Skip to main content
Log in

Iterative detection of turbo-coded offset QPSK in the presence of frequency and clock offsets and AWGN

  • Original Paper
  • Published:
Signal, Image and Video Processing Aims and scope Submit manuscript

Abstract

The key contribution of this paper is to develop transmitter and receiver algorithms in discrete-time for turbo-coded offset QPSK signals. The procedure for simulating a clock offset between the transmitter and receiver is described. Due to the use of up-sampling, matched filtering and a differential correlation approach at the receiver, the time required for detecting the start of frame (SoF) is just around 500 symbols, which is also the length of the preamble. The initial estimate of the SoF and the frequency offset, obtained using the differential correlation approach, is improved using an iterative process. A novel two-step maximum likelihood (ML) frequency offset estimation is proposed, which significantly reduces the complexity over the conventional ML estimation. The decision-directed carrier and timing recovery algorithms use simple first-order IIR filters to track the carrier phase and clock slip. The proposed synchronization and detection techniques perform effectively at an SNR per bit close to 1.5 dB, in the presence of a frequency offset as large as 30% of the symbol-rate and a clock offset of 25 ppm (parts per million). It is shown via simulations that the performance loss with respect to the bare turbo code is only about 0.5 dB, for a preamble length of 500 and a BER of 10−7. The proposed techniques are well suited for software implementation.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. D’Amico A.A., D’Andrea A.N., Reggiannini R.: Efficient non-data-aided carrier and clock recovery for satellite DVB at very low signal-to-noise ratios. IEEE J. Select. Areas Commun. 19(12), 2320–2330 (2001)

    Article  Google Scholar 

  2. Harris F.J., Rice M.: Multirate digital filters for symbol timing synchronization in software defined radios. IEEE J. Select. Areas Commun. 19(12), 2346–2357 (2001)

    Article  Google Scholar 

  3. Gardner F.M.: Interpolation in digital modems—Part I: fundamentals. IEEE Trans. Commun. 41(3), 501–507 (1993)

    Article  MATH  Google Scholar 

  4. Erup L., Gardner F.M., Harris R.A.: Interpolation in digital modems—Part II: implementation and performance. IEEE Trans. Commun. 41(6), 998–1008 (1993)

    Article  Google Scholar 

  5. Cupo R.L., Gitlin R.D.: Adaptive carrier recovery systems for digital data communications receivers. IEEE J. Select. Areas Commun. 7(9), 1328–1339 (1989)

    Article  Google Scholar 

  6. Caouras, N., Morawski, R., Le-Ngoc, T.: Fast carrier recovery for burst-mode coherent demodulation using feedforward phase and frequency estimation techniques. In: Proceedings of the IEEE Canadian Conference on Electrical and Computer Engineering, pp. 79–83. Edmonton, Canada, May 1999

  7. Saito S., Suzuki H.: Fast carrier-tracking coherent detection with dual-mode carrier recovery circuit for digital land mobile radio transmission. IEEE J. Select. Areas Commun. 7(1), 130–139 (1989)

    Article  Google Scholar 

  8. Kobayashi K., Sakai T., Kubota S., Morikura M., Kato S.: A new carrier recovery circuit for land mobile satellite communication. IEEE J. Select. Areas Commun. 10(8), 1306–1314 (1992)

    Article  Google Scholar 

  9. Uchishima, M., Tozawa, Y., Miyo, T., Takenaka, S.: Burst DSP demodulator for low E b /N 0 operation. In: Proceedings of IEEE International Conference on Communications, pp. 226–230. June 1991

  10. Kobayashi, K., Matsumoto, Y., Seki, K., Kato, S.: A full digital modem for offset type modulation schemes. In: Proceedings of the 3rd IEEE International Symposium on Personal, Indoor and Mobile Radio Communication, pp. 596–599. Oct 1992

  11. Lorenzelli F., Testa L., Visintin M., Biglieri E., Pent M.: Clock-aided carrier recovery in trellis-coded PSK. IEEE J. Select. Areas Commun. 7(9), 1307–1317 (1989)

    Article  Google Scholar 

  12. Sangriotis M., Xezonakis I.: Digital costas loop like PLL for the carrier recovery of a QPSK signal. Electron. Lett. 29(10), 897–899 (1993)

    Article  Google Scholar 

  13. Karam, G., Kervarec, J., Sari, H., Vandamme, P.: All-digital implementation of the carrier recovery loop in digital radio systems. In: Proceedings of IEEE International Conference on Communications, pp. 175–179. June 1991

  14. Benani, A.M., Gagnon, F.: Comparison of carrier recovery techniques in M-QAM digital communication systems. In: Proceedings of the IEEE Canadian Conference on Electrical and Computer Engineering, pp. 73–77. Mar. 2000

  15. Kim, K.-Y., Choi, H.-J.: Design of carrier recovery algorithm for high-order QAM with large frequency acquisition range. In: Proceedings of IEEE International Conference on Communications, pp. 1016–1020. June 2001

