Ultra Wide Band (UWB) systems induce interference on communication systems operating at range frequency from 0 to 10.6 GHz. This is the reason leading to an accurate choice of the pulse shape in order to avoid severe ...
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ISBN:
(纸本)9781424418435
Ultra Wide Band (UWB) systems induce interference on communication systems operating at range frequency from 0 to 10.6 GHz. This is the reason leading to an accurate choice of the pulse shape in order to avoid severe interference and to respect systems coexistence. FCC and ETSI gave indications about the spectral limits to be respected, so, in this regard, the goal should be to fit the spectral mask. The choice of Gaussian-like pulses is largely suboptimal from a power emission point of view since they are unable to maximize the signal-to-noise ratio (SNR). The goal of this contribution is to achieve a good compromise between spectral emission and synchronization errors robustness via a modified version of the parks-mcclellan method.
The interference induced by UWB communication on systems operating in the frequency range between 0 and 10.6GHz is the main reason why the essential role in these systems' design is played by the pulse shape selec...
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ISBN:
(纸本)9781424463985
The interference induced by UWB communication on systems operating in the frequency range between 0 and 10.6GHz is the main reason why the essential role in these systems' design is played by the pulse shape selection. That's why an accurate shaping choice can lead to avoid severe performance reduction and to guard systems coexistence. To this end, FCC (and ETSI in the near future) gave strict indications about the spectral limits to be respected, so as to define, as the purpose of UWB systems realization, the compliance with this spectral mask. The, widely used, choice of Gaussian-like pulses is, however, largely suboptimal from a power emission point of view since they are unable to maximize the signal-to-noise ratio (SNR). Goal of this contribution is to achieve a good compromise, in a cognitive way, between spectral emission, rate and synchronization errors robustness, via a modified version of the parks-mcclellan method, considering channel impairments due to its frequency-selective nature, to the inter-pulse interference and in-band interference.
The objective of this work was the implementation of a computational algorithm that allowed the electrooculographics signals analysis, which represented different types of saccadics and antisaccadics movements. A stud...
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ISBN:
(纸本)9780819469236
The objective of this work was the implementation of a computational algorithm that allowed the electrooculographics signals analysis, which represented different types of saccadics and antisaccadics movements. A study about the nature of the electrooculographics signals was made to determine the signals frequency composition. This study yielded that the electrooculographics signals studied mainly have low frequency elements, although they possess elements belonging to a wide range of high frequencies, but that as a whole, these elements constitute a smaller part of the signals. Computational routines were developed which allowed filtering the signals to eliminate the noise that could be contained in the signal and improve the quality of the original signal. In the implementation of these routines, two mathematical algorithms were used: Wavelet Transform and the parks-mcclellan or Remez algorithm for the low pass filters design. The results showed that it was faster filtering the signal with the Wavelet Transform, but the filters designed with the parks-mcclellan algorithm did not distort the original signal in an appreciable way. Once filtered the signals the characterization takes place, which consisted on the automatic detection of the regions corresponding to saccades. In this detection was used another Wavelet Transform application, as is the locating of abrupt changes in the signals. It was carried out the determination of the parameters from each saccade: Amplitude, Duration, Gain, Peak Velocity and Latency. Some important relations between the saccades parameters of the electrooculographics signals were obtained and others found by different authors were verified.
In this paper, a novel surround sound system operated by DSP boards is developed. Besides woofer(s) and tweeter(s), the audio system has been improved by adding additional speakers for handling mid-frequencies by desi...
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ISBN:
(纸本)9781538646496
In this paper, a novel surround sound system operated by DSP boards is developed. Besides woofer(s) and tweeter(s), the audio system has been improved by adding additional speakers for handling mid-frequencies by designing a particular band-pass filter to process its mid-range. Meanwhile, three audio amplifiers are built to drive woofer (low frequency), mid-frequency speaker, and tweeter (high frequency), respectively. The practical audio amplifiers are also created with moderate gains in order to power speakers, in which the amplification circuits are modified using the data sheet of audio chip LM386 IC. Three different types of filters, which are low-pass, band-pass and high-pass, are also designed using the Remez exchange algorithm by MATLAB. Then, the obtained filter coefficients are loaded into two DSP boards (TMS320C6713) to process the sound signals in the full audio frequency range. Finally, the processed audio data are enhanced by audio amplifiers strong enough to power three sets of speakers: bass, mid-range, and tweeters. In addition to developing and testing the system, the research methodology and design is summarized and future improvements are discussed.
Adaptive pulses in ultra wideband (UWB) wireless communication system are applied by forming notches at some frequencies as a way to suppress its interference to the existing narrowband systems. This paper proposes a ...
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Adaptive pulses in ultra wideband (UWB) wireless communication system are applied by forming notches at some frequencies as a way to suppress its interference to the existing narrowband systems. This paper proposes a novel method in designing adaptive pulses by using the Cognitive Radio technology and parks-mcclellan algorithm. Cases of arbitrary narrowband interferences are studied. The simulation results show that the power spectrum density of the proposed pulses not only meets the constraints of the FCC indoor mask but also avoid the narrowband interferences. The comparison of bit error rate performance is presented by using the proposed pulses and the fifth-order derivative Gaussian pulse to the time hopping UWB system in the additive white Gaussian noise channel. With low computational complexity, the proposed pulses have lower bit error rate and hence improve whole UWB system performance.
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