Abstract:
PURPOSE: A method for increasing an LLR(Log Likelihood Ratio) reliability based on a MIMO(Multi Input Multi Output) MMSE(Minimum Mean Square Error) receiver is provided to determine the LLR of a vector which does not satisfy the reciprocity as 0. CONSTITUTION: If an SINR(Signal and Interference and Noise Ratio) information about each existing stream is not available, the SINR is the same about the each stream, the LLR of an MMSE symbols which do not satisfy a reciprocity is determined as 0(204). Therefore, it is prevented that the LLR value of the high error probability is used for the channel encoding. If the SINR information of each stream is available, or the SINR of each stream is not same, the removed a priori item is calculated using the reciprocity information.
Abstract:
PURPOSE: A method for detecting a signal and a receiving device is provided to detect and decode the signal with low complexity at a receiving terminal of a communications system including a multiple input/ output antenna. CONSTITUTION: The distance of a receiving signal vector and a transmitting symbol vector is squared(S210). The square of distance is classified as a first component and a second component. A first component is minimized. A plural first soft symbol estimates are obtained(S220). The solution set of the first component is obtained(S230). A second component is minimized. A plurality of second soft symbols are obtained(S240). The solution set of the second component is obtained(S250). The solution set of the first component and solution set of the second component are combined. The final solution set is obtained(S260).
Abstract:
본 발명은 이동통신망에서 채널을 추정하는 방법 및 이를 수행하는 장치에 관한 것이다. 본 발명에 따르면, 직교주파수다중분할(Orthogonal Frequency Division Multiplexing: OFDM)방식을 사용하는 이동통신망에서 인접 기지국의 간섭이 존재하는 채널 환경하에 대한 채널 추정 방법에 관한 것이다. 채널 추정을 위하여 하나의 클러스터를 2개의 부-클러스터로 분리하고 OFDM 심볼 방향으로 하나 이상의 부-클러스터(Cluster) 내에 포함되어 있는 파일럿 부반송파 신호를 사용한다. 따라서, 단일 클러스터 내에 포함되어 있는 파일럿 부반송파를 사용하여 채널을 추정하는 방법에 비하여 성능을 향상시킬 수 있는 효과가 있다. 간섭(Interference), 채널 추정(Channel Estimaton)
Abstract:
본 발명은 로그우도비 산출 방법 및 송신 신호 검출 방법에 관한 것이다. 본 발명은 수신된 신호에 기초해 송신 심볼 후보 벡터를 검출하면, 임계치와 각 송신 심볼 후보 벡터에 대한 ML 메트릭을 산출하고, 임계치보다 큰 ML 메트릭은 임계치로 갱신한다. 그리고, 갱신된 ML 메트릭과 임계치를 이용하여 각 송신 신호 비트에 대한 로그우도비를 산출하고, 이를 이용하여 송신 신호를 검출한다. 송신 심볼 후보 벡터, 로그우도비, 유클리디언 거리, ML 메트릭
Abstract:
다중 송수신 시스템의 비트 우도비 계산 방법은, 채널을 추정하여 재정렬하고, 재정렬된 채널에 기초하여 복수의 레이어를 재정렬한다. 그리고, 재정렬된 채널과 재정렬된 복수의 레이어를 이용하여 송신 신호 후보군을 검출하며, 검출된 송신 신호 후보군을 이용하여 복수의 레이어의 각 비트에 대한 비트 우도비를 산출한다. 송신 신호 후보군, 비트 우도비, 성상점, 레이어, 유클리디언 거리
Abstract:
A method and an apparatus for dividing a receiving symbol signal modulated into a bit reflected gray code to bit information are provided to simplify the complexity of the division of the bit information inputted to an iterative decoder. A bit information dividing device includes a positive integer converting unit(130), a code determining unit(140) and an operation unit(150). The positive integer converting unit calculates the positive integer for the receiving symbol signal. The code determining unit determines the code of the receiving symbol signal. The operation unit converts the receiving symbol signal into the bit information by using the value of the receiving symbol signal, and the arrangement value of the bits and a coordinate axis movement value of the bit group.
Abstract:
본 발명은 시공간 블록코드를 이용하는 통신시스템의 비트단위 복호 로그 근사율 계산 방법 및 장치에 관한 것으로, 시공간 블록코드를 사용하는 통신시스템에서 다중경로 채널을 거쳐 수신된 신호에 대한 비트단위 복호를 위한 로그 근사율을 계산하는데 있어, 수신 신호의 영역판별을 위한 기준점을 생성하고, 보정된 수신 신호에 대한 잡음분산을 계산하고, 잡음분산을 이용하여 모드에 따른 가중치를 선택한 후에, 기준점과 가중치를 이용하여 로그 근사율을 계산함으로써, 최적의 성능을 유지하면서 복잡도를 최소화할 수 있다. 시공간 블록코드, 로그 근사율, STBC, LLR
Abstract:
A method and an apparatus for calculating an LLR(Log Likelihood Rate) in a communication system are provided to minimize complexity while maintaining an optimum performance in obtaining a decoding LLR. A channel estimator of a receiving unit estimates a channel with respect to signal distortion generated while passing through a multi-path channel(S210). A reference point calculator generates a reference point for discriminating a region of a reception signal by using the channel estimation result(S220). A space-time block code decoding unit corrects a signal received via the multi-path channel by using the channel estimation result(S230) and transfers the corrected signal to a noise distribution calculator and a QAM(Quadrature Amplitude Modulation) demapper. The noise distribution calculator calculates a noise distribution with respect to the signal inputted from the space-time block code decoding unit(S240) and inputs a corresponding result value to a weight value selector. The weight value selector selects weight values according to a QAM mode by using the noise distribution(S250). The QAM demapper calculates an LLR by using the selected weight values(S260).
Abstract:
A method and an apparatus for operating a WiBro(Wireless Broadband Internet) system channel decoder at high speed are provided to double decoding speed by installing a forward operation part and a reverse operation part in implementing a MAP decoder, the core block of a CTC(Convolutional Turbo Code) decoder, and executing decoding at both operation parts at the same time. A combining block(7) executes simple addition operation, without using division operation. A reverse symbol selector(8), a randomizer(11), and a CRC block(12) execute byte-unit operation. In calculating the probabilistic weight of a MAP decoder in a CTC decoder, forward state matric operation and reverse state matric operation are executed in parallel. Decoding time can be shortened by half by executing probabilistic weight operation from a time of N/2 after storing the results of forward state matric operation and reverse state matric operation in their respective memories.
Abstract:
A method and apparatus for forming smart antenna beam in a mobile communication base station using OFDM(Orthogonal Frequency Division Multiplexing) is provided to minimize influence of the noise and interference signals by forming a main beam in a direction of a required signal and a null in a direction of the interference signal. Plural received signals are processed to extract plural data sub-carrier matrixes allocated to an original signal which are required by a base station. A nominal angle is estimated for the plural received signal based on the data sub-carrier matrixes(S110). The original signal and an interference signal are distinguished from the received signals using the nominal angle(S130). A covariance matrix of the interference signal and noise is generated by using the nominal angle, and plural beam formation vectors for the signal are generated by using the covariance matrix(S140). One resultant beam is formed by combining plural beams(S160).