calculated, If the difference is equal to or greater than the threshold value Sth output from the signal detection unit 9, the phase timing φx obtained from the integral value SD _x is acquired as the synchronization timing, and a window signal generation unit is generated according to the control signal from the synchronization unit 71. The phase timing of the window signal Swin output from 8 is fixed to the phase timing φx. The operation for generating the threshold value Sth will be described later.

On the other hand, if the difference between the integral value SD _x and the integral value SD _x−1 is less than the threshold value Sth, the phase timing of the window signal Swin is moved again from φ1 to φn by the synchronization unit 71, and the integral value SD1 at each phase timing is obtained. ˜SDn is acquired, and this operation is repeated until the difference between the integral value SD _x and the integral value SD _x−1 becomes equal to or greater than the threshold value Sth.

  Thereby, the timing of the pulse P of the pulse synchronization pulse train A1 (preamble) in the communication frame A and the timing of the pulse width Ton at which the window signal Swin is at the high level, that is, the window period are synchronized. Then, a notification signal S2 indicating that the synchronization is performed at the phase timing φx is output from the synchronization unit 71 to the threshold value generation unit 91.

  Next, the operation of the signal detection unit 9 will be described. 5 and 6 are explanatory diagrams for explaining the operation of generating the threshold value Sth by the signal detection unit 9. 5 and 6, the cycle Trep is constituted by four phase timings φ1 to φ4, that is, the cycle Trep = pulse width Ton × 4. An example is shown in which the phase timing φ3 is the synchronous phase timing. In this case, the time of the pulse width Ton in the window signal Swin synchronized with the phase timing φ3 corresponds to the synchronous window period.

  In this case, after the synchronization processing by the synchronization unit 71 is performed, a notification signal S2 that indicates synchronization at the phase timing φ3 is output from the synchronization unit 71 to the calculation unit 96. Next, referring to FIG. 5, in response to the control signal from operation unit 96, window signal Swin is output from window signal generation unit 8 to amplifier 3 and integrator 5 at the phase timing of φ1.

  Then, the noise received by the antenna 2 at the phase timing of φ1, that is, the timing not synchronized with the pulse P, is amplified by a plurality of periods in the period Trep, for example, by N amplifiers 3 and detected by the detector 4. Integration is performed by the integrator 5 and digital conversion is performed by the AD converter 6 to obtain an integration value SD. This integrated value SD is stored in the average processing unit 95 as an integrated value SD1 of noise at the phase timing of φ1.

  Similarly, the integration values SD2 and SD4 are also stored in the average processing unit 95 for the phase timings of φ2 and φ4 that are not synchronized with the pulse P, and further, the integration processing unit 95 uses the integration values SD1, SD2, and SD4. An average value Save1 is calculated. In this case, the integrated values SD1, SD2, and SD4 of the noise obtained at the phase timings φ1, φ2, and φ4 that are not synchronized with the pulse P are the internal circuit of the wireless receiver 1 such as the noise received by the antenna 2 and the amplifier 3. The noise generated in Fig. 2 can be approximated as a Gaussian distribution.

  Further, in response to the control signal from the calculation unit 96, the pulse P received by the antenna 2 at the phase timing of φ3, that is, the synchronization timing, is amplified by a plurality of periods in the period Trep, for example, the N-time amplifier 3, and the detector 4, the frequency component of the pulse P is extracted by a high-pass filter 93 from the integrated value SD3 obtained by integration by the integrator 5, integration by the integrator 5, and digital conversion by the AD converter 6, as shown in FIG. The value is output as Shpf to the effective value calculator 94, and the effective value calculator 94 calculates the effective value SDrms of the frequency component.

  Next, based on the average value Save1 calculated by the average processing unit 95 and the effective value SDrms calculated by the effective value calculating unit 94, the arithmetic unit 96 calculates the threshold value Sth as, for example, Save1 + SDrms × 3. And is output to the demodulator 92 and the controller 7.

