Results 221 to 230 of about 224,801 (264)
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A group of modulation schemes for adaptive modulation
2008 11th IEEE Singapore International Conference on Communication Systems, 2008Adaptive modulation increases the throughput of a wireless network by adjusting the modulation scheme to the channel status. To have more capacity and more flexibility in using adaptive modulation, our research attempts to find a group of modulation schemes, which includes M-QAM where the number of signal points is not a power of 2, as well as non ...
null Anh Tuan Le, null Kiyomichi Araki
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Adaptive Companded Pulse Code Modulation
IEEE Transactions on Communications, 1983In this paper, a novel quantization scheme-adaptive companded pulse code modulation (ACPCM)-is proposed. It is shown that, for fine quantization of analog signals, ACPCM will outperform the widely used PCM and DPCM in the sense of minimizing the meansquared quantizing error. For autoregressive (AR)signals, ACPCM is shown to reduce to DPCM.
James A. Bucklew, F. T. Tzeng
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Stochastic Learning Algorithms for Adaptive Modulation
2006 IEEE International Conference on Acoustics Speed and Signal Processing Proceedings, 2005Adaptive modulation has been widely studied as a means of increasing the capacity of wireless communications systems. In this paper, we present stochastic learning algorithms for the design of next-generation adaptive modulation systems. In the past, the design of adaptive modulation systems has relied on analytic and functional approximation ...
Anup Misra +2 more
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Concept of Adaptability in Space Modules
Journal of Aerospace Engineering, 1990The space program is aiming towards the permanent use of space; to build and establish an orbital space station, a Moon base and depart to Mars and beyond. We must look after the total independency from the Earth's natural resources and work in the design of a modular space base in which each module is capable of duplicating one natural process, and ...
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IETE Journal of Research, 1971
In this paper, design principles of a delta modulator are discussed to arrive at the design parameters. For a sampling rate of 25 K/bits and reference frequency of speech at 1ยท12 KHz, the maximum signal to quantization noise ratio is found to be around 24 db.
H. P. Jaiswal +2 more
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In this paper, design principles of a delta modulator are discussed to arrive at the design parameters. For a sampling rate of 25 K/bits and reference frequency of speech at 1ยท12 KHz, the maximum signal to quantization noise ratio is found to be around 24 db.
H. P. Jaiswal +2 more
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2009 IEEE/LEOS Summer Topical Meeting, 2009
In this presentation we will discuss recent advances in adaptive modulation schemes for ultra high bit capacity optical networks. This paper focuses on optimising the sub-carrier spacing for such high capacity networks..
A.D. Ellis +6 more
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In this presentation we will discuss recent advances in adaptive modulation schemes for ultra high bit capacity optical networks. This paper focuses on optimising the sub-carrier spacing for such high capacity networks..
A.D. Ellis +6 more
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Single-Integration, Adaptive Delta Modulation
Bell System Technical Journal, 1975An estimate of optimum performance is derived for a single-integration, adaptive delta modulator. Several simulations of adaptive delta modulators with single integrators have all produced signal-to-noise ratios near or below the estimate. The derivations presented here indicate that the performance of a single-integration delta modulator is dependent ...
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Channel-Adaptive Modulation [PDF]
, 1995 Packet Reservation Multiple Access (PRMA) assisted adaptive modulation suing 1,2 and 4 bit/symbol transmissions is proposed as an alternative to Dynamic Channel Allocation (DCA) in order to maximise the number of users supported in a traffic cell. The cell is divided in three concentric rings and in the central high Signal-to-Noise ratio (SNR) region ...
Williams, J, Hanzo, L, Steele, R
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Step Response of an Adaptive Delta Modulator
Bell System Technical Journal, 1976N. S. Jayant has proposed a simple but effective form of adaptive delta modulation which uses two positive parameters, P and Q, to adjust the step size. The values P = Q = 1 describe linear delta modulation (LDM), and Jayant has recommended using Q = 1/P and 1 1, it converges to the new level when PnQ < 1, and when PnQ = 1, it eventually settles into
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Adaptive and Reconfigurable Modulation
2011This chapter contains sections titled: Coded Modulation Adaptive Coded Modulation for Fading Channels ...
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