Recursive LLR combining in iterative multiuser decoding of coded CDMA
2007 (English)In: Australian Communication Theory Workshop, 2007, 104-109 p.Conference paper (Refereed)
Due to the prohibitive complexity of optimal multiuserdetection, suboptimal structures are commonly suggestedfor use in iterative multiuser decoders. The use of suboptimalcomponents in the iterative structure leads to performance lossesin terms of system load, bit error rate (BER), and convergencespeed. In this paper, we introduce a simple recursive filteringstructure into the iterative multiuser decoder, aimed at improvingthe performance. Optimal filter coefficients are determined basedon the joint likelihood function of the correlated output loglikelihoodratios (LLRs) over iterations. Numerical results showthat iterative multiuser systems with recursive LLR filteringand a posteriori feedback at the single-user decoder stage canachieve superior BER performance, produce convergence infewer iterations, and accommodate an increasing number ofactive users.
Place, publisher, year, edition, pages
2007. 104-109 p.
IdentifiersURN: urn:nbn:se:kth:diva-63210OAI: oai:DiVA.org:kth-63210DiVA: diva2:481805
Australian Communication Theory Workshop, AusCTW'07. Adelaide, Australia. 5-7 Feb. 2007
QC 201205162012-01-222012-01-222012-05-16Bibliographically approved