WO2008010283A1 - Appareil de détection de signal - Google Patents

Appareil de détection de signal Download PDF

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Publication number
WO2008010283A1
WO2008010283A1 PCT/JP2006/314415 JP2006314415W WO2008010283A1 WO 2008010283 A1 WO2008010283 A1 WO 2008010283A1 JP 2006314415 W JP2006314415 W JP 2006314415W WO 2008010283 A1 WO2008010283 A1 WO 2008010283A1
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WIPO (PCT)
Prior art keywords
signal
information
addition
unit
result
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PCT/JP2006/314415
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English (en)
Japanese (ja)
Inventor
Tsuyoshi Kobayashi
Original Assignee
Mitsubishi Electric Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Mitsubishi Electric Corporation filed Critical Mitsubishi Electric Corporation
Priority to JP2008525762A priority Critical patent/JP4685937B2/ja
Priority to PCT/JP2006/314415 priority patent/WO2008010283A1/fr
Publication of WO2008010283A1 publication Critical patent/WO2008010283A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems

Definitions

  • the present invention relates to a signal detection device that performs detection of a desired signal and the like in a receiver that constitutes a communication device, and in particular, detects a desired signal and a symbol timing using a known signal. It is related with the signal detection apparatus to perform.
  • a known signal waveform is added before a signal for transmitting data, and the known signal waveform is transmitted to a communication device belonging to the communication system. It constantly monitors whether or not it exists on the transmission line. And when a communication device detects the presence of a known signal waveform, it does not transmit even if there is transmission data, and performs a receiving operation. Also, in the case of a communication system using the TDMA (Time Division Multiple Access) method, the base station periodically transmits a known signal waveform so that the terminal can synchronize with the basic period and timing of time division. In some cases, the terminal performs synchronization by detecting this known signal waveform. Such a known signal waveform is called a preamble, and the operation of detecting whether or not the signal of the communication system of the device is present on the transmission path is called carrier detection or carrier sense. is there.
  • CSMA Carrier Sense Multiple Access
  • a communication device In conventional carrier detection, a communication device simply receives received signal power (RSSI).
  • RSSI received signal power
  • the RSSI measurement result is compared with a certain threshold value, and if the RSSI measurement value is larger than the threshold value, it is determined that a signal is present, and the RSSI measurement value is smaller than the threshold value V, In case it was judged that there was no signal, it was.
  • the correlation value between the signal waveform on the transmission line and the preamble signal waveform which is a known waveform is constantly monitored, and when the correlation value is greater than a certain threshold, it is determined that a signal exists, A method for more reliably detecting the presence of a signal in the target communication system by determining that the signal does not exist when the correlation value is smaller than the threshold value. (For example, Patent Document 1).
  • the reception side obtains the correlation value of the received waveform in the same manner as the carrier detection described above, and the symbol timing is determined based on the timing of the peak position where the correlation value is maximum. Detection methods are used (for example, Non-Patent Document 1).
  • Patent Document 1 Japanese Patent Application Laid-Open No. 2005-295085 (Page 3-6, Fig. 1)
  • Non-Patent Document 1 Supervised by Masahiro Moriya and Shuji Kubota “Revised 802.11 High-Speed Wireless LAN Textbook” Impress Inc., January 1, 2005, P206-212
  • the detection determination based on the conventional RSSI is based only on the power, even if the power of other system signals or noises exceeds the threshold, the carrier is detected. O There is a problem that it is judged to be a detection, that is, there is a high possibility of performing a false detection.
  • the present invention has been made in view of the above, and an object of the present invention is to obtain a signal detection device that realizes highly accurate carrier detection and timing detection.
  • a signal detection apparatus for detecting a desired signal modulated by a medium power OFDM system of a received signal.
  • the signal conversion means for converting the received signal into frequency domain information (first frequency domain signal) for each carrier, and signals of a plurality of carriers that include predetermined known information and have different frequencies and initial phases are multiplexed.
  • known frequency information generating means for generating frequency domain information (second frequency domain information) for each carrier, and complex of the second frequency domain information output from the known frequency information generating means
  • the complex conjugate generating means for generating a conjugate for each carrier, the first frequency domain signal for each carrier, and the complex conjugate for each carrier generated by the complex conjugate generating means have the same frequency.
  • a multiplication means for multiplying the areas, an addition means for adding a part or all of the multiplication outputs of the multiplication means, an absolute value of the addition result or a square value of the addition result,
  • Signal detecting means for performing detection determination of a desired signal using a prescribed predetermined threshold value.
  • the received preamble signal is converted into frequency domain information by FFT, and the result obtained by multiplying the converted information by the complex conjugate value of a known preamble pattern is used.
