Research On Bistatic Integration Of Communication And Radar Based On OFDM

With the development of science and technology,great progress has been made in radar and communication respectively.The similarities in the basic theory,application scenarios,and system components,provide the possibility for constructing the integration system.The integration of radar and communication that can reduce equipment volume,increase equipment utilization,spectrum utilization and system function is a trend of future,has attracted more and more attentions in this field.In the integrated system,based on the OFDM is an effective method.The existing research mainly focuses on one part of the integration,lacking of systematic research.This thesis adopts OFDM,analyzes the similarities and differences of communication system and radar system,and builds several integrated system models that are suitable for different scenarios based on the bistatic model.The simulations show the feasibility of the scheme.The main work in this thesis contains:1.This thesis analyzes the feasibility of the integrated system,pointing out the key technology of the integration of the radar and communication system is OFDM.This thesis chooses the OFDM system in communication as one basic system,analyzes the principles and procedures of OFDM system,and finds that the application of Fourier transform in modulation and demodulation of OFDM can turn wide-band channel into multiple narrowband channels.This method can improve system utilization of spectrum and reduce transmission loss.2.This thesis adopts bistaic scenario,analyzes the key techniques of the radar system,derives OFDM signals and pulse-compression of OFDM signal.And then the OFDM radar system model is built.Simulations show that the signal of OFDM radar system has the characteristics of randomness.This conclusion makes the integration of communication and radar system possible.In motionless bistatic integrated system,the receiver reconstructs the original communication symbols firstly.Then the reference signal which is used in radar signal processing can be built.Through the integrated system,the aim of signal processing without original reference signal can be achieved.Simulations verify feasibility of this scheme.3.In motion conditions,channel differs.The motionless bistatic integrated model is not suitable in the scene.Some techniques are used in the model.And this thesis proposed two integrated system models based on channel estimation.The block type pilot pattern is used in low-speed scene.And current result of channel estimation is applied to the next pulse.The comb type pilot pattern is used in high-speed scene.And channel estimation is carried in each pulse.After channel estimation,bit error of communication can be decreased and performance of radar can be increased.Simulations show that the two models can play a good role in their respective scenarios.The conclusions can provide support for practical application of the integrated system.