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A fundamental problem for the delay and backlog analysis across multihop paths in wireless networks is how to account for the random properties of the wireless channel. Since the usual statistical models for radio signals in a propagation environment do not lend themselves easily to a description of the available service rate, the performance analysis of wireless networks has resorted to higher-layer...
This paper addresses the data-aided signal-to-noise ratio (SNR) estimation in time-variant flat Rayleigh fading channels. The time-variant fading channel is modeled by considering the Jakes' model and the first order autoregressive (AR1) model. Closed-form expressions of the Cramér-Rao bound (CRB) for data-aided SNR estimation are derived for fast and slow fading Rayleigh channels. As a special case,...
This paper presents a new spectrum sensing scheme using an energy detector and multiple antennas. This scheme helps us finding the low level signals to realize a spectrum sharing in a primary and secondary system. The spectrum sensing by using multiple antennas has a problem that the channel state information of the primary signal is required for obtaining the diversity gain. However, the primary...
This paper investigates the use of genetic algorithms in the identification of Wiener model. The parameters describing the linear system and the static nonlinearity are estimated from input-output measurements by minimizing the error between the actual and identified systems. Using genetic algorithms, systems with non-minimum phase characteristics can be identified. Simulation results reveal the effectiveness...
In this paper, we propose a robust STBC transmission scheme to combat the timing synchronization errors over frequency-selective multiple-access channels. First, the equivalent channel model in the presence of timing synchronization errors is derived and we find that the synchronization errors result in an equivalent channel model with larger number of correlated channel taps. Based on this correlated...
Orthogonal frequency division multiplexing (OFDM) is the modulation scheme of choice for digital video broadcasting-handheld (DVB-H), which is required to operate under high mobility conditions resulting in significant Inter-carrier Interference (ICI). To mitigate ICI, several cancellation schemes have been proposed but they require reliable channel information at the receiver which is quite challenging...
Orthogonal frequency division multiplexing (OFDM) is the modulation scheme of choice for digital video broadcasting-handheld (DVB-H) which is required to operate under high mobility conditions resulting in significant Inter-Carrier Interference (ICI). Under these conditions, the conventional one-tap per subcarrier channel estimation and equalization is suboptimal since it does not account for ICI...
The Oil/Gas industry is facing two major problems with its aging electric power generators. First, the Oil/Gas industry experience long outages of these power generation units for re-winding, during a time when power is extremely needed. Second, these fixed-interval scheduled maintenance practices are very costly as on average they cost around US$1 million per machine. To address these problems, we...
Signal-to-noise ratio is used for evaluation of the quality of random signal transmission. In case of compression, noise error is not always created and the signal-to-distortion ratio be the evaluation criteria, as, in general it is equal to signal deviation root-mean-square to error root-mean-square ratio, which are expressed in decibels. In This work the criteria of speech compression quality estimation...
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