  Next, in response to the control signal from the synchronization unit 71, the window signal Swin synchronized with the phase timing φ3 is output from the window signal generation unit 8 to the amplifier 3 and the integrator 5, and the period of the pulse width Ton in the window signal Swin Only the signal amplification operation by the amplifier 3 and the integration operation by the integrator 5 are executed, and the integration value SD3 based on the pulse P in the pulse synchronization pulse train A1 is transferred from the AD converter 6 to the control unit 7 by the same operation as described above. It is output to the detection unit 9.

  Then, the demodulation unit 92 compares the integration value SD3 at the synchronization timing with the threshold value Sth. If SD3 <Sth, it is determined that the data is “0”, and if SD3 ≧ Sth, the data is “1”. And the determination value is output to the outside as reception data Sout.

  In this case, if the noise amount such as noise received by the antenna 2 is approximated as having a Gaussian distribution, the probability that the noise exceeds the threshold value Sth is 0.3%. Therefore, the probability that the data values “0” and “1” in the received data Sout obtained as described above are correct values is 99.7%.

  As a result, the threshold value Sth is set according to the noise level obtained when the pulse synchronization pulse train A1 is received and the level of the pulse P, which is an effective signal, and data is demodulated based on the threshold value Sth. The reliability of the received data Sout can be improved.

  In addition, although the example calculated as Sth = Save1 + SDrms × 3 is shown, the multiplier of SDrm may be set by increasing / decreasing according to the reliability of the requested data, and the multiplier is not limited to “3”. For example, the multiplier may be “1”, that is, Sth = Save1 + SDrms.

  Further, since the window signal Swin is input to the control terminal of the amplification factor in the amplifier 3, the signal amplification operation by the amplifier 3 is performed only during the period of the pulse width Ton in the window signal Swin, and the amplifier other than the period of the pulse width Ton. As a result, the current consumption in the amplifier 3, that is, the power consumption can be reduced.

(Second Embodiment)
Next, a radio reception apparatus according to the second embodiment of the present invention will be described. FIG. 7 is a block diagram showing an example of the configuration of the wireless reception device 1a according to the second embodiment of the present invention. The radio reception device 1a shown in FIG. 7 is further synchronized with the integration value SD at the synchronization timing when the control unit 7a executes a predetermined program stored in the ROM, unlike the radio reception device 1 shown in FIG. ΔS calculation unit 72 that calculates the difference of the integral value SD at the timing not to perform, a decimation processing unit 73 that sets a ratio for causing the amplifier 3 to perform an amplification operation in the window period, and a window time width setting that sets the time width of the window period A continuous transmission / reception stop unit 75 that determines whether or not the second and subsequent communication frames A among a plurality of, for example, three consecutively transmitted communication frames A can be received, and stops the reception operation including the amplification operation of the amplifier 3 It differs in that it works.

  In addition to the threshold value Sth, the signal detection unit 9 further outputs the average value Save1 calculated by the average processing unit 95 and Vn = SDrms × 3 calculated by the calculation unit 96 to the control unit 7a. Different.

  Since other configurations and operations are the same as those of the wireless reception device 1 shown in FIG. 1, the description thereof will be omitted, and operations of the present embodiment will be described below. First, in the same manner as the wireless receiver 1 shown in FIG. 1 described above, when the pulse synchronization pulse train A1 is received, the average of the integration values SD1, SD2, SD4 at the timing not synchronized with the pulse P by the averaging processor 95. The value Save1 is calculated, the average value Save1 is output to the ΔS calculation unit 72, and the SDrms × 3 calculated by the calculation unit 96 is used as the reference value Vn, the thinning processing unit 73, the window time width setting unit 74, and the continuous value The data is output to the transmission / reception stop unit 75.

