31. |
- Svensson, Arne, 1955, et al.
(författare)
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A Class of Reduced-Complexity Viterbi Detectors for Partial Response Continuous Phase Modulation
- 1984
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Ingår i: IEEE Transactions on Communications. - 0090-6778 .- 1558-0857. ; 32:10, s. 1079-1087
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Tidskriftsartikel (refereegranskat)abstract
- Partial response continuous phase modulation (CPM) gives constant envelope digital modulation schemes with excellent power spectra. Both narrow main lobe and low spectral tails can be achieved. When these signals are detected in an optimum coherent maximum likelihood sequence detector (Viterbi detector), power efficient schemes can also be designed, sometimes at the expense of receiver complexity. This paper describes a general class of simple Viterbi detectors with reduced complexity compared to the optimum case. The key idea is that the approximate receiver is based on a less complex CPM scheme than the transmitted scheme. The asymptotically optimum reduced-complexity receiver is found for a variety of transmitted schemes and various complexity reduction factors, for a specific class of receivers and modulation indexes. A new distance measure is introduced for the performance analysis. Smooth schemes based on raised cosine pulses are analyzed and simulated for the case of simplified reception. A graceful performance degradation occurs with the reduction of complexity.
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32. |
- Svensson, Arne, 1955, et al.
(författare)
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Distance Measure for Simplified Receivers
- 1983
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Ingår i: Electronics Letters. - 1350-911X .- 0013-5194. ; 19:23, s. 953-954
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Tidskriftsartikel (refereegranskat)abstract
- A distance measure is derived for simplified coherent receivers for general digital modulation schemes. This measure gives the asymptotic error probability performance on the additive white Gaussian noise channel. It is applied to some simple examples considering phase modulated signals.
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33. |
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34. |
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35. |
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36. |
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37. |
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38. |
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39. |
- Svensson, Arne, 1955, et al.
(författare)
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Optimum MSK-Type Receivers for CPM on Gaussian and Rayleigh Fading Channels
- 1984
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Ingår i: IEE Proceedings-F, Communications, Radar and Signal Processing. ; 131:5, s. 480-490
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Tidskriftsartikel (refereegranskat)abstract
- Power efficient schemes with excellent power spectra are contained among the continuous phase modulation (CPM) schemes. This is a constant envelope digital modulation technique, which in general requires a maximum-likelihood sequence detector (Viterbi detector) for efficient detection. This optimum receiver is sometimes complex. In this paper a parallel MSK-type receiver is studied. It is useful for binary schemes with modulation index h = 1/2. We consider coherent detection of signals transmitted over an additive white Gaussian noise channel and also over a Rayleigh fading channel. The MSK-type receiver can be implemented with only two filters and simple decision logic. Error probability formulas are given both for the nonfading and the fading channel. A simple algorithm giving the optimum filter for the Gaussian channel for high signal/noise ratios is presented. The optimum filter for low signal/noise ratios is also derived. For intermediate signal/noise ratios numerical optimisations are presented, both for the Gaussian and the Rayleigh fading channels. We have also considered diversity schems with ideal two-branch maximal ratio combining and selection combining. The optimum receiver filters are given for some selected schemes. It is shown that also, for the more complex CPM schemes, the loss compared to the optimum receiver is moderate.
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