Research On Dual-function Radar Communication System Using Code Domain Index Modulation For Information Embedding

The dual-function radar communication system realizes both radar and communication functions through a single hardware platform,which can effectively transmit information between wireless devices while detecting and identifying targets.It provides the possibility for alleviating the crisis of spectrum congestion and has great application value.To facilitate the coexistence of radar and communication,this thesis puts forward an integration scheme based on spherical code.We embedded the communication information into the radar waveform by means of index modulation and use the rich orthonormal basis to achieve high-speed communication.It does not affect radar detection performance and improves spectrum utilization efficiency.To improve the communication rate of integrated radar and communication system,the spherical code with rich orthogonal basis is proposed.First,spherical t-design codes and spherical Reed-Muller codes are introduced according to the design objective of enriching orthogonal basis.Then a radar and communication integration scheme based on index modulation using spherical code is designed and the closed-form expressions of the upper and lower bounds of the accessible rate are derived.In this thesis,an integrated scheme of mono-static radar and communication integrated system using index modulation is proposed,which makes use of the characteristics of a rich number of code words of spherical t-design codes.The communication information is embedded into Rectangular pulse waveform and LFM waveform respectively.For communication function,the maximum likelihood detector is designed to demodulate the communication information.For radar function,the radar waveform ambiguity function before and after embedding communication information is analyzed.The simulation results show that the ambiguity function of LFM waveform embedded with spherical code is better than that of CDMA waveform,and the bit error rate performance is similar to that of CDMA waveform.In addition,the communication rate,ambiguity function and bit error rate performance of multiple spherical t-design codes and Hadamard codes are compared.According to the characteristic that each codeword of spherical Reed-Muller code contains multiple groups of orthogonal code vectors,a scheme of integration of multi-static radar and communication integrated system is designed in this thesis.The orthogonality of waveforms between each code vector meets the requirement of orthogonality waveforms between MIMO radar antennas.The communication speed of index modulation can be greatly improved by using the characteristic of rich orthogonal basis.The simulation results show that the error rate performance of the multi-static integrated system is better than that of the mono-static integrated system,and it can provide the ability of networking detection.In addition,the ambiguity function and bit error rate performance are analyzed and compared between different element waveforms.