TY - GEN
T1 - MMSE turbo equalization for multicode DS-CDMA
AU - Takeda, Kazuaki
AU - Adachi, Fumiyuki
PY - 2006/12/1
Y1 - 2006/12/1
N2 - Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can replace the conventional rake combining with significantly improved bit error rate (BER) performance of multicode DS-CDMA in a frequency-selective fading channel. However, the presence of residual inter-chipinference (ICI) after MMSE-FDE produces the orthogonality distortion among the spreading codes and the BER performance degrades as the number of multiplex order increases. Recently, we have proposed a frequency-domain ICI cancellation to improve the uncoded performance. To further improve the BER performance, in this paper, we propose MMSE turbo equalization. In the proposed scheme, MMSE-FDE and ICI cancellation are incorporated into iterative maximum a posteriori (MAP) decoding, resulting in an MMSE turbo equalization. MMSE weight taking into account the residual ICI is updated in each iteration. The effect of MMSE turbo equalization is confirmed by computer simulation.
AB - Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can replace the conventional rake combining with significantly improved bit error rate (BER) performance of multicode DS-CDMA in a frequency-selective fading channel. However, the presence of residual inter-chipinference (ICI) after MMSE-FDE produces the orthogonality distortion among the spreading codes and the BER performance degrades as the number of multiplex order increases. Recently, we have proposed a frequency-domain ICI cancellation to improve the uncoded performance. To further improve the BER performance, in this paper, we propose MMSE turbo equalization. In the proposed scheme, MMSE-FDE and ICI cancellation are incorporated into iterative maximum a posteriori (MAP) decoding, resulting in an MMSE turbo equalization. MMSE weight taking into account the residual ICI is updated in each iteration. The effect of MMSE turbo equalization is confirmed by computer simulation.
KW - DS-CDMA
KW - Frequency-domain equalization
KW - ICI cancellation
KW - MMSE turbo equalization
UR - http://www.scopus.com/inward/record.url?scp=46949093231&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=46949093231&partnerID=8YFLogxK
U2 - 10.1109/ICCS.2006.301488
DO - 10.1109/ICCS.2006.301488
M3 - Conference contribution
AN - SCOPUS:46949093231
SN - 1424404118
SN - 9781424404117
T3 - 2006 IEEE Singapore International Conference on Communication Systems, ICCS 2006
BT - 2006 IEEE Singapore International Conference on Communication Systems, ICCS 2006
T2 - 10th IEEE Singapore International Conference on Communications Systems, ICCS 2006
Y2 - 30 October 2006 through 1 November 2006
ER -