Coded Slotted Aloha (CSA) with Capture

Abstract:
The Coded Slotted Aloha (CSA) scheme has been proposed for the uncoordinated, non orthogonal multiple access. CSA achieves an outstanding performance by exploiting segmentation, code diversity, and interference cancellation. In the literature, the CSA performance has been evaluated assuming the conventional erasure channel. Purpose of this paper is to extend the evaluation to the more realistic capture channel. To this aim, two approaches are considered: an ideal full capture one, in which the position of the segments is known by the receiver, and a mixed approach, in which the reception of a single uncollided segment is required. A code redesign is also proposed for the situation in which the nodes transmit with a constant power, while, the more general scenario characterized by fading and power diversity is investigated by extensive Monte Carlo evaluations.