DocumentCode :
1382716
Title :
Widely Linear versus Conventional Subspace-Based Estimation of SIMO Flat-Fading Channels: Mean Squared Error Analysis
Author :
Abdallah, Saeed ; Psaromiligkos, Ioannis N.
Author_Institution :
Dept. of Electr. & Comput. Eng., McGill Univ., Montreal, QC, Canada
Volume :
60
Issue :
3
fYear :
2012
fDate :
3/1/2012 12:00:00 AM
Firstpage :
1307
Lastpage :
1318
Abstract :
We analyze the mean squared error (MSE) performance of widely linear (WL) and conventional subspace-based channel estimation for single-input multiple-output (SIMO) flat-fading channels employing binary phase-shift-keying (BPSK) modulation when the covariance matrix is estimated using a finite number of samples. The conventional estimator suffers from a phase ambiguity that reduces to a sign ambiguity for the WL estimator. We derive accurate closed-form expressions for the MSE of the two estimators under four ambiguity resolution scenarios. In the first three scenarios, the receiver resolves the ambiguity using some clairvoyant knowledge about the channel. The first scenario, used as a reference, is the ideal case of optimal resolution. The second scenario assumes that one of the channel coefficients is known and the third assumes knowledge of the coefficient with the largest magnitude. The fourth scenario considers the more realistic case where pilot symbols are employed for ambiguity resolution. Our work demonstrates that there is a strong relationship between the accuracy of ambiguity resolution and the relative performance of WL and conventional subspace-based estimators, showing that the WL estimator performs better when partial or inaccurate channel information is employed for ambiguity resolution.
Keywords :
MIMO communication; channel estimation; covariance matrices; fading channels; mean square error methods; phase shift keying; BPSK; MSE; ambiguity resolution scenarios; binary phase-shift-keying modulation; channel coefficients; clairvoyant knowledge; conventional subspace-based channel estimation; conventional subspace-based estimation; covariance matrix; finite number; mean squared error analysis; partial channel information; pilot symbols; single-input multiple-output flat-fading channels; widely linear estimator; Binary phase shift keying; Channel estimation; Closed-form solutions; Eigenvalues and eigenfunctions; Estimation; Signal resolution; Vectors; Channel estimation; improper signals; phase ambiguity; sign ambiguity; single-input multiple-output (SIMO); subspace methods; widely linear processing;
fLanguage :
English
Journal_Title :
Signal Processing, IEEE Transactions on
Publisher :
ieee
ISSN :
1053-587X
Type :
jour
DOI :
10.1109/TSP.2011.2177261
Filename :
6086772
Link To Document :
بازگشت