Title :
Log likelihood ratio calculation without SNR estimation for forward link DS-CDMA receivers
Author_Institution :
Sch. of Electr. Eng., Seoul Nat. Univ., South Korea
fDate :
6/1/2004 12:00:00 AM
Abstract :
This letter deals with the log likelihood ratio computation for the turbo decoder operating on the forward link of a CDMA system. It is shown that the log likelihood ratio contains a time-varying factor, which is the power ratio between the data and the pilot channels. Two alternative techniques for estimating the power ratio are compared along with an ideal scheme.
Keywords :
code division multiple access; maximum likelihood estimation; spread spectrum communication; turbo codes; MAP; forward link DS-CDMA receivers; log likelihood ratio calculation; pilot channels; power ratio; time-varying factor; turbo decoder; turbo scaling; 3G mobile communication; Amplitude estimation; Analysis of variance; Base stations; Decoding; Fading; Mathematical model; Multiaccess communication; Multipath channels; Standards development; DS-CDMA; log likelihood ratio; turbo decoding; turbo scaling;
Journal_Title :
Signal Processing Letters, IEEE
DOI :
10.1109/LSP.2004.826665
