Advertisement

Wireless Personal Communications

, Volume 69, Issue 4, pp 1773–1781 | Cite as

Data Rate Loss Due to Quantized SNR Estimates in Adaptive Bit Loading Algorithms

  • Güneş Karabulut Kurt
Article
  • 155 Downloads

Abstract

Adaptive bit loading enables OFDM systems to optimize the transmit power levels and/or transmission data rates. These algorithms require the knowledge of ideal signal to noise ratio (SNR) for each data subcarrier at both the transmitter and the receiver. However, in practice the channel SNR can only be obtained and shared between the destination and the information source in a quantized fashion. In this paper, we analyze the effect of SNR quantization on the system data rate. We analytically obtain the average data rate loss due to quantization of SNR estimates. We show, via measurement results on powerline communication channels, that the effect of SNR quantization on the system data rate is not negligible if a midtread quantizer with less than 8 bits is used in the SNR estimation process for powerline communications. We also compare obtained results with theoretical capacity values in order to emphasize the data rate loss due to making use of quantized SNR estimates.

Keywords

Adaptive bit loading Orthogonal frequency division multiplexing (OFDM) Powerline communication systems Quantization Signal to noise ratio (SNR) estimation 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Cover T. M., Thomas J. A. (1991) Elements of information theory. Wiley, USAzbMATHCrossRefGoogle Scholar
  2. 2.
    Hughes-Hartogs, D. (1987). Ensemble modem structure for imperfect transmission media. U.S. Patent 4 679 227.Google Scholar
  3. 3.
    Chow P. S., Chioffi J. M., Bingham J. A. C. (1995) A practical discrete multitone transceiver loading algorithm for data transmission over spectrally shaped channels. IEEE Transactions on Communications 43(243): 773–775CrossRefGoogle Scholar
  4. 4.
    Wyglinski A. M., Labeau F., Kabal P. (2005) Bit loading with BER-constraint for multicarrier systems. IEEE Transactions on Wireless Communications 4(4): 1383–1387CrossRefGoogle Scholar
  5. 5.
    Wang D., Cao Y., Zheng L. (2010) Efficient two-stage discrete bit loading algorithms for OFDM systems. IEEE Transactions on Vehicular Technology 59(7): 3407–3416CrossRefGoogle Scholar
  6. 6.
    Gong H., Ye W., Feng S., Song H. (2007) A subcarrier allocation algorithm for efficiently reducing power in multiuser OFDM systems. Wireless and Personal Communications 40: 233–243CrossRefGoogle Scholar
  7. 7.
    Xu J., Seo J.-S. (2010) Adaptive subcarrier and power allocation with fairness for multi-user space-time block coded OFDM system. Wireless and Personal Communications 53: 163–177CrossRefGoogle Scholar
  8. 8.
    Tan P., Beaulieu N. C. (2004) Reduced ICI in OFDM systems using the better than raised-cosine pulse. IEEE Communications Letters 8(3): 135–137CrossRefGoogle Scholar
  9. 9.
    Mourad H. M. (2006) Reducing ICI in OFDM systems using a proposed pulse shape. Wireless Personal Communications 40: 41–48CrossRefGoogle Scholar
  10. 10.
    Le K. N. (2008) Insights on ICI and its effects on performance of OFDM systems. Digital Signal Processing 18(6): 876–884CrossRefGoogle Scholar
  11. 11.
    Le K. N. (2008) Bounds on inter-carrier interference power of OFDM in a Gaussian scattering channel. Wireless Personal Communications 47(3): 355–362CrossRefGoogle Scholar
  12. 12.
    Le, K. N., & Dabke, K. P. (2011). Channel capacity of OFDM systems employing diversity in fading environments. Wireless Communications and Mobile Computing. doi: 10.1002/wcm.1078.
  13. 13.
    Forney G. D. Jr., Eyuboglu M. V. (1991) Combined equalization and coding using precoding. IEEE Communication Magazine 29(12): 25–34CrossRefGoogle Scholar
  14. 14.
    Papandreou N., Antonakopulos T. (2005) A new computationally efficient discrete bit-loading algorithm for DMT applications. IEEE Transactions on Communications 53(5): 785–789CrossRefGoogle Scholar
  15. 15.
    IEEE Std. 1901–2010. (2010). IEEE standard for broadband over power line networks: Medium access control and physical layer specifications.Google Scholar

Copyright information

© Springer Science+Business Media, LLC. 2012

Authors and Affiliations

  1. 1.Department of Electronics and Communications, Faculty of Electrical and Electronics EngineeringIstanbul Technical UniversityIstanbulTurkey

Personalised recommendations