  • carrier detection and timing determination are performed by determining the similarity between the received preamble signal and the preamble pattern, compared with the case where carrier detection is performed only with the power that was conventionally used. As a result, the frequency of erroneous detection can be suppressed, and the carrier detection accuracy can be increased.
  • FIG. 1 is a diagram illustrating a configuration example of a communication device (transmitter) on a side that transmits data to a communication device including a signal detection device according to the present invention.
  • FIG. 2 is a diagram illustrating a configuration example of a first embodiment of a communication device (receiver) including a signal detection device according to the present invention.
  • FIG. 3 is a diagram illustrating a configuration example of a carrier detection timing determination unit according to Embodiment 1.
  • FIG. 4 is a diagram illustrating a configuration example of a carrier detection timing determination unit according to Embodiment 2.
  • Figure 5 shows an example of the relationship between the leading position of the preamble signal and ⁇ relative to the FFT input range.
  • FIG. 1 A first figure.
  • FIG. 6 is a diagram illustrating a configuration example of a receiver according to the fourth embodiment.
  • FIG. 7 is a diagram illustrating a configuration example of a receiver according to the fifth embodiment.
  • FIG. 8 is a diagram illustrating a configuration example of a carrier detection timing determination unit according to the sixth embodiment.
  • FIG. 9 is a diagram illustrating another configuration example of the carrier detection timing determination unit according to the sixth embodiment.
  • FIG. 1 is a diagram showing a configuration example of a communication apparatus (transmitter) that transmits data by OFDM modulation to a communication apparatus including a signal detection apparatus according to the present invention, and 1 indicates a transmitter.
  • This transmitter 1 has transmission information 10 that also has bit string power as input, a modulation section 11 that outputs the modulation result, an IFFT section 12 that converts the output of the modulation section 11 into frequency domain power, and I FFT
  • the digital Z / analog converter (D / A) 13 that converts the output of the unit 12 into an analog format and the known signal (hereinafter called the preamble) for carrier detection and timing determination
  • a preamble generation unit 40 for generating a preamble pattern to be 14 is an analog converted transmission signal, and 2 is a transmission path.
  • FIG. 2 is a diagram showing a configuration example of the first embodiment of the communication device (receiver) including the signal detection device according to the present invention, and 3 shows the receiver.
  • the receiver 3 includes an analog Z / digital converter (A / D) 33 that converts the received signal 34 from the transmission side into a digital format, and A An FFT unit 32 that converts the output of the ZD conversion unit 33 from the time domain to the frequency domain, a demodulator 31 that demodulates the output of the FFT unit 32 and generates reception information 30 that also has bit string power, and an FFT unit 32 And a carrier detection timing determination unit 50 that performs carrier detection and timing detection based on the output of. 2 is the same transmission path as shown in FIG. 1, and the transmitter 1 and the receiver 3 forming the communication system exchange signals via this transmission path 2.
  • a / D analog Z / digital converter
  • the transmitter 1 generates a transmission signal based on the transmission information 10
  • the receiver 3 receives the generated signal, and demodulates it to generate the reception signal 30 (restore the transmission information 10). ) The operation will be described.
  • the preamble generation unit 40 When transmitting a preamble signal, the preamble generation unit 40 generates a known preamble pattern that is determined in advance. This preamble pattern is a pseudo-random pattern consisting of a bit string of “0” and “1”, for example, called an M-sequence.
  • the generated preamble pattern is input to the modulation unit 11.
  • the modulation unit 11 is in accordance with a modulation scheme such as BPSK (Binary Phase Shift Keying), QPSK (Quadrate Phase Shift Keying), or QAM (Quadrate Amplitude Modulation).
  • the input preamble pattern (bit string) is divided for each subcarrier and further mapped onto the complex plane. For example, if the preamble pattern is to be BPSK modulated, the bit string that is also input to the preamble generator 40 is divided into lbits. If it is “0”, it is “—l + 0j”, if it is “1”, it is “1”. + Oj "to convert to complex data representing two points on the complex plane.
  • the complex data generated by the modulation unit 11 is input to the I FFT unit 12 as frequency domain information for each subcarrier.
  • the IFFT unit 12 converts the input information into time domain information, and outputs digital time waveform information equal to a combined wave obtained by combining waveforms for each subcarrier. Further, the digital time waveform information is converted into an analog signal by a digital Z analog conversion unit (hereinafter referred to as a DZA conversion unit) 13 and sent to the transmission path 2 as a transmission signal 14.
  • a digital Z analog conversion unit hereinafter referred to as a DZA conversion unit
  • the preamble pattern may be assigned to all subcarriers or only some of the subcarriers may be used.
