TY - GEN
T1 - Cooperative OFDM channel estimation with frequency offsets
AU - Zhang, Zhongshan
AU - Zhang, Wei
AU - Tellambura, Chintha
PY - 2008
Y1 - 2008
N2 - This paper discusses channel estimation in a cooperative orthogonal frequency-division multiplexing (OFDM) network in the presence of frequency offsets. Both the amplify- and-forward (AF) and decode-and-forward (DF) relaying modes are analyzed. In order to eliminate the multiple access inter- ference(MAI), the maximumnumberof activeAF and DF relays are I and respectively, where N is the total number of subcarriers, L is the channel order and [a] is the maximum integer part of a. The pairwise error probability (PEP) of orthogonal space-time coding in cooperative OFDM due to both the frequency offset and channel estimation errors is also evaluated. The optimal power allocation ratio between the source and the set of the relays to minimize the PEP is derived for both the relay modes. When L< 16, the DF mode always outperforms the AF mode in terms of PEP. Given 16 active relays and with L = 4, the proposed DF mode outperforms the AF mode by about 9 dB for a frequency offset error variance of 10-3, and this gap increases to about 11.3 dB when the variance increases to 1010-3.
AB - This paper discusses channel estimation in a cooperative orthogonal frequency-division multiplexing (OFDM) network in the presence of frequency offsets. Both the amplify- and-forward (AF) and decode-and-forward (DF) relaying modes are analyzed. In order to eliminate the multiple access inter- ference(MAI), the maximumnumberof activeAF and DF relays are I and respectively, where N is the total number of subcarriers, L is the channel order and [a] is the maximum integer part of a. The pairwise error probability (PEP) of orthogonal space-time coding in cooperative OFDM due to both the frequency offset and channel estimation errors is also evaluated. The optimal power allocation ratio between the source and the set of the relays to minimize the PEP is derived for both the relay modes. When L< 16, the DF mode always outperforms the AF mode in terms of PEP. Given 16 active relays and with L = 4, the proposed DF mode outperforms the AF mode by about 9 dB for a frequency offset error variance of 10-3, and this gap increases to about 11.3 dB when the variance increases to 1010-3.
UR - http://www.scopus.com/inward/record.url?scp=67249158961&partnerID=8YFLogxK
U2 - 10.1109/GLOCOM.2008.ECP.704
DO - 10.1109/GLOCOM.2008.ECP.704
M3 - Conference contribution
AN - SCOPUS:67249158961
SN - 9781424423248
T3 - GLOBECOM - IEEE Global Telecommunications Conference
SP - 3665
EP - 3669
BT - 2008 IEEE Global Telecommunications Conference, GLOBECOM 2008
T2 - 2008 IEEE Global Telecommunications Conference, GLOBECOM 2008
Y2 - 30 November 2008 through 4 December 2008
ER -