TY - GEN
T1 - Frequency offset and channel estimation in co-relay cooperative OFDM systems
AU - Zhang, Zhongshan
AU - Liu, Jian
AU - Long, Keping
AU - Fan, Yong
PY - 2012
Y1 - 2012
N2 - Frequency offset and channel estimation in cooperative orthogonal frequency division multiplexing (OFDM) systems is studied in this paper. We consider the scenario of two or more source nodes sharing the same relay, i.e., corelay cooperative communications, and a new preamble, which is central-symmetric in time-domain, is proposed to perform the frequency offset and channel estimation. The non-zero samples in the proposed preamble are sparsely distributed with two neighboring non-zero samples being separated by μ > 1 zeros. As long as μ > 2L - 1 is satisfied, the multipath interference can be effectively eliminated, where L stands for the channel order. Unlike [1], the proposed preamble has a much lower Peak-to-Average Power Ratio (PAPR). The interference among the multiple source nodes can also be eliminated by using a backoff modulation scheme on the proposed preamble in each source node, and the mean-square error (MSE) of the proposed Least-Square (LS) channel estimator can be minimized by ensuring the orthogonality among the source nodes. The Pairwise Error Probability (PEP) performance of the proposed system by considering both the frequency offset and channel estimation errors is also derived in this paper. For a given Signalto-Noise-Ratio (SNR), by keeping the total power consumption to the source nodes and the relay to be constant, the PEP can be minimized by adjusting the ratio between the power allocated to the source nodes and the total power.
AB - Frequency offset and channel estimation in cooperative orthogonal frequency division multiplexing (OFDM) systems is studied in this paper. We consider the scenario of two or more source nodes sharing the same relay, i.e., corelay cooperative communications, and a new preamble, which is central-symmetric in time-domain, is proposed to perform the frequency offset and channel estimation. The non-zero samples in the proposed preamble are sparsely distributed with two neighboring non-zero samples being separated by μ > 1 zeros. As long as μ > 2L - 1 is satisfied, the multipath interference can be effectively eliminated, where L stands for the channel order. Unlike [1], the proposed preamble has a much lower Peak-to-Average Power Ratio (PAPR). The interference among the multiple source nodes can also be eliminated by using a backoff modulation scheme on the proposed preamble in each source node, and the mean-square error (MSE) of the proposed Least-Square (LS) channel estimator can be minimized by ensuring the orthogonality among the source nodes. The Pairwise Error Probability (PEP) performance of the proposed system by considering both the frequency offset and channel estimation errors is also derived in this paper. For a given Signalto-Noise-Ratio (SNR), by keeping the total power consumption to the source nodes and the relay to be constant, the PEP can be minimized by adjusting the ratio between the power allocated to the source nodes and the total power.
UR - http://www.scopus.com/inward/record.url?scp=84864987282&partnerID=8YFLogxK
U2 - 10.1109/VETECS.2012.6240004
DO - 10.1109/VETECS.2012.6240004
M3 - Conference contribution
AN - SCOPUS:84864987282
SN - 9781467309905
T3 - IEEE Vehicular Technology Conference
BT - IEEE 75th Vehicular Technology Conference, VTC Spring 2012 - Proceedings
T2 - IEEE 75th Vehicular Technology Conference, VTC Spring 2012
Y2 - 6 May 2012 through 9 June 2012
ER -