In this article, three novel systems for wireless sensor networks based on Alamouti decoding were investigated and then compared, which are Alamouti space–time block coding multiple-input single-output/multiple-input multiple-output multicarrier modulation (MCM) system, extended orthogonal space–time block coding multiple-input single-output MCM system, and multiple-input multiple-output system. Moreover, the proposed work is applied over multiple-input multiple-output systems rather than the conventional single-antenna orthogonal chirp division multiplexing systems, based on the discrete fractional cosine transform orthogonal chirp division multiplexing system to mitigate the effect of frequency-selective and time-varying channels, using low-complexity equalizers, specifically by ignoring the intercarrier interference coming from faraway subcarriers and using the LSMR iteration algorithm to decrease the equalization complexity, mainly with long orthogonal chirp division multiplexing symbols, such as the TV symbols. The block diagrams for the proposed systems are provided to simplify the theoretical analysis by making it easier to follow. Simulation results confirm that the proposed multiple-input multiple-output and multiple-input single-output orthogonal chirp division multiplexing systems outperform the conventional multiple-input multiple-output and multiple-input single-output orthogonal frequency division multiplexing systems. Finally, the results show that orthogonal chirp division multiplexing exhibited a better channel energy behavior than classical orthogonal frequency division multiplexing, thus improving the system performance and allowing the system to decrease the equalization complexity.

中文翻译：

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无线传感器网络中双色散信道下的MIMO-OFDM/OCDM低复杂度均衡

在本文中，研究并比较了三种基于 Alamouti 解码的无线传感器网络新系统，它们是 Alamouti 时空块编码多输入单输出/多输入多输出多载波调制 (MCM) 系统，扩展正交空时分组编码多输入单输出MCM系统和多输入多输出系统。此外，所提出的工作适用于多输入多输出系统，而不是传统的单天线正交线性调频分复用系统，基于离散分数余弦变换正交线性调频分复用系统，以减轻频率选择和时间的影响。 - 使用低复杂度均衡器改变频道，具体通过忽略来自较远子载波的载波间干扰，采用LSMR迭代算法来降低均衡复杂度，主要采用长正交chirp分复用符号，如TV符号。提供了所提议系统的框图，以通过使其更易于遵循来简化理论分析。仿真结果证实，所提出的多输入多输出和多输入单输出正交啁啾分复用系统优于传统的多输入多输出和多输入单输出正交频分复用系统。最后，结果表明正交线性调频分复用比经典正交频分复用表现出更好的信道能量特性，