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This paper deals with the design of measurement-based correlation models for shadow fading. Based on the correlation model, we design a simulation model using the sumof-sinusoids (SOS) method to enable the simulation of spatial lognormal processes characterizing real-world shadow fading scenarios. The model parameters of the simulation model are computed by applying the Lp-norm method (LPNM). This...
Firstly, we prove that the probability density function (PDF) of the end-to-end signal-to-noise ratio (SNR) for dual-hop amplify-and-forward (AF) relaying in Nakagami-m fading with non-integer fading parameters given by [1, Theorem 1] diverges near origin for any parameters, which is in contradiction with simulations. Secondly, the reason for the divergence is clarified. Thirdly, closed-form lower...
We consider multiuser multicarrier systems, where each non-symmetrically distributed user reports only partial indices of subcarriers whose normalized SNRs exceed the predetermined threshold so that only partial feedback information is available at the base station. To accommodate both efficiency and fairness, the base station is assumed to perform the normalized SNR based proportional fair scheduling...
Dynamic allocation of power, rate and channel access is a critical task in wireless networks. Capitalizing on convex optimization and stochastic approximation tools, this paper develops a stochastic resource allocation algorithm that minimizes average transmit power under individual average rate constraints. Focus is placed on networks where users transmit orthogonally over a set of parallel channels...
This article derives a new exponential-type integral representation for the generalized M-th order Marcum Q-function, QM(alpha, beta), when M is not necessarily an integer. Our new representation includes a well-known result due to Helstrom for the special case of positive integer M and an additional integral correction term that vanishes when M is an integer. The new form has both computational utility...
Statistical properties of the four IEEE ultra-wide bandwidth channel models are derived. In particular, the correlations and probability density functions for the gains and powers of different multipath components are calculated. It is shown that most multipath components are correlated, and that most multipath components donpsilat follow a lognormal distribution. These results are useful in evaluating...
Underwater acoustic channel (UACh) requires robust techniques to get high speed data transmission for reliable communication. This paper presents the adaptive transmission technique in conjunction with the maximal ratio combining (MRC) diversity technique to adapt the UACh fluctuation based on a statistical channel model. Simulation analysis shows that we can optimize the data rate allowing the transmit...
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...
In this paper, we consider a new channel probing scheme for opportunistic scheduling in the uplink of orthogonal frequency division multiplexing (OFDM)-based wireless systems. To reduce signaling overhead for the probing, we consider a two-step channel probing process; called pre-probing and mainprobing. Good subchannels are first estimated through the pre-probing process using a probing signal transmitted...
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