摘要:
A supervisory apparatus able to prevent recirculation of a supervisory frame when sending a supervisor frame for supervision, which supervises an optical communications apparatuses connected to transmission lines in cooperation with the same by adding a sequence number to a supervisory frame when sending the supervisory frame.
摘要:
A network monitoring system includes a network, a monitoring device connected to the network, and a plurality of monitored devices connected to the network, each of the monitored devices having various statuses thereof summarized as a summary status, and sending the summary status to the monitoring device when sending a response in reply to a summary-status collecting command issued from the monitoring device as well as when sending other information that is not the response, wherein the monitoring device controls the summary status of a given one of the monitored devices based on the summary status received from the given one of the monitored devices.
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 receiver having an array antenna estimates arrival directions of multiple paths that arrive with an angular spread. Consequently, arrival direction estimation accuracy can be ensured without increasing throughput even if the power every path is low by estimating an average arrival direction of an entire set of multiple paths having the angular spread from a result of one angular spectrum by multiple correlation operation units that perform mutual correlation operations with pilot signals for baseband signals received by the array antenna, a path detection unit that detects multiple arrival path receiving timings by generating a delay profile based on output of each of the correlation operation units, a path correlation value synthesis unit that synthesizes a correlation operation value calculated in the multiple correlation operation units and an arrival direction estimation unit that collectively estimates multiple path arrival directions using output of the path correlation value synthesis unit.
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:
A device for estimating a direction-of-arrival of a radio wave, the device comprising an array antenna including a plurality of antenna elements for receiving a high frequency signal, a demultiplexer for demultiplexing the received high frequency signal for each of the plurality of antenna elements to generate a plurality of frequency component signals and a direction estimating unit for estimating the direction-of-arrival of the radio wave by using two or more of the plurality of frequency component signals which are contiguous in a frequency direction.
摘要:
A transmission weight computing section computes a transmission weight for directional transmission using an OFDM signal. A transmission correcting value memory section stores one correcting value for correcting the transmission weight for each sub-carrier of an OFDM signal or each band gathering a plurality of sub-carriers. A transmission weight correcting section corrects the transmission weight by the correcting value. A transmitting branch weights transmission data by a transmission weight outputted from the transmission weight correcting section on a sub-carrier-by-sub-carrier basis and delivers it to an antenna.
摘要:
An adaptive antenna radio communication device comprises a divided band direction estimating unit (4) for estimating the direction by calculating the cross correlations between a pilot signal and sub-carrier signals of the respective divided bands received by an array antenna (1) and calculating a spatial profile from correlation matrices determined by combining the correlation values between antenna elements of the different sub-carriers according to the output of the cross correlation calculation; a divided band array weight creating unit (5) for creating a weight of a receive array having a directional beam in the direction of estimation for each divided band; and a sub-carrier directivity creating unit (6) for creating a directivity by multiplication-combining the created receive array weight with the corresponding sub-carrier signal.
摘要:
A receiver having an array antenna estimates arrival directions of multiple paths that arrive with an angular spread. Consequently, arrival direction estimation accuracy can be ensured without increasing throughput even if the power every path is low by estimating an average arrival direction of an entire set of multiple paths having the angular spread from a result of one angular spectrum by multiple correlation operation units that perform mutual correlation operations with pilot signals for baseband signals received by the array antenna, a path detection unit that detects multiple arrival path receiving timings by generating a delay profile based on output of each of the correlation operation units, a path correlation value synthesis unit that synthesizes a correlation operation value calculated in the multiple correlation operation units and an arrival direction estimation unit that collectively estimates multiple path arrival directions using output of the path correlation value synthesis unit.