  In this paper, coded slotted ALOHA (CSA) is introduced as a powerful random
access scheme to the MAC frame. In CSA, the burst a generic user wishes to
transmit in the MAC frame is first split into segments, and these segments are
then encoded through a local a packet-oriented code prior to transmission. On
the receiver side, iterative interference cancellation combined with decoding
of the local code is performed to recover from collisions. The new scheme
generalizes the previously proposed irregular repetition slotted ALOHA (IRSA)
technique, based on a simple repetition of the users' bursts. An interpretation
of the CSA interference cancellation process as an iterative erasure decoding
process over a sparse bipartite graph is identified, and the corresponding
density evolution equations derived. Based on these equations, asymptotically
optimal CSA schemes are designed for several rates and their performance for a
finite number of users investigated through simulation and compared to IRSA
competitors. Throughputs as high as 0.8 are demonstrated. The new scheme turns
out to be a good candidate in contexts where power efficiency is required.
