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A simple closed-form expression is provided for the coverage probability of cellular systems under Hoyt (Nakagami-q) fading, which models fading scenarios more severe than Rayleigh. The accuracy of the proposed framework is validated through Monte Carlo simulations.
Since many years the Gaussian or normal distribution has been a useful tool to model data observations in fields as physics or astronomy. In communication systems, for instance, this distribution is widely used to model thermal noise. However, there exist many natural physical phenomena that exhibit tails decay following a power law that cannot be modelled by the classical Gaussian distribution. In...
Ergodic capacity is not a suitable information-theoretic measure for delay sensitive applications over fading channels. On the other hand, delay-limited capacity becomes zero for Rayleigh channels. In this case, the Capacity with Probabilistic Delay Constraint becomes useful. In, the maximum constant source rate that may be supported in a wireless system with a probability ?? of exceeding certain...
This paper gathers some of the authors' work with the family of the elliptically contoured distributions and its application to the analysis of performance in communication systems. Specifically, the Pearson type VII distribution is used to derive a closed-form expression for the BER in an LTE uplink system over a Rayleigh fading channel. ECDs possess many nice properties similar to those of multivariate...
In this work, we derive analytical expressions for the maximum attainable user rate by accomplishing a probabilistic delay constraint in an uncorrelated Rayleigh channel. These rates are derived for two representative scheduling schemes, round robin (RR) and best channel (BC) allocation, but presented tools can be applied to any scheduling policy. On the basis of the effective bandwidth theory, the...
One of the novelties of the forthcoming LTE technology is the use of SC-FDMA as the transmission technique in the uplink. In this paper a study of the BER in an interleaved SC-FDMA system over a fading channel is presented. This study provides the mathematical grounds to obtain a closed-form