关键词: 短波信道, 抛物电离层, 时延扩展, 相干带宽

Abstract: The authors explain a double layers and plane valley electron density profile The coherence bandwidth of shortwave channel is calculated by using the density profile and wave propagation features in ionosphere Finally, coherence bandwidths for different operating frequencies and ground distances are obtained Because the double layers and plane valley model can analyze more exactly the multipath components and their path losses, it can obtain coherence bandwidths more closely to the measured values than those of the single layer model

Key words: shortwave channel, parabolic ionosphere, delay spread, coherence bandwidth