Design And Verification Of Physical Layer Of Multi-Rate Frequency Hopping Wireless Communication Between Unmanned Aerial Vehicles

At present,with the large-scale application of unmanned aerial vehicles such as drones and unmanned airships,how to improve the effectiveness and reliability of communication between them has become a hot spot.Aiming at such application scenarios,this thesis designs a multi-rate ad hoc network physical layer that supports frequency hopping and spread spectrum.The main research contents are as follows:First,realize multi-rate data transmission of physical layer links to cope with changes in communication distance and channel environment.Under the 6.4MHz bandwidth,this thesis designs six physical layer links with different transmission rates,of which the lowest transmission rate is 0.945 Mbps and the highest is 12.945 Mbps.The traditional multi-rate implementation is that the two parties negotiate in advance which rate to use to complete the information transmission.The physical layer link designed in this thesis independently determines which rate to sample at the origin according to the channel characteristics,and the receiver can automatically identify and complete demodulation,which can reduce the overhead of negotiation.Second,it realizes the frequency hopping function of high hopping rate of physical layer links.Traditional frequency hopping needs to wait for a frame of data to be sent before hopping,but the physical layer long frame link designed in this thesis has 3 hops,which can be frequency hopping within the frame,and the frequency hopping rate is9000hop/s,that is,the time of each hop data is 110 us,which can be used for fast intelligent frequency selection,select better frequency points for work,and avoid interference encountered in communication.Third,the physical layer link of two communication channels of long and short frames is designed.Among them,the data transmission reliability of short frames is the highest,which can be used for network control and maintenance management,ensure the reliability of the network,and avoid the paralysis of the entire network communication.Long frames can be used for data transmission,and the most appropriate rate is selected from the lowest to the highest MCS for physical layer communication depending on the channel environment.Fourth,multi-channel spectrum sensing and reception functions are realized.Because the aerial electromagnetic environment is very complex,this thesis designs 8frequency hopping frequency points on the communication bandwidth of 56 MHz,and the communication situation of the 8 frequency hopping frequency points is detected at the same time at the end to select the best frequency hopping frequency point to work.The multi-rate hopping wireless communication physical layer designed in this thesis can adapt to a variety of different typical application scenarios,improve the effectiveness and reliability of the physical layer link,and have certain significance for the design of the physical layer link of wireless communication between unmanned aerial vehicles.