Call Admission Control in Wireless DS-CDMA Systems using Actor-Critic Reinforcement Learning

Abstract

This paper addresses the call admission control (CAC) problem for multiple services in the uplink of a cellular system using direct sequential code division multiple access (DS-CDMA) when taking into account the physical layer channel and receiver structure at the base station. The problem is formulated as a semi-Markov decision process (SMDP) with constraints on the blocking probabilities and signal-to-interference ratio (SIR). The objective is to find a CAC policy which maximizes the throughput while still satisfying these quality-of-service (QoS) constraints. To solve for a near optimal CAC policy, an online decision-making algorithm based on an actor-critic with temporal-difference learning from a paper is modified by parameterizing the reward signal to deal with the QoS constraints. The proposed algorithm circumvents the computational complexity experienced in conventional dynamic programming techniques