TY - GEN
T1 - Detection of OFDM signals in fast time-varying channels with ICI self-cancellation
AU - Hsieh, Tsung Da
AU - Chang, Ming Xian
PY - 2009
Y1 - 2009
N2 - In fast time-varying environments, an OFDM system needs to insert denser pilot symbols among transmitted symbols for tracking the variation of the channel. To reduce the number of pilots, several algorithms including blind, semi-blind, and decision-directed (DD) approaches are proposed. Most of these algorithms assume the channel varies block-wisely, but remain invariant within one OFDM block duration. However, such channel model neglects the inter-(sub)channel interference (ICI) and may be not practical for fast time-varying channels. In this paper, we propose an ICI self-cancellation algorithm under an architecture that could be readily incorporated into an OFDM system that does not take the ICI into consideration. Our algorithm involves only periodic extension and linear combination, and incurs almost no additional complexity. The ICI can be completely removed if the variation of each path in the channel is linear with time during one extended OFDM block. Our algorithm also provides a trade-off between performance and throughput. To validates the proposed algorithm, we incorporate it into an OFDM system with pseudo-pilot (PP) detection. The simulation validates the efficiency of the proposed algorithm, and that neglecting the ICI in fast time-varying channels is impractical.
AB - In fast time-varying environments, an OFDM system needs to insert denser pilot symbols among transmitted symbols for tracking the variation of the channel. To reduce the number of pilots, several algorithms including blind, semi-blind, and decision-directed (DD) approaches are proposed. Most of these algorithms assume the channel varies block-wisely, but remain invariant within one OFDM block duration. However, such channel model neglects the inter-(sub)channel interference (ICI) and may be not practical for fast time-varying channels. In this paper, we propose an ICI self-cancellation algorithm under an architecture that could be readily incorporated into an OFDM system that does not take the ICI into consideration. Our algorithm involves only periodic extension and linear combination, and incurs almost no additional complexity. The ICI can be completely removed if the variation of each path in the channel is linear with time during one extended OFDM block. Our algorithm also provides a trade-off between performance and throughput. To validates the proposed algorithm, we incorporate it into an OFDM system with pseudo-pilot (PP) detection. The simulation validates the efficiency of the proposed algorithm, and that neglecting the ICI in fast time-varying channels is impractical.
UR - http://www.scopus.com/inward/record.url?scp=67650660922&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67650660922&partnerID=8YFLogxK
U2 - 10.1109/SARNOF.2009.4850288
DO - 10.1109/SARNOF.2009.4850288
M3 - Conference contribution
AN - SCOPUS:67650660922
SN - 9781424433827
T3 - 2009 IEEE Sarnoff Symposium, SARNOFF 2009 - Conference Proceedings
BT - 2009 IEEE Sarnoff Symposium, SARNOFF 2009 - Conference Proceedings
T2 - 2009 IEEE Sarnoff Symposium, SARNOFF 2009
Y2 - 30 March 2009 through 1 April 2009
ER -