遇险示位标是全球卫星搜救系统(COSPAS-SARSAT)的一个重要组成部分。目前遇险示位标大多是第一代窄带示位标,采用固定的调制变频架构,存在集成度低、功能单一、升级需要更换硬件电路等问题。针对这些问题,文中设计了一种基于ZYNQ7000+AD9361 软件定义无线电集成架构的第二代遇险信标示位标信号产生电路,其优点是信息内容、信号格式、发射参数可软件灵活定义。文中首先根据COSPAS-SARSAT 系统第二代遇险示位标信号的格式规范,设计了扩频、滤波、调制等信号处理流程,仿真验证了信号特性;然后,用ZYNQ7000+AD9361 软件定义无线电架构完成了PL 和PS 设计,实现了符合第二代COSPAS-SARSAT 示位标规范的发射信号;最后进行了测试,结果表明该设计方法符合设计要求,有效可行。该设计具有分立器件少、集成度很高、高度可编程性、可灵活实现示位标的在线维护升级和信号转换等优点。

Distress beacon is an important part of the global satellite search and rescue system (COSPAS-SARSAT). However, most of the distress beacons at present are first-generation narrowband beacons, which adopt fixed modulation frequency conversion architecture, and have defects of low integration, single function, hardware circuit replacement and so on. In order to solve these problems, based on ZYNQ7000+AD9361 software defined radio integrated architecture, a second-generation of distress beacon signal generating circuit is designed in this paper, with which the information content, signal format and transmission parameters can be flexibly defined by software. According to the format specification of the second-generation distress beacon signal of COSPASSARSAT system, signal processing processes such as spread spectrum, filtering and modulation are first designed in this paper, and signal characteristics are simulated and verified. Then, ZYNQ7000+AD9361 software define radio architecture is used to complete the PL and PS design, realizing the transmitting signal in accordance with the second-generation COSPAS-SARSAT beacon standard. Finally, the test results show that the design method effectively and feasibly meets the design requirements. The design has the advantages of few discrete devices, high integration, high programmability, and flexible realization of online maintenance and upgrading of beacon and signal conversion.

TN96

国家自然科学基金资助项目(U21A20450)