# Practical Performance Analysis of Interference in DSS System
### Related Work  
In this section, we compare some existing literature related to DSS interference. The authors of [37] proposed a zero-breaking beamforming approach for interference cancellation in a cognitive radio. However, these authors focused their research on the channel estimation problem that accompanies the adoption of the zero-breaking beamforming approach. This reference only mentions the idea of dynamic spectrum access as a candidate solution and does not provide an in-depth analysis, and the proposed interference solution does not explicitly target the DSS interference scenario. Reference [38] has a similar research direction as [37], which is also based on dynamic spectrum access for a cognitive radio. The authors of [38] proposed three solutions for mobile spectrum shortage, namely, interleaved CR, underlay CR, and overlay CR. The interference mitigation methods are proposed are not for 4/5G DSS interference scenarios and without field test. In our paper, compared with these two literature references, we focus on the 4/5G interference in DSS scenarios, and propose two interference mitigation methods, namely, rate matching and buffer setting, to mitigate the interference. We add a large number of field tests based on simulation which can verify our proposed methods more comprehensively. The authors of [39] proposed an adaptive system model of downlink interference for 5G mobile communication applications. The interference impact of the downlink 5G system was measured with two different mobile terminals: MediaTek (MTK) and Qualcomm (QC). That is, the existence of interference was determined by field verification, but no effective solution for interference mitigation was proposed, simulated and measured. Our paper proposes two interference mitigation solutions for the severe interference found in the DSS, which is the core research point of our paper. We further conduct an in-depth study and analysis of the feasibility and effectiveness of these two interference mitigation solutions by conducting simulations and field tests. The research background of references [36; 40] is also similar to the research conducted in this paper. Therefore, we have a foundation for our paper. However, the authors of [36; 40] only compared the performance of several modes at 20 MHz bandwidth. The presence of interference was determined by field verification, but no interference mitigation scheme was proposed, simulated, and measured. On the other hand, our paper carries out many extended studies based on references [36; 40]. We further realize the prospective study of references [36; 40] by conducting research and analysis in a larger bandwidth scenario, and further propose two interference mitigation solutions for the severe interference in the DSS. Our paper presents simulations and field tests on the feasibility and effectiveness of these two solutions. An in-depth study and analysis is conducted based on the previous work, and the interference problems found in the previous work are effectively solved.  
The remainder of the paper is organized as follows. Section 2 introduces the motivation and contribution of this paper. Section 3 investigates the technical solution of the DSS. In Section 4, the principle of intra-frequency interference under the DSS network architecture and two interference mitigation solutions of rate matching and buffer setting are presented. Section 5 provides the field test results and analysis of interference, and verification of buffer setting and rate matching solutions. Section 6 summarizes the conclusion.