Presented by:
M.N.N.V.SAIRAM
M.SUBRAMANYAM KUMAR
G.RAHUL VARMA

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Preamble-based SNR Estimation in Frequency Selective Channels for Wireless OFDM Systems
AIM:
To develop an efficient algorithm for the average SNR estimation in wireless OFDM systems.
BACK GROUND:
• OFDM is a multicarrier modulation scheme that provides strong robustness against inter symbol interference (ISI) by dividing the broadband channel into many narrowband sub- channels in such a way that attenuation across each sub channel stays flat.
• Orthogonalization of sub channels is performed with low complexity by using the fast Fourier transform (FFT).
• The serial high-rate data stream is converted into multiple parallel low-rate streams, each modulated on a different subcarrier.
ABSTRACT:
• Data-aided (DA) estimators are based on either perfect or estimated knowledge of the transmitted data.
• For packet based communications, block of information data is usually preceded by several training symbols (preambles) of known data used for synchronization and equalization purposes.
• DA SNR estimators can utilize preambles without additional throughput reduction.
BLOCK DIAGRAM:
ADVANTAGES:
• Efficient algorithm for the average SNR estimation in wireless OFDM systems.
• Algorithm is robust against frequency selectivity.
• APPLICATIONS:
• The SNR of a wireless OFDM system can be measured.