Title :
Programmable multiuser synchronization for OFDM-CDMA
Author :
Wu, Shan-Tsung ; Chen, Kwang-Cheng
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan
Abstract :
A more effective synchronization is required for multiuser detection because of its high sensitivity to estimation errors of timings, carrier phases, and amplitudes. From the multiuser synchronization approach proposed in Chang et al., (2000), we develop a linear-complexity programmable multiuser synchronization structure for OFDM-CDMA in a multiray fading channel. Based on LMMSE and BLUE, we develop joint estimation of timings, carrier phases, and amplitudes. The structure can be programmed to various OFDM-CDMA by adjusting system parameters and its performance is also verified by simulations. An algorithm is further proposed to avoid irrelevant calculations of FFT. The proposed structure is valuable and desirable for its programmability and near-far resistance
Keywords :
OFDM modulation; amplitude estimation; code division multiple access; fading channels; fast Fourier transforms; interference suppression; least mean squares methods; multiuser channels; phase estimation; synchronisation; BLUE; FFT; LMMSE; OFDM-CDMA; amplitude estimation; carrier phase estimation; linear complexity; multiray fading channel; multiuser detection; near-far resistance; programmable multiuser synchronization; timing estimation; Amplitude estimation; Equalizers; Estimation error; Fading; Frequency synchronization; Multiaccess communication; Multiple access interference; Multiuser detection; OFDM; Timing;
Conference_Titel :
Vehicular Technology Conference, 2001. VTC 2001 Spring. IEEE VTS 53rd
Conference_Location :
Rhodes
Print_ISBN :
0-7803-6728-6
DOI :
10.1109/VETECS.2001.944495