  • the input to the modulation unit 11 becomes an arbitrary transmission information bit string (transmission information 10) instead of the known pattern input from the preamble generation unit 40.
  • the basic operations of the modulation unit 11, the IFFT unit 12, and the DZA conversion unit 13 are the same as the operations at the time of preamble signal transmission described above.
  • the transmission information modulation scheme need not be the same as the preamble modulation scheme, and other modulation schemes may be used.
  • the implementation method of the preamble generation unit 40 includes a method of generating a preamble pattern using a shift register and an XOR operation circuit if it is a pseudo-random sequence such as an M sequence, or a preamble as a memory. There is a method of storing patterns.
  • the preamble generation unit 40 has a memory configuration, digital time waveform information of the preamble signal may be stored. In this case, the output of the preamble generation unit 40 is directly input to the DZA conversion unit 13.
  • an analog Z digital conversion unit (hereinafter referred to as AZD conversion unit) 33 converts it into digital time waveform information.
  • the FFT unit 32 corresponding to the signal conversion means generates complex data as frequency domain information for each subcarrier by converting the input from the AZD conversion unit 33 into the frequency domain.
  • the demodulator 31 demaps the input from the AZD converter 33 to a bit string for each subcarrier according to a predetermined demodulation method such as BPSK, QPSK, QAM, etc.
  • Receive information 30 is generated.
  • the preamble signal reception process is the same as the data reception process until the FFT unit 32 converts the input of the AZD conversion unit 33 into a time domain power frequency domain.
  • the complex data for each subcarrier generated by the FFT unit 32 is input to the carrier detection timing determination unit 50, and the carrier detection timing determination unit 50 performs carrier detection and timing determination.
  • FIG. 3 is a diagram illustrating a configuration example of the carrier detection timing determination unit 50 included in the receiver according to the present embodiment.
  • the carrier detection timing detection unit 50 is the same as that transmitted from the transmitter 1.
  • a preamble pattern generator 51 that generates frequency information for each subcarrier of a known signal (preamble signal), a complex conjugate 52 that converts complex numbers to complex conjugate values, a complex multiplier 53, and a sum of multiple complex numbers
  • the complex summation unit 54 for calculating the absolute value, the absolute value calculation unit 55 for calculating the absolute value of the complex number, and the absolute value of the calculated complex number are compared with a predetermined threshold value.
  • a carrier detection determination unit 56 that determines that a carrier has been detected in the above case.
  • the complex number information for each subcarrier input from the FFT unit 32 to the carrier detection timing detection unit 50 is X (i is a subcarrier number).
  • a preamble pattern generation unit 51 corresponding to known frequency information generation means generates complex number information P (i is a subcarrier number) for each subcarrier in the preamble signal, and generates complex conjugate thereof.
  • a complex conjugate 52 corresponding to the means converts to a complex conjugate value P *.
  • the complex multiplier 53 corresponding to the multiplication means multiplies the P * by the complex number information X of the received signal to obtain Y.
  • the sum total value Z of Y is calculated by the complex summation device 54 corresponding to the adding means. Z thus obtained can be expressed by the following equation (1).
  • the absolute value calculation unit 55 calculates the absolute value of the total value Z output from the complex totalizer 54.
  • the absolute value of the square value of the total value Z (corresponding to power) as shown in the following equation (3) is calculated.
  • the carrier detection / determination unit 56 may perform carrier detection using the square value of the total value Z, for example, by the calculation by the unit 55.
  • Z 2 A 2 + B 2 --(3)
  • the total value for all the subcarriers (the sum of all the multiplication results Y ; ) is used as V, and instead of only some of the subcarriers (the multiplication result Y ; (Addition value for a part selected from the above) may be calculated, and the subsequent processing may be performed using the addition result.
  • the absolute value calculation unit 55 and the carrier detection unit 56 constitute a signal detection unit.
  • the carrier detection determination unit 56 can determine carrier detection when the absolute value exceeds a predetermined threshold for signal detection determination in consideration of transmission path characteristics and the like. The timing when the preamble signal is present can be detected.
  • the preamble pattern is BPSK modulated has been described as an example, but the same applies when other modulation schemes are used.
  • the threshold for signal detection determination is determined based on the relationship between the absolute value of the total value when a preamble signal is received and the absolute value of the total value when a signal other than the preamble signal is received! / To do.
  • the bit pattern used as the preamble pattern, the comparison target at the time of carrier detection judgment (LV, whether to use the absolute value of the total value or the square value of the absolute value as the value to be compared) Type of information to be added when calculating the total value (what kind of processing is performed on the input X to the carrier detection timing judgment unit) To be calculated) and the number of objects to be added when calculating the total value (number of information to be added). It is also possible to select and use the optimum threshold value as appropriate according to the transmission path characteristics from a plurality of threshold values determined in advance in consideration of the transmission path characteristics. Decide it in advance and use it while adjusting the appropriate value according to the transmission path characteristics.
