公开(公告)号：US07315576B1

公开(公告)日：2008-01-01

申请号：US10376060

申请日：2003-02-26

申请人： Didier Johannes Richard van Nee ,  Vincent Knowles Jones, IV ,  Geert Arnout Awater ,  James Gardner

发明人： Didier Johannes Richard van Nee ,  Vincent Knowles Jones, IV ,  Geert Arnout Awater ,  James Gardner

IPC分类号： H04L27/00 ,  H04L27/28 ,  H04L27/06 ,  H04B7/02

CPC分类号： H04L27/2032 ,  H04L25/03006 ,  H04L25/067 ,  H04L2025/03414 ,  H04L2025/03426

摘要： A soft symbol decoder for use in a multiple input multiple output (MIMO) and OFDM (orthogonal frequency division multiplexing) system. The decoder generates soft symbol values for a digital signal that represents a number of source bits. The source bits are transmitted as symbols in corresponding to points in a signaling constellation. Soft metrics are determined by searching for all possible multi-dimensional symbols that could have been transmitted. The method includes transmitting a sample of the multi-dimensional symbol using K transmit antennas. The multi-dimensional symbol is represent-able as a complex, K-dimensional vector x. Each vector component of vector x represents a signal transmitted with one of the K transmit antennas. After transmission through a communication channel, a sample corresponding to the transmitted sample is received. The received sample is represented by a complex, N-dimensional vector y, where N is the number of receive antennas in the MIMO system. After the sample is received, a soft metric L(bi) is determined for each bit bi encoded by x according to the equation: L ⁡ ( b i ) = σ - 2 · ( min x j ⁢  b i = - 1  ⁢  y - Hx j  2 - min x j ⁢  b i = + 1  ⁢  y - Hx j  2 ) , and xj represents all possible values for x. In addition, a reduced complexity method is used for providing soft metric values in the MIMO system. This exemplary aspect reduces the complexity of the above computations from 2BK to 2B(K−1), where B is the number of bits transmitted per symbol per antenna.