Research On Interference Suppression Technologies In Cognitive-Based Differential Frequency Hopping Network

The research on Differential Frequency Hopping (DFH) has been an active area in military and academic society since 1990s, when it revealed by U.S. Army. The performance of anti-jamming and anti-interception are favoring. In recent years, digital battlefield combat mode is shifted from a platform centric to network-centric. But DFH networking technology has been restricted by the poor performance of multiple accesses. Cognitive radio (CR) users can use the CR technology to sense the surrounding RF environment, search for available spectrum resources and access spectrum dynamically. This smart radio technology was recognized as the miracle drug to resolve the interference and spectrum resource depletion in futurity.This thesis addresses on Multiple Access Interference (MAI) and anti-jamming of the DFH network. According to the characteristics of DFH and CR technology, the CogDFH network architecture is proposed. Based on the Interference Temperature (IT) model, the IC-colorings of graphs and the Latin squares of applied mathematics, some novel algorithms are proposed.The contributions of this thesis include:1. The CogDFH network architecture:This thesis proposes the CogDFH transceiver. According to the trait of the military communications scenario, the CogDFH network architecture is proposed, and the MAC layer and link layer protocol are studied. Then simulations of the CogDFH network are performed.2. The spectrum sensing based frequency set adaptive optimization (FSAO) algorithm: In order to avoid Partial Band Jamming (PBJ) and Multi-Tone Jamming (MTJ), this thesis proposes the frequency set adaptive optimization (FSAO) algorithm. FSAO users can sense and get the clean frequencies information, then chose some of the frequencies for an adaptive frequency set.3. The IT model based multiple access (IC-ITMA) algorithm:A novel multiple access algorithm is proposed to restrain the MAI of DFH networks. This algorithm is based on the IT model, the IC-colorings and IC-indices of graphs. In short, the interference temperatures on the detection trellis at the receiving antenna, which are caused by the transmitters, are restricted and measured by the receiver. The transmitters can be distinguished by the dissimilar values of the interference temperatures. The maximal IC-coloring method is used to compute the predisposed value of each user's interference temperature.4. The frequency micro-sets dissimilar adaptive optimization algorithm:The Latin squares based frequency set adaptive optimization (LS-FSAO) algorithm is proposed. In short, the frequency set is divided into many frequency micro-sets after the spectrum sensing, and the micro-sets are assigned to DFH users with dynamic Latin squares. The users'frequency micro-sets are dissimilar during a same time slot to cut down the MAI. For a Large-scale CogDFH network, this thesis proposes a LS-FSAO aid IC-ITMA model, and it can obtain favorable network performance.