  • the transmission side transmits, as preamble signals, signals that have been assigned a predetermined preamble pattern to a plurality of predetermined frequencies.
  • the preamble signal when the preamble signal is received, information is separated for each frequency using the FFT, and the result obtained by multiplying them with the complex conjugate value of the preamble pattern is used.
  • carrier detection and timing determination are performed by determining the similarity between the received preamble signal and the preamble pattern. As a result, the possibility of erroneous detection can be reduced compared to the case where carrier detection or the like is performed using only power that has been conventionally used.
  • the FFT unit 32 and the complex multiplier 53 are circuits normally provided for data reception by a general OFDM receiver, and it is not necessary to perform carrier detection and data demodulation at the same time.
  • the same circuit can be used for carrier detection. That is, the above-described receiver can be realized with a small circuit scale as compared with the conventional carrier detection based on correlation in the time domain.
  • the carrier detection determination is performed by using the sum of the FFT result of the received signal and the complex multiplication result of the conjugate complex value of the preamble pattern.
  • the preamble signal reception timing is determined in finer units than the time interval input to the FFT using the result of the complex multiplication of the conjugate complex value of the preamble pattern and the result of conjugate complex multiplication between the two subcarriers. The case where it does is demonstrated.
  • the transmitter of the present embodiment has a configuration similar to that of the transmitter of the first embodiment described above (see FIG. 1).
  • the receiver has the same configuration as that of the receiver of Embodiment 1 (see FIG. 2), but the detailed configuration of the carrier detection timing determination unit is partially different. Therefore, this embodiment In the above, description of parts other than the carrier detection timing determination unit will be omitted, and only the operation of the timing detection determination unit (in this embodiment, the timing detection determination unit 50a) will be described.
  • FIG. 4 is a diagram illustrating a configuration example of the carrier detection timing determination unit 50a according to the second embodiment.
  • This carrier detection timing determination unit 50a further adds a (second) complex conjugate 52 and a (second) complex multiplication after the complex multiplier 53 to the carrier detection timing determination unit 50 of the first embodiment.
  • a phase calculation unit 57 and a timing determination unit 58 are added.
  • Other portions are denoted by the same reference numerals as those of the carrier detection timing determination unit 50, and the description thereof is omitted.
  • the subsequent complex conjugate unit 52 converts a complex conjugate value (Y, Y, ..., Y) other than Y (ie, Y, Y, ..., Y) from the output of the preceding complex multiplier 53.
  • the downstream complex multiplier 53 is connected to the complex conjugate 52
  • the complex summation unit 54 is the summation value Z k of the output of the complex multiplier 53 in the subsequent stage.
  • the vector has a phase rotation amount according to the interval frequency. If the subcarrier interval frequency is constant, it becomes a vector (complex number information) having the same phase between all subcarriers.
  • the output of the complex summation device 54 is input to the absolute value calculation unit 55 and the phase calculation unit 57.
  • the processing in absolute value calculation unit 55 and carrier detection determination unit 56 is the same as that in the first embodiment described above.
  • the threshold for signal detection determination used by carrier detection determination unit 56 is different from that used in the first embodiment. That is, the carrier detection determination unit 56, for example, the type of information to be added when the complex summation unit 54 calculates the summation value (the complex multiplier 52 and the complex multiplier 53 are input to the input X to the carrier detection timing determination unit).
  • the information obtained by modifying the threshold value used in the first embodiment is used in consideration of what kind of processing is executed and adding the information obtained by the processing.
  • the timing at which the input value (the output of the absolute value calculation unit 55) exceeds the threshold in the carrier detection determination 56 is used as the preamble signal detection timing.
  • the time waveform input to the FFT unit 32 has a time interval width corresponding to the input range of the FFT unit 32, and timing information beyond this time interval cannot be obtained (detection accuracy cannot be increased). . Therefore, in the present embodiment, in order to obtain more detailed timing, first, the phase calculator 57 obtains the phase of the total value Z using the following equation (5).
  • Figure 5 shows the relationship between the preamble signal start position and 0 for the FFT input range.
  • the timing determiner 58 uses the following equation (6) to calculate the deviation ⁇ between the current received signal input range to the FFT unit 32 and the start position of the preamble, and uses ⁇ to determine the reception timing.
  • T is a time corresponding to the input range of the FFT unit 32.
  • the phase The calculation unit 57 and the timing determination unit 58 constitute the timing determination means c [Equation 5]
  • Data can be demodulated at the timing.
