Author
Panayırcı, E., Şenol, H., Uysal, Murat, Poor, H. V.
Publication Date
2016-01-01
Publication Place
-
IEEE
Subject
Underwater Acoustic Channel Estimation, OFDM, AF Relaying, SAGE, Matching Pursuit, Continuous gaussian mixture
Type
Periodical
Language
English
Digital
Yes
Manuscript
No
Library
Özyeğin University
Library Asset ID
1053-587X
Record ID
c44832f5-8974-456e-9184-d3688cbf4b08
Library Location
Electrical & Electronics Engineering
Date
2016-01-01
Notes
Due to copyright restrictions, the access to the full text of this article is only available via subscription.
Sample Text
This paper is concerned with a challenging problem of channel estimation and equalization for amplifyand- forward cooperative relay based orthogonal frequency division multiplexing (OFDM) systems in sparse underwater acoustic (UWA) channels. The sparseness of the channel impulse response and prior information for the non-Gaussian channel gains, modeled by an exact continuous Gaussian mixture (CGM), are exploited to improve the performance of the channel estimation algorithm. The resulting novel algorithm initially estimates the overall sparse complex-valued channel taps from the source to the destination as well as their locations using the matching pursuit (MP) approach. The effective time-domain non- Gaussian noise is approximated well as a Gaussian noise in the frequency-domain, where the estimation takes place. An efficient and low complexity algorithm is developed based on the combinations of the MP and the maximum a posteriori probability (MAP) based space-alternating generalized expectationmaximization technique, to improve the estimates of the channel taps and their locations in an iterative way. Computer simulations show that the UWA channel is estimated very effectively and the proposed algorithm exhibits excellent symbol error rate and channel estimation performance.
