Iterative equalization and decoding using reduced-state sequence estimation based soft-output algorithms /

Bibliographic Details
Main Author:	Tamma, Raja Venkatesh, 1979-
Other Authors:	Narayanan, Krishna R. (Thesis advisor)
Format:	Thesis eBook
Language:	English
Published:	[College Station, Tex.] : [Texas A&M University], [2003]
Subjects:	Major electrical engineering. turbo equalization M-BCJR low-complexity equalizers convergence behavior true LLRs' estimation
Online Access:	Link to OAK Trust copy

Description
Abstract:	We study and analyze the performance of iterative equalization and decoding (IED) using an M-BCJR equalizer. We use bit error rate (BER), frame error rate simulations and extrinsic information transfer (EXIT) charts to study and compare the performances of M-BCJR and BCJR equalizers on precoded and non-precoded channels. Using EXIT charts, the achievable channel capacities with IED using the BCJR, M-BCJR and MMSE LE equalizers are also compared. We predict the BER performance of IED using the M-BCJR equalizer from EXIT charts and explain the discrepancy between the observed and predicted performances by showing that the extrinsic outputs of the $M$-BCJR algorithm are not true logarithmic-likelihood ratios (LLR's). We show that the true LLR's can be estimated if the conditional distributions of the extrinsic outputs are known and finally we design a practical estimator for computing the true LLR's from the extrinsic outputs of the M-BCJR equalizer.
Item Description:	"Major Subject: Electrical Engineering" Title from author supplied metadata. Electronic resource.
Physical Description:	1 online resource.
Bibliography:	Includes bibliographical references.