短波IP网络中速率自适应与SR-ARQ性能分析

短波信道的时变特性将严重影响短波通信的传输效率,同时在短波IP（Internet protocol）组网通信中影响更为显著。为此,在短波IP数据传输中给出基于选择重发ARQ (selective repeat automatic repeat-requst，SR-ARQ)的自适应调整速率的短波通信系统。系统选择有效吞吐率作为速率自适应阈值判决标准，得出了一般有效吞吐率表达式，以及不同速率判决的最佳阈值。理论分析和仿真验证了与单一速率系统相比较，系统吞吐率有明显提高。最后通过理论计算和仿真分析证明在数据分组和IP数据包在排队性能上,系统同样具有明显优越性。

Performance analysis of rate adaptation and SR-ARQ in high frequency IP network

The high frequency (HF) channel which is a time varying channel, impacts the the transmission efficiency of the HF communication,while much more seriously in HF IP network communications.  A rate adaptation technique based on selective repeat automatic repeat requst (SR-ARQ) in HF data communication is proposed. Throughput of the communication system is used as the performance index. And the general closed form expression of the average throughput is presented,as well as the decision threshold for different rate. Through the theoretical analysis and simulation the advantage of which system throughput rate have improved significantly is verified compared with single rate system. After the theoretical calculation and the simulation analysis, the superiority of the system in throughput and queuing performance about data frame and the IP frame is proved.