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信道拥塞会导致数据包碰撞和丢失,使安全相关的消息无法可靠发送.而传统的信道拥塞控制通过检测信道占有率、信噪比和当前时刻节点数目,对功率进行被动控制,且大部分算法是开环控制,具有滞后性和不精确性.针对传统功率控制的滞后性和不精确性,基于模糊逻辑提出一种车联网自适应功率控制策略FAPCS(Adaptive Power Control Strategy Based On Fuzzy Logic).首先,建立了传输范围预测模型,通过预测交通流密度值,预测出满足90%数据包递送率的传输范围;然后,针对隐藏终端和预测密度的误差对数据包递送率的影响,设计了传输范围自适应调整模型,该模型通过模糊逻辑推理,得到满足90%数据包递送率的真实传输范围.仿真结果表明,该控制策略能够避免信道拥塞,使数据包递送率满足安全相关应用的需要,且具有较快收敛速度.
Congestion of the channel leads to data packet collision and loss, which makes the security-related message unable to be sent reliably.Traditional channel congestion control can passively control the power by detecting the channel occupancy, the signal-noise ratio and the number of nodes at the current time, and most of the algorithms Is open-loop control, with hysteresis and inaccuracies.Aiming at the lag and inaccuracy of traditional power control, an Adaptive Power Control Strategy Based On Fuzzy Logic (FAPCS) is proposed based on fuzzy logic. Firstly, the transmission range prediction model is established. By predicting the traffic flow density value, the transmission range of 90% of the packet delivery rate is predicted. Then, in view of the influence of the error of the hidden terminal and the prediction density on the packet delivery rate, The model adaptively adjusts the model by using fuzzy logic to get the true transmission range that satisfies 90% packet delivery rate.The simulation results show that this control strategy can avoid the channel congestion and make the packet delivery rate meet the needs of safety-related applications, And has a faster convergence rate.