  • Y ' may be obtained between adjacent subcarriers, and the sum value may be used.
  • Y' may be obtained between arbitrary subcarriers. Only some of the subcarriers may be used. However, when Y ′ is obtained between arbitrary subcarriers, the phase of Y ′ is set to a value corresponding to the phase rotation at the frequency interval between one subcarrier according to the frequency interval between the subcarriers. Correction such as calculating the total value ⁇ is required.
  • the transmission side transmits, as preamble signals, signals that have been assigned a predetermined preamble pattern to a plurality of predetermined frequencies.
  • preamble signals signals that have been assigned a predetermined preamble pattern to a plurality of predetermined frequencies.
  • information is separated for each frequency using the FFT, and the result obtained by multiplying them with the complex conjugate value of the preamble pattern is used.
  • carrier detection and timing determination are performed by determining the similarity between the received preamble signal and the preamble pattern. As a result, the possibility of erroneous detection can be reduced compared to the case where carrier detection or the like is performed using only power that has been conventionally used.
  • the FFT unit 32 and the complex multiplier 53 are circuits that a general OFDM receiver normally includes for data reception, and it is not necessary to perform carrier detection and data demodulation at the same time.
  • the same circuit can be used for carrier detection. That is, the above-described receiver can be realized with a small circuit scale as compared with the conventional carrier detection based on correlation in the time domain.
  • the output range of the IFFT unit 12 at the time of preamble signal generation and the FFT unit 32 at the time of reception Pay attention to the phase rotation of the FFT output when the input ranges do not match, and know the timing of the preamplifier signal at which timing within the input range to the FFT unit 32. Can do.
  • the above embodiment describes the case where a preamble signal generated from a predetermined known preamble pattern is used without repetition.
  • the preamble pattern is continuously repeated a plurality of times.
  • the carrier detection and timing determination in the case where the blemble signal generated based on the repetition is used will be described.
  • the transmitter of the present embodiment has the same configuration as the transmitter of the first embodiment described above (see FIG. 1), and only the preamble signal generation operation is different from the first embodiment.
  • the receiver also has the same configuration as that of the receiver of the first embodiment (see FIG. 2), and only the carrier determination operation is different from that of the first embodiment.
  • the configuration of the carrier detection timing determination unit provided in the receiver may be the same as that in the second embodiment.
  • the transmitter differs from the transmitter of Embodiment 1 in that, in the preamble signal transmission operation, a signal is generated by repeatedly repeating the same preamble pattern a plurality of times and transmitted as a preamble signal.
  • the number of preamble pattern repetitions is L.
  • Other operations are the same as those in the first embodiment.
  • the carrier detection determination unit 56 does not immediately determine carrier detection when the threshold value is exceeded only once, but based on M (M ⁇ L) consecutive FFT processing results. If the absolute value (or the square value of the absolute value) of Z (the output of the complex summer 54) exceeds the threshold value N times (N ⁇ M), it is determined that the carrier is detected.
  • the timing determination unit 58 includes the M consecutive FFT processing results, Average of phase ⁇ of Z when carrier detection determination unit 56 determines that the threshold value is exceeded
  • ⁇ is calculated using the average value of and the reception timing is determined. Or timing The determination unit 58 determines the phase of Z when the carrier detection determination unit 56 determines that the threshold value has been exceeded.
  • the carrier detection determination unit 56 determines whether ⁇ is obtained, and the average value of ⁇ is obtained.
  • the reception timing is determined using the average value of ⁇ ⁇
  • the transmitting side uses a signal that is assigned a predetermined preamble pattern to a plurality of predetermined frequencies and continuously transmitted a plurality of times as a preamble signal. To do.
  • the information obtained by separating the information for each frequency using the FFT and multiplying it by the complex conjugate value of the preamble pattern is used, as in demodulating data.
  • carrier detection and timing determination are performed by determining the similarity between the received preamble signal and the preamble pattern multiple times.
  • the error is detected.
  • the possibility of performing detection can be reduced.
  • the FFT unit 32 and the complex multiplier 53 are circuits that a general OFDM receiver normally includes for data reception, and it is not necessary to perform carrier detection and data demodulation at the same time.
  • the same circuit can be used for carrier detection. That is, the above-described receiver can be realized with a small circuit scale as compared with the conventional carrier detection based on correlation in the time domain.
  • the IF FT at the time of preamble signal generation Pay attention to the phase rotation of the FFT output when the output range of the unit 12 and the input range of the FFT unit 32 at the time of reception do not match, and the phase deviation amount power between subcarriers Any timing within the time of the input range to the FFT unit 32 It is possible to know whether or not the beginning of the preamble signal has been received.
