Research On Technologies Of Radar Communication Integration Based On Software Radio

With the rapid development of electronic technology, combat platform is facing more and more threat. The platform has to be equipped with a variety of electronic equipments, such as radar and communication devices, to improve the survival ability and the comprehensive operational capability. However, the increasement of electronic equipments will not only bring more energy and space requirements, but also cause the decline of platform’s mobility. An effective way to solve these problems is to share the hardware of the system as much as possible, namely, to achieve integration. Another research focus is Software Radio technology, software programming to achieve the radio system, which not only effectively improves the reusability of the radio system, but also greatly reduces the system’s space requirements. It will be of great significance if communication function can be loaded into the radar system on combat platform based on the Software Radio technology.This paper explores the key technologies of radar-communication integration with Software Radio technology with the background of high-speed mobile platform and the foundation of Universal Software Radio Peripheral(USRP). The system is designed and verified through USRP platform.Firstly, the feasibility for USRP platform to communicate in radar mode is discussed based on the realization mechanism of radar and communication system; The method of USRP platform working in radar mode is obtained through deep research on the upper computer and USRP platform, and the actual verification is carried out with GNU Radio software platform. Secondly, this paper disscusses the key technologies of radar-communication integration, studying carrier and timing synchronization of the system emphatically. To achieve carrier synchronization, the reasearch is focused on the double order differential method. As to the timing synchronization, the structure of the polyphase filter bank is analyzed, and the maximum likelihood timing error estimation algorithm is applied to the structure. Then implementation and simulation in GNU Radio are conducted respectively on carrier and timing sunchronization. The sequence of carrier synchronization and timing synchronization is disscussed when applied in radar-communication system, and synchronization scheme of “FLL+ Maximum likelihood timing synchronization+Double-order differential carrier synchronization” is determined through theoretical derivation and simulation results comparison. Finally, the design and verification of the integrated system are carried out. The integration system is divided into three modules: radar-mode hardware front end, software transceiver and baseband communication system. Through the research of the software radio platform, the hardware front end adopts the automatic control mode; The sofeware reansceiver uses Python built-in timer, switching between the sending and receiving state; Communication function of the integrated system is designed in GNU Radio, in which the MAC layer and the physical layer of the system are designed in the perspective of transmitter and receiver. The BER performance and the data packet transmission performance of the system are measured based on the USRP hardware platform.The final results show that the system designed can realize communicating in the way of radar, and still have a certain ability to communicate in the presence of a certain carrier frequency/phase offset and timing offset.