  When receiving the pulse synchronization pulse train A1, the ΔS calculation unit 72 calculates the average value Save2 of the integration value SD3 at the synchronization timing, that is, the average value Save2 of the integration value SD3 and the synchronization window period in the synchronization window period. A difference value ΔS that is a difference between the average values Save1 of the integration values SD1, SD2, and SD4 in the excluded period is calculated as ΔS = Save2−Save1.

  Next, when ΔS> Vn is satisfied by the thinning-out processing unit 73 based on the difference value ΔS obtained by the ΔS calculation unit 72 and the reference value Vn obtained by the calculation unit 96 in the synchronous window period, the window signal Swin The ON pulse at, that is, the timing for operating the amplifier 3 and the integrator 5 is thinned out.

  Specifically, in order for the wireless reception device 1a to receive the communication frame A, the condition of the following formula (1) may be satisfied.

ΔS ÷ Sth ≧ 1 (1)
Therefore, when the ON pulse in the window signal Swin is output Nx times in a certain period Tx, for example, a period 10 times the period Trep, the difference value obtained when the integration of the pulse P by the integrator 5 is repeated Nx times. When ΔS is ΔSax and the integral value per on-pulse in the window signal Swin is the integral value ΔSint, the following equation (2) is established.

ΔSax = Nx × ΔSint (2)
Here, if the number of thinning on pulses of the window signal Swin in the period Tx is Ny, the number of on pulses after thinning the Ny number of on pulses is Nx−Ny.

  Then, the number Ny of on-pulses that satisfy the following expression (3) can be thinned out during the period Tx.

ΔSax ÷ Nx × (Nx−Ny) ÷ Sth ≧ 1 (3)
Since there are ten on-pulses of the window signal Swin during the period Tx, for example, if ΔSax ÷ Sth = 5, the relationship expressed by the following equation (4) is obtained from the equation (2).

5 ÷ 10 × (10−Ny) ≧ 1 (4)
From Equation (4), Ny ≦ 8, and the thinning processing unit 73 thins out the ON pulse of the window signal Swin during the period Tx eight times, and the window signal generation unit 8 is in accordance with the control signal from the thinning processing unit 73. To the period Tx, the on-pulse of the window signal Swin is output twice, and the amplifier 3 and the integrator 5 are operated.

  As a result, the thinning-out processing unit 73 changes the period between the integral value obtained by the integrator 5 in the synchronous window period and the difference between the integral value obtained by the integrator 5 in the window period excluding the synchronous window period. Since the ratio of the number of on-pulses of the window signal Swin during Tx is decreased, the ratio of the number of on-pulses of the window signal Swin within the communicable range according to the signal level and the noise level, that is, the time for operating the amplifier 3 The ratio can be reduced, and the power consumption in the amplifier 3 can be reduced.

  Further, the window time width setting unit 74 sets the time width of the pulse width Ton so as to maximize the ratio of the difference value ΔS to the reference value Vn. 8 and 9 are explanatory diagrams for explaining the operation of the window time width setting unit 74. FIG. As shown in FIG. 8A, in the state where the pulse P and the window signal Swin are synchronized, the pulse width in the signal S1 obtained by amplifying and detecting the pulse P received by the antenna 2 is , Smaller than the pulse width Ton. Since the integrator 5 performs an integration operation during the pulse width Ton, the higher the ratio of the pulse width of the signal S1 in the pulse width Ton, the higher the S / N ratio (signal-to-noise ratio) and the better the received signal. can get.

  On the other hand, ΔS / Vn = (Save2−Save1) / Vn, and Save1 represents a noise component. Therefore, ΔS / Vn increases and decreases according to the increase and decrease of noise. That is, when the S / N ratio increases or decreases, ΔS / Vn also increases or decreases.

  Further, as shown in FIG. 8B, for example, when the pulse width Ton is shortened while the signal pulse in the signal S1 is within the pulse width Ton, the occupation ratio of the signal pulse in the pulse width Ton increases and S The / N ratio is improved. However, if the position of the signal pulse deviates from the center of the pulse width Ton, as shown in FIG. 8C, if the pulse width Ton is further shortened, the signal pulse deviates from the pulse width Ton, and conversely, S / N ratio will become small. That is, the S / N ratio becomes maximum when the pulse width Ton becomes a predetermined value as shown in FIG.

