The ubiquity of global navigation satellite system (GNSS)-based positioning and timing services is often frustrated by the necessity to operate in harsh environments, where the carrier-to-noise ratio is low, and hence, decoding of navigation data and even tracking of an acquired symbol are difficult. We consider the possibility of improving the decoding performance of the GNSS data component by trading the spreading gain against the coding rate. The rationale is that spreading codes can be seen as a form of repetition coding that can be (at least partially) replaced by more robust coding forms to improve robustness to (any form of) noise. This is true both for the classical additive white Gaussian noise channel case and for more realistic GNSS channel formats severely degraded by multiple access interference and near-far effects. By bringing results on finite-block-length channel capacity and coding rates from information/communication theory to the GNSS domain, we are able to establish and discuss the expected performance gap, as well as the limits of such tradeoff.

中文翻译：

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用编码率交换扩频增益及其在GNSS数据组件设计中的应用

无处不在的基于全球导航卫星系统 (GNSS) 的定位和授时服务常常因需要在恶劣的环境中运行而受挫，在这些环境中，载噪比很低，因此需要对导航数据进行解码甚至跟踪获得的符号是困难的。我们考虑了通过将扩展增益与编码率进行交换来提高 GNSS 数据组件解码性能的可能性。基本原理是扩频码可以被视为一种重复编码形式，可以（至少部分）由更稳健的编码形式替代，以提高对（任何形式的）噪声的稳健性。这对于经典的加性高斯白噪声信道情况和因多址干扰和远近效应严重降级的更现实的 GNSS 信道格式都是正确的。