Research On The Theory And Performance Analysis Of1/2Continues Frequency Chirp Keying

With the rapid development of the information society,people have set requirements forhigher data rate. Owing to the limitation of frequency resources and lower band efficiency,it’simperative to solve the conflict between scarcity of the spectrum resources and the urgentdemand for high capacity digital communication systems.After Walker proposed a newmodulation approach named as Variable Phase Shifting Keying (VPSK),Ultra Narrow Band(UNB) as a new type of wireless digital mudulation technology whose energy is highlyconcentrated is becoming a hot issue.Using the idea of Very Minimum Chirp Keying (VMCK) for reference,the paper proposesa new digital modulation technology named as1/2-Continous Frequency Chirp Keying(1/2-CFCK).The characteristic of time-frequency domain and Bit Erro Rate (BER) is analyzedby software and hardware platforms.1/2-Continous Phase Chirp Keying (1/2-CPCK),which isthe optimized modulation waveforms of1/2-CFCK,can further improve energy concentrationof the modulated signals. The detail researches are as follows．To begin with,VMCK modulation method is analyzed. Aiming at the drawbacks ofVMCK,1/2-CFCK is proposed.The characteristics of modulated signal,including PowerSpectral Density (PSD) and the correlation of waveforms samples,and BER performance ofthe Wireless Communication System (WCS) are researched by theoretical derivation andsimulations.In order to validate the significant characteristics of1/2-CFCK and explore itsimplementation schemes in project practice,1/2-CFCK communications link hardwareplatform is constructed based on Field Programmable Gata Array (FPGA).The feasibility andvalidity of the communication system based on1/2-CFCK are verified from the viewpoint ofhardware tests.Finally,1/2-CPCK which optimizes1/2-CFCK modulated waveforms by realizing thecontinuity of signal phase,can further improve energy concentration of the modulatedsignals.The modulated signal of1/2-CPCK and the performances of communication systembased on1/2-CPCK are analyzed using the same analytical procedures in1/2-CFCKcommunication system.