Study On Techniques Of Integration Of Radar Sensing And Communication System Based On Interleave Division Multiplexing

Facing the more complex electromagnetic environment and target threat,the combat platform needs to equip more electronic equipments in order to survive in modern electronic war.As radar and communication systems are the necessary equipments on the combat platform,the critical research topic for the combat platform is to combine the two systems together and make an integration of the radar and communication systems on the platform.Interleave-division multiple access(IDMA)is a special case for code division multiple access(CDMA).It has a strong ability to combat the interference and multipath effects.The complexity of the multi-user detector(MUD)at the receiver is relatively low.Besides,IDMA can be combined with orthogonal frequency division multiplexing(OFDM).OFDM-IDMA inherits advantages from both OFDM and IDMA.Therefore,OFDM-IDMA seems attractive in the area of wireless communications.The integration of radar and communication based on interleave-division multiplexing(IDM)is studied in this paper.The specific work in this paper is as follows.(1)The interleavers are the only means to separate data from different users in IDMA systems.With proper values of p and q,a set of orthogonal interleavers based on reversal of(p,q)alternate-decimal indexing are designed for IDMA systems in this paper.Few registers are needed because only the values of p and q should be stored for each user.In order to be easy to realize interleavers in hardware,the values of p and q are chosen to be powers of two.The index after interleaving can be generated by reversing the binary form block by block.The simulation results show that the performance of the system with the proposed interleavers is better than the system with random interleavers.(2)The differences and the similar points of radar and communication systems are analyzed in this paper.The integration of radar and communication system based on single carrier IDM is proposed in this paper.The simulation and analysis of radar sensing is presented.The results of the simulation show that the system can be used for range sensing and it is difficult to be used for Doppler estimation.(3)The multi-carrier integration system based on IDM is proposed in order to deal with the Doppler estimation.The modulation symbol-based approach is used in radar signal processing.Analysis and simulations are carried out.With this approach,the system can estimate the Doppler and range profile simultaneously.The system is robust to the interference.(4)Since direct-conversion transceivers are always used in OFDM-IDMA systems,compensations should be considered to deal with the in-phase and quadrature-phase imbalance(IQI)caused by the imperfectness of the analog devices.An iterative time domain no-feedback compensation method is proposed in the uplink of OFDM-IDMA system.The compensation for a specific user can not eliminate the IQI from other users,so the iterative detection can not be used with the presence of residual IQI from other users.The iterative detection should be modified.Simulations of the modified detection is carried out in this paper,and the results show that the proposed compensation alleviate the effect of IQI.