Abstract: The authors introduce equivalent antipodes at the receiver to transform the antipodal propagation to several equivalent point-to-point communication systems. Since many communication directions are permitted in the antipodal propagation, especially each of which carries on different propagation modes with respective time delay and received power, the channel experiences a strong characteristic of frequency selective fading. In order to strengthen the received power and increase the coherence bandwidth, an adaptive antenna array is applied in the transmitter with narrow beams spatially concentrating the transmission energy on the main path and suppressing the other multipath resulting in delay spread. Simulation results verify the efficiency of this proposal.

Key words: antipodal propagation, coherence bandwidth, narrow beam, equivalent antipode

摘要： 通过在接收端引入等效对跖点，将短波对跖通信转化成了若干个等效对跖通信链路。由于对跖通信收发两点间可传播方向很多并且各方向上存在具有不同传输时延和输出功率的传输模式，导致通信信道具有很强的频率选择性衰落特性。提出在发射端采用自适应天线阵列形成窄波束的方法, 在空间上将发射能量对准主路径同时抑制其他路径信号，增强了接收信号功率及提高相干带宽。计算结果证实了该方法的有效性。

关键词: 对跖通信, 相干带宽, 窄波束, 等效对跖点