Single Carrier FDMA (Interleaved FDMA) Presented Pr esented by; b y;
Alik Saha Surya Prakash Prakas h Tama amang. ng. Department of ETC 2/5/13
INTRODUCTION
Modified version of OFDM.
Currently
adopted as the uplink multiple access scheme for 3GPP LTE.
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Why SC-FDMA ?
To
overcome the problem of high PAPR in OFDM.
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PAPR of OFDM PAPR
of OFDM is approximately N. (where N is the no. of subcarriers).
Significantly
Caused
high.
due to preprocessing of IFFT ( Data symbols can add up to produce high peak value signal.
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PAPR of OFDM
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Affect of PAPR in OFDM
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BLOCK DIAGRAM OF OFDM
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MODIFICATION IN OFDM
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PRINCIPLE OF SC-FDMA
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Block Diagram of SCFMDA
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TYPES OF MAPPING
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Comparision of PAPR
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Role of SC-FDMA Decreases
the PAPR of OFDM.
Maintains
the no. of subcarriers (N), so less amount of information will be effected in cyclic prefixs.
Maintains 2/5/13
the properties of OFDM.
Ongoing Research Channel
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estimation for OFDM/SC-FDMA
Ø
Coherent demodulation used in OFDM/SCFDMA ,
Ø
Slight change in signal results in loss of message.
Conclusion Not
only reduces the PAPR of OFDM as well as maintains the no. of subcarriers.
Two
types of SC-FDMA – IFDMA and LFDMA.
PAPR of IFDMA is less than LFDMA.
On
going research in 4G transmission is “Channel Estimation of OFDM/SC-FDMA.
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Reference [1]
Hyung G. Myung, Junsung Lim, and David J. Goodman, “Single Carrier FDMA for Uplink Wireless Transmission.” IEEE Vehicular Technology,
[2]
H. Ekström, A. Furuskär, J. Karlsson, M. Meyer, S.Parkvall, J. Torsner, and M. Wahlqvist, “Technical Solutions for the 3G Long-Term Evolution,” IEEE Commun. Mag.,vol. 44, no. 3, pp. 38-45.
[3]J.
Lim, H. G. Myung, K. Oh, and D. J. Goodman, “Channel-Dependent Scheduling 2/5/13
