基于PID的信道自适应跨层优化无线视频传输

无线网络信道带宽有限、误码率高且实变性强。为了平衡无线网络视频服务中相互竞争、相互制约的2个重要指标,即抗错性能和传输效率,该文从跟踪无线网络的信道状态出发,提出了一种基于PID(比例积分微分)控制技术的无线视频传输框架,自适应地跨层优化无线视频通信系统的传输效率,使其在稳定性和传输效率之间达到有效的折衷。仿真实验表明了该方法的可行性和有效性,在同等条件下传输效率比传统方法提高10%~20%,尤其在无线信道误码率变化剧烈的情况下,效果更加明显。该算法对原有编解码器改动不大,具有较强的实用性。

PID-based channel-adaptive cross layer optimizing design for wireless video transmissions

In wireless networks with limited bandwidth,the error rates and high variety,robustness and transmission efficiency are always the two key incompatible parameters to evaluate the performance of wireless video service. A PID(proportional-integral-derivative) control scheme that tracks wireless channel conditions was desposed to adaptively optimize the transmission efficiency through a cross layer design.This PID control scheme provides the best utilization of limited wireless network resources while reducing channel errors.Simulations show that the method effectively increases transmission efficiency with few changes in the encoder or decoder,so it is quite practicable.