LOG LIKELIHOOD RATIO DETECTION METHOD, TRANSMIT SIGNAL DETECTION METHOD AND RECEIVER

摘要

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.