Digitalized Hf MIMO Polarized Model Establishment And Collision Cancellation Algorithm Design

HF communication utilizes the frequency band from 3MHz to 30 MHz.It uses the ionosphere as the reflect medium,and its sky-wave transmission is a commonly used way for long distance communication.Since the HF communication has few requirements for infrastructures,convenience in dynamic networks,and availability under severe conditions,HF communication is put under light in recent years.However,HF communication is also faced with several defects,such as precious bandwidth resources and low utilization rate of the frequency band for the analog means of HF.Therefore,digitalized HF communication will become the future of HF,and its combination with novel technologies will help to enhance the data rate compared to traditional HF.This paper is under the background of HF development,and combines HF with the multiple-input-multiple-output(MIMO)technology,followed by theoretical innovation,simulation validation and experiments verification,so this paper provides a solution for digitalized HF communication.The first part of this paper proposes a co-located HF MIMO statistical model.This statistical model verifies HF MIMO gain from the polarization point of view.Compared to traditional HF channel simulation programs,like ray-tracing program,the proposed model acts as a new method to simulate HF MIMO channel.This model achieves a channel capacity gain same as the theory from the water-filling algorithm.The valuable result is the same as other papers,as the channel capacity has an upper limit when the HF channel modes are limited.The second part of this paper focuses on distributed HF MIMO system,which is a possible way to enhance MIMO capacity further more since co-located HF MIMO capacity is limited as concluded from the first part of this paper.In distributed HF MIMO system,because of the long communication distance,co-channel interference is easy to happen.The collision will greatly reduce the data rate and the frequency band utilization rate.Therefore,we conduct a research on two kinds of co-channel interference cancellation algorithms under distributed HF MIMO system: cancellation by uni-antenna and cancellation by multi-antennas.Cancellation algorithms will separate collided signals and ensure the system performance.The last part of this paper aims to deploy digital HF communication network.However,with the help from the analog HF radio station(ICOM-718),the first step is to alter the analog station to a digital one.This paper develops a digital modulation-demodulation platform and a proposal for digitalized HF communication.The platform and the proposal help to realize digital HF communication with an analog HF radio station.Most importantly,the platform and the proposal are with low cost and they act as a solution for further digitalized HF communication network.