Study On Power Allocation Methods For Integrated Millimeter Wave Communication And Positioning Systems

Integrated millimeter wave communication and positioning system is considered as one of the key technologies for future wireless network development,which has important research significance and wide application prospects.However,due to the limited power resources of the integrated system,the study of the power allocation method becomes the key to optimize the performance of the integrated communication and positioning system.To this end,by considering the mutual influence relationship between estimated communication rate and Cramér-Rao bound(CRB)in power-constrained integrated millimeter wave communication and positioning systems,a robust communication and positioning power allocation method is investigated for single-user integrated systems.Then,for the low-power single-user integrated system,the expression of the error lower bound,the Ziv-Zakai bound(ZZB),is derived,and an optimal communication and positioning power allocation method is investigated.Moreover,for the multi-user integrated system with occlusions,the reconfigurable intelligent surface(RIS)technology is used to assist the construction of the integrated system model.Based on this system,an inter-user power allocation method is studied.The main research contents and innovations of this dissertation are as follows:(1)Mutual Influence Relationship Between Estimated Communication Rate andCRB in Power-Constrained Integrated SystemsAiming at the problem that the estimated communication rate and CRB are affected by power allocation in integrated systems,the mutual influence relationship between estimated communication rate and CRB is studied when the power is limited in the integrated system.This relationship provides a theoretical basis for the study of the communication and positioning power allocation.First,based on the information interaction,a signal transmission model is proposed for the integrated communication and positioning system.Then,by considering the influence of spatial wideband effect,a wideband positioning estimation method is proposed by using inverse fast Fourier transform(IFFT)and quasi-Newton methods.In addition,the expression of the positioning error lower bound,the CRB,is derived.On this basis,the CRB is used to model the positioning error,and the expression of the estimated communication rate is derived in combination with the positioning estimation location.To this end,the mutual influence relationship between estimated communication rate and CRB is obtained when the power is limited in the integrated system.Simulations are carried out for verification and analysis.(2)Robust Communication and Positioning Power Allocation in CRB-BasedSingle-User Integrated SystemsAiming at the problem of communication and positioning power competition due to limited power resources in integrated systems with positioning errors,a robust communication and positioning power allocation method is investigated based on the CRB for single-user integrated millimeter wave systems.First,the explicit expression of the CRB is derived based on the delay estimation information,which is used to measure the positioning performance in integrated systems.Then,by considering the mutual influence relationship between estimated communication rate and CRB,a robust power allocation optimization problem is established by minimizing the CRB subject to the rate outage probability and total power.For the established non-convex problem,Bernstein-type inequality and successive convex approximation(SCA)method are proposed to solve it.Simulation results verify the robustness of the proposed integrated system,and analyze the trade-off between communication rate and positioning error in the CRB-based integrated system.(3)Optimal Communication and Positioning Power Allocation in ZZB-BasedSingle-User Integrated SystemsTo address the limitation that CRB ignores a priori information and only provides a tight lower bound at high signal to noise ratio(SNR),by using the delay information extracted from ranging parameters and channel amplitude fading,the explicit expression of the ZZB is derived for low power single-user integrated millimeter wave communication and positioning systems.This lower bound is used to measure the positioning performance in integrated systems.Then,an optimal communication and positioning power allocation method is investigated by maximizing the transmission rate under the constraints of ZZB and total power.Moreover,the bisection method is used to solve the established optimization problem.Simulation results show that compared to the traditional expected Cramér-Rao bound(ECRB)and weighted Cramér-Rao bound(WCRB),the ZZB provides a tighter theoretical bower bound for the minimum mean square error(MMSE)estimator over a wide range of SNRs.In addition,simulations analyze the trade-off between communication rate and positioning error in the ZZB-based integrated system.(4)Beam Alignment and Inter-User Power Allocation in RSI-Aided Multi-UserIntegrated SystemsAiming at the problem of signal transmission masking in multi-user integrated systems,RIS is introduced to assist the construction of the integrated millimeter wave communication and positioning system.For this system,in order to analyze the influence of the RIS phase on the power allocation of integrated systems,the beam direction of RIS and base station(BS)as well as the inter-user power allocation are jointly optimized.This method establishes the optimization problem by minimizing the transmit power under the constraints of communication transmission rate and CRB.Moreover,the non-convex problem is solved by using an alternating optimization(AO)algorithm based on the exhaustive search method and the semidefinite relaxation(SDR)method.Simulation results show that the proposed integrated system can simultaneously achieve high-speed data transmission and high-accuracy positioning estimation in different transmission environments.There are totally 31 figures,4 tables,and 162 references in this dissertation.