论文标题
用于水下声学通信的自适应多源MCDM
Adaptive Multiuser MCDM for Underwater Acoustic Communications
论文作者
论文摘要
CHIRP信号已在雷达和水下声学（UW-A）通信系统中广泛利用，以使其对多径和上相关性能的稳健性。我们提出了多级多载波Chirp-Division多路复用（MU-MCDM）系统，该系统正交CHIRP扩展频谱用于多源应用程序的频率子载波中。此外，开发了正交的CHIRP变换（OCT）和离散的正交CHIRP变换（DOUD），以连续和离散的MCDM系统实现。此外，我们设计了能够同步，通道估计和符号检测的最大可能性（ML）接收器。 MU-MCDM系统考虑了因素，包括序言长度，子载体数量，一部分飞行员，后卫期间和多用户访问方案，以适应时间变化的UW-A通道。在模拟研究中评估了比特率率（BER）性能和自适应传播。因此，我们在模拟中展示了MCDM调制系统，它们可以自适应地提高UW-A通信的性能并支持多个用户。此外，可以在高阶调制中应用MCDM架构，以在UW-A通道中提供更高的传输速率。
Chirp signals have been exploited extensively in radar and underwater acoustic (UW-A) communication systems for their robustness to multipath and superior correlation properties. We present a multiuser multicarrier chirp-division multiplexing (MU-MCDM) system which orthogonal chirp spread spectrum are utilized in frequency subcarriers for multiuser applications. Furthermore, orthogonal chirp transform (OCT) and discrete orthogonal chirp transform (DOCT) are developed for continuous and discrete implementations of MCDM systems. In addition, we design a maximum likelihood (ML) receiver capable of synchronization, channel estimation, and symbol detection. MU-MCDM systems consider factors, including preamble length, number of subcarriers, portion of pilots, guard period, and multiuser access scenarios to adapt time-variant UW-A channels. The bit-error-rate (BER) performance and adaptive transmission are evaluated in simulation studies. Therefore, we have demonstrated MCDM modulation systems in simulations that they improve performance of UW-A communications adaptively and support multiple users. Moreover, MCDM architectures can be applied in higher order modulations for providing higher transmission rates in UW-A channels.
