Performance Analysis And Search Agorithm For Analog Cancellation In Full Duplex

One important goal of future mobile communication systems is to improve the spectrum efficiency of FDD and TDD,and degrade the utility and management difference of the spectrum resources.The co-time co-frequency full-duplex(CCFD)technology based on self-interference suppression is a potential solution to achieve this goal.Currently,full-duplex mainly focus on indoor hotspot coverage,outdoor relay,and D2D(Device-to-Device).With the progress and maturity of full-duplex technology,it is believed that more innovative scenarios of full-duplex will be presented.From the equipment level,the core issue of CCFD is how the co-time and co-frequency self-interference signal transmitted by the local device itself is effectively suppressed at the local receiver.The research on communication theory and engineering technology has been fully carried out in the industry.At present,self-interference suppression always contains space domain,analog domain,and digital domain suppression.The spatial self-interference suppression mainly depends on the antenna location optimization,beamforming,high isolation antenna and other technical means to achieve spatial self-interference radiation isolation.The core idea of the self-interference suppression in the analog domain is to construct the canceling signal,which is opposite to the amplitude of the received self-interference signal,and complete the cancellation in the radio frequency(RF)analog domain.The digital domain self-interference suppression mainly rebuilds signal to eliminate the residual linear and nonlinear self-interference.The main problem to be solved in this thesis is the performance and implementation of RF analog cancellation.We focus on the research and analysis of analog cancellation and its performance.Mathematical modeling and simulation is carried out,as well as the assessment of the impact of related hardware parameters.Moreover,we investigate many high-dimensional search algorithms in RF analog cancellation and select several algorithms suitable for analog cancellation.Furthermore,we modify these high-dimensional search algorithms according to some practical constraints.In this research,we consider the number of taps,delay,recovery power,quantization of the analog cancellation circuit and analyze their impacts on the cancellation performance.These results would provide guidance for the RF analog cancellation implementation.Specially,the improved coordinate rotation high-dimensional search algorithm proposed in this paper achieves a good compromise in complexity and performance.Therefore,the research content of this thesis has very important value for both design and engineering implementation of the RF analog cancellation.