OFDM is a modulation method which was often used in the channels. It has better capability against the fading and can realized paralleltransmission.
正交频分复用调制（OFDM）是一种信道利用率很高的调制方式，具有良好的抗衰落能力，可实现并行传送。
2
Transmission lines stretch parallel to the road and make it impossible to get lost.
输电线路平行着马路延伸，跟着输电线路走不会迷路。
3
In this paper, we propose a new multiple access control (MAC) protocol for underwater acoustic Ad hoc networks, namely, the paralleltransmission multiple access (PTMA) protocol.