Research On UFMC Transmission Technology Of Medium High Data Rate Wireless Sensor Networks

Wireless sensor network technology integrates modern wireless communication technology,micro sensor technology and network technology organically,and has broad application prospects and commercial value in national defense,environmental monitoring,home automation,transportation and many other fields.Different from the traditional wireless sensor network,the high-speed sensor network is characterized by high data rate and real-time requirements for multimedia data transmission.Universal Filtered Multi-Carrier(UFMC)uses shorter filter lengths to support short-burst communications and can handle emerging scenarios that support massive machine communications and low-cost Internet of Things transmissions.This thesis chooses the 802.11 standard as the implementation technology and explores the application of UFMC waveforms to the physical layer of medium and medium high data rate sensor networks to improve the network-related performance.In this thesis,we first focus on the key technology channel estimation for physical layer in high-speed wireless sensor networks,Least Square(LS)algorithm,Minimum Mean Square Error(MMSE)algorithm and singular value decomposition(SVD).The advantages and disadvantages of the three kinds of channel estimation algorithms are analyzed and illustrated.Combining the comprehensive requirements of the accuracy and complexity of the network scenario,this thesis improves the existing UFMC channel estimation algorithm.Through simulation and comparison,it is proved that the design improves the system performance effectively with reasonable channel estimation algorithm complexity.For the part of pilot structure and channel interpolation algorithm,theoretical analysis and simulation are carried out in this thesis.Comb-shaped,block-shaped and scatter-shaped pilot structures are introduced,followed by linear interpolation algorithm,binomial interpolation algorithm and Spline interpolation algorithm.The advantages and disadvantages of the three channel estimation algorithms are analyzed and explained.The pilot structure design in the existing IEEE 802.11 a system cannot be applied to a wider range of wireless sensor network channel scenarios.By simplifying the original design,this thesisr presents an improved pilot design and channel estimation mechanism.Simulation verification proves that by adjusting the channel estimation process and setting the thresholds reasonably,it can further adapt to the channel estimation of fast fading channels under different channel environments such as Doppler effects.For multiple protocol layers of medium and medium high data rate wireless sensor networks,this thesis introduces the medium and medium high data rate wireless sensor network protocol stacks including the physical layer,data link layer and network layer,and studies the multi-channel and multiple interfaces based on the error model.The multi-interface multi-channel algorithm based on error code model is proposed in the hierarchical Ad-hoc network.By optimizing the module structure and the analog channel characteristics,the multi-level high-speed wireless sensor network simulation on the NS2 simulation platform is realized and the throughput of OFDM and UFMC under different network settings compared.