摘要:
Systems and methods for reducing overhead by using block acknowledgment with an all polling technique while attempting to meet latency and QoS requirements. Each node transmits a number of packets upon receiving a polling message. The Access Point (AP) then replies with a Block Acknowledgement (BlockAck), which is combined with a subsequent polling message and contains a bitmap that indicates 1 for a successfully received packet and 0 for a failed reception.
摘要:
To correct a sensor data acquisition time with a simple hardware configuration, provided is a wireless sensor-network system including: a base station; and a plurality of sensing terminal nodes, the base station transmitting a beacon at predetermined intervals to the plurality of sensing terminal nodes, the plurality of sensing terminal nodes measuring data and transmitting, based on a reception of the beacon transmitted from the base station, the sensor data thus obtained to the base station, in which the plurality of sensing terminal nodes obtain, based on an internal clock, a time at which the beacon is received and transmit the time to the base station, and the base station corrects, based on the reception time transmitted from each of the plurality of sensing terminal nodes, the sensor data acquisition time.
摘要:
The present invention conducts the initial synchronization acquisition of the rapid and high precision ultra-wideband signal without complicatedness of hardware and increase in power consumption. For this purpose, a communication apparatus for exchanging information with an intermittent pulse train signal searches all phases among the pulses in the predetermined search resolution in the process to acquire initial synchronization of the input pulse, estimates the region where the peak phase of the largest output value exists, narrows the region where the peak phase exists up to the predetermined range by repeating the search for all phases in the estimated region in the next step, and conducts acquisition of detailed synchronization in the estimated region. In every step, the threshold value for judging existence of signal or a gain in the analog circuit is controlled for each step. Moreover, the search resolution is set coarse for estimation of the peak phase and set fine for acquisition of detailed synchronization.
摘要:
With the objective of enhancing receiving performance of a receiver with respect to pulse signals spread by spread codes, the receiver comprises an RF front-end section which performs amplification, an AD converter section which AD-converts signals outputted from the RF front-end section, a baseband section which inversely spreads the output of the AD converter section and performs signal detection and demodulation thereon, a reception environment measuring section which measures reception environment using the input signals of the baseband section, and a parameter setting section which sets parameters for respective parts on the basis of signals outputted from the reception environment measuring section. The parameter setting section sets the parameters for the respective parts to the optimum according to the environmental condition measured by the reception environment measuring section.
摘要:
A pulse generator for UWB transmission, lower power consumption, and suppression of LO leakage by nonuse of the LO signal. The pulse generator includes a clock generator (CLK) for giving clock of a predetermined period; a delay circuit (DLY) equipped with a function of controlling a delay time and for delaying the clock; a square-wave pulse generation circuit (SWPG) that receives information being spread by a spread code and modulates phases of square wave pulses that have a pulse width corresponding to a differential delay for one stage of the delay circuit; and an amplitude control unit (AMPC) that outputs an impulse sequence having the pulse width of the square wave in a predetermined amplitude and combines the impulses; and outputs pulses that have a predetermined envelope form.
摘要:
A node location system for detecting a node by receiving two or more access points. The node location system includes a node, a reference station, multiple access points, a server, and a network. After receiving a location signal, the reference station sends a reference signal, and the access points receive a position measurement signal and a reference signal, and detects a specified pattern from the received location signal and reference signal, and measures the time from detecting the specified pattern from the location signal until detecting the time from the reference signal, and sends the signal-receive-time information including that measured time to the server, and the server calculates the difference between the time the reference station received the location signal and the time that the access points received the location signal, and then calculates the node position based on this calculated differential.
摘要:
An invention for estimating the first path of an arrival signal by a method and device with a simple structure and lower power consumption. In this method, the nominal pulse repetition frequency or its integer multiple are A/D converted at a frequency less than the multiplicative inverse of the pulse width, the AD conversion timing is offset by time resolution Δt and the receive signal measured, data stored in a RAM, and the first path output time is estimated based on sequentially rearranging of the stored waveform data.
摘要:
A node position measuring system according to this invention includes a node, a reference station, base stations, a server that calculates a position of the node, and a network. The reference station includes a positioning signal reception module and a reference signal generation module that transmits a reference signal after the positioning signal reception module receives the positioning signal. Each of the base stations includes a signal reception module, a reception time measuring module that detects specific patterns from the positioning signal and the reference signal received by the signal reception module to measure a detection time, and a communication module that transmits time information, which is generated from the time measured by the reception time measuring module, to the server. The server includes a position calculation module that calculates the position of the node based on the time information transmitted from the base station.
摘要:
The present invention conducts the initial synchronization acquisition of the rapid and high precision ultra-wideband signal without complicatedness of hardware and increase in power consumption. For this purpose, a communication apparatus for exchanging information with an intermittent pulse train signal searches all phases among the pulses in the predetermined search resolution in the process to acquire initial synchronization of the input pulse, estimates the region where the peak phase of the largest output value exists, narrows the region where the peak phase exists up to the predetermined range by repeating the search for all phases in the estimated region in the next step, and conducts acquisition of detailed synchronization in the estimated region. In every step, the threshold value for judging existence of signal or a gain in the analog circuit is controlled for each step. Moreover, the search resolution is set coarse for estimation of the peak phase and set fine for acquisition of detailed synchronization.
摘要:
An ultra-wideband transmitter is provided which can reduce a leak of a local signal into a transmitted signal with a pulse train output from an antenna in UWB-IR communication. The transmitter comprises a pulse generator 0140 for generating a pulse signal having a pulse train of pulses produced intermittently according to data to be transmitted, an oscillator 0120 for producing a local signal, a frequency converter 0130 to which the pulse signal output from the pulse generator and the local signal output from the oscillator are input, and for frequency-converting the pulse signal to output a RF signal, an amplifier 0110 for amplifying the RF signal output from the frequency converter, and an antenna 0000 for emitting the RF signal output from the amplifier in the air. In a period corresponding to a pause period of the pulses produced intermittently, a leak of the local signal into the RF signal output from the antenna is reduced using a control signal 0300.