The Design Of Low Probability Of Interception Communication Waveform

In modern warfare, the invisibility performance is the key factor of aircrafts’ survival and defense penetration ability. To fulfill the need of Low Probability of Interception (LPI) and anti-jamming performance for battle field communication, a good LPI performance for the communication system becomes the primary condition of achieving victory. LPI communication technology has become a hot topic of contemporary military communication technologies and is getting more and more attention.Firstly, this thesis introduces the background, development and current research situation of LPI communication waveform design. The basic concepts and methods of evaluating LPI communication waveform performance are introduced.Secondly, this thesis studies the performance of each part of the waveform. The performance of channel coding technology is analyzed first. The simulation result indicates that m-ary Low Density Parity Check (LDPC) code has a better anti-jamming capability. Then the performance of different modulation schemes is analyzed, and an adaptive modulation scheme is proposed. An adaptive modulation adjusts the modulation scheme based on the feedback channel. The performance of Direct Sequence Spread Spectrum (DSSS) is also analyzed. The simulation result indicates that the LPI and anti-jamming performance can be improved by enlarging the spread factor. Then the sequence and anti-jamming performance of Frequency Hopping technology is analyzed. The simulation results indicate that Frequency Hopping system has a very good performance against wideband interference. For stalk jamming and interception, improving hop rate can effectively avoid the stalk.Thirdly, a whole solution of LPI communication waveform design is determined based on the research:A combination of n-ary LDPC code, adaptive modulation scheme, DSSS and fast rate Frequency Hopping of wide interval.At last, a graphic simulation platform based on Matlab is developed. The platform can run real time simulation, generate FH code, show simulation results.