The white noise hypothesis (WNH) assumes that in the uniform pulse code modulation (PCM) quantization scheme the errors in individual channels behave like white noise;i. e., they are independent and identically distri...
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The white noise hypothesis (WNH) assumes that in the uniform pulse code modulation (PCM) quantization scheme the errors in individual channels behave like white noise;i. e., they are independent and identically distributed random variables. The WNH is key to estimating the mean square quantization error ( MSE). But is the WNH valid? In this paper we take a close look at the WNH. We show that in a redundant system the errors from individual channels can never be independent. Thus to an extent the WNH is invalid. Our numerical experiments also indicate that with coarse quantization the WNH is far from valid. However, as the main result of this paper we show that with. ne quantizations the WNH is essentially valid in that the errors from individual channels become asymptotically pairwise independent, each uniformly distributed in [-Delta/ 2,Delta/ 2), where Delta denotes the stepsize of the quantization.
Mappings for square quadrature amplitude modulation (QAM) are investigated in terms of the achievable capacity in bit-interleaved coded modulation (BICM). In [11 it is conjectured that Gray labelings maximize this cap...
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ISBN:
(纸本)9781424402656
Mappings for square quadrature amplitude modulation (QAM) are investigated in terms of the achievable capacity in bit-interleaved coded modulation (BICM). In [11 it is conjectured that Gray labelings maximize this capacity. However, Gray mappings are not unique and it can be shown that the conjecture cannot hold in general for QAM constellation sizes larger than 16. Based on the bit level capacities of mappings, structures determining capacity are analyzed. Construction guidelines leading to capacity maximizing Gray mappings are presented.
IRIG-106 Chapter 10 has become the recording standard for most of the new flight test programs and many of the current ongoing programs. The primary goal of the standard was to define a common format for recording 100...
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pulse-code-modulation (PCM) encoding of digital audio signals has had a long and successful history in the era of the Compact Disc (CD). This brief survey paper argues that it forms the logical way to extend either th...
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pulse-code-modulation (PCM) encoding of digital audio signals has had a long and successful history in the era of the Compact Disc (CD). This brief survey paper argues that it forms the logical way to extend either the bandwidth or the signal-to-noise ratio of a digital audio system, or both, to encompass even higher resolution. Underpinning its operation there are the iron-clad theorems that govern both the sampling-and-reconstruction and the dithered-quantizing processes that lie at its heart. It is adaptable enough to allow fully distortion-free noise shaping to be used if wordlength reduction is necessary, provided that the wordlength is not reduced so far as to cause quantizer overload when using proper dithering.
This paper presents the development of an explicit predictive control strategy for a stand-alone PEM (Polymer Electrolyte Membrane) fuel cell. This fuel cell can be considered as a good benchmark since it is represent...
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ISBN:
(纸本)9781424414970;1424414970
This paper presents the development of an explicit predictive control strategy for a stand-alone PEM (Polymer Electrolyte Membrane) fuel cell. This fuel cell can be considered as a good benchmark since it is representative of the state of the art of PEM technology and is used by many research groups. The experiments are performed on a detailed nonlinear simulator of a fuel cell which has been validated experimentally. In order to achieve real-time implementation of the control strategy, the predictive control algorithm must be computed in a explicit way because of the sampling time of this system, which is in the order of milliseconds. The work shows the development and simulation results of the constrained explicit predictive controller that reduces the computational effort needed.
The internet traffic gets exploded due to the increasing demand for bandwidth as more number of users gets added to the internet. In order to meet the demands of the growing needs, the working of various devices and o...
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ISBN:
(纸本)0769525547
The internet traffic gets exploded due to the increasing demand for bandwidth as more number of users gets added to the internet. In order to meet the demands of the growing needs, the working of various devices and operations has to be redesigned. One of the areas is the design of the high performance router. The traditional router performs two basic tasks in forwarding a packet. Firstly, looking up the packet's destination address in the router's database and secondly, switching the packet to one or more of the outgoing links. The classification of packets at the router based upon multiple fields is called as packet classification. In this paper, we propose an Aggregate Bit Vector Packet Classification using Prefix Computation Model (ABVPC using PCM) which combines the effect of both scalability and parallelization. It is aimed at overcoming the defects of the existing ABV algorithms. Simulation Results illustrate that the folding technique using PCM significantly improves the performance.
Correlation analysis (CA) is one from main ingredients of DSP and often used in many fields of science and technology particularly in computational intelligence and control systems. Signals representation in PCM forma...
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ISBN:
(纸本)9781424407255
Correlation analysis (CA) is one from main ingredients of DSP and often used in many fields of science and technology particularly in computational intelligence and control systems. Signals representation in PCM format allows to calculate correlation functions (CF) with assign accuracy, however at the same time causes a large number of multi-bit operations and leads to insufficient fast-acting of CA. Therefore, in such tasks it is expedient to use small-bit differential methods without multiplications. However, the known approaches to differential CA are not enough studied. This paper purpose is increasing of the fast-acting and resolution of algorithms of noisy signals CA in real time on the basis of Modified Differential PCM (MDPCM) as well as Sign Delta modulation (SignDM).
The paper presents results for PCM- and DPCM-like signal compression schemes that incorporate lowpass-filtering and downsampling prior to the actual encoder, and corresponding upsampling and filtering to reconstruct t...
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ISBN:
(纸本)9781424404124
The paper presents results for PCM- and DPCM-like signal compression schemes that incorporate lowpass-filtering and downsampling prior to the actual encoder, and corresponding upsampling and filtering to reconstruct the signal to the original rate after the decoder. This scheme is suggested by rate-distortion theory for coding signals with monotonically decaying spectra at low rate. The cutoff frequencies are optimized for best performance.
In 2004 ACRA CONTROL introduced XidML as a published standard for instrumentation definition via XML. After two years in the field, much feedback and two revisions, this paper outlines where the standard is now, some ...
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This paper presents the design of a continuous-time multibit cascade 2-2-1 ∑Δ modulator for broadband telecom systems. The modulator architecture has been synthesized directly in the continuous-time domain instead o...
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