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对于差分编码的系统,接收端可利用差分编码自身的结构来进行解调,无需知道信道状态信息。因此基于时间选择性衰落信道的基扩展模型,提出一种新型的应用于时间选择性衰落信道下多输入多输出系统的差分空时多普勒(DSTD)编码方案,由该方案组成的系统可以配备任意数目的发送和接收天线。该DSTD系统发送端由频谱编码器、差分编码器和OFDM调制器串联组成,能提供最大空间-多普勒分集增益和显著的编码增益。差分编码器中酉结构的引入可以实现线性空时分离的最大似然检测,降低了译码的复杂度。仿真分析表明与已有差分系统相比,文中所提出的差分编码方案可以获得更高的分集增益。
Abstract：Differential encoding is known to simplify receiver implementation because it by-passes channel estimation.Relying on a basis expansion model for time-selective channels,we derive a new differential space-time-doppler modulation scheme for systems that are equipped with an arbitrary number of transmit and receive antennas and operate in time-selective channels.The proposed DSTD modulator consists of a concatenating spectral encoder,differential encoder and OFDM modulator that offer full spatio-doppler diversity and significant coding gain.A unitary structure is imposed on the differential encoder to admit linear,decoupled maximum likelihood(ML) detection in space and time. Simulation results show that the proposed! DSTD codes achieve higher diversity gain in time-selective channels than some existing differential schemes.
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基本信息:
DOI：10.16441/j.cnki.hdxb.2008.02.030
中图分类号:TN911.2
引用信息:
[1]蔚娜,赵犁丰,杨莘元.时间选择性衰落信道下的差分空时多普勒编码[J].中国海洋大学学报(自然科学版),2008,No.161(02):331-334+302.DOI:10.16441/j.cnki.hdxb.2008.02.030.
基金信息:
国防基金(51401040703CB0102);; “十一五”预研项目(11001060404)资助
2008-03-15
2008-03-15