Abstract:
PURPOSE: A direct conversion receiving device of a wireless mobile communication system is provided to remove a variable DC offset value caused when a strong interference signal is inputted to a receiving band and is induced to an LO(Local Oscillator) input, thereby preventing system performance deterioration. CONSTITUTION: An RF signal inputted to an antenna end(601) passes through an LNA(Low Noise Amplifier)(602) and an RF receiving band filter(603), and is mixed with a signal of an LO(605) by an I/Q mixer(604), then becomes an I/Q analog baseband signal. The analog baseband signal passing through a baseband low pass filter(606) produces a DC offset. A DC offset value is amplified by a baseband variable gain amplifier(608). The baseband analog signal passes through an ADC(612), is compared with plus/minus values of a symbol, and a difference between the signal and the values is applied to a DPRAM(614). The DPRAM(614) outputs a digital value corresponding to the difference. An output value of the DPRAM(614) is converted into a DC value through a DAC(615). An addition/subtraction unit(607) subtracts the DC value from an initial DC offset value to remove the DC offset value.
Abstract:
PURPOSE: A passive RFID reader digital demodulating device for a manchester subcarrier signal and a method thereof are provided to efficiently demodulate a tag signal even though the tag signal with a baseband end receives a DC offset noise. CONSTITUTION: A subcarrier digital demodulator(410) eliminates a square pulse of a first half period from a symbol of a tag signal. The subcarrier digital demodulator eliminates a sub carrier cycle within a second half period. A DC offset eliminator(420) eliminates a DC offset distortion noise from the tag signal using a matching filter.
Abstract:
PURPOSE: A receiving sense improving apparatus of an RFID reader and an apparatus thereof are provided to easily output a tag response signal and to prevent transmission leakage signal from an input signal. CONSTITUTION: A branch unit(402) branches off an input signal into a first signal and a second signal. A first processing unit(403) changes the phase of the first signal. A second processing unit(406) extracts a transmission leakage signal from the second signal. A controlling unit(410) outputs a tag response signal from the input signal by using the extracted transmission leakage signal.
Abstract:
PURPOSE: A mobile RFID(Radio Frequency IDentification) device and a data communication method thereof are provided to reduce the errors of a command or response received and transmitted between a mobile communication terminal unit and an RFID reader. CONSTITUTION: A mobile communication terminal(111) provides a command, and an mRFID(mobile RFID) reader unit(112) provides the mobile communication terminal with the response for the command provided from the mobile communication terminal. The mobile communication terminal and the mRFID reader unit respectively include a CRC circuit for inspecting whether or not there is an error in a protocol message of the command or response. The mobile communication terminal unit retransmits the command to the mRFID reader unit according to the inspection result.
Abstract:
PURPOSE: An RFID reader demodulation device and a method thereof are provided to perform coherent detection from DC offset noise-removed tag signal, thereby improving the reliability in demodulation of a tag signal, even if offset distortion noise is generated in the receives tag signal. CONSTITUTION: An RFID(Radio Frequency Identification System) reader demodulation device(100) comprises a DC(Direct Current) offset removal unit(102), a carrier removal unit(103), and a phase recover(104). The DC offset removal unit removes DC offset distortion noises of the received tag signal. The carrier removal unit removes a carrier signal in the output signal of the DC offset removal unit. The phase recover detects the phase information in the output signal of the carrier removal unit for the coherent detection.
Abstract:
시간 구간을 이용한 송신 누설 신호 제거 방법 및 장치를 개시한다. 본 발명의 실시예에 따른 시간 구간을 이용한 송신 누설 신호 제거 방법은, 태그로 송신되는 송신 신호로부터 송신 신호 관련 정보를 검출하여 인지하는 단계; 상기 송신 신호 관련 정보에 기초하여, 수신 경로로 유입되는 수신 신호로부터 상기 송신 신호만이 존재하는 시간 구간을 식별하는 단계; 및 상기 식별된 시간 구간에 존재하는 상기 송신 신호를 제거하는 단계를 포함한다. RFID, 송신 누설 신호 제거, 기저대역, 등화기, 시간 구간
Abstract:
PURPOSE: An apparatus and a method for suppressing a transmission leakage signal and an rfid reader including the apparatus are provided to suppress a transmission leakage signal, thereby improving isolation of a transceiving signal. CONSTITUTION: The first power splitter(101) outputs the first transmission signal and the second transmission signal. The second power splitter(102) outputs the third transmission signal and fourth transmission signal. An amplitude/phase detector(103) detects a difference value of the amplitude and phase of a receiving signal. An amplitude/phase controller(104) changes the amplitude and phase of the third transmission signal. A power combiner(105) suppresses a transmission leakage signal included in the receiving signal.
Abstract:
본 발명은 RFID(Radio Frequency Identification) 리더 동기화 장치 및 그 방법에 관한 것이다. 본 발명에서는, 먼저 전체 주파수 대역을 한 채널당 일정 크기를 갖는 적어도 하나의 대역폭으로 분리한 후, 분리된 각 대역폭을 토대로 하는 주파수 채널 중, 서로 인접하는 주파수 채널이 소정 크기의 이격 거리를 각각 갖는 추출 기준을 토대로, 적어도 하나의 주파수 채널을 추출한다. 그리고, 추출된 주파수 채널을 그룹화하여 각 클러스터(Cluster)로 할당한다. 이때, 클러스터에는 할당 받은 주파수 채널의 개수에 따라 적어도 하나의 리더가 배치된다. 이후, 클러스터 내 리더는 할당 받은 주파수 채널의 사용 유무를 파악하는 신호인 비컨(Beacon) 신호를 자신과 같은 클러스터 내 배치된 다른 리더로 전송하며, 그에 따라 미 사용 중인 주파수 채널을 검색한다. 그리고, 검색된 주파수 채널을 통해 물품에 부착된 태그를 인식한다. 이를 통해, 좁은 공간에 다수의 리더가 배치되는 멀티 리더의 환경 속에서, 리더간의 전파 간섭이나 충돌을 최소화할 수 있다. 무선 인식(RFID), 클러스터(CLUSTER), 리더(READER), 비컨(BEACON) 신호
Abstract:
A channel zone production method and a tag identifying method for using a channel zone in a radio frequency identifying for forming a channel zone sharing the channel selected by an arbitration reader are provided to improve the recognition rate of the RFID tag by identifying the tag through a plurality of the channel zone. One of a plurality of channels is selected by a reader(S101). The reader determines the presence of a channel zone sharing the selected channel according to predetermined sync signal(S103). In case the channel zone exists, it determines the reader is in the channel zone(S107). In case it is classified into the channel zone, the channel zone is formed with the arbitration reader for the channel zone(S109).