Optimal blocked random access algorithm for CDMA-random access systems

Code-division multiple-access-random access systems are considered. Specifically, the authors consider a generalised common receiver model with transmitter-based code assignment and study a class of random access algorithms known as blocked random access algorithms. It is assumed that the number of active users at the beginning of a collision resolution epoch is known. An appropriate state of the system and control variables that constitute a Markovian decision process (MDP) are identified aid it is shown that the problem of optimal collision resolution algorithm is equivalent to the first passage problem of this MDP. The optimal control actions specify the number of users to be enabled separately for each code. The algorithm is illustrated with numerical examples