  Therefore, the window time width setting unit 74 outputs a control signal to the window signal generation unit 8 to increase or decrease the pulse width Ton, and the difference value ΔS obtained by the ΔS calculation unit 72 and the reference obtained by the calculation unit 96. ΔS / Vn is calculated from the value Vn, and a pulse width Ton at which ΔS / Vn is maximized, that is, a pulse width Ton at which the S / N ratio is maximized is searched and set in the window signal generator 8.

  Thereby, ΔS / Vn, that is, the pulse width Ton can be set so as to maximize the S / N ratio, and the reception sensitivity of the wireless reception device 1a can be improved.

  Further, ΔS / Vn is calculated by the continuous transmission / reception stop unit 75 from the difference value ΔS obtained by the ΔS calculation unit 72 and the reference value Vn obtained by the calculation unit 96, which is sufficient to ensure communication reliability. If the calculated ΔS / Vn is larger than the preset value set as ΔS / Vn for obtaining a good S / N ratio, a plurality of communication frames A, for example, three consecutive transmissions as shown in FIG. Even if the first communication frame A is received, it is considered that the reliability of communication can be ensured by receiving the first communication frame A. Therefore, after the reception processing of the first communication frame A is completed, continuous transmission / reception is stopped. In response to the control signal from the unit 75, the window signal generator 8 sets the window signal Swin to a low level, and the amplification operation of the amplifier 3 is stopped.

  Thereby, when a plurality of communication frames A are continuously transmitted, the amplification operation of the amplifier 3 when receiving the second and subsequent communication frames A can be stopped, and the power consumption in the amplifier 3 can be reduced.

(Third embodiment)
Next, a radio receiving apparatus according to the third embodiment of the present invention will be described. FIG. 10 is a block diagram illustrating an example of a configuration of a wireless reception device 1b according to the third embodiment of the present invention. The radio reception device 1b shown in FIG. 10 is different from the radio reception device 1a shown in FIG. 7 in that the signal detection unit 9a, the ΔS calculation unit 72a, and the thinning-out processing unit 73a receive the data part A2. The difference is that the threshold value Sth, the difference value ΔS, and the on-pulse thinning rate in the window signal Swin are updated.

  Since other configurations and operations are the same as those of the wireless reception device 1a shown in FIG. 7, the description thereof will be omitted, and the characteristic operations of the present embodiment will be described below. First, when the pulse synchronization pulse train A1 is received, after the synchronization processing by the synchronization unit 71 is performed, the arithmetic unit 96 converts the average value Save1 and the effective value SDrms by the same operation as the wireless reception device 1a illustrated in FIG. Based on this, the threshold value Sth is calculated and stored as, for example, Save1 + SDrms × 3, and is output to the demodulation unit 92 and the control unit 7.

  In the wireless reception device 1a shown in FIG. 7, the data is then received by the demodulator 92 based on the threshold value Sth calculated when the pulse synchronization pulse train A1 is received as described above, even when the data portion A2 is received. Is determined, and the determination value is output to the outside as received data Sout.

  On the other hand, in the radio reception apparatus 1b shown in FIG. 10, the signal detection unit 9a extracts the frequency component of the pulse P by the high-pass filter 93 from the integral value SD3 obtained at the time of reception of the data unit A2, and generates the signal Shpf. The effective value calculation unit 94 outputs the effective value SDrms of the frequency component. Based on the average value Save1 calculated by the average processing unit 95 when the pulse synchronization pulse train A1 is received and the effective value SDrms obtained by the effective value calculation unit 94 while receiving the data part A2, the calculation is performed. The unit 96 newly calculates the threshold value Sth as, for example, Save1 + SDrms × 3, and outputs the threshold value Sth and the reference value Vn (= SDrms × 3) to the demodulation unit 92 and the control unit 7.

