  The random access scheme is a fundamental scenario in which users transmit
through a shared channel and cannot coordinate each other. In recent years,
successive interference cancellation (SIC) was introduced into the random
access scheme. It is possible to decode transmitted packets using collided
packets by the SIC. The coded slotted ALOHA (CSA) is a random access scheme
using the SIC. The CSA encodes each packet using a local code prior to
transmission. It is known that the CSA achieves excellent throughput. On the
other hand, it is reported that in the coding theory time shift improves the
decoding performance for packet-oriented erasure correcting codes. In this
paper, we propose a random access scheme which applies the time shift to the
CSA in order to achieve better throughput. Numerical examples show that our
proposed random access scheme achieves better throughput and packet loss rate
than the CSA.
