Combined modulation and coding for continuous-phase FSK with nonuniform alphabet

The problem of combined coding and modulation is addressed for M-ary continuous-phase frequency-shift-keying (CPFSK) with a redundant symbol alphabet. It is shown that in many cases of interest, the use of a nonuniform mapping between coded bits and phase increments at the CPFSK modulator allows for a significant increase of free Euclidean distance in the coder/modulator state trellis as compared to the uniform alphabet case. A systematic search for optimum encoder/mapper/modulator structures is carried out for short constraint length rate 1/2 and 2/3 codes combined with 4-ary and 8-ary CPFSK, respectively, and for a relevant set of rational modulation indexes. The power-bandwidth efficiency of the optimum schemes is discussed and compared with that exhibited by the best coder/modulator structures previously proposed in the literature. >

[1]  Carl-Erik W. Sundberg,et al.  Minimum Euclidean distance for combinations of short rate 1/2 convolutional codes and CPFSK modulation , 1984, IEEE Trans. Inf. Theory.

[2]  Peter J. McLane,et al.  Power spectral density of digital continuous phase modulation with correlated data symbols. Part 1: Autocorrelation function method , 1986 .

[3]  Umberto Mengali,et al.  Carrier Phase and Clock Recovery for Continuous Phase Modulated Signals , 1987, IEEE Trans. Commun..

[4]  Gottfried Ungerboeck,et al.  Channel coding with multilevel/phase signals , 1982, IEEE Trans. Inf. Theory.

[5]  Iwao Sasase,et al.  Coded continuous phase modulation combined with nonuniform mapping and multi-h scheme , 1988, IEEE Global Telecommunications Conference and Exhibition. Communications for the Information Age.

[6]  Jr. G. Forney,et al.  The viterbi algorithm , 1973 .

[7]  Stephen G. Wilson,et al.  An improved algorithm for evaluating trellis phase codes , 1984, IEEE Trans. Inf. Theory.

[8]  Marco Luise,et al.  Symbol Timing Recovery in Multi-h Phase Coded Systems , 1988 .

[9]  Bixio Rimoldi,et al.  Design of coded CPFSK modulation systems for bandwidth and energy efficiency , 1989, IEEE Trans. Commun..

[10]  J. Huber,et al.  Double trellis-coded CPM , 1988, IEEE International Conference on Communications, - Spanning the Universe..

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

[12]  John B. Anderson,et al.  A bandwidth-efficient class of signal-space codes , 1978, IEEE Trans. Inf. Theory.

[13]  Stephen G. Wilson,et al.  Convolutional Coding Combined with Continuous Phase Modulation , 1985, IEEE Trans. Commun..

[14]  Lin-Shan Lee,et al.  Multi-H phase-coded modulations with asymmetric modulation indexes , 1989, IEEE J. Sel. Areas Commun..

[15]  M. Simon,et al.  Trellis Coding with Asymmetric Modulations , 1987, IEEE Trans. Commun..

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

[17]  T. Aulin,et al.  Continuous Phase Modulation - Part II: Partial Response Signaling , 1981, IEEE Transactions on Communications.

[18]  Tor Aulin,et al.  Digital Phase Modulation , 1986, Applications of Communications Theory.