| Recently,with the development and progress of the technology,and the urgent reqirement of the people in life,the 5th generation(5G)mobile communication system,based on the power spring of pursuing a user-centered,has been irreplaceable for the future communication standard.And the Internet of Things(IoT)was elected as the backbone network of the 5G,which can be pursuing to a new model of future information ecosystem.Short distance wireless communication technology is the part of the wireless body area network(WBAN)for IoT,meanwhile,it has permeated each fields of economy,medical treatment,human life and so on.Ultra-Wideband(UWB)is the most competitive communication technology in short distance wireless communication.Last two decades,owe to the contribution of huge researchs,it was very popular that the modulation schemes,based on the chaos and its improved versions,can be applied into UWB for the unique advantages of low cost,low complexity and low power and so on.Hence,it is much more significant to do research of the high spectrum efficiency and energy efficiency of differential chaos shift keying(DCSK)communication system,which aims to the application in industry.In this paper,we discuss and investigate the capacity peculiarity of DCSK modulation system,and the key technologies of the improved chaos modulation system based on the spatial modulation technique.So,the main work of this dissertation mainly includes the following aspects:(1)It is an evaluative criteria of analysis performance for the communication system,which can be a reference of channel coding.The non-coherent capacity of M-ary DCSK communication system are dedrived,which is considered with the influence of different parameters of inter-symbol interference(ISI),channel state information(CSI),soft-decision/hard-decision(SD/HD)method in the detector,modulation dimension M,fading path number L and so on.The numerica results can be shown by the Monte Carlo,and we analyze and conclude the influence of parameters on the capacities for the design reference of channel coding.Last,it is proven that the U-shaped capacities exist for the simulation example of low density parity check codes(LDPC)channel coding communication system.(2)To improve the spectrum efficiency and energy efficiency of DCSK modulation system,based on the theory of spatial modulation technology,the differentially spatial modulated chaos shift keying(DSMCSK)modulation system is proposed,which does not only overcome the requirement of channel state information in the receiver,but also improves the reliability,notice that spatial modulation is a multi-antenna technology,while the chaos-based modulation is a modulation scheme.Besides,the capacity of DSMCSK communication system is analyzed and derived through the knowledge in Part(1).It is matched for the theoretical curves and simulated curves at high bit-signal noise ratio(bit-SNR),but there is a difference between them for the ignored high-term noise for the convenient calculation.of upper bound on the average bit error probability(ABEP).Compated with the conventional chaos-based modulation system at the same spectrum efficiency,the proposed DSMCSK communication system can get more gain of the energy efficiency.It is first that the spatial modulation technology is introduced into the chaos-based communication system.(3)Focus on the pursuing of low power in the relay communication system,the differentially spatial modulated chaos shift keying modulation relay(DSMCSK-Relay)system based on the spatial modulation technology is proposed with the decode-and-forward(DF)protocol,which does not only overcome the CSI,but also improves the performance.Analyzed and derived the closed formulas of upper bound on ABEP of the proposed DSMCSK-Relay communication system,it is proven that the scheme is rational,notice that we can ignore the high-term noise for the convenient calculation of upper bound of ABEP at low bit-SNR.Meanwhile,the proposed chaos relay system can get more performance gain than the traditional chaos-based relay communication system. |
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