  16. Hou, H.-A.: Modified 128-QAM constellation schemes allowing low complexity non-data aided carrier recovery. In: Proceedings of the 16th IEEE International Symposium on Personal, Indoor and Mobile Radio Communication, pp. 2557–2561. (2005)

  17. Dauwels, J., Loeliger, H.-A.: Phase estimation by message passing. In: Proceedings of IEEE International Conference on Communications, pp. 523–527. June 2004

  18. Sutskover I., Shamai S.: Iterative decoding of low-density parity-check codes over compound channels. IEEE Trans. Commun. 54(2), 308–318 (2006)

    Article  Google Scholar 

  19. Nuriyev R., Anastasopoulos A.: Pilot-symbol-assisted coded transmission over the block-noncoherent AWGN channel. IEEE Trans. Commun. 51(6), 953–963 (2003)

    Article  Google Scholar 

  20. Komninakis C., Wesel R.D.: Joint iterative channel estimation and decoding in flat correlated Rayleigh fadin. IEEE J. Select. Areas Commun. 19(9), 1706–1717 (2001)

    Article  Google Scholar 

  21. Feher K., Takhar G.S.: A new symbol timing recovery technique for burst modem applications. IEEE Trans. Commun. 26(1), 100–108 (1978)

    Article  Google Scholar 

  22. Koblents, B., McLane, P.J.: Asynchronous timing recovery in DSP based PSK modems. In: Conference Record of the 26th Asilomar Conference on Signals, Systems and Computers, pp. 632–641. Oct. 1992

  23. Shi K., Serpedin E.: Fast timing recovery for linearly and non-linearly modulated systems. IEEE Trans. Veh. Technol. 54(6), 2017–2023 (2005)

    Article  Google Scholar 

  24. Shirato, Y., Yoshioka, H., Watanabe, K.: A novel timing recovery circuit with high tracking ability for burst-mode multilevel QAM transmission. In: IEEE Wireless Communications and Networking Conference (WCNC), pp. 578–583. Mar. 2005

  25. Barry J.R., Kavc̆ić A., McLaughlin S.W., Nayak A., Zeng W.: Iterative timing recovery. IEEE Sig. Proc. Mag. 21(1), 89–102 (2004)

    Article  Google Scholar 

  26. Bergel I., Weiss A.J.: Cramér-Rao bound on timing recovery of linearly modulated signals with no ISI. IEEE Trans. Commun. 51(4), 634–640 (2003)

    Article  Google Scholar 

  27. Ryan, W.E.: A turbo code tutorial (1997) available online at: http://www.ece.arizona.edu/~ryan/

  28. Brown J.L. Jr.: First-order sampling of bandpass signals—A new approach. IEEE Trans. Info. Theor. 26(5), 613–615 (1980)

    Article  Google Scholar 

  29. Vasudevan, K.: Digital communications and signal processing, 2nd edition (CDROM included). Universities Press (India), Hyderabad, (2010) www.universitiespress.com

  30. Vasudevan, K.: Synchronization of bursty offset QPSK signals in the presence of frequency offset and noise. In: Proceedings of IEEE TENCON, Hyderabad, India, Nov. 2008

  31. Vasudevan, K.: DSP-based algorithms for voiceband modems, masters thesis, Indian Institute of Technology, Madras (1995)

  32. Proakis J.G., Manolakis D.G.: Digital Signal Processing: Principles, Algorithms and Applications, 2nd edn . Maxwell MacMillan, Toronto (1992)

    Google Scholar 

  33. Meyr H., Moeneclaey M., Fechtel S.A.: Digital Communication Receivers vol. 2: Synchronization, Channel Estimation and Signal Processing. Wiley, London (1997)

    Google Scholar 

  34. Choi Z.Y., Lee Y.H.: Frame synchronization in the presence of frequency offset. IEEE Trans. Commun. 50(7), 1062–1065 (2002)

    Article  Google Scholar 

  35. Rife D.C., Boorstyn R.R.: Single-tone parameter estimation from discrete-time observations. IEEE Trans. Info. Theor. 20(5), 591–598 (1974)

    Article  MATH  Google Scholar 

  36. Bahl L., Cocke J., Jelinek F., Raviv J.: Optimal decoding of linear codes for minimizing symbol error rate. IEEE Trans. Inf. Theor. 20(2), 284–287 (1974)

    Article  MathSciNet  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to K. Vasudevan.

Additional information

This work is supported by the Defense Electronics Applications Lab (DEAL), Dehradun, India, under Grant DEAL/02/4043/2005-2006/ 02/016. This work was presented in part at the IEEE TENCON conference, Hyderabad, India, Nov. 2008.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Vasudevan, K. Iterative detection of turbo-coded offset QPSK in the presence of frequency and clock offsets and AWGN. SIViP 6, 557–567 (2012). https://doi.org/10.1007/s11760-010-0184-6

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11760-010-0184-6

Keywords

Navigation