Electronics and Telecommunications Research Institute

Dong Han Lee

Jong Suk Chae

Won Kyu Choi

Gil Young Choi

Chan Won Park

Ji Hoon Bae

Kwang Soo Cho

Man Sik Park

Cheng Hao Quan

Hyun Jae Lee

Hee Sang Chung

Han Hyub Lee

Won Kyoung Lee

Sun Hyok Chang

Moo Jung Chu

Yong Bae Lee

Provided is a symbol synchronization apparatus and method of a passive RFID reader. The symbol synchronization apparatus includes: an edge clock detector generating edge clocks by detecting phase inversion positions of a received signal; a preamble detector detecting a preamble section by analyzing the generation times of the edge clocks; a symbol decision time extractor extracting a symbol decision time by averaging distances between the edge clocks consecutively generated in the preamble section, when the preamble section is detected; and a symbol decider deciding a symbol by analyzing the magnitude of the received signal, when the time reaches the symbol decision time.

Symbol synchronization apparatus and method of passive RFID reader

Disclosed are a passive RFID (Radio Frequency Identification) system and method capable of recognizing a great deal of tags at a high speed. A reader of a passive RFID system, including: a processor dividing slots and subchannels to configure a round, recognizing subchannels that are not involved in a collision and interference by the slots, and changing the subchannels that are not involved in a collision and interference, into a sleep state; a transmission unit encoding a command generated through the processor, performing an amplitude jitter modulation on the encoded command, and transmitting the modulated command; and a reception unit acquiring and demodulating tag signals received through a plurality of subchannels by the slots, and providing the demodulated tag signals to the processor.

Passive RFID system and method

The present invention provides an apparatus and method for compensating for the variation of a gain spectrum attributable to the temperature variation of a fiber amplifier, and a long-wavelength band dispersion-compensating hybrid amplifier equipped with the gain spectrum compensating apparatus. The apparatus includes a DCF located between a first amplification stage and a second amplification stage to compensate for dispersion of an optical signal output from the first amplification stage and perform Raman amplification of the optical signal using input pumping light; at least one pumping light provision means for providing forward or backward pumping light to the DCF; first and second temperature detection means for detecting temperature variations of the first and second amplification stages, respectively; and control means for controlling intensity of the pumping light of the pumping light provision means according to the detected temperature variations.

Apparatus and method for gain-spectrum-tilt compensation in long-wavelength band dispersion-compensating hybrid fiber amplifier

Growing community of inventors

Daejeon, South Korea

Dong Han Lee