徐 硕1 ，王 宇 1，沈丹丹2，黄其泉1
（1中国水产科学研究院渔业工程研究所，中国水产科学研究院渔业信息工程研究中心，
中国水产科学研究院渔业信息工程功能实验室，北京 100141；
2.上海海洋大学信息学院，上海 201306）

摘要：针对超短波信道快衰落、远近效应、多径效应等特点，针对现有渔船超短波通信系统噪声高、通信距离下降的问题，提出一种适用于渔船超短波通信系统的前端功率控制算法：利用双chirp前导信号实现发送端信号功率控制和接收端自动增益控制，先通过一次检测chirp波相关峰值，获得信道的增益初估计，反馈调整AD前端的自动增益放大器，使信号达到合适的处理增益；通过检测第二个chirp波相关峰值，获得第二次增益估计；最后通过AR模型实现增益的精确估计与调整。仿真结果表明，该算法对接收端可以实现40 dB以上的增益调整，发送端可以节省30%以上的功耗。该算法的应用，可以降低超短波信道的背景噪声，改善渔业超短波信道环境，网络性能可得到提高。

关键词：渔船；chirp信号；信道增益；自动功率控制；超短波通信

Algorithm for transmission power control based on chirp signal
XU Shuo1，WANG Yu 1，SHEN Dandan2，HUANG Qiquan1
1 Institute of Fisheries Engineering of Chinese Academy of Fishery Sciences, Fisheries Information Engineering Research Center of Chinese Academy of Fishery Sciences, Fisheries Information Engineering Functional Lab of Chinese Academy of Fishery Sciences, Beijing 100141, China
2 College of Information, Shanghai Ocean University, Shanghai 201306, China ）

Abstract: There are some unfavorable characteristics for ultrashort wave channel, such as high noise, fast fading, near-far effect and multipath effect. This paper proposed a front-end power control algorithm which could used in fishing vessel to improve the reliability of ultrashort wave communication. Based on dual chirp preamble signal, the algorithm realized the signal power estimate and automatic gain control. Through the detection of first chirp signal, the system could obtain channel’s preliminary estimate and then feedback and adjust the automatic gain amplifier of front-end AD, so as to make the gain meet the processing needs. By receiving second chirp wave, the system regulated the gain again to complete automatic gain control accurately. Basing on AR model, the algorithm could improve gain control of above 40dB and save more than 30% power of transmitting terminal. This algorithm can achieve the goals of fine performance in SNR, reliable transmission and the whole performance of the network.

Key word: fishing vessel; chirp signal; channel gain; automatic gain control; UW communication