Integrated Sensing And Communication Scrambling Complementary Code Construction And System Design

With the development of the Sixth Generation(6G)mobile communication systems,Integrated Sensing and Communication has come into being.This technology integrates the dual functions of sensing and communication to achieve reciprocity and save spectrum resources,but the interference between the two functions is inevitable.To address the interference problem,the spread spectrum codes have been explored in various researches.However,these codes can hardly meet the requirements of both communication and sensing,because they cannot have ideal autocorrelation and cross-correlation characteristics simultaneously.In addition,spread spectrum technology increases the spectral overhead of the system.To solve this problem,a Scrambling Complementary Code technology is proposed together with two integrated schemes.The main research contents and innovations involved are as follows:On the one hand,addressing the problems of multi-access interference,multi-path interference and integrated interference in multi-user communication and multi-target sensing scenarios,a coexistence scrambling complementary code is proposed.This code combines multicarrier technology and multi-antenna technology,which can have ideal autocorrelation and cross-correlation characteristics at the same time,and can realize the sharing of three-dimensional time-frequency-space resources while suppressing interference.Then,a communication-sensing coexistence system model based on the scrambling complementary code is designed.The system adopts scrambling technology to achieve signal modulation,which can solve the problem of spectrum resource waste caused by spread spectrum technology.Finally,the simulation analysis shows that this scheme can not only improve the user’s access ability and anti-multipath interference ability by adjusting the codebook parameters but also achieve a trade-off between sensing and communication performance.On the other hand,in view of the problem that random data will deteriorate the sensing performance in the Orthogonal Frequency Division Multiplexing(OFDM)integrated sensing and communication systems.A integrated scrambling complementary code is first designed,whose autocorrelation and cross-correlation characteristics can help improve the influence of random data and realize multi-access in OFDM integrated system.Then,an integrated system model matching this code is designed,and a new communication decoding algorithm and a method for eliminating communication data in echo signals are studied.Finally,the simulation shows that the integrated scrambling complementary code has an ideal distance ambiguity function,which can improve the interference of random data.In addition,the sense resolution can be improved by adjusting the codebook dimension.In conclusion,the scrambling complementary code technology proposed in this paper not only suppresses the interference in the integrated sensing and communication systems,but also improve the spectrum efficiency.In addition,this technology can be flexibly combined with OFDM and Multiple Input Multiple Output(MIMO)technologies to effectively share three-dimensional time-frequency-space resources,which provides a basis for future research on integrated systems in the code domain.