Iterative maximum-likelihood sequence estimation for space-time coded systems

Yingxue Li, Costas N. Georghiades, Garng Morton Huang

Research output: Contribution to journalArticle

73 Citations (Scopus)

Abstract

In recent work on decoding space-time codes, it is either assumed that perfect channel state information (CSI) is present, or a channel estimate is obtained using pilot symbols and then used as if it were perfect to extract symbol estimates. In the latter case, a loss in performance is incurred, since the resulting overall receiver is not optimal. In this letter, we look at maximum-likelihood (ML) sequence estimation for space-time coded systems without assuming CSI. The log-likelihood function is presented for both quasi-static and nonstatic fading channels, and an expectation-maximization (EM)-based algorithm is introduced for producing ML data estimates, whose complexity is much smaller than a direct evaluation of the log-likelihood function. Simulation results indicate the EM-based algorithm achieves a performance close to that of a receiver which knows the channel perfectly.

Original languageEnglish
Pages (from-to)948-951
Number of pages4
JournalIEEE Transactions on Communications
Volume49
Issue number6
DOIs
Publication statusPublished - 1 Jun 2001
Externally publishedYes

Fingerprint

Channel state information
Maximum likelihood
Space time codes
Fading channels
Decoding

Keywords

  • Complexity
  • EM algorithm
  • Performance
  • Sequence estimation
  • Space-time coding

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

Iterative maximum-likelihood sequence estimation for space-time coded systems. / Li, Yingxue; Georghiades, Costas N.; Huang, Garng Morton.

In: IEEE Transactions on Communications, Vol. 49, No. 6, 01.06.2001, p. 948-951.

Research output: Contribution to journalArticle

@article{9fef9d1ed7e84540b6d3aa3227fb7fda,
title = "Iterative maximum-likelihood sequence estimation for space-time coded systems",
abstract = "In recent work on decoding space-time codes, it is either assumed that perfect channel state information (CSI) is present, or a channel estimate is obtained using pilot symbols and then used as if it were perfect to extract symbol estimates. In the latter case, a loss in performance is incurred, since the resulting overall receiver is not optimal. In this letter, we look at maximum-likelihood (ML) sequence estimation for space-time coded systems without assuming CSI. The log-likelihood function is presented for both quasi-static and nonstatic fading channels, and an expectation-maximization (EM)-based algorithm is introduced for producing ML data estimates, whose complexity is much smaller than a direct evaluation of the log-likelihood function. Simulation results indicate the EM-based algorithm achieves a performance close to that of a receiver which knows the channel perfectly.",
keywords = "Complexity, EM algorithm, Performance, Sequence estimation, Space-time coding",
author = "Yingxue Li and Georghiades, {Costas N.} and Huang, {Garng Morton}",
year = "2001",
month = "6",
day = "1",
doi = "10.1109/26.930622",
language = "English",
volume = "49",
pages = "948--951",
journal = "IEEE Transactions on Communications",
issn = "0096-1965",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "6",

}

TY - JOUR

T1 - Iterative maximum-likelihood sequence estimation for space-time coded systems

AU - Li, Yingxue

AU - Georghiades, Costas N.

AU - Huang, Garng Morton

PY - 2001/6/1

Y1 - 2001/6/1

N2 - In recent work on decoding space-time codes, it is either assumed that perfect channel state information (CSI) is present, or a channel estimate is obtained using pilot symbols and then used as if it were perfect to extract symbol estimates. In the latter case, a loss in performance is incurred, since the resulting overall receiver is not optimal. In this letter, we look at maximum-likelihood (ML) sequence estimation for space-time coded systems without assuming CSI. The log-likelihood function is presented for both quasi-static and nonstatic fading channels, and an expectation-maximization (EM)-based algorithm is introduced for producing ML data estimates, whose complexity is much smaller than a direct evaluation of the log-likelihood function. Simulation results indicate the EM-based algorithm achieves a performance close to that of a receiver which knows the channel perfectly.

AB - In recent work on decoding space-time codes, it is either assumed that perfect channel state information (CSI) is present, or a channel estimate is obtained using pilot symbols and then used as if it were perfect to extract symbol estimates. In the latter case, a loss in performance is incurred, since the resulting overall receiver is not optimal. In this letter, we look at maximum-likelihood (ML) sequence estimation for space-time coded systems without assuming CSI. The log-likelihood function is presented for both quasi-static and nonstatic fading channels, and an expectation-maximization (EM)-based algorithm is introduced for producing ML data estimates, whose complexity is much smaller than a direct evaluation of the log-likelihood function. Simulation results indicate the EM-based algorithm achieves a performance close to that of a receiver which knows the channel perfectly.

KW - Complexity

KW - EM algorithm

KW - Performance

KW - Sequence estimation

KW - Space-time coding

UR - http://www.scopus.com/inward/record.url?scp=0035362079&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035362079&partnerID=8YFLogxK

U2 - 10.1109/26.930622

DO - 10.1109/26.930622

M3 - Article

VL - 49

SP - 948

EP - 951

JO - IEEE Transactions on Communications

JF - IEEE Transactions on Communications

SN - 0096-1965

IS - 6

ER -