Design and analysis of multi-carrier multiple access systems without feedback

In this paper we study a multiple access system without feedback supporting multiple carriers for delay critical applications with a small loss tolerance. In such a system, users transmits R times within the next N timeslots, in order to improve their success probability. In an earlier work [1], we considered the same problem in a single carrier system and demonstrated that the distribution of properly designed user codes significantly improved the success probability over a random selection strategy. These user codes, that determine the R slots used for transmission, corresponded to so-called 2-(N, R, 1) designs.