Fig. 1. OFDMA frame structure on TDD mode
Fig. 2. Block diagram of OFDMA transmitter
Fig. 3. ISI with no cyclic prefix
Fig. 4. ISI with cyclic prefix
Fig. 5. OFDMA channel structure
Fig. 6. Block diagram of Transmitter and Receiver
Fig. 7. Block diagram of Digitizer H/W
Fig. 8. Block diagram of Digitizer Core
Fig. 9. Constellation diagram and EVM for QPSK signal
Fig. 10. Result for moving average
Fig. 11. Searching the symbol start point on OFDMA
Fig. 12. Result for extracting reference level
Fig. 13. Searching for symbol timing
Fig. 14. Result for FFT calculation
Fig. 15. Result for FFT Shift
Fig. 16. Value of amplitude compensation
Fig. 17. Value of phase compensation
Fig. 18. Before amplitude and phase compensation
Fig. 19. After amplitude and phase compensation
Fig. 20. EVM vs. Sub-carrier
Fig. 21. EVM vs. Symbol
Fig. 22. Test Block Diagram
Fig. 23. Test result for algorithm
Fig. 24. Test result with K Company VSA S/W
Table 1. Comparison for test result
References
- IEEE 802.16 Working Group Officers, "IEEE Standard for Local and metropolitan area networks,(IEEE 802.16e) " IEEE, 2006.
- K. Balachandran, D. Calin, "Design and Analysis of an IEEE 802.16e-Based OFDMA Communication System", Bell Labs Technical Journal Vol.11, No.4, pp.53-73 2007 DOI: https://doi.org/10.1002/bltj.20196
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- W. Henkel, G. Taubock, P. Odling, P.O. Borjesson, N. Petersson, "The Cyclic Prefix of OFDM/DMT, An Analysis", 2002 International Zurich Seminar on Broadband Communications Access, Feb. 2002 DOI: https://doi.org/10.1109/IZSBC.2002.991762
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- E. S. Kim, H. J. Kim, K. W. Shin, "A performance analysis of layered LDPC decoder for mobile WiMAX system ", Journal of the Korea Institute of Information and Communication Engineering, Vol. 15, No. 4, pp.921-929,April. 2011 DOI: https://doi.org/10.6109/jkiice.2011.15.4.921