  Then, based on the threshold value Sth newly obtained by the calculation unit 96, the demodulation unit 92 determines the data value, and the determination value is output to the outside as the reception data Sout.

  As a result, the distance between the wireless transmission device 11 and the wireless reception device 1b changes during reception of the data part A2, or an obstacle is placed between the wireless transmission device 11 and the wireless reception device 1b. When the signal intensity of the pulse P changes due to the above reason and the value of the effective value SDrms obtained by the effective value calculation unit 94 changes, the threshold value Sth is reset based on the new effective value SDrms after the change of the signal intensity. Since the data is demodulated based on the new threshold value Sth, the reliability of the reception data Sout can be improved in response to a change in the reception state of the radio signal.

  In addition, when receiving the data part A2, the ΔS calculation part 72a calculates the average value Save2 of the integration value SD3 at the synchronization timing, and when receiving the new average value Save2 and the pulse synchronization pulse train A1, the average value Save2 is calculated. Based on the average value Save1 calculated by the processing unit 95, the difference value ΔS = Save2−Save1 is calculated, that is, the difference value ΔS is updated based on the pulse P newly received during reception of the data part A2. .

  Next, when ΔS> Vn is satisfied based on the difference value ΔS newly obtained by the ΔS calculation unit 72a by the thinning processing unit 73a and the threshold value Sth newly obtained by the calculation unit 96, the above-described operation is performed. Similarly, the number Ny of satisfying Expression (3) is recalculated, and the on-pulse thinning rate in the window signal Swin is changed.

  As a result, when the signal strength of the pulse P becomes strong during reception of the data part A2, for example, because the distance between the wireless transmission device 11 and the wireless reception device 1b becomes short, a window is displayed according to the new signal strength. The on-pulse decimation rate in the signal Swin is increased, the ratio of the number of on-pulses in the window signal Swin during the period Tx is decreased, and the window signal Swin is within a communicable range according to the change in the signal level during reception of the data part A2. Since the ratio of the number of on-pulses, that is, the ratio of the time during which the amplifier 3 is operated can be reduced, the power consumption in the amplifier 3 can be reduced.

It is a block diagram which shows an example of a structure of the radio | wireless receiver which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows an example of the radio signal received by the radio | wireless receiver shown in FIG. It is a block diagram which shows an example of a structure of the signal detection part shown in FIG. It is a signal waveform diagram for demonstrating operation | movement of the synchronizing part shown in FIG. It is explanatory drawing for demonstrating the production | generation operation | movement of the threshold value Sth by the signal detection part shown in FIG. It is explanatory drawing for demonstrating the production | generation operation | movement of the threshold value Sth by the signal detection part shown in FIG. It is a block diagram which shows an example of a structure of the radio | wireless receiver which concerns on the 2nd Embodiment of this invention. It is explanatory drawing for demonstrating operation | movement of the window time width setting part shown in FIG. It is explanatory drawing for demonstrating operation | movement of the window time width setting part shown in FIG. It is a block diagram which shows an example of a structure of the radio | wireless receiving apparatus which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows the radio | wireless receiver of UWB communication which concerns on background art. It is explanatory drawing for demonstrating the method of taking the pulse synchronization in the radio | wireless receiver shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a, 1b Wireless receiver 2 Antenna 3 Amplifier 4 Detector 5 Integrator 6 AD converter 7, 7a Control part 8 Window signal generation part 9, 9a Signal detection part 72, 72a ΔS calculation part 73, 73a Thinning process part 74 Window time width setting unit 75 Continuous transmission / reception stop unit 91 Threshold generation unit 92 Demodulation unit 93 High-pass filter 94 RMS value calculation unit 95 Average processing unit 96 Calculation unit

Claims (9)

