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An Improved LLR Generation Technique for SC-FDMA Systems Using Frequency Domain MMSE Equalization  

Kim, Jin-Min (중앙대학교 전자전기공학부)
Im, Tae-Ho (중앙대학교 전자전기공학부)
Kim, Jae-Kwon (연세대학교 원주캠퍼스 컴퓨터정보통신공학부)
Yi, Joo-Hyun (삼성전자 정보통신연구소)
Cho, Yong-Soo (중앙대학교 전자전기공학부)
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.34, no.12C, 2009 , pp. 1197-1207 More about this Journal
Abstract
Orthogonal Frequency Division Multiple Access (OFDMA) is widely used as a multiple access technique for next generation mobile communication systems, however, its main drawback is the high peak-to-average ratio (PAPR). Thus for the uplink case where the transmit power is strictly limited due to the battery life of mobile units, single carrier frequency division multiple access (SC-FDMA) with low PAPR is preferred to OFDMA method. In this paper, we propose a method to improve the performance of SC-FDMA using frequency domain MMSE equalization. The proposed improved log-likelihood ratio (LLR) generation method exploits both the diversity characteristic of channels and the reciprocity that is obtained from the received signals. The complexity of the proposed method is analyzed and its performance gain is demonstrated via a set of computer simulations.
Keywords
SC-FDMA; LTE; MMSE; Diversity; LLR;
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