Capture model for mobile radio slotted ALOHA systems

Abstract

It is well known that the capture effect can considerably improve system throughput of mobile radio slotted ALOHA networks. Most of the capture models described in the literature are based on the signal-to-interference power ratios, with the assumption that the captured packet is error-free. In the paper, a capture model is proposed for slotted ALOHA systems employing symbol erasures and error-and-erasure correcting codes. In contrast to previous models, the model uses a target bit error rate as the capture measure, which in turn is controlled by a symbol-erasure threshold. Performance of the proposed model is analysed taking into account modulation and coding techniques, the signal-to-noise ratio, the user spatial distribution as well as Rayleigh channel fading.