In this letter, the orthogonal multirate (MR) modulation signal is constructed by the orthogonal multiplexing of block-precoded component modulation waveforms occupying the Nyquist bandwidth and shown to outperform th...
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In this letter, the orthogonal multirate (MR) modulation signal is constructed by the orthogonal multiplexing of block-precoded component modulation waveforms occupying the Nyquist bandwidth and shown to outperform the conventional nonorthogonal MR modulation signal in error performance, while giving the same bandwidth efficiency.
Block-coded modulation (BCM) combines bandwidth-efficient modulation techniques with error-correction capabilities to allow efficient data transmission over mobile communication channels. The main shortcoming of BCM i...
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Block-coded modulation (BCM) combines bandwidth-efficient modulation techniques with error-correction capabilities to allow efficient data transmission over mobile communication channels. The main shortcoming of BCM is the complex decoding process for which, until today, mainly suboptimum decoding methods are used, because existing approaches for trellis decoders are limited to a small subset of possible BCM schemes. The authors address this shortcoming by introducing a new technique for the construction of trellis decoders for arbitrary BCM schemes. This technique is based on a new approach for the calculation of the trellis state vector and a computationally efficient recursive method for the construction of the trellis. A large number of simulation results for BCM schemes with various QAM constellations are presented, and comparisons in terms of performance and decoding complexity allow the formulation of guidelines for the choice of efficient coding schemes.
A closed-form expression for the average error probability of circular 16-ary differential amplitude and phase shift keying with postdetection diversity combining is obtained for frequency-nonselective Rayleigh fading...
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A closed-form expression for the average error probability of circular 16-ary differential amplitude and phase shift keying with postdetection diversity combining is obtained for frequency-nonselective Rayleigh fading channels. The effect of random FM noise is also considered in the evaluation, Since both amplitude and phase are encoded and decoded independently, their detailed performances are analysed separately. System parameters such as the ring ratio and decision thresholds have been optimised for a number of fading conditions. The optimal and suboptimal decision thresholds are evaluated, The optimal ring ratio of the modulation is generally a function of Doppler frequency. The results have shown that postdetection diversity is a powerful technique for reducing the effects of random FM noise.
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