摘要
由于水下信道的复杂性,可靠的水声通信非常困难。传统的方法采用非相干调制方式及基于能量的符号检测,可以获得可靠的通信,缺点是频谱效率低导致通信速率低。近十多年来,相干调制由于频谱效率高,逐步成为研究的焦点。相干调制对符号检测技术提出了更高的要求。迭代检测能极大提高性能,尤其是在信噪比低的环境下可以获得远好于传统非迭代检测的性能,因此探索其在水下通信中的可行性具有重要的意义。本文介绍了采用迭代检测技术的水声通信系统,通过试验数据展示了迭代检测带来的性能增益。
Underwater acoustic channels are very challenging, and it is difficult to achieve reliable communications. A conventional way to improve reliability is to adopt the non-coherent modulations and the energy-based symbol detection. The non-coherent modulations, however, has a low spectrum efficiency and limits the transmission rate. In the past ten years, spectrum-efficient coherent modulations are attracting more research attentions. A system employing the coherent modulations, however, demands for more advanced symbol detection techniques. Turbo detection significantly improves the system performance, especially at low signal-to-noise ratio(SNR) scenarios. Therefore, it is important to investigate its feasibility in underwater acoustic communications. In this paper, a system adopting the turbo detection technique is presented, and experimental results demonstrate the performance gain of the turbo detection.
引文
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