Super multi-carrier trellis coded 256 QAM digital microwave radio

Describes an outage-free 256-QAM (quadrature amplitude modulation) digital radio system. The degradation factors related to multipath fading and their countermeasure are discussed. Based on these considerations, supermulticarrier trellis-coded 256-QAM is proposed as a modulation scheme in multipath environments. The overall outage probability improvement factors derived from Rummler's (1987) composite fade margin concept and linear amplitude dispersion (LAD) statistics are compared with the performance of the existing 256-QAM digital radio system. A preliminary laboratory experiment on eight-carrier 256-QAM signal transmission shows the validity of the predicted improvement. The study also shows one possible direction for digital radio systems for dispersive radio channels.<<ETX>>

[1]  M. Kavehrad.  Convolutional coding for high-speed microwave radio communications , 1985, AT&T Technical Journal.

[2]  Desmond P. Taylor,et al.  Telecommunications by microwave digital radio , 1986 .

[3]  K. Watanabe,et al.  256 QAM 400 Mb/s microwave radio system with DSP fading countermeasures , 1988, IEEE International Conference on Communications, - Spanning the Universe..

[4]  S. Sakagami,et al.  Some Experimental Results on In-Band Amplitude Dispersion and a Method for Estimating In-Band Linear Amplitude Dispersion , 1982, IEEE Trans. Commun..

[5]  G. Ungerboeck,et al.  Trellis-coded modulation with redundant signal sets Part II: State of the art , 1987, IEEE Communications Magazine.

[6]  H. Yamamoto,et al.  Advanced 16-QAM techniques for digital microwave radio , 1981, IEEE Communications Magazine.

[7]  Teruaki Yoshida,et al.  SYSTEM DESIGN AND NEW TECHNIQUES FOR AN OVER-WATER 100 KM SPAN DIGITAL RADIO. , 1983 .

[8]  W. Rummler,et al.  Multipath fading channel models for microwave digital radio , 1986, IEEE Communications Magazine.

[9]  G. David Forney,et al.  Efficient Modulation for Band-Limited Channels , 1984, IEEE J. Sel. Areas Commun..

[10]  M. Shafi,et al.  Outage calculation methods for microwave digital radio , 1987, IEEE Communications Magazine.

[11]  Y. Daido,et al.  Modulation techniques for microwave digital radio , 1986, IEEE Communications Magazine.

[12]  W. Rummler,et al.  A Comparison of Calculated and Observed Performance of Digital Radio in the Presence of Interference , 1982, IEEE Trans. Commun..

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