Space-time diversity systems based on linear constellation precoding
Space-time diversity systems based on linear constellation precoding
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DOI：
10.1109/twc.2003.808970
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发表时间：
2003-03
期刊：
影响因子：
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通讯作者：
Yan Xin;Zhengdao Wang;G. Giannakis
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文献类型：
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作者：
Yan Xin;Zhengdao Wang;G. Giannakis
我们提出了一个统一的方法来设计空时（ST）分组码使用线性星座预编码（LCP）。我们的设计是基于酉矩阵的参数化，或代数数论的建设。利用任意数量的N/sub t/发射天线和N/sub r/接收天线，ST-LCP在（可能相关的）准静态和快衰落信道上实现速率1符号/s/Hz并且享有高达N/sub t/N/sub r/的分集增益。作为品质因数，我们使用多样性和编码增益，以及底层多输入多输出系统的互信息。我们表明，在正交幅度调制和脉冲幅度调制，我们的LCP实现的上界的编码增益的所有线性预编码器的某些值的N/子t/和接近这个上界的其他值的N/子t/，在相关和独立的衰落信道。与现有的ST块码坚持正交设计（ST OD）相比，ST LCP提供不仅更好的性能，而且更高的互信息N/sub t/>2。对于解码ST-LCP，我们采用近最佳球解码算法，以及降低复杂度的次优替代品。尽管ST-OD码提供了更简单的解码，但当N/sub t/、N/sub r/或系统的频谱效率增加时，性能和速率与复杂度之间的权衡有利于ST-LCP码。模拟证实了我们的理论发现。
We present a unified approach to designing space-time (ST) block codes using linear constellation precoding (LCP). Our designs are based either on parameterizations of unitary matrices, or on algebraic number-theoretic constructions. With an arbitrary number of N/sub t/ transmit- and N/sub r/ receive-antennas, ST-LCP achieves rate 1 symbol/s/Hz and enjoys diversity gain as high as N/sub t/N/sub r/ over (possibly correlated) quasi-static and fast fading channels. As figures of merit, we use diversity and coding gains, as well as mutual information of the underlying multiple-input-multiple-output system. We show that over quadrature-amplitude modulation and pulse-amplitude modulation, our LCP achieves the upper bound on the coding gain of all linear precoders for certain values of N/sub t/ and comes close to this upper bound for other values of N/sub t/, in both correlated and independent fading channels. Compared with existing ST block codes adhering to an orthogonal design (ST-OD), ST-LCP offers not only better performance, but also higher mutual information for N/sub t/>2. For decoding ST-LCP, we adopt the near-optimum sphere-decoding algorithm, as well as reduced-complexity suboptimum alternatives. Although ST-OD codes afford simpler decoding, the tradeoff between performance and rate versus complexity favors the ST-LCP codes when N/sub t/, N/sub r/, or the spectral efficiency of the system increase. Simulations corroborate our theoretical findings.