Research On Chaotic Modulation Technology And Its Application In Software Radio Communication

Chaos,as a ubiquitous nonlinear phenomenon,has broad application prospects in communication research due to its unique characteristics.At present,in the field of software radio communication,with the trend of miniaturization and diversification of equipment functions,it is necessary for equipment to have both radar detection and communication functions,which strengthens the demand for integrated waveform design of synesthesia.The characteristics of chaotic encoding enable it to be applied to the design of synesthesia integrated signals.On the basis of studying the characteristics and performance of chaotic sequences,this thesis adds phase encoding based on chaotic codes to orthogonal frequency division multiplexing signals,and designs a chaotic phase encoded OFDM signal.The signal uses an improved Logistic chaotic sequence as the phase encoding sequence to encode the subcarriers of the integrated signal.This not only improves the error rate and transmission rate,but also enables the radar to have better target resolution.In order to solve the problem of high peak to average power ratio in OFDM synesthesia integrated signals,this thesis improves the selective mapping algorithm(SLM)in probabilistic algorithms based on chaotic sequences.The improved SLM algorithm introduces a set of chaotic sequences for phase weighting of the transmitted signal,and selects the candidate signal with the lowest peak to average power ratio as the transmitted signal.This algorithm not only successfully reduces the peak to average power ratio of the signal,but also reduces the auxiliary sideband information that needs to be sent,reducing implementation complexity.Finally,this thesis implements the designed chaotic phase coded OFDM signal and the improved SLM algorithm for reducing PAPR based on the domestic CHX801 platform.