Joint Frequency-Domain Differential Detection and Equalization for 2-Dimensional Spread/Chip-Interleaved DS-CDMA Uplink Transmis

—The multiple-access interference (MAI) limits the performance of the DS-CDMA uplink transmission. 2 dimensional (2D) spread/chip-interleaved DS-CDMA is an MAI-free system, where single-user coherent frequencydomain equalization (FDE) can be used instead of complicated multiuser detection (MUD). However, coherent FDE needs channel estimation. Pilot-assisted channel estimation is not reliable in a fast fading environment. In this paper, we apply joint frequencydomain differential detection and equalization (FDDDE) that requires no channel estimation to 2D spread/chipinterleaved DS-CDMA in a multiuser/multipath environment. The filter coefficient used in FDDDE is updated by estimating the normalized Doppler frequency. Computer simulation results show that 2D spread/chipinterleaved DS-CDMA using FDDDE is robust against fast fading. Keywords - Differential detection, DS-CDMA uplink transmission, chip interleaving, 2-dimensional spreading.

• Type: Conference
• Year: 2006
• Where: VTC
• Authors: Le Liu, Fumiyuki Adachi
• Keywords: Channel Estimation, DS-CDMA, DS-CDMA Uplink Transmission, VTC 2006