摘要:
Provided are a distance measuring device and a distance measuring method which can easily distinguish a reflected signal from a desired tag from an unnecessary wave so as to improve the distance measuring accuracy even when IR-UWB is used for measuring a distance. The method uses a reader ID indicated by a code string formed by P bits (P is a natural number) for identifying a base station and a tag ID indicated by a code string formed by Q bits (Q is a natural number) for identifying a radio terminal. The method generates a unique word containing P pulses, each of which is ON/OFF-modulated depending on whether each of P bits indicating the reader ID is 1 or 0. The method generates a frame containing 2 M unique words and a burst containing Q frames. The method further outputs a transmission signal containing a plurality of bursts. A radio terminal Amplitude Shift Keying (ASK)—modulates the transmission signal depending on whether each of the Q bits indicating the tag ID is 1 or 0. The ASK-modulated signal is sampling-received at timings of different phases by 1/M (M is an integer not smaller than 1) of the transmission clock cycle.
摘要:
A radio arrival direction estimation device that accurately estimates the arrival direction of radio waves from a desired tag, even when there are multiple antennas disposed at short intervals. When ID detection timing is provided from a timing detector (114) to a switch (201), relative amplitude/phase data related to the tag ID digital value “1” or “0” is obtained by an arrival direction estimation unit (125). One relative amplitude/phase datum is formed for each unit cycle in a first adder (202), which adds the relative amplitude/phase datum related to the tag ID digital value “1” to each element in a matrix, and a second adder (203), which adds the relative amplitude/phase datum related to the tag ID digital value “0” to each element in a matrix. An OOK signal causes an arithmetic unit (204) to subtract the relative amplitude/phase data produced by the second adder (203) from the relative amplitude/phase data produced by the first adder (202), and extract the phase of a signal corresponding to the phase of the digital value “1.”
摘要:
Disclosed are a radio terminal device and the like, which achieve an improvement in the accuracy of ranging between a UWB reader and a UWB tag regardless of whether an active method or a semi-passive method. In a terminal (300), a timing control unit (340) outputs, to a transmission amplifier (350), a control signal for performing on-off control such that on the basis of the reception timing of a pulse signal transmitted from a base station (200) and a representative value of a circuit delay time required from when a reception pulse signal is received until a transmission pulse signal generated in response to a detection signal of the reception pulse signal is transmitted, the transmission amplifier (350) amplifies a reradiation pulse generated in response to a detection signal of the pulse signal transmitted from the base station (200); and a re-reradiation pulse generated in response to a detection signal of the reradiation pulse.
摘要:
Disclosed are a radio terminal device and the like, which achieve an improvement in the accuracy of ranging between a UWB reader and a UWB tag regardless of whether an active method or a semi-passive method. In a terminal (300), a timing control unit (340) outputs, to a transmission amplifier (350), a control signal for performing on-off control such that on the basis of the reception timing of a pulse signal transmitted from a base station (200) and a representative value of a circuit delay time required from when a reception pulse signal is received until a transmission pulse signal generated in response to a detection signal of the reception pulse signal is transmitted, the transmission amplifier (350) amplifies a reradiation pulse generated in response to a detection signal of the pulse signal transmitted from the base station (200); and a re-reradiation pulse generated in response to a detection signal of the reradiation pulse.
摘要:
A positioning system and a positioning method which suppress the occurrence of jitter to improve positioning accuracy. A base station (100) of a positioning system (10) which comprises the base station (100) and a radio terminal (200), and measures the position of the radio terminal (200) to be positioned using a pulse signal, wherein a pulse generating block (103) transmits a pulse signal sequence, and an ID positioning block (110) calculates the time required for reciprocation between the transmission timing of the pulse signal sequence and the reception timing of a response pulse signal sequence transmitted from the radio terminal (200) which has received the pulse signal sequence, and calculates the position of the radio terminal (200) on the basis of the time required for reciprocation. Then, in the radio terminal (200) an LNA (203) amplifies the received pulse signal sequence and transmits the amplified pulse signal sequence to the base station (100) as a response pulse signal.
