Combined multiuser reception and channel decoding for TDMA cellular systems

This paper presents a method of combating the detrimental effects of multiple-access interference present in coded time division multiple access (TDMA) systems. The optimal asynchronous multiuser detector is adapted for use by TDMA systems, which are characterized by a single desired user and a small number of strong interferers operating in adjacent cells with identical spreading codes. The proposed receiver features a soft-input/soft-output (SISO) multiuser detector and a SISO channel decoder operating in an iterative feedback, or "turbo" configuration. Simulation results are shown for the case when two users, the desired user and one strong interferer, are jointly detected and each user employs a weak recursive systematic convolutional code.