Double turbo equalization of continuous phase modulation with frequency domain processing

In this paper, a doubly-iterative linear receiver, equipped with a soft-information aided frequency domain minimum mean-squared error (MMSE) equalizer, is proposed for the combined equalization and decoding of coded continuous phase modulation (CPM) signals over long multipath fading channels. In the proposed receiver architecture, the front-end frequency domain equalizer (FDE) is followed by the soft-input, soft-output (SISO) CPM demodulator and channel decoder modules. The receiver employs double turbo processing by performing back-end demodulation/decoding iterations per each equalization iteration to improve the a priori information for the front-end FDE. As presented by the computational complexity analysis and simulations, this process provides not only a significant reduction in the overall computational complexity, but also a performance improvement over the previously proposed iterative and noniterative MMSE receivers.

[1]  L. Litwin,et al.  Error control coding , 2001 .

[2]  C.-E. Sundberg,et al.  Continuous phase modulation , 1986, IEEE Communications Magazine.

[3]  Mutlu Koca,et al.  Frequency-Domain Doubly-Iterative Equalization of Continuous Phase Modulation , 2006 .

[4]  David Falconer,et al.  Frequency domain equalization for single-carrier broadband wireless systems , 2002, IEEE Commun. Mag..

[5]  T. Aulin,et al.  Continuous Phase Modulation - Part I: Full Response Signaling , 1981, IEEE Transactions on Communications.

[6]  Mutlu Koca,et al.  WLCp1-03: Frequency-Domain Doubly-Iterative Equalization of Continuous Phase Modulation , 2006, IEEE Globecom 2006.

[7]  Andrew C. Singer,et al.  Turbo equalization: principles and new results , 2002, IEEE Trans. Commun..

[8]  Hikmet Sari,et al.  Transmission techniques for digital terrestrial TV broadcasting , 1995, IEEE Commun. Mag..

[9]  Gordon L. Stüber,et al.  MLSE and soft-output equalization for trellis-coded continuous phase modulation , 1997, IEEE Trans. Commun..

[10]  Keith M. Chugg,et al.  Reduced state adaptive SISO algorithms for serially concatenated CPM over frequency-selective fading channels , 2001, GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270).

[11]  Tor Aulin,et al.  Generalized APP detection of continuous phase modulation over unknown ISI channels , 2005, IEEE Transactions on Communications.

[12]  Bixio Rimoldi,et al.  A decomposition approach to CPM , 1988, IEEE Trans. Inf. Theory.

[13]  G.M. Vitetta,et al.  Equalization algorithms in the frequency domain for continuous phase modulations , 2005, GLOBECOM '05. IEEE Global Telecommunications Conference, 2005..

[14]  Jun Tan,et al.  Frequency-domain equalization for continuous phase modulation , 2005, IEEE Transactions on Wireless Communications.

[15]  Hakan Deliç,et al.  Doubly Iterative Equalization of Continuous-Phase Modulation , 2007, IEEE Transactions on Communications.