  • the signal detection apparatus In Embodiment 3 described above, the preamble signal transmitted by the transmitter continues the preamble pattern a plurality of times. In the present embodiment, the case where the received time waveform is averaged and used to determine the carrier detection is described. To do.
  • the transmitter of the present embodiment has the same configuration as that of the transmitter of the first embodiment described above, and only the operation of generating a preamble signal is different from that of the first embodiment.
  • This transmitter is the same as the transmitter of Embodiment 1 in that it generates a signal in which the same preamble pattern is repeated a plurality of times in succession and transmits this as a preamble signal in the preamble signal transmission operation. Different.
  • the number of repetitions of the preamble pattern is L times. Other operations are the same as those in the first embodiment.
  • FIG. 6 is a diagram illustrating a configuration example of a receiver according to the fourth embodiment.
  • the receiver according to the present embodiment has a configuration in which a time signal averaging unit 35 is added to the receiver according to the first embodiment described above.
  • the other parts are the same as those of the receiver of the first embodiment, so the same reference numerals are given and the description thereof is omitted.
  • the receiver of this Embodiment is described as the receiver 3b.
  • the receiver 3b performs the same operation as the receiver 3 of the first embodiment. That is, when there is an input of the received signal 34, the AZD conversion unit 33 converts it into digital time waveform information and inputs the converted received signal to the FFT unit 32. Subsequent operations are the same as those shown in the first embodiment.
  • the time signal averaging unit 35 outputs the output of the AZD conversion unit 33 unit every time corresponding to the input range of the FFT unit 32.
  • the previous time waveform (1 ⁇ L) is averaged, and the averaged AZD conversion unit 33 unit output is output to the FFT unit 32.
  • the output S (t) from the time signal averaging unit 35 at time t can be expressed as the following equation (8). it can.
  • the FFT unit 32 converts the averaged time waveform S (t) expressed by the above equation (8) into frequency domain information.
  • the present embodiment has been described as a configuration in which the time signal averaging unit 35 is added to the receiver of the first embodiment, the present invention is not limited to this.
  • a configuration in which a time signal averaging unit 35 is added to the receiver of form 2 may be adopted.
  • carrier detection and timing determination carrier detection may be performed based on a plurality of determination results as described in the third embodiment.
  • the transmission side assigns a predetermined preamble pattern to each of a plurality of predetermined frequencies and uses a signal that is continuously transmitted a plurality of times as a preamble signal. To do.
  • the information is separated for each frequency using the FFT as in the case of data demodulation, and the information is separated from the complex conjugate value of the preamble pattern.
  • Carrier detection and timing determination are performed by determining the similarity between the received preamble signal and the preamble pattern using the results obtained by multiplying each.
  • the FFT unit 32 and the complex multiplier 53 are circuits that a general OFDM receiver normally includes for data reception, and it is not necessary to perform carrier detection and data demodulation at the same time.
  • the same circuit can be used for carrier detection.
  • the above-described receiver can be realized with a small circuit scale. Can be realized.
  • the IF FT at the time of preamble signal generation Pay attention to the phase rotation of the FFT output when the output range of the unit 12 and the input range of the FFT unit 32 at the time of reception do not match, and the phase deviation amount power between subcarriers Any timing within the time of the input range to the FFT unit 32 It is possible to know whether or not the beginning of the preamble signal has been received.
  • the signal detection apparatus In Embodiment 4 described above, the received time waveform is averaged to determine carrier detection. However, in this embodiment, frequency information after FFT processing is averaged and used to perform keying. A case where determination of carrier detection is performed will be described.
  • the transmitter of the present embodiment has the same configuration as that of the transmitter of the first embodiment described above, and only the operation for generating a preamble signal is different from that of the first embodiment.
  • This transmitter is the same as the transmitter of Embodiment 1 in that it generates a signal in which the same preamble pattern is repeated a plurality of times in succession and transmits this as a preamble signal in the preamble signal transmission operation. Different.
  • the number of repetitions of the preamble pattern is L times. Other operations are the same as those in the first embodiment.
  • FIG. 7 is a diagram illustrating a configuration example of a receiver in the fifth embodiment.
  • the receiver of the present embodiment has a configuration in which a frequency information averaging unit 36 is added to the receiver of the first embodiment described above.
  • the other parts are the same as those of the receiver of the first embodiment, so the same reference numerals are given and the description thereof is omitted.
  • the receiver of this Embodiment is described as the receiver 3c.
  • the receiver 3c performs the same operation as the receiver 3 of the first embodiment.
  • frequency information averaging unit 36 when receiving a preamble signal and performing carrier detection and timing determination, complex data for each subcarrier, which is an output from the FFT unit 32, is input to the frequency information averaging unit 36.
