MaximumLikelihood Synchronization and Channel Estimation for OFDMA Uplink Transmissions

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Maximum-Likelihood Synchronization and Channel
Estimation for OFDMA Uplink Transmissions

• Chi-En Li
• Directed by Prof. Jung-Shan Lin
• Graduate Institute of Communication Engineering
• National Chi Nan University
• 12/ 11/ 2008

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Outline

• System model and signal model
• CFO estimation
• Estimation of the timing offsets and channel
• Simulation
• Conclusion

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System model
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Signal model
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CFO estimation

• Alternating-Projection Frequency Estimator (APFE)

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CFO estimation
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CFO estimation
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CFO estimation
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CFO estimation

• Approximate Alternating-Projection Frequency
  Estimator (AAPFE)

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Estimation of the timing offsets and channel
responses
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Estimation of the timing offsets and channel
responses
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Simulation parameters

• Operation 5GHz
• Signal bandwidth 20MHz
• L 8
• Ng 28
• QPSK
• N 128
• CFO -0.32 , 0.32
• Delay 0 , 20 (sample period)
• HIPERLAN/2 channel model

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Simulation
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Simulation
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Simulation
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Simulation
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Conclusion

• APFE and AAPFE
• Simulation
• The M value
• The number of user
• The signal power of user

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Reference

• Maximum-likelihood synchronization and channel
  estimation for OFDMA uplink transmissionsPun,
  M.-O. Morelli, M. Kuo, C.-C.J.Communications,
• IEEE Transactions on Volume 54,  Issue 4, 
  April 2006 Page(s)726 - 736 Digital Object
  Identifier 10.1109/TCOMM.2006.873093