Gao Shuyi, Xie Sheng, Feng Renhai, Chen Rui, Zhang Qijia, She Meiqi
Appl Opt. 2024 Feb 20;63(6):1546-1552. doi: 10.1364/AO.511302.
Underwater wireless optical communication (UWOC) has attracted considerable interest owing to its capability of high data rates and low latency. As a crucial component of UWOC, the transmission characteristics of an underwater channel directly impact the system's performance metrics. However, the existing channel models cannot exactly capture the underwater channel states, thus degrading the observability of channel states. This paper proposes a hybrid-field channel model containing both far-field and near-field path components, in which the signal-dependent shot noise (SDSN) is incorporated as well to accurately describe the underwater channel behavior. Then an improved orthogonal matching pursuit (I-OMP) algorithm that estimates the far-field and near-field path components independently with different transform matrices is developed to obtain the underwater channel state. The performance analyses show that I-OMP can improve the estimation accuracy of underwater channels by iteratively minimizing the mean square error (MSE) and utilizing two different transform matrices, demonstrating the advantage of the proposed I-OMP over the existing methods.
水下无线光通信（UWOC）因其高数据速率和低延迟的能力而引起了广泛关注。作为UWOC的关键组成部分，水下信道的传输特性直接影响系统的性能指标。然而，现有的信道模型无法准确捕捉水下信道状态，从而降低了信道状态的可观测性。本文提出了一种包含远场和近场路径分量的混合场信道模型，其中还纳入了信号相关散粒噪声（SDSN）以准确描述水下信道行为。然后，开发了一种改进的正交匹配追踪（I-OMP）算法，该算法使用不同的变换矩阵独立估计远场和近场路径分量，以获得水下信道状态。性能分析表明，I-OMP可以通过迭代最小化均方误差（MSE）并利用两个不同的变换矩阵来提高水下信道的估计精度，证明了所提出的I-OMP相对于现有方法的优势。
