Abstract:
PURPOSE: A cooperative STBC-OFDM(Space-Time Block Coded-Orthogonal Frequency Division Multiplexing) signal relaying method, a receiving method, a relay device, a receiving device, and a transceiving system are provided to obtain a diversity gain without exchanging information between a source node and a relay node. CONSTITUTION: A receiving unit(910) receives a first transmission signal from a source node. A transmission unit(920) encodes a second transmission signal before a symbol section of a first transmission signal. The transmission unit transmits the encoded signal to a destination node. The destination node encodes signals received from the source node and a relay node by removing interference signals. [Reference numerals] (900) Relay device; (910) Receiving unit; (920) Transmission unit
Abstract:
개시된 기술은 직교 주파수 분할 다중 접속 시스템에서 채널을 추정하는 방법에 관한 것이다. 실시 예들 중에서, 수신기가 수신된 블록의 채널을 추정하는 방법은 수신된 블록에서, 동일한 OFDM 심볼 내의 파일럿 심볼에 대한 채널 주파수 응답 을 각각 산출하는 단계; 상기 산출된 채널 주파수 응답 를 기초로, 상기 파일럿 심볼이 존재하는 OFDM 심볼에 대한 채널 주파수 응답 을 각각 추정하는 단계; 파일럿 심볼이 위치하는 OFDM 심볼들에 대하여 각각 추정된 상기 채널 주파수 응답 간의 가중치 합(Weighted Sum) 연산을 통하여 상기 추정된 주파수 채널 응답 을 보정하는 단계; 및 상기 보정된 주파수 채널 응답에 시간 축으로 보간법 또는 보외법을 수행하여 블록 내 채널 주파수 응답 을 추정하는 단계를 포함한다.
Abstract:
PURPOSE: A method for estimating a doppler frequency and a receiver for estimating a doppler frequency for an OFDM(Orthogonal Frequency Division Multiplexing) system are provided to improve the performance of a receiver by offering an excellent performance for estimating a doppler frequency. CONSTITUTION: A method for estimating a doppler frequency through a receiver in an orthogonal frequency division multiplexing system includes a step in which a channel frequency response is estimated for a pilot symbol in a block received. The method for estimating the doppler frequency includes the step in which an average correlation value of the channel frequency response is calculated. The method for estimating the doppler frequency includes the step in which the average value of accumulated R1 is calculated for the block of Nacc. The method for estimating the doppler frequency includes the step in which the doppler frequency is calculated based on the average value of the R1 calculated.
Abstract:
PURPOSE: A P-SCH(Primary Synchronization CHannel) detection method and a receiver for the same are provided to minimize the deterioration of the P-SCH detection performance due to the correlation characteristic deterioration in a multi path fading environment. CONSTITUTION: A frequency offset estimator(110) comprises a linear phase rotation value estimating unit and phase rotation amount calculation unit. The frequency offset estimator estimates the phase rotation amount rotated by the frequency offset. A compensator(120) compensates according to the phase rotation value which is offered from the frequency offset estimator. A correlator(130) performs cross correlation based on the phase rotation value compensated received signal. A P-SCH detector(140) detects a P-SCH based on the output from the correlator.
Abstract:
PURPOSE: A method for estimating a channel and interference of a wireless communication system and a device thereof are provided to perform channel estimation and interference estimation by using a reference symbol of a received signal and a temporarily detected data symbol. CONSTITUTION: A detector detects a temporary data symbol in a received signal which the channel compensation and interference cancellation are performed. A channel estimator(380) presumes an initial channel by using a reference symbol of a received signal including a reference symbol and a data symbol. The channel estimator presumes a final channel by using the temporary data symbol. An interference estimator presumes an initial interference by using the reference symbol of a received signal including the reference symbol and the data symbol. The interference estimator presumes a final interference by using the presumed final channel and the temporary data symbol.
Abstract:
인말새트 통신의 하향 링크 수신기가 개시된다. 인말새트(INMARSAT) 통신의 하향 링크 수신기는 아날로그 수신신호를 디지털로 변환하여 디지털 신호 r(k)를 출력하는 에이디씨(Analog to Digital Converter); 디지털 신호 r(k)를 이용하여 제1 데이터를 복원하는 제1 인터폴레이터(interpolater); r(k)와, r(k-1)의 켤레 복소수를 곱하여 차동 신호를 생성하고, 차동신호의 파워를 이용하여 유니크 워드(Unique Word)의 유무를 판단하는 UW 검출기; 차동신호를 입력받아 제2 데이터를 복원하는 제2 인터폴레이터; 제2 데이터에서 시간상 오차를 검출하여 시차를 출력하는 시차 검출기; 시차에 따른 심볼 복원 중심 상수 및 심볼 복원 간격 상수를 출력하는 컨트롤러를 포함하되, 심볼 복원 중심 상수 및 심볼 복원 간격 상수는 제1 및 제2 인터폴레이터에 입력되는 것을 특징으로 한다. 본 발명에 따르면, 인말새트 Mini-m 시스템을 이용한 통신환경에서, 수신되는 수신신호로부터 신뢰성이 있도록 데이터 심볼을 샘플링한다는 장점이 있다. 인말새트, 하향 링크 수신기, 샘플링, 지터, 시차
Abstract:
A correlation apparatus for frequency synchronization in a broadband wireless access communication system and a correlation method thereof are provided to improve the frequency synchronization performance by performing the frequency synchronization according to the highest correlation value. A frequency synchronizing unit(300) includes a delay and conjugate complex processor(350) and a correlator(340). The delay and conjugate complex processor delays as much as the predetermined interval after the FFT(Fast Fourier Transform) and generates a first signal by multiplying the signal after the FFT(Fast Fourier Transform) processing by the conjugate complex processed reception signal. The correlation unit receives a first signal, a second signal, and a third signal, and obtains the highest correlation value by producing the differential correlation value about the first signal and third signal. The second signal is generated by multiplying the conjugate complex of the reference signal by the delayed signal based on the reference signal. The third signal is produced by the signal delaying the second signal by the conjugate complex signal. A frequency controller(330) performs the frequency synchronization according to the highest correlation value.
Abstract:
An apparatus and a method for compensation of estimation error are provided to improve spectrum leakage and noises by compensating for estimation error of a channel impulse response before selecting a valid channel impulse response. A initial channel estimation machine(403) estimates a primary channel. By performing IFFT calculation in the presumed primary channel value, An IFFT(Inverse Fast Fourier Transform) operator(404) estimates CIR(Channel Impulse Response). A maximum power route detection part(420) detects route has the maximum power reserve about presumed CIR. A CIR error compensation part(430) uses the CIR value and the CIR estimation error function of the maximum power route in order to compensate for the CIR estimation error about all routes.