  • the frequency information averaging unit 36 has a frequency for the output range of the FFT unit 32.
  • the frequency information (complex data) of the immediately preceding (1 ⁇ L) is averaged for each band, and the averaged frequency information is output to the carrier detection timing determination unit 50.
  • the carrier detection timing determination unit 50 performs carrier detection and timing determination based on the averaged frequency information D (t) expressed by the above equation (10).
  • Carrier detection motion avr Carrier detection motion avr
  • the operation and timing determination operation are the same as those shown in the first embodiment.
  • the frequency information averaging unit 36 is added to the receiver of the first embodiment.
  • the present invention is not limited to this, and the reception of the second embodiment is performed.
  • a frequency information averaging unit 36 may be added to the machine.
  • carrier detection and timing determination carrier detection or the like may be performed based on a plurality of determination results as described in the third embodiment.
  • the transmission side assigns a predetermined preamble pattern to each of a plurality of predetermined frequencies and uses a signal that is continuously transmitted a plurality of times as a preamble signal. To do.
  • preamble signal reception information is separated for each frequency using an FFT, the information after separation is averaged, and the averaged information is multiplied by the complex conjugate value of the preamble pattern.
  • FFT Fast Fourier transform
  • the FFT unit 32 is a complex multiplier 53, which is a circuit normally provided for data reception by a general OFDM receiver, and it is not necessary to perform carrier detection and data demodulation at the same time.
  • the same circuit can be used for carrier detection. That is, the above-described receiver can be realized with a small circuit scale as compared with the conventional carrier detection based on correlation in the time domain.
  • the IF FT at the time of preamble signal generation Pay attention to the phase rotation of the FFT output when the output range of the unit 12 and the input range of the FFT unit 32 at the time of reception do not match, and the phase deviation amount power between subcarriers Any timing within the time of the input range to the FFT unit 32 It is possible to know whether or not the beginning of the preamble signal has been received.
  • the signal detection apparatus according to the sixth embodiment will be described.
  • the received time waveform and the frequency information after FFT are averaged to determine carrier detection.
  • immediately before carrier detection and A case will be described in which information immediately before timing determination is averaged and carrier detection and timing determination are performed using the averaged information.
  • the transmitter of the present embodiment has the same configuration as that of the transmitter of the first embodiment described above, and only the preamble signal generation operation is different from that of the first embodiment.
  • This transmitter is the same as the transmitter of Embodiment 1 in that it generates a signal in which the same preamble pattern is repeated a plurality of times in succession and transmits this as a preamble signal in the preamble signal transmission operation. Different.
  • the number of repetitions of the preamble pattern is L times. Other operations are the same as those in the first embodiment.
  • the configuration of the receiver is the same as that of the receiver of Embodiment 1, but the carrier detection timing is The detailed configuration of the ring determination unit is partially different. For this reason, in the present embodiment, description of parts other than the carrier detection timing determination unit will be omitted, and only the operation of the timing detection determination unit will be described.
  • FIG. 8 is a diagram illustrating a configuration example of the carrier detection timing determination unit according to the sixth embodiment.
  • FIG. A time averaging unit 59 is added to average the information immediately before detection.
  • the carrier detection timing determination unit having this configuration is referred to as a carrier detection timing determination unit 50d.
  • portions other than the time averaging unit 59 are denoted by the same reference numerals as those of the carrier detection timing determination unit 50, and description thereof is omitted.
  • FIG. 9 is a diagram illustrating another configuration example of the carrier detection timing determination unit according to the sixth embodiment.
  • FIG. 9 illustrates the carrier detection timing determination unit 50a according to the second embodiment (see FIG. 4).
  • a time averaging unit 59 for averaging information immediately before carrier detection is added.
  • the carrier detection timing determination unit having this configuration is referred to as a carrier detection timing determination unit 50e.
  • portions other than the time averaging unit 59 are denoted by the same reference numerals as those of the carrier detection timing determination unit 50, and description thereof is omitted.
  • the time averaging unit 59 corresponding to the addition result averaging unit outputs the output of the complex summation unit 54 once (1 ⁇ L ) Minute frequency information is averaged and output. If the total value obtained at time t is Z (t) and the time for the input range of the FFT unit 32 is T, the time averaging unit 59 at time t
  • the output information Z (t) can be expressed by the following equation (11).
  • absolute value calculation unit 55 and phase calculation unit 57 show the above-described embodiment 1 or 2 based on the output from time averaging unit 59. Execute the process. And carrier detection unit 56, Taimin Based on the output from the absolute value calculation unit 55 and the output from the phase calculation unit 57, the determination unit 58 executes the process shown in the first or second embodiment described above, respectively. .
