Research On Cooperative Routing Algorithm For Wireless Multi-hop Networks

Following the rapid development of new technologies in wireless communication and the increasing popularity of low-cost communication equipment,wireless multi-hop networks are expected to play an important role in the future "Internet of Everything" communication world because of their strong scalability and distributed self-organization.As the most promising research topic in wireless multi-hop networks,it is of great significance to study multi-hop routing technology.Taking into account the fading characteristics of wireless channels,the limited energy,and communication capabilities of low-cost communication devices,and designing multi-hop routing transmission schemes for potential application scenarios of various wireless multi-hop networks,so that data packets can be timely,reliably,and energy-efficiently delivered to the destination node is the current research focus and difficulty.In order to further improve the transmission energy efficiency of the network and reduce the transmission delay,this dissertation designs high-energy-efficiency,low-energy consumption,and low-latency cooperative routing algorithms based on cooperative communication,simultaneous wireless information and power transfer(SWIPT)communication,and interference coordination technologies,and validates the effectiveness of the proposed algorithm through simulation.Specifically,the main contributions of this dissertation are three-folded:(1)Aiming at the problem that the end-to-end energy efficiency needs to be optimized in the existing cooperative routing schemes,a two-stage cooperative routing(TSCR)scheme is proposed to improve the end-to-end energy efficiency.A two-stage cooperative transmission model is firstly designed in which the core helper is introduced to determine the helper set for cooperation.Then,the two-stage link cost is formulated.By selecting the optimal core helper,the two-stage link cost of each link can be optimized.Finally,based on the optimized two-stage link cost,a distributed cooperative routing scheme is further proposed to find the optimal path from the source to destination.The simulation simulates the proposed TSCR scheme can effectively improve both the energy efficiency and network lifetime compared with the existing schemes.(2)Aiming at the energy-saving problem of wireless multi-hop energy-harvested networks,an energy-minimized cooperative routing scheme is proposed to minimize the end-to-end energy cost.Referring to SWIPT model,an energy harvested two-stage cooperative model is proposed and a harvest-then-cooperate helper is introduced to enhance the single-hop transmission.Then on the basis of this cooperative model,the end-to-end energy minimization problem is formulated.Referring to the closed-form solution of optimal end-to-end energy cost,the link cost is designed and a distributed cooperative routing is further proposed to explore the optimal end-to-end path.Finally,we propose a fixed point-based iterative algorithm to ensure the optimality of the end-to-end transmit energy.Numerical simulations validate the convergence of the iterative algorithm and prove the outperformance of the proposed scheme in end-to-end performance.(3)Aiming at the multiple-data-flow scenario,an interference coordinated cooperative routing scheme is proposed to achieve end-to-end low-latency transmission.Considering a new-generated data flow in the network,a low-latency interference-aware routing algorithm is proposed where the end-to-end delay and spatial resource cost are defined as the link cost.Then,for a given link set,an interference coordinated power allocation algorithm is proposed to obtain the power allocation of concurrent communication of these links.Finally,combining initial routing and concurrent communication,a guard-zone based selection(GBS)algorithm is further proposed to iteratively explore the maximum feasible link set for each time slot.Simulation verified that the proposed scheme can shorten the end-to-end transmission delay,promote better transmission concurrence and,therefore,better spatial reuse.To sum up,this dissertation mainly studies the energy-efficient and low-delay cooperative routing algorithm in wireless multi-hop networks.The corresponding system models and performance goals are introduced based on the varied communication scenarios,and a practical cooperative routing algorithm is proposed.The effectiveness of our research is verified by the theoretical analysis and simulation results.