A HMM-Based Spectrum Access Method Used for HF Communication
Gang Herbert Lin, Yunpeng Cheng, Han Jiang · 2015
Aiming at the drawbacks of spectrum access strategy based on listening before transport in HF ALE protocols, a modified HMM is proposed to predict the channel availability and decide channel access. Giving full consideration to the usage regulation of HF channel, this model makes better use of the 'partially available' channel which is considered as 'occupied' under traditional two-state channel partition mechanism by a three-state one. The simulation results tells that in comparison to existing two-state HMM, this method uses channel longer with a lower switch rate and has higher predicting accuracy and channel utilization compared with traditional listening before transport strategy especially when 'partially available' channel appears frequently or SNR is low.