  • the power of adding time averaging section 59 to the carrier detection timing determining section provided in the receiver of Embodiment 1 or 2 is not limited to this.
  • a time averaging unit 59 may be added to the carrier detection timing determination unit that performs the operation shown in form 3.
  • the transmitting side assigns a predetermined preamble pattern to each of a plurality of predetermined frequencies, and uses a signal that is continuously transmitted a plurality of times as a preamble signal. To do.
  • information used for carrier detection and timing detection is time-averaged, and the results are used to perform carrier detection and timing determination.
  • the carrier detection is performed without averaging the information used for carrier detection and timing detection shown in the above-described embodiment when carrier detection is performed using only power that has been conventionally used. The possibility of erroneous detection can be reduced compared to the case where detection or the like is performed.
  • the FFT unit 32 is a complex multiplier 53, which is a circuit that is generally provided for data reception by a general OFDM receiver, and it is not necessary to perform carrier detection and data demodulation at the same time.
  • the same circuit can be used for carrier detection. That is, the above-described receiver can be realized with a small circuit scale as compared with the conventional carrier detection based on correlation in the time domain.
  • the phase rotation of the FFT output when the output range of IFFT unit 12 at the time of preamble signal generation and the input range of FFT unit 32 at the time of reception do not match
  • the power of phase deviation between subcarriers it is possible to know the key that received the beginning of the preamble signal at any timing within the input range to the FFT unit 32.
  • the signal detection apparatus is useful for a communication system, and in particular, based on a known signal, a desired signal and symbol timing can be increased with a small circuit scale. It is suitable for a receiver provided in a communication device that detects accurately.

Abstract

La présente invention concerne un appareil de détection de signal destiné à détecter un signal de module OFDM désiré parmi des signaux reçus. L'appareil de détection de signal comprend une partie FFT qui convertit des signaux reçus en premiers signaux à dimension fréquentielle des porteuses respectives ; une partie de génération de motif de préambule (51) qui génère une seconde information de domaine fréquentiel des porteuses respectives, basés sur les signaux qui comprennent de l'information connue prédéfinie, qui a différentes fréquences et différentes phases initiales et qui est obtenu en multiplexant les signaux d'une pluralité de porteuses ; des conjugateurs complexes (52) qui génèrent des conjugués complexes de la seconde information de domaine fréquentiel pour les porteuses respectives ; des multiplicateurs complexes (53) qui multiplient les premiers signaux à dimension fréquentielle des porteuses respectives par les conjugués complexes des porteuses respectives générés par les conjugateurs complexes ; un amplificateur de sommation complexe (54) qui ajoute ensemble une partie ou toutes les sorties de multiplication des moyens de multiplication ; et des moyens de détection de signal (une partie de calcul de valeur absolue (55), une partie de détermination/détection de porteuse (56)) qui calcule une valeur absolue d'un résultat d'addition ou qui calcule une valeur quadratique du résultat d'addition et qui utilise une valeur seuil prédéterminée pour détecter/déterminer un signal désiré.
PCT/JP2006/314415 2006-07-20 2006-07-20 Appareil de détection de signal WO2008010283A1 (fr)

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PCT/JP2006/314415 WO2008010283A1 (fr) 2006-07-20 2006-07-20 Appareil de détection de signal

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JP2011515925A (ja) * 2008-03-12 2011-05-19 テレフオンアクチーボラゲット エル エム エリクソン（パブル） 複数のｏｆｄｍａリソース・エレメントを含む所与のセットにおいて所与の信号が受信されたかを調査する方法及び装置
JP2011530869A (ja) * 2008-08-08 2011-12-22 インテル コーポレイション 送信方法、無線通信装置及び無線通信システム
WO2012064030A2 (fr) * 2010-11-08 2012-05-18 한국전자통신연구원 Procédé et dispositif de détection de fréquence pour systèmes ofdm

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EP2559212B1 (fr) 2010-04-12 2014-07-23 Telefonaktiebolaget L M Ericsson (PUBL) Procédé et appareil de détection de sourdine d'un signal de référence dans un réseau de communication sans fil

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JP2009124301A (ja) * 2007-11-13 2009-06-04 Sumitomo Electric Ind Ltd 通信装置及び位相回転量推定方法
JP2011515925A (ja) * 2008-03-12 2011-05-19 テレフオンアクチーボラゲット エル エム エリクソン（パブル） 複数のｏｆｄｍａリソース・エレメントを含む所与のセットにおいて所与の信号が受信されたかを調査する方法及び装置
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WO2012064030A2 (fr) * 2010-11-08 2012-05-18 한국전자통신연구원 Procédé et dispositif de détection de fréquence pour systèmes ofdm
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