Multiuser detection with an unknown number of active users: receiver design

In multiuser detection, the set of users active at any time may be unknown to the receiver. In these conditions, optimum reception consists of detecting simultaneously the set of activeusers and their data, problem that can be solved exactly by applying random-set theory (RST) and Bayesian recursions (BR). However, implementation of optimum receivers may be limited by their complexity, which grows exponentially with the number of potential users. In this paper we examine three strategies leading to reduced-complexity receivers.In particular, we show how a simple approximation of BRs enables the use of Sphere Detection (SD) algorithm, whichexhibits satisfactory performance with limited complexity.

Comunicació presentada en la 16th European Signal Processing Conference (EUSIPCO 2008), celebrada els dies 25, 26, 27, 28 i 29 d’agost de 2008 a Lausana (Suïssa), organitzada per la European Association for Signal Processing (EURASIP).

The work of Ezio Biglieri was supported by the Spanish Ministery of Education and Science under Project TEC2006-01428/TCM, and by the STREP project No. IST-026905(MASCOT) within the 6th framework program of the European Commission.