Research On BER And PAPR Collaborative Optimization Method Based On OTFS Waveform

With the continuous evolution of wireless communication technology,the new generation of mobile communication systems is gradually breaking free from the constraints of traditional ground cellular communication systems and is starting to integrate with emerging technologies such as satellite communication,drone communication,and high-speed rail communication.In the new application areas,new requirements have been put forward for the performance and functionality of mobile communication systems.OTFS(Orthogonal Time Frequency Space)waveform,as one of the candidate waveforms for the new generation of communication systems,obtains significant diversity gain in the time-delay Doppler domain through twodimensional discrete symplectic Fourier transform and has higher robustness to fast timevarying channels compared to traditional OFDM(Orthogonal Frequency Division Multiplexing)waveforms,thus attracting widespread attention.This thesis focuses on joint control and coordinated optimization methods for the error rate and peak-to-average power ratio performance of OTFS waveforms from the perspectives of integrated algorithms and integrated waveforms.Firstly,this thesis introduces the basic principles of the OTFS waveform and the WFRFT(Weighted Fractional Fourier Transform),and gives the matrix expression of the OTFS modulation and WFRFT process.Combined with the transmission characteristics of fast timevarying channels,the input-output relationship and interference composition of the OTFS waveform in fast time-varying channels are analyzed.The theoretical derivation and software simulation demonstrate the bit error rate and peak-to-average power ratio performance of the OTFS system under different resource allocation modes,verifying the performance advantage of the OTFS system over the OFDM system.Secondly,this thesis proposes a nonlinear compression active constellation extension algorithm suitable for the OTFS waveform.Based on the idea of traditional active constellation extension schemes,this method achieves high peak-to-average power ratio suppression of OTFS signals from the perspective of integrated algorithms.This method introduces continuously adjustable multidimensional parameters,which realize flexible control of signal peak-to-average power ratio and bit error rate performance based on parameter changes.In addition,this thesis discusses the applicability of classical peak-to-average power ratio suppression algorithms commonly used in multicarrier systems to the OTFS system,compares the suppression effects of different methods,and analyzes the mutual exclusion and coordination mechanisms among multiple performance metrics in peak-to-average power ratio suppression.Finally,this thesis proposes a WFRFT-OTFS integrated waveform framework that combines the WFRFT technique with the OTFS waveform.Based on the two-dimensional adjustable parameters of this framework,various waveform frameworks can be extended and integrated.By deriving the hybrid carrier fusion mechanism,the theoretical bit error rate performance of the WFRFT-OTFS integrated waveform in a static channel is analyzed,and the MP algorithm is applied to the WFRFT-OTFS waveform framework.Through simulation,the parameter flexibility advantage of this framework is demonstrated.In addition,this thesis builds a sensory integration platform based on the WFRFT-OTFS integrated waveform framework,and using the advantages of multi-parameter flexible control,achieves highprecision perception of a single target.