A receiving unit that receives a signal for wireless communication in which pulses are arranged in a predetermined cycle and accommodates predetermined data;
An amplifying unit for amplifying a signal received by the receiving unit;
An integrator that integrates the signal amplified by the amplifier in a window period that is a partial period in the period;
A synchronizing unit that synchronizes the timing of the pulse and the timing of the window period in the signal received by the receiving unit;
A demodulator that demodulates the signal for wireless communication based on the integrated value to obtain the data;
A radio receiving apparatus comprising: a control unit that causes the amplification unit to perform the amplification operation in a synchronous window period that is a window period synchronized with the timing of the pulse. Discrimination between the wireless communication signal and noise based on the integration value obtained by the integration unit in the synchronization window period and the integration value obtained by the integration unit in a period excluding the synchronization window period A threshold generation unit that generates the threshold and causes the amplification unit to perform the amplification operation in a period excluding the synchronization window period until the threshold is generated;
The demodulator performs the demodulation by determining the value of the data according to whether or not an integrated value obtained by the integrator in the synchronization window period exceeds a threshold value generated by the threshold value generator. The radio reception apparatus according to claim 1. The threshold generation unit
A high-pass filter that obtains a frequency component of the pulse from an integration value obtained by the integration unit in the synchronization window period;
An effective value calculation unit for calculating an effective value of the signal obtained by the high-pass filter;
An average processing unit that averages the integration values obtained by the integration unit in a period excluding the synchronization window period;
The threshold value is generated by adding the average value obtained by the average processing unit and the reference value obtained by multiplying the effective value calculated by the effective value calculation unit by a predetermined set value. The wireless receiver according to claim 2. The threshold generation unit
Multiplying the average value obtained by the average processing unit and a new effective value obtained by the high-pass filter and the effective value calculating unit by a predetermined set value in the synchronization window period after the threshold is generated The radio reception apparatus according to claim 3, wherein the threshold is updated using a value obtained by adding the obtained reference value as a new threshold. The control unit causes the amplification unit to perform the amplification operation in a predetermined ratio of the synchronization window periods of the plurality of synchronization window periods in a plurality of cycles, and according to the integration value obtained by the integration unit in the synchronization window period. The ratio is decreased in accordance with the increase or decrease of the difference between the first value that is the calculated value and the second value that is the value corresponding to the integration value obtained by the integration unit in the window period excluding the synchronous window period. In addition, the wireless reception device according to claim 2, wherein the amplification unit performs the amplification operation in a period excluding the synchronization window period until the difference is calculated. The control unit responds to increase / decrease in the difference between the third value and the second value, which is a value corresponding to the integration value obtained by the integration unit in the synchronization window period after the difference is calculated. The wireless receiver according to claim 5, wherein the ratio is repeatedly increased and decreased. The wireless communication signal includes a plurality of communication frames containing the same data.
When the ratio of the integral value obtained by the integration unit in the synchronization window period with respect to the threshold value generated by the threshold value generation unit is greater than or equal to a preset setting value, the control unit The amplification operation of the amplification unit in the synchronization window period is stopped after at least one communication frame of the plurality of communication frames is demodulated by the demodulation unit. The wireless receiving device described. The synchronization unit is based on a value corresponding to the integration value obtained by the integration unit in the synchronization window period and a value corresponding to the integration value obtained by the integration unit in a window period excluding the synchronization window period. The wireless reception device according to claim 1, wherein a time width of the synchronization window period is set. Receiving a signal for wireless communication in which pulses are arranged at a predetermined cycle and accommodating predetermined data; and
Amplifying the received signal by an amplification unit that amplifies the signal;
Integrating the amplified signal in a window period which is a part of the period;
Synchronizing the timing of the pulse and the timing of the window period in the received signal;
Demodulating the wireless communication signal based on the integrated value to obtain the data;
And a step of causing the amplifying unit to perform the amplifying operation in a synchronous window period that is a window period synchronized with the timing of the pulse.

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