Abstract:
A log likelihood ratio calculating method, a transmission signal detecting method and a receiver are provided to detect a transmission signal by using the log likelihood ratio calculating method which has lower complexity and excellent performance in an MIMO(Multiple Input Multiple Output) system using the SM(Spatial Multiplexing) method. A signal processing unit(110) performs the scrambling, error correcting coding and interleaving for transmission data, and then outputs the processed data. A symbol mapping unit(120) converts the transmission data signal-processed by the signal processing unit into high-speed symbols, and then outputs the converted results. A de-multiplexer(130) divides the high-speed symbols into four low-speed layers, outputs the divided results, and then transmits the four outputted low-speed layers through each transmission antenna, at the same time. A channel estimating and layer sorting unit(210) perform the channel estimation and re-arranges/outputs layers and channels. A candidate group setting unit(220) determines transmission symbol candidate vectors by using the re-arranged layers and channels. An LLR calculation unit(230) produces soft decision values of each bit of a plurality of layers. A multiplexer(240) and signal processing unit(250) perform the inverse functions of the de-multiplexer and signal processing unit of a transmitter(100), execute the channel decoding by using the produced soft decision values, and then detect transmission signals.
Abstract:
A method for detecting a space-time code in a mobile communication system is provided to detect a space-time code B for plural transmission antennas using a newly defined ML matrix and perform two dependent sphere decoding of the newly defined ML matrix, thereby reducing the amount of matrix operation. A method for detecting a space-time code in a mobile communication system comprises the following steps of: receiving signals from the nr number of receiving antennas; determining whether channels from transmission antennas 3,4 are better than the conditions of channels from transmission antennas 1,2; performing Cholesky decomposition for acquiring the F of an ML(Maximum Likelihood) matrix generated for performing sphere decoding; detecting x3 and x4 using two dependent sphere decoders; detecting x1 and x2 using a single symbol detection method; performing the Cholesky decomposition when the channels from the transmission antennas 1,2 are better than the conditions of the channels from the transmission antennas 3,4; detecting the x1 and the x2 using the two sphere decoders previously; detecting the x3 and the x4 using the single symbol detection method; and updating the radiuses of the sphere decoders if the x1, the x2, the x3, and the x4 are all detected.
Abstract:
인지무선및 다중무선접속시스템에서의단말은복수의주파수대역중 제1 주파수대역으로부터수신신호검출을수행하고, 상기제1 주파수대역으로부터수신신호가존재하는경우에, 상기수신신호를저장하면서상기수신신호의종류를확인하며, 상기복수의주파수대역중 제2 주파수대역으로부터수신신호검출을수행한다. 그리고상기수신신호의종류를확인하는동시에상기복수의주파수대역중 제2 주파수대역에대해수신신호검출을수행한다.
Abstract:
The present invention relates to an apparatus for measuring the carrier frequency offset of OFDM signals transmitted and received through a plurality of multi-polarized antennas and a method for measuring the carrier frequency offset thereof, which accurately measure the carrier frequency offset used for carrier frequency synchronization acquisition when there is interference between polarized waves.
Abstract:
PURPOSE: A multicast signal demodulation apparatus and method thereof are provided to demodulate a multicast signal which is received from a terminal in order to obtain macro diversity effect. CONSTITUTION: A synchronization module(410) confirms whether a signal that a plurality of base stations transmits is received to a terminal. The synchronization module recognizes the starting time point of the signals that are transmitted to a plurality of base stations. A control module(420) selects a demodulation section based on the starting time of the signals. A demodulation module(430) demodulates a multicast signal which the received signal includes.
Abstract:
PURPOSE: An operating parameter change system of a BS and a method thereof are provided to transmit a communication signal with an MS with a separate arbitrary operating parameter in the handover process of the BS. CONSTITUTION: In case the handover of an MS(Mobile Station) is required, a BS(Base Station) assigns user data(A1,B1) to temporary areas(30,50). The MS receives a service through a first operating parameter. The user data are allocated to the MS. The temporary area receives a service through a temporary operating parameter. In case the handover of the MS is completed, the BS assigns the allocated user data to unicast areas(20,40).
Abstract:
PURPOSE: A signal detecting device and method thereof using a block data analysis decomposition are provided to conveniently detect an active signal in a poor communication environment which has poor SNR and SINR. CONSTITUTION: An extracting unit(130) extracts a main eigen vector having relatively large eigen value among eigen vectors of matrix. The matrix obtains a matrix decomposition algorithm by applying the algorithm. A correlation value calculation unit(150) calculates correlation between a pre-stored main eigen vector including the characteristic information of a carrier signal and standards matrices.
Abstract:
무선 통신 시스템의 모뎀을 시험하는 장치는 시뮬레이터 및 시험 보드를 포함한다. 여기서 시뮬레이터는 상기 모뎀을 시험하기 위한 가상 환경을 설정하여, 가상 환경에 따른 적어도 하나의 제어 신호를 생성한다. 그리고 시험 보드는 적어도 하나의 제어 신호에 따라 모뎀이 수신하는 신호 형태의 복수의 제1 수신신호를 모뎀으로 출력하고, 모뎀이 송신하는 신호 형태의 복수의 제1 송신신호를 모뎀으로부터 수신한다. 여기서 복수의 제1 수신신호는 복수의 안테나에 의한 복수의 채널에 각각 대응하는 신호이고, 복수의 제1 송신신호는 복수의 채널에 각각 대응하는 신호이다. 또한, 시험 보드는 무선 신호 처리부를 포함하며, 무선 신호 처리부는 적어도 하나의 제어 신호에 따라, 복수의 안테나가 각각 수신하는 신호 형태의 복수의 제2 수신신호를 복수의 채널로부터 각각 수신하고, 복수의 안테나가 각각 송신하는 신호 형태의 복수의 제2 송신신호를 상기 복수의 채널로 각각 출력한다. 모뎀, 기지국, 단말기, 송신, 수신, 시험장치, 시뮬레이터
Abstract:
본 발명은 OFDMA(Orthogonal Frequency Division Multiple Access) 시스템에서의 RF(Radio Frequency) 중계기 사용을 위한 동기 확보 방법에 대한 것으로, 기지국으로부터 기지국 신호를 수신하고, 상기 기지국 신호에서 프리앰블을 제거하고, 상기 프리앰블이 제거된 기지국 신호를 상기 단말기로 전송한다. 직교 주파수 분할 다중, RF 중계기, 동기 확보