Every year more interest is focused on high frequencies (HF) communications for remote sensing platforms due to their capacity to establish links of more than 250 km without a line of sight and due to them being a low-cost alternative to satellite communications. In this article, we study the ionospheric ordinary and extraordinary waves to improve the applications of near vertical incidence skywave (NVIS) on a single input multiple output (SIMO) configuration. To obtain the results, we established a link of 95 km to test the diversity combining of ordinary and extraordinary waves by using selection combining (SC) and equal-gain combining (EGC) on a remote sensing platform. The testbench is based on digital modulation transmissions with power transmission between 3 and 100 W. The results show us the main energy per bit to noise spectral density ratio (E_b/N₀) and the bit error rate (BER) differences between ordinary and extraordinary waves, SC, and EGC. To conclude, diversity techniques show us a decrease of the power transmission need, allowing for the use of compact antennas and increasing battery autonomy. Furthermore, we present three different improvement options for NVIS SIMO remote sensing platforms depending on the requirements of bitrate, power consumption, and efficiency of communication.

中文翻译：

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强大的NVIS遥感平台的电离层极化技术

每年，由于其能够建立250公里以上的视线而无视线，并且由于它们是卫星通信的低成本替代品，因此遥感平台的高频（HF）通信越来越受到关注。在本文中，我们研究了电离层的寻常波和非寻常波，以改善单输入多输出（SIMO）配置上近垂直入射天波（NVIS）的应用。为了获得结果，我们建立了一个95 km的链路，通过在遥感平台上使用选择组合（SC）和等增益组合（EGC）来测试普通波和非常规波的分集组合。测试平台基于数字调制传输，功率传输在3到100 W之间。_b / N ₀）以及普通波和异常波，SC和EGC之间的误码率（BER）差异。总而言之，分集技术向我们展示了电力传输需求的减少，从而允许使用紧凑型天线并增加了电池自主性。此外，根据比特率，功耗和通信效率的要求，我们为NVIS SIMO遥感平台提供了三种不同的改进选项。