Research On Anti-jamming Capacity Domain Of Multi-antenna Relay Network Based On Energy Harvesting

The wireless relay network is widely used in the communication field since it can increase the network coverage area.Traditional transmission methods can no longer meet the maximum achievable capacity of wireless multi-hop networks.Besides,network coding can reprocess information at relay nodes,thereby shortening the transmission time slot and making the network capacity achievable.Therefore,compared with traditional transmission methods,it is more suitable for information transmission in wireless relay networks.Moreover,a large number of nodes carry limited energy because networks are assigned different tasks,which limits the network lifetime.Additionally,the recovery of this energy is difficult and easily pollutes the environment.With the advent of green communication,energy harvesting technology has been applied as an emerging technology that can harvest energy from the surrounding environment to supplement energy and extend the network life cycle.Also,the shared nature of the wireless network makes it vulnerable to attack,and beamforming as one of the key technologies of antenna arrays can achieve the purpose of anti-jamming by changing the phase and make the transmission direction targeted.Thus,combining the above technologies in the wireless relay network will get a better network performance gain.Based on the above techniques,this paper conducts research based on dual-hops wireless relay networks,focusing on the solution of converting the non-convex optimization problem to the convex optimization problem,characterizing the rate-energy domain,and verifying the model’s anti-jamming ability.In the process of transforming from a non-convex problem to a convex problem,it is proved that the optimization problem with five constraints proposed in this paper satisfies the rank-1 decomposition,which provides a basis for the application of semi-definite relaxation.The main work of this paper can be summarized as follows:In the first part,based on analog network coding and the beamforming technology,we established the system of the dual-hop energy harvesting multi-antenna relay network.Then,analyze its information transmission process,give the model constraints and build a mathematical optimization model that maximizes the SINR based on the conditions.Observing the optimization model,we can see that the problem is non-convex,and the relay transmission process is a matrix model.Generally,the inner product of the matrix has strict requirements on the dimension of the matrix.The inner product will increase the final dimensionality.Besides,the Kronecker product has an advantage in this respect.Additionally,the singular value decomposition has more applications in matrix dimensionality reduction.Therefore,we use the Kronecker product and the combination of the two to simplify the original optimization model,and establish two new models.Subsequently,based on the singular value decomposition we prove the structure of the optimal beamforming matrix.Then,in this process,the matrix dimension is reduced from K2 to Kr.Next,the rank-1 constraint of the problem is non-convex.However,the rank-1 decomposition is only applicable to optimization problems with no more than four constraints.We proved that the optimization problem proposed in this paper satisfies the rank-1 decomposition and transformed the nonconvex problem into a semidefinite programming problem.Finally,study and analyze the rate-energy region of the model.Network capacity gain is the key part of network coding gain,and capacity is the focus of wireless network research.Therefore,research on capacity is necessary.Besides,between the harvested energy and achievable rate exist a tradeoff,since the existence of energy harvesting nodes allows relay nodes to allocate part of the transmission power to transmission energy.Based on the energy harvesting constraint and the total power constraint of the relay node,the definition of the rate-energy region of the model is given.Since the boundary point plays an important role when analyzing the rateenergy region,we give the closed-form solution and the suboptimal solution of two special boundary points.The second part simulates and analyzes the relative performance of the two schemes proposed in this article.The study examines two aspects,namely the rate-energy region and anti-jamming ability.First,the influence of the number of antennas and the total power of the relay node on the rate-energy region is discussed separately.From this simulation,the tradeoff between the achievable rate and harvest energy is proved.Also,the increase of the number of relay antennas and the total power cannot make the wireless expansion of this region.Next,investigate the model’s anti-jamming ability under the influence factors of the achievable rate.The influencing factors are the number of relay antennas,the relay transmission scheme,and the harvested energy threshold.The conclusion verifies that the strategies proposed in this paper have better anti-jamming performance.Finally,the running time of the two schemes’ simulation program is compared.It can be known from this process that the singular value decomposition can get better delay performance.