水声MIMO信道模型和容量分析

On the Model and Capacity of MIMO Underwater Acoustic Channels (UWACs)

水声通信系统对数据率的更高要求提出了水声信道容量限的问题。信息理论的研究表明,采用多输入多输出(MIMO)结构具有改善信道容量的潜力。文章对MIMO水声信道模型及信道容量进行了研究。借助于瑞利衰落统计模型和射线模型,建立了时变的MIMO水声信道模型,分析了多径时延以及发射、接收阵元数对时变水声信道容量的影响。文中还基于湖试信道测量数据,给出了信道的功率延迟线和不同信道的中断容量结果。仿真和测量的结果表明,相比单输入单输出(SISO)信道,MIMO水声信道可以获得明显的容量改善;而且相比平坦衰落信道,多径MIMO水声信道可以获得更大的容量增益。

The growing need for higher data rates poses the problem of capacity limit of UWACs.Past research has demonstrated a potentially huge gain of capacity in multiple input multiple output（MIMO） systems.In order to realize a part of this huge gain,we deal with the model of MIMO UWACs and the capacity of MIMO UWACs;sections 1,2,and 3 explain our method for realizing an obvious gain.Sections 1 and 2 brief respectively the model and capacity of MIMO channel.The core of section 3 is that,introducing a physically motivated Rayleigh fading MIMO UWAC model,it gives Tables 1 and 2 that give the values of the channel parameters needed in numerical simulation.Section 4 applies our method to the numerical simulation of the capacities respectively of two specific channels;it studies the influence of physical parameters such as multipath spread and system parameters such as the number of sensors for both ergodic capacity and outage capacity;Figs.1 and 2 give the results of numerical simulation.Section 5 describes the lake channel measurements;the power delay curves are given in Fig.3 and outage capacity results in Fig.4 from these measurements are discussed for different channels.Numerical and lake measurement results demonstrate preliminarily that obvious capacity gain can be obtained from MIMO UWACs compared with single input single output（SISO） UWACs,and in the MIMO case,delay spread channels may provide advantages over flat fading channels.