Improving the Performance of HF Radio Networks in the Presence of Interference through Automatic Link Establishment with Frequency Hopping Technique

Automatic Link Establishment (ALE) is crucial to channel assignment and data exchange in HF radio networks. The link establishment interval and quality are two main concerns in this context. In jamming environments, the jammer signals seriously influence the channel quality. The Frequency Hopping (FH) approach supports communication links to overcome the jamming impairments, so using the FH technique in the traditional ALE algorithm can make it more stable. This paper develops the ALE algorithms to handle different jamming scenarios and establish robust connections to exchange data using the proposed Frequency Hopping Based Automatic Link Establishment (FH-ALE) system. Besides, in the proposed algorithm, we consider the link establishment interval almost identical to the traditional ALE scenario. To evaluate the performance of the proposed system, we simulate the FH-ALE system and the Traditional ALE system in MATLAB software. Also, we calculate the link Establishment Probability and the throughput value for both systems in different channel conditions, including the AWGN channel without a jammer and in presence of Partial-band, Follower, and Multi-tone jammers. Hence, the throughput value is approximately identical in the proposed and traditional cases in the normal channel condition. The simulation results represent the superiority of the proposed FH-ALE approach in jamming environments. Thus, depending on the jammer type and the desired conditions for link establishment, including the channel noise status, the proposed system has about 1 to 5dB performance improvement in comparison to the traditional ALE systems.