Modelling of capture effect and analysis in LEO satellite channel

Capture effect can improve the throughput of random multiple access protocols. An evaluation model of the capture effect is proposed for coherent BPSK demodulation. The model introduces the concept of carrier synchronisation probability conditioned upon the carrier-to-interference ratio into the evaluation of the capture probability. Moreover, the effect of bit-sync offset of interfering packets on the capture probability is also taken into account. An attempt is made by means of the proposed model to investigate the capture effect in the LEO satellite channel. The result shows that a relatively large link margin can result in a remarkable capture probability, and consequently benefit slotted ALOHA protocols with a substantial throughput improvement.