On the performance analysis of SC-FDMA uplink communication systems using multiple-CFO synchronization with null-subcarriers


Reşat M. A. , Ertuğ Ö.

Semantic Scholar Comp. Sci., cilt.1, no.1, ss.1-10, 2013 (Hakemsiz Dergi)

  • Cilt numarası: 1 Konu: 1
  • Basım Tarihi: 2013
  • Dergi Adı: Semantic Scholar Comp. Sci.
  • Sayfa Sayıları: ss.1-10

Özet

3GPP has selected single-carrier frequencydivision multiple-access (SC-FDMA) for Long Term Evolution (LTE) uplink access scheme due to its low peakto-average power ratio (PAPR) advantage. However, like all the orhogonal frequency-division multiplexing (OFDM) based schemes, SC-FDMA also suffers from carrier frequency-offset (CFO), and this is a major problem especially for LTE uplink, where more than one CFOs exist. CFO synchronization is harder in uplink than downlink, due to this multiple CFOs. There are two kinds of effects that occur owing to CFO; inter-carrier interference (ICI), which occurs between a user’s own subcarriers and multiple-access interference (MAI), which occurs between different users’ subcarriers. In this paper, we proposed a suppression method to overcome the multiple CFOs estimation and suppression in LTE uplink problem. In this algorithm, null subcarriers which are present in LTE uplink standard are used. The main idea is to measure the energy of the signal in null subcarriers and use the CFO value which provides minimum energy during CFO suppression. In addition, the effects of FFT size, number of users and subcarrier mapping scheme on the overall system performance are analyzed.