The Research On Intelligent Anti-jamming Decision Technology Of NC-OFDM System

NC-OFDM(Non-Contiguous Orthogonal Frequency Division Multiplexing) is a highly efficient multi-carrier modulation technology which has a good anti-jamming performance by selecting the sub-band without interference to transmit data in interference environment.This paper apply the artificial intelligence techniques in communication system. Mainly study two types of intelligent decisions engine, one is rule-based and the other is genetic algorithm And we verify system performance under various typical interference environments.Our contributions are summarized as follows:The first part consist of the second chapter. In this part, we present the basic theories of two classes of decision algorithms, including optimization algorithms and learning algorithms. Pros and cons of each algorithms are analyzed, which provide a theoretical basis for the design of intelligent anti-jamming decision engine.The second part includes the third and fourth chapters. In the third chapter, at first, we design the rule-based intelligent anti-jamming decision engine. And focuses on two intelligent anti-jamming decision algorithms: adaptive modulation and coding algorithm based on the difference of two neighboring SNR(Signal to Noise Ratio) and packet error rate algorithm and cognitive interference based ASBS(Adaptive Sub-Band Selection) algorithm. We implement the algorithms in the NC-OFDM system, the simulation results shows that the AMC we proposed is better than traditional methods, as in a typical fading channel environment it can guarantee the bit error rate performance under the premise of effectively improve system capacity; ASBS algorithm has strong anti-interference ability in a typical environment.In the fourth chapter, We implement the rule-based intelligent anti-jamming decision engine in the NC-OFDM system and verify its anti-jamming performance under various typical jamming environments. The jamming include partial-band noise jamming, spot jamming, comb jamming, pulse jamming and swept frequency jamming. The simulation results show that: the NC-OFDM system which uses rule-based intelligent anti-jamming decision engine can intelligently adapt to the changing channel environment to get low BER(Bit Error Rate) and high data rate.The third part is the fifth chapter which studies anti-jamming performance of genetic algorithm(Genetic Algorithm, GA) based intelligent anti-jamming decision engine in NC-OFDM system analysis. Firstly, the GA-based decision engine framework and optimization decision unit within the decision engine is introducted; then analyze and make a choice of the decision unit parameter; at last, the performance of the decision engine based on GA and adaptive genetic algorithm(Adaptive Genetic Algorithm, AGA) is analyzed. Simulation results show: that GA and AGA-based intelligent decision engine has the same efficiency, they all can effectively improve system capacity; at the same bit error rate requirements, the information transfer rate is slightly higher than rules-based decision engine, but needs some advance knowledge and more training channel information.