Carrier Index Differential Chaos Shift Keying Modulation And The Corresponding Simultaneous Wireless Information And Power Transfer Technology

The Internet of Things(IoT)is a revolutionary technology which seamlessly connects all people and things in the world through various intelligent devices.With the expansion of the IoT,wireless sensor networks(WSNs)combined with IoT,play an important role in production and academic researches.As the number of nodes accessing to WSNs increases by explosion,the consume of the sensor nodes increase a lot in the process of sending,receiving and processing data.Hence,it becomes even more critical to incorporate green and sustainable technologies into WSNs for energy saving.Above all,the system designed in this paper adopts two design criteria of green wireless communication system:first,high energy efficiency(EE);second,wireless carrying communication function.In order to improve EE of the system and integrate the self-sufficient energy collection function,we study the following contents based on the low-power,low-complexity DCSK modulation.(1)In order to overcome the disadvantages of DCSK,a new carrier index differential chaos shift keying(CI-DCSK)modulation which combines carrier index modulation(CIM)with multicarrier DCSK(MC-DCSK)is proposed.Two schemes employing two different index selectors and detectors to implement IM and demodulation are introduced.The new designed index selectors are one-to-one mappings between the index symbols and the carrier activation patterns,which can avoid the disaster caused by the previous designed selectors.By setting the value ofp1,either system can offer different data rates and performances.Simulation results verify the superiority of one scheme in EE and another scheme in spectral efficiency(SE),respectively,compared with MC-DCSK.(2)In the CIM-based systems,the information bits are transmitted by the active carriers,while nothing is transmitted on the inactive carriers.In this paper,two carrier index differential chaos shift keying with simultaneous wireless information and power transfer(CI-DCSK SWIPT)schemes are proposed,which integrate carrier index differential chaos shift keying(CI-DCSK)modulation with wireless power transfer.Since the signal obeying normal distribution has low correlation with chaotic signal,it is chosen as the energy signal which is conveyed on the inactive carriers.For simplicity,the signals on all inactive carriers are set to be the same.To provide both the best performance and self-sustainability,the ratio of energy on the inactive carriers and TS coefficient are optimized.Simulation results show that though performances of the proposed schemes are a little worse than CI-DCSK with the same spectral efficiency(SE),the proposed schemes are all self-sustainable.(3)Base on MC-MDCSK and CIM,two CI-MDCSK are proposed which extent the binary CI-DCSK to M-ary.By adjusting the number of carriers and the size of the constellation,CI-MDCSK1/2 can provide different data rate,EE and SE.Compared with MC-MDCSK of the same number of carriers and constellation size,CI-MDCSK1 has better BER performance but sacrifices SE,and CI-MDCSK2 has better SE and BER performance in some cases,especially for the case of M being 4,CI-MDCSK2 has better BER performance and SE.