Improvement of time-reversal communications using adaptive channel equalizers
Improvement of time-reversal communications using adaptive channel equalizers
复制标题
DOI：
10.1109/joe.2006.876139
复制
发表时间：
2006-04-01
影响因子：
4.1
通讯作者：
Akal, T.
中科院分区：
文献类型：
--
作者：
Song, H. C.;Hodgkiss, W. S.;Akal, T.
时间反转方法的空间和时间聚焦特性可用于海底声学通信。空间聚焦减轻了信道衰落，并在预期接收器处产生高信噪比（SNR）沿着在其他地方被拦截的低概率。虽然时间聚焦（压缩）显著地减少了符号间干扰（ISI），但是取决于发射机的数量、它们的空间分布（空间分集）和信道的复杂性，总是存在一些残余ISI。此外，在双向传播间隔上的环境中的轻微变化引入附加ISI。在浅海环境下，采用多级正交幅度调制（M-QAM），通过级联接收到的时间序列和自适应信道均衡器来消除残留的码间干扰，可以显著提高时间反转通信的性能。
The spatial and temporal focusing properties of time-reversal methods can be exploited for undersea acoustic communications. Spatial focusing mitigates channel fading and produces a high signal-to-noise ratio (SNR) at the intended receivers along with a low probability of interception elsewhere. While temporal focusing (compression) reduces significantly intersymbol interference (ISI), there always is some residual ISI depending upon the number of transmitters, their spatial distribution (spatial diversity), and the complexity of the channel. Moreover, a slight change in the environment over the two-way propagation interval introduces additional ISI. Using multilevel quadrature amplitude modulation (M-QAM) in shallow water, we demonstrate that the performance of time-reversal communications can be improved significantly by cascading the received time series with an adaptive channel equalizer to remove the residual ISI.