摘要:
Provided is a Media Access Control (MAC) forwarding method for multi-hop routing in a communication system between vehicles. The method includes the steps of: a) receiving a frame from all nodes and checking whether there are duplicate frames; b) partly updating forwarding cache table (FCT) information, or updating SNT information and checking whether a destination address is a corresponding node; c) updating the FCT information, transmitting an Ack signal and transferring the frame to the upper layer, or searching whether the destination address is registered as “d_addr”; d) updating the FCT information and transmitting a delay ACK frame or checking whether the transmitted frame is a flooding frame; and e) updating the FCT information, checking whether the other node does not transmit the “d_ack” and inserting a flooding frame, otherwise, updating the FCT information and abandoning the frame.
摘要:
Provided are a tag signal receiving apparatus that can perform digital Amplitude Shift Keying (ASK) demodulation onto signals received in a tag, decode the demodulated tag signal in synchronization, and acquire tag data in a mobile RFID reader, and a method thereof. The tag signal receiving apparatus includes: a digital demodulating block for performing ASK demodulation onto a digital tag signal received through a reader antenna and converted into a digital tag signal in an analog-to-digital (AD) converter; and a decoding block for detecting edge position information of the demodulated tag signal by performing accumulation and decoding the demodulated tag signal by using the detected edge position information. The digital demodulating block includes a channel level comparator, a phase inverter, a signal converter; and an adder. The decoding block includes an edge information detector, a correlator, and a bit data decider.
摘要:
The present invention provides a microstrip patch antenna and array antenna using dielectric superstrate in order to enhance the antenna gain by stacking radiating patches and dielectric layers. The microstrip patch antenna using a dielectric superstrate for having high gain and wide bandwidth, includes: a lower patch antenna layer having a dielectric layer and a ground plane for radiating energy by exciting current by a feedline; a upper patch antenna layer having dielectric film electromagnetically coupled by the lower radiating patch; a foam layer for distancing the upper patch antenna layer from the lower patch antenna layer; and a dielectric superstrate located by being predeteremined distant from the upper patch antenna layer.
摘要:
A radio frequency identification (RFID) smart shelf system manages a product through communication with an RFID tag that is attached to the product on a shelf, and includes an RFID reader, a plurality of reader antennas, and an RF switch that is connected between the RFID reader and the plurality of reader antennas. The RF switch periodically varies a phase difference between RF signals of a portion of a plurality of output connection ports that set a connection to each of the plurality of reader antennas.
摘要:
A time synchronization method in a wireless sensor network, a low power routing method using a reservation scheme, and an apparatus for performing the method are provided. The time synchronization method in the wireless sensor network may include: receiving a first synchronization request command packet from a parent node that manages time synchronization for a predetermined synchronization region; receiving, from the parent node, a second synchronization request command packet that has a transmission timestamp value of the first synchronization request command packet; and performing time synchronization for a child node based on a reception time of the first synchronization request command packet, a reception time of the second synchronization request command packet, and the transmission timestamp value of the first synchronization request command packet.
摘要:
Provided are an RFID reader and a method for controlling a gain thereof. The RFID reader includes an amplifier and an AGC circuit. The amplifier controls the gain of an RX signal, received from an RFID tag, in response to an AGC signal. The AGC circuit measures a signal level in an ante-preamble period of the RX signal and generates an AGC signal to control the gain of the RX signal, on the basis of the measured signal level.
摘要:
Provided are a sensor node included in a sensor network, an update server updating the sensor node, and a method of updating a sensor node. The update server updating a sensor node included in a sensor network includes an execution code manager managing execution codes for a plurality of sensor nodes included in the sensor network, a rule generator generating an update rule based on a result of comparing an existing execution code managed by the execution code manager with an update execution code required for a new function update of the sensor node, and a downloader causing the sensor node to download the update rule generated by the rule generator. Accordingly, an execution code can be updated by a small amount of data transmission.
摘要:
Provided are an RFID reader and a method for suppressing transmission leakage signals thereof. The RFID reader includes a first loop, a second loop, and a digital signal processor. The first loop suppresses a first transmission leakage signal of an RX signal in response to a first leakage control signal. The second loop suppresses a second transmission leakage signal of the RX signal, received through the first loop, in response to a second leakage control signal. The digital signal processor generates the first leakage control signal and the second leakage control signal. The digital signal processor generates the first leakage control signal until the level of the first transmission leakage signal becomes equal to or lower than the level of a first reference transmission leakage signal.
摘要:
Disclosed is a synchronization method between a reader and tag according to an example embodiment, the method including: transmitting, by the reader, a first write command message to the tag at a first time; detecting, by the tag, the first write command message from the reader at a second time and transmitting a first response message to the reader in response to the first write message; transmitting, by the reader, a second write command message including first time information of the first time to the tag; and correcting, by the tag, a clock offset using a difference between the first time and the second time.
摘要:
Provided is a power amplifier sharing system for a mobile communication system having a mobile Radio Frequency Identification (RFID) function, particularly, a power amplifier sharing system that can reduce the power consumption and the size of a circuit in a mobile communication terminal having a mobile RFID function. The system includes a mobile communication transceiver for transmitting/receiving a mobile communication signal; a mobile RFID transceiver for transmitting/receiving a mobile RFID signal; a power amplifier for amplifying a signal; a switch for connecting the mobile communication transceiver and the mobile RFID transceiver to the power amplifier; and a transceiver controller for controlling the switch and the power amplifier.