注：国家自然科学基金（No. 51974250）；国家自然科学基金（No. 41874158）；陕西省自然科学基础研究计划（No. 2018JQ5133）；陕西省教育厅重点实验室项目（No. 17JS106）

作者：徐飞，党博，王新亚，欧姗姗，毕凌志 

单位：西安石油大学，陕西西安 710065

中图分类号：TN914.31          

文献标识码：A            

文章编号：1006-883X(2020)01-0018-05

收稿日期：2019-12-05

 

摘要：针对井下声波传输数据速率低、误码率高等问题提出了基于AD9838的FSK调制信号系统。首先，井下温度传感器DS18B20采集井下温度数据，然后将这些温度数据发送给dsPIC主控制器。dsPIC通过十进制转二进制算法将这些数据转换成二进制数据，随后，通过内部定时器模块将这些二进制数据转换成八位的码元序列。最后，主程序外针对码元序列的值是1还是0对AD9838芯片写入不同的频率控制字，改变AD9838输出正弦波的频率，从而达成FSK调制。实验结果表明，相对于传统的硬件调制电路，该方法可有效降低传输误差，并具有结构小，易于切换调制频率等优点。

关键词：声波传输；dsPIC；AD9838；FSK调制

 

FSK-Modulated Signal System for Downhole Acoustic Transmission Based on AD9838

XU Fei, DANG Bo, WANG Xin-ya, OU Shan-shan, BI Ling-zhi

Xian Shiyou University, Xian 710065, China

Abstract: Aiming at the problems of low data rate and high bit error rate of downhole acoustic wave transmission, an FSK-modulated signal system based on AD9838 is proposed. Firstly, the downhole temperature sensor DS18B20 collects downhole temperature data and sends these data to the dsPIC main controller. Then, dsPIC converts these data into binary data with the decimal-to-binary algorithm and converts these binary data into an eight-bit symbol sequence with internal timer module. Finally, according to the value of the symbol sequence outside the main program, 1 or 0, different frequency control words are written into AD9838 to change the frequency of the sine wave output of the AD9838 to achieve FSK modulation. The experimental results show that this method can reduce the transmission error effectively compared with the traditional hardware modulation circuits, and has the advantages of small structure and easy to switch the modulation frequencies.

Key words: Acoustic transmission; dsPIC; AD9838; FSK modulation

 

 

备注：2020年 第26卷 第01期