Study On Resource Allocation In Non-continuous Spectrum For L-band Digital Aeronautical Communication System

Aeronautical L band has already been occupied by a large number of radio-frequency legacy systems,so L-DACS1(L-band Digital Aeronautical Communication System 1)could only work on the spectrum hole of DME(Distance Measuring Equipment)in aeronautical L band.In aviation communication scenario,the frequent changes of neighbor aircrafts leads the spectrum changed frequently.Meanwhile,the dynamic spectrum occupancy of DME systems in each aircraft may also make the spectrum change frequently.Therefore,the spectrum environment changes frequently in L band which makes remaining available spectrum holes non-continuous and non-deterministic.So how to allocate the non-continuous spectrum resource in dynamic spectrum environment is a key issue to L-DACS1 system.This thesis unites the project “Research on civil aviation macro cellular network and relay communication link”,which is sponsored by Civil Aircraft Research Projects of Ministry of Industry and Information Technology of China,“Research on networking and key technologies of transoceanic civil aeronautical mobile broadband communication networks”,which is sponsored by National Natural Science Foundation of China and “Greener Aeronautics International Networking 2 KGT4-CNS/ATM for greener air transport”,which is sponsored by China Aviation Academy aims at the problem of the spectrum collision caused by time-varied bandwidth of spectrum holes in L band dynamic spectrum environment,the time-varied available resource in sub-carriers group when L-DACS1 adopts sub-carriers group based resource allocation and different QoS(Quality of Service)requirement for L-DACS1 hybrid multi-service.The detail of the study and main contributions of this thesis include the following aspects.(1)To solve the issue of spectrum collision caused by time-varied bandwidth of spectrum holes in L band dynamic spectrum environment,this thesis presents a novel probability density function through order statistics as well as its simplified form to describe the statistical properties of spectrum holes,with which a statistical spectrum allocation model for L-DACS1 based on stochastic multiple knapsack problem is formulated.To reduce the computational complexity,thie thesis transform this stochastic programming problem into two subs multiple knapsack problem to solve.Simulation results illustrate that the proposed statistical spectrum allocation algorithm can reduce the spectrum collision and achieve high throughput when the bandwidth of spectrum holes is time-varied.(2)To solve the issue of time-varied available resource in sub-carriers group when L-DACS1 adopts sub-carriers group based resource allocation,this thesis derive the opportunistic capacity of sub-carriers group through CTSMC(Continuous Time Semi-Markov Chain)and based on this,a joint power and spectrum allocation model for L-DACS1 by considering statistical properties of spectrum resource was proposed.To reduce the computational complexity,the model is split into two sub-problems and solved via Lagrangian dual method.Simulation results illustrate that the proposed opportunistic capacity based spectrum allocation may make use of spectrum efficiently and achieve good performance when the spectrum environment is time-varied.(3)For applying the proposed allocation algorithms to L-DACS1 and solving the issue of different QoS(Quality of Service)requirements for L-DACS1 hybrid multi-service,this thesis proposed a hybrid multi-service resource allocation and schedule model and an EXP/PF based hybrid multi-service resource schedule algorithm for L-DACS1.This schedule algorithm adopts different calculation method for scheduling factor to support ATM service in sufficient bandwidth scenario and limited bandwidth scenario.It can achieve a good performance comparing to traditional EXP/PF algorithm which cannot meet the ATM service needs in limited bandwidth scenario.Simulation results illustrate that the proposed schedule algorithm can effectively reduce the timeout ratio of ATM(Air Traffic Management)and AOC(Aeronautical Operational Control).