Differential Space-Time Coding Dispensing With Channel Estimation Approaches the Performance of Its Coherent Counterpart in the Open-Loop Massive MIMO-OFDM Downlink
Differential Space-Time Coding Dispensing With Channel Estimation Approaches the Performance of Its Coherent Counterpart in the Open-Loop Massive MIMO-OFDM Downlink
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DOI：
10.1109/tcomm.2018.2867528
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发表时间：
2018-08
影响因子：
8.3
通讯作者：
Naoki Ishikawa;R. Rajashekar;Chao Xu;S. Sugiura;L. Hanzo
中科院分区：
文献类型：
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作者：
Naoki Ishikawa;R. Rajashekar;Chao Xu;S. Sugiura;L. Hanzo
在本文中，我们提出了一个简单而强大的映射方案，将任何传统的基于平方矩阵的差分空时编码（DSTC）到一个非基于平方矩阵的DSTC。这使得DSTC方案可以实际用于开环大规模多输入多输出场景。我们提出的方案可以被视为差分对应的相干空间调制（SM），广义SM，贝尔实验室分层空时架构，和子载波索引调制。现有的DSTC方案的根本障碍是由酉约束施加的过度复杂性。具体地，传统DSTC方案的传输速率随着发射天线的数量增加而衰减。我们提出的方案消除了这个障碍，从而实现了显着更高的传输速率。我们介绍了四种新的构造方法的非方形码字，其中一些包括一个任意数量的非零元素在每个码字列。我们的分析表明，所提出的编码技术降低了傅里叶逆变换和检测过程的复杂性。我们所提出的方案被证明接近其相干对应的低移动性的情况下，发射天线的数量增加到256的性能。
In this paper, we propose a simple yet powerful mapping scheme that converts any conventional square-matrix-based differential space-time coding (DSTC) into a nonsquare-matrix-based DSTC. This allows DSTC schemes to be used practically in open-loop large-scale multiple-input multiple-output scenarios. Our proposed scheme may be viewed as the differential counterpart of coherent spatial modulation (SM), of the generalized SM, of Bell Laboratories layered space-time architecture, and of subcarrier-index modulation. The fundamental impediment of the existing DSTC schemes is the excessive complexity imposed by the unitary constraint. Specifically, the transmission rate of conventional DSTC schemes decays as the number of transmit antennas increases. Our proposed scheme eliminates this impediment and thus achieves a significantly higher transmission rate. We introduce four novel construction methods for the nonsquare codewords, some of which include an arbitrary number of nonzero elements in each codeword column. Our analysis shows that the proposed encoding technique reduces the complexity of both the inverse Fourier transform and the detection processes. Our proposed scheme is shown to approach the performance of its coherent counterpart for low-mobility scenarios, where the number of transmit antennas is increased up to 256.