摘要： 为提高空时编码传输效率,提出一种在X 信道中为每个用户配置2 根天线的改进空时编码传输方案。每个用户采用全速率全分集空时分组码,将每个码字的部分元素旋转适当的角度,并且对每个码字进行两层预编码。通过一层预编码使得每个接收端的非期望接收码字对齐,在每个码字中引入零向量以及接收端的线性运算,消除每个接收端的非期望接收码字。通过另一层预编码使得每个接收端的期望接收码字正交传输,从而
消除多用户干扰。仿真结果显示,与相同场景中已有空时编码传输方案相比,该方案能有效提高传输效率,且可靠性较优。
关键词:
X 信道,
空时分组码,
预编码,
多用户干扰,
传输效率,
全分集
Abstract: An improved space-time coding transmission scheme is proposed in X channel with two antennas at each user.
Each user employs full-rate full-diversity space-time block code. Part elements of each codeword are rotated by a certain angle and each codeword is pre-coded twice. One-level pre-coding aligns the unwanted codewords at each receiver. The unwanted codewords for each receiver are eliminated by the introduction of zero vector at each codeword and the linear operation at the receivers. The wanted codewords keeps orthogonal by the other pre-coding,thus the multi-user interference is cancelled. The transmission efficiency is improved compared with the existing space-time coding transmission for the same scene. Simulation results show that,with the same transmission rate,the transmission efficiency of the proposed scheme it can improve transmission efficiency,and has high reliability in same transmission rate.
Key words:
X channel,
space-time block code,
pre-coding,
multi-user interference,
transmission efficiency,
full diversity
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