【摘要】 将平坦衰落信道的对角代数空时码(ＤＡＳＴ)推广到频率选择性衰落信道,提出了对角空频分组码(ＤＳＦ)。基于多输入多输出天线和正交频分复用(ＯＦＤＭ),ＤＳＦ码将满秩的旋转信号星座和子载波分组结合起来,以对角发送方式(每时刻只有一个天线发射)发射旋转信息符号向量的每个分量。成对错误概率分析表明:在频率选择性信道中,通过选择最佳的旋转矩阵,这种ＤＳＦ ＯＦＤＭ系统能实现满分集增益和最大的编码增益。系统采用了球型解码器对ＤＳＦ码实施最大似然解码,它的解码复杂性是中等的,并且,解码算法的复杂性与信号星座的维数无关。码复杂性是中等的,并且,解码算法的复杂性与信号星座的维数无关。此外,和先前所提出的一些方法相比,提出的空频码还具有频谱效率高的性能特点。更多还原

【Abstract】 This paper generalize diagonal algebraic space time block codes over flat fading channel to frequency selective fading channel and proposes a diagonal space frequency(DSF) block codes. Based on multiple input and multiple output together with orthogonal frequency division multiplexing(OFDM), the DSF codes are constructed by the combination of rotated constellations having full modulation diversity and subchannel grouping. The system send the components of a rotated version of the information symbol vector over N T transmit antennas in diagonal form(only one antenna transmits at any given time) . By analyzing the pairwise error probability(PEP), we prove that the DSF OFDM system can achieve full diversity gain and maximum coding gains over frequency selective fading channel by choosing optimum rotation matrix .The Maximum likelihood(ML) decoding of the proposed codes can be implemented by the sphere decoder at a moderate complexity and the complexity of the decoding algorithm is independent of signal constellation size. Compared with previous schemes,moreover,using the proposed space frequency code yields better performances with high spectral efficiency.更多还原