In this paper, we consider and compare several different detection techniques for the down link of a MC-CDMA system in terms of bit error rate (BER) performance. In addition, an analysis of the linear detection approach named minimum mean square error (MMSE) multi-user detection per user (MMSE MUD) is presented. | ’ Tap ch´ Tin hoc v` Diˆu khiˆ n hoc, , (2007), 15—26 ı e e . . a ` . A STUDY ON DETECTION TECHNIQUES FOR DOWNLINK IN MULTI-CARRIER CDMA SYSTEM NGUYEN NGOC TIEN1 , NGUYEN VIET KINH2 , SEONG RAG KIM1 1 Electronic and Telecommunication Research Institute - ETRI, 161 Gajeong-dong, Yuseong-gu, Daejeon, 305-350 KOREA 2 Hanoi National University Abstract. In this paper, we consider and compare several different detection techniques for the down link of a MC-CDMA system in terms of bit error rate (BER) performance. In addition, an analysis of the linear detection approach named minimum mean square error (MMSE) multi-user detection per user (MMSE MUD) is presented. The investigations are carried out by examining the relationship between MMSE combining (MMSEC) detection technique and MMSE MUD technique. Simulation results show that in a full-load system, both MMSEC and MMSE-MUD technique have the same performance, while in a non full-load system, MMSE-MUD technique outperforms its MMSEC counterpart. ´ T´m t˘t. Trong b`i b´o n`y ch´ ng tˆi phˆn t´ v` d´nh gi´ mˆt sˆ k˜ thuˆt t´ch t´ hiˆu cho kˆnh o a a a a u o a ıch a a a o o y a a ın e e . ´ . . .`.ng xuˆng cua hˆ thˆng CDMA da s´ng mang thˆng qua chı tiˆu chˆ t tı sˆ lˆ i b´ (BER). ´ ´ ˜ ´ ’ e o ’ o o ıt ’ e o du o o o a . ´ . ` ´ o ´ ’ Dˆ ng th`.i ch´ ng tˆi c˜ng nghiˆn c´.u chi tiˆt mˆt giai ph´p t´ch tuyˆn t´ o o o a y a a ın u o u e u e a a e ınh, d´ l` k˜ thuˆt t´ch t´ . . .`.i d` ng trˆn lˆ i b` trung b` tˆi thiˆ u (MMSE) trˆn t`.ng ngu.`.i d` ng ’ ˜ ınh ´ e o ınh o e e u o u hiˆu da ngu o u e . . ´ (MMSE MUD). Nghiˆn c´.u tiˆn h`nh thˆng qua phˆn t´ su. quan gi˜.a ph´p e u u a e a o a ıch . . ´ ´ . ’ o ’ a a a e n`y v` k˜ thuˆt t´ch t´ hiˆu kˆt theo thuˆt to´n MMSE (MMSEC). C´c kˆt qua mˆ phong a a y a a ın e e . . . ´ ´ ´ ’ ’ cho thˆ y dˆi v´.i hˆ thˆng du ngu.`.i d`ng, ca hai k˜ thuˆt n`y dˆu c´ chı tiˆu chˆ t nhu. nhau. a o o e o o u y a a ` o
