Turbo/katlamalı kodlanmış SFBC/STBC-OFDM sistemlerinde yinelemeli kanal kestirimi
Author
Doǧan, H.
Çırpan, H. A.
Panayırcı, Erdal
Date
2006-04Source Title
2006 IEEE 14th Signal Processing and Communications Applications Conference
Pages
[1] - [4]
Language
Turkish
Type
Conference PaperItem Usage Stats
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Abstract
We consider the design of turbo receiver structures for space-frequency block coded (SFBC/STBC) OFDM systems in unknown frequency selective fading channels. The Turbo receiver structures for SFBC/STBC-OFDM systems under consideration consists of an iterative MAP Expectation/Maximization (EM) channel estimation algorithm, soft MMSE SFBC/STBC decoder and a soft MAP outer-channel-code decoder. MAP-EM employs iterative channel estimation and it improves receiver performance by re-estimating the channel after each decoder iteration. Moreover, the MAP-EM approach considers the channel variations as random processes and applies the Karhunen-Loeve (KL) orthogonal series expansion. The performance of the proposed approaches are studied in terms of mean square error and bit-error rate. Through experimental results, the effect of a pilot spacing on the channel estimator performance and sensitivity of turbo receiver structures on channel estimation error are studied. © 2006 IEEE.
Keywords
DecodersKarhunen-Loeve (KL) orthogonal series expansion
Turbo receiver
Bit error rate
Block codes
Fading channels
Iterative decoding
Mean square error
Optimization
Orthogonal frequency division multiplexing
Turbo codes
Channel estimation