摘要:
Disclosed is a wireless signal receiving apparatus, and more particularly, disclosed is a parallel automatic frequency offset estimation apparatus and method for tracking a frequency offset in an early stage by calculating, in parallel, frequency offsets of a received signal. The parallel automatic frequency offset estimation apparatus includes a receiving unit to receive a data frame; and a frequency offset estimation unit to calculate, in parallel, frequency and phase deviations at different bit intervals within a particular section of the received data frame, to add together the frequency and phase deviations to obtain a first sum of the frequency and phase deviations, and to add the first sum to a frequency phase deviation calculated for each bit after the particular section in the received data frame to obtain a second sum of the frequency and phase deviations. Accordingly, transmission frequency tracking can be performed at higher speed, compared to the conventional systems in which frequency offset acquisition is carried out in stages. Also, accurate tracking of a transmission frequency is possible in an initial frame.
摘要:
An active radio frequency identification (RFID) apparatus having an additional transmitter in addition to a single transmitter is provided. The active RFID apparatus includes a first transmitter including a first pseudo noise (PN) code generator to generate a direct sequence spread spectrum (DSSS) introduced by ISO/IEC (International Organization for Standardization/International Electrotechnical Commission) 24730-2 or ISO/IEC 18185-5 type B; and a second transmitter including a second PN code generator to perform an AND operation on an initial value and a fed back value and shift the resultant value of the AND operation, to perform an XOR operation on particular bits from among the shifted bits and to perform an XOR operation again on the shifted bits and the resulting value of the XOR operation to finally generate a PN code. Accordingly, where an additional PN code is added besides an existing PN code, a PN code having excellent auto correlation characteristics allowing discrimination of the PN code itself and cross-correlation characteristics providing a code discrimination ability with respect to another code can be generated.
摘要:
A method of storing sensor data in a sensor tag is provided. The method comprises receiving new sensor data output from a sensor, comparing the received new sensor data with immediately previous sensor data to determine whether the comparison result satisfies a predetermined criterion, and storing the new sensor data in a tag memory when it is determined that the criterion is satisfied. Accordingly, efficient use of the tag memory is possible.
摘要:
The present invention relates to an antenna for an RFID tag chip. The antenna includes a dielectric material, a radiating patch that scatters a signal from the RFID tag chip for transmitting the scattered signal, and microstrip lines having a terminal for the RFID tag chip. Accordingly, a small antenna that can be attached to metal can be realized.
摘要:
Disclosed is a Radio Frequency Identification (RFID) tag antenna. The tag antenna includes a lower dielectric substrate and an upper dielectric substrate. The lower dielectric substrate is provided at a lower surface thereof with a ground plane and at an upper surface thereof with two microstrip lines. The microstrip lines each have an open-end, the open ends spaced apart from each other from a middle of the lower dielectric substrate while facing each other to form a radiating slot from which radiation of electromagnetic waves occurs. The upper dielectric substrate is provided at an upper surface thereof with at least one electric capacitive device and is stacked on the lower dielectric substrate. The RFID tag antenna enhances radiation efficiency while achieving miniaturization.
摘要:
An antenna for an RFID tag having an RFID tag chip includes a dielectric material, a radiating patch radiating a signal from the RFID tag chip, and a feed line supplying power to the RIFD tag chip through magnetic-coupling with the radiating patch. Accordingly, a small antenna that can be attached to metal can be realized.
摘要:
Disclosed are a sensor node having a self localization function and a self localization method of the sensor node. The sensor node calculates a location thereof by receiving location information measured at each of two mobile nodes at different times and using four location information of the received location information. Additional cost and power consumption required for installing additional equipment such as an anchor node, a ultrasonic transceiver and a signal amplifier are reduced.
摘要:
Disclosed are a sensor node having a self localization function and a self localization method of the sensor node. The sensor node calculates a location thereof by receiving location information measured at each of two mobile nodes at different times and using four location information of the received location information. Additional cost and power consumption required for installing additional equipment such as an anchor node, a ultrasonic transceiver and a signal amplifier are reduced.
摘要:
A large data transmission method in a sensor network based on a media access control (MAC) is provided. The method includes dividing data to be transferred into a plurality of data segments; generating a plurality of media access control (MAC) segmented data frames by including in each data segment an indication that the data is generated by segmentation and assigning a sequence number to the data segment; transmitting the generated MAC segmented data frames sequentially; receiving a MAC reception failure frame indicating reception failure for a predetermined period of time from a receiving sensor node after completing the transmitting of all the MAC segmented data frames; and retransmitting the MAC segmented data frames which correspond to at least one sequence number included in the received MAC reception failure frame. Accordingly, large data transmission times can be reduced in a MAC for a sensor network.
摘要:
Disclosed is a Radio Frequency Identification (RFID) tag antenna. The tag antenna includes a lower dielectric substrate and an upper dielectric substrate. The lower dielectric substrate is provided at a lower surface thereof with a ground plane and at an upper surface thereof with two microstrip lines. The microstrip lines each have an open-end, the open ends spaced apart from each other from a middle of the lower dielectric substrate while facing each other to form a radiating slot from which radiation of electromagnetic waves occurs. The upper dielectric substrate is provided at an upper surface thereof with at least one electric capacitive device and is stacked on the lower dielectric substrate. The RFID tag antenna enhances radiation efficiency while achieving miniaturization.