传统的认知无线电技术主要针对主用户和感知用户静止的认知网络,近年来对于用户移动性的研究逐渐成为了研究热点。认知网络在多媒体接入技术中应用广泛,而多媒体接入技术的协议多是基于时间分配的,本文对主用户移动场景下感知用户的时间分配方法开展了研究工作:首先构建了认知无线电网络下主用户在感知用户的干扰域内和干扰域外的时间分配模型,并从用户移动的角度给出了单个感知用户可用的传输时间,并提出了感知时间门限的问题,即由于主用户的移动性,频谱感知算法的感知准确性不会因为感知时间的延长而提高。之后为了给出实际中可以应用的时间参数设计方法,特别针对随机模型中最为常用的随机游走模型,给出了单感知用户占用频谱情况下最优传输时间和感知时间门限的表达式,并进行了仿真实验以验证方法的正确性。
Traditional cognitive radio techniques mainly aim at the primary user and cognitive user in static.For the past few tears,the research on the mobility of the user has become a hot research topic,the cognitive network is widely used in multimedia access technology,and the protocols of multimedia access technology are mostly based on the allocation of time.This paper focuses on time allocation method of cognitive users under mobile scenarios of primary users.In this paper,we firstly construct the time distribution model of the primary user in and out of the interference region of the cognitive radio network.From the view of the user's movement,the available transmission time for a single user and the problem of sensing time threshold are put forward.Secondly,Because of the mobilityof the primary users,the sensing accurate of spectrum sensing algorithm would not be improved although using the longer sensing time.In order to give the time parameter design method of the application,especially for the random walk model which is most commonly used,a single user's optimal transmission time and sensing time threshold are given.The simulation is completed to verify the correctness of the algorithm.