Research On MPPSK Pulse Communication Based Wireless Sensor Networks

Internet of things(IoT)technology has been on the rise with the expansion of network.The importance of wireless sensor network(WSN),as a kind of IoT realization forms,is emphasized in many aspects,such as national defense,environment and traffic.But in today's society,energy and environmental protection are two big problems.So,how to implement WSN technology with high efficiency and energy conservation have become the focus of industry.Begin at the WSN bottom to reconsider modulation-demodulation technology across-the-board,is a very important idea.This thesis first introduces M-ary Position Phase Shift Keying(MPPSK)modulation,and what in detail is its waveform expression,power spectrum,and the bit error rate(BER)formula.Then the MPPSK modulation is extended to the MPPSK pulse modulation,along with its waveform expression,power spectrum and BER formula.The advantage in energy consumption of the MPPSK pulse modulation technology is presented.Secondly,the system optimization of the MPPSK pulse modulation is discussed in two aspects:one is to restrain its emission spectrum by addition of a narrow forming filter,and the other is to improve its BER performance by combination with BCH coding.The effectiveness of these optimizations is verified by simulation experiment.Thirdly,the OPNET,a kind of network simulation software,is introduced,the MPPSK_MODEM simulation model is built,and the channel of MPPSK pulse modulation is modeled,which lay a theoretical basis for WSN energy consumption under this network condition.After the OPNET based simulation modeling of WSN topology,transmission channel,and frame structure,the MPPSK pulse modulation WSN performance is simulated and evaluated.Energy consumption advantages of MPPSK pulse modulation system are analyzed by simulation comparison with traditional modulations.The contrast of these simulation results with that of the current WSN node scheme of Sigfox company,inspires the research on energy consumption of small data packet transmission,and theoretical analysis and simulation results verifies the MPPSK pulse modulation system energy consumption advantages.In the end,the WSN nodes and the network itself are mathematically modeled.Through some reasonable assumptions and estimates,the formula of node energy consumption per unit of bits is got;and through modeling CSMA/CA mechanism,channel and network,the average energy formula of WSN is deduced.The simulation and experiment results demonstrate the correctness of these formula,which will provide theory support for subsequent studies.