摘要:
Provided are a distance measuring device and a distance measuring method which can easily distinguish a reflected signal from a desired tag from an unnecessary wave so as to improve the distance measuring accuracy even when IR-UWB is used for measuring a distance. The method uses a reader ID indicated by a code string formed by P bits (P is a natural number) for identifying a base station and a tag ID indicated by a code string formed by Q bits (Q is a natural number) for identifying a radio terminal. The method generates a unique word containing P pulses, each of which is ON/OFF-modulated depending on whether each of P bits indicating the reader ID is 1 or 0. The method generates a frame containing 2 M unique words and a burst containing Q frames. The method further outputs a transmission signal containing a plurality of bursts. A radio terminal ASK-modulates the transmission signal depending on whether each of the Q bits indicating the tag ID is 1 or 0. The ASK-modulated signal is sampling-received at timings of different phases by 1/M (M is an integer not smaller than 1) of the transmission clock cycle.
摘要:
Provided is an array signal processing device capable of, when a spatial averaging method is applied to array signal processing, reducing the number of antennas constituting an array antenna while making use of the spatial averaging method. In the array signal processing device (300), an array antenna (310) comprises four antennas (311-1 to 311-4) disposed at the four vertices of a parallelogram. Correlation calculation units (341-1, 2) calculate, based on a received signal, spatial correlation matrices for respective sub-array antenna (312-1) and sub-array antenna (312-2), the sub-array antenna (312-1) comprising the antennas (311-1, 3) disposed at the opposing two vertices and the antenna (311-2), the sub-array antenna (312-2) comprising the antennas (311-1, 3) and the antenna (311-4). An array rotation unit (342) converts a first spatial matrix of the calculated two spatial matrices to the complex conjugate thereof. A spatial averaging unit (343) averages the complex conjugate of the first spatial matrix and a second spatial matrix.
摘要:
A radio arrival direction estimation device that accurately estimates the arrival direction of radio waves from a desired tag, even when there are multiple antennas disposed at short intervals. When ID detection timing is provided from a timing detector (114) to a switch (201), relative amplitude/phase data related to the tag ID digital value “1” or “0” is obtained by an arrival direction estimation unit (125). One relative amplitude/phase datum is formed for each unit cycle in a first adder (202), which adds the relative amplitude/phase datum related to the tag ID digital value “1” to each element in a matrix, and a second adder (203), which adds the relative amplitude/phase datum related to the tag ID digital value “0” to each element in a matrix. An OOK signal causes an arithmetic unit (204) to subtract the relative amplitude/phase data produced by the second adder (203) from the relative amplitude/phase data produced by the first adder (202), and extract the phase of a signal corresponding to the phase of the digital value “1.”
摘要:
Provided is an array signal processing device capable of, when a spatial averaging method is applied to array signal processing, reducing the number of antennas constituting an array antenna while making use of the spatial averaging method. In the array signal processing device (300), an array antenna (310) comprises four antennas (311-1 to 311-4) disposed at the four vertices of a parallelogram. Correlation calculation units (341-1, 2) calculate, based on a received signal, spatial correlation matrices for respective sub-array antenna (312-1) and sub-array antenna (312-2), the sub-array antenna (312-1) comprising the antennas (311-1, 3) disposed at the opposing two vertices and the antenna (311-2), the sub-array antenna (312-2) comprising the antennas (311-1, 3) and the antenna (311-4). An array rotation unit (342) converts a first spatial matrix of the calculated two spatial matrices to the complex conjugate thereof. A spatial averaging unit (343) averages the complex conjugate of the first spatial matrix and a second spatial matrix.
摘要:
A wireless distance measurement system and wireless terminal improve the accuracy of distance measurement when the UWB communication scheme is used. In wireless terminal 200, a route of signals varies between a distance measuring operation and a synchronization establishing operation, and, when the distance measuring operation is performed, a detection result is inputted to comparator 208 without passing through integrator 204. By this means, the distance measuring operation of wireless terminal 200 does not involve integration processing, so that delay time due to integration processing is not produced and, consequently, it is possible to improve the accuracy of distance measurement. Further, the distance measuring operation uses the integration result acquired integrator 204 for a comparison reference voltage used in comparator 208. By this means, the integration result removing noise signal components from a detection signal is used for the comparison reference voltage, so that the comparison reference voltage is optimized. Consequently, it is possible to further improve the accuracy of distance measurement.