1.The principal of wavelet denoising is introduced and the replicability of GPS multipath effect in dynamic environment is discussed firstly.

1.介小波滤波去噪的原理并讨论动态环境下GPS多路径效应的重复性问。

2.OFDM (Orthogonal Frequency Division Multiplexing) is a method that can combat multipaths, fully use the frequency band and has high data rate, and has a promising future in UWA communication.

2.摘要正交频分复用(OFDM)技术具有抗多径、频带利用充分、传输数据率高的，水声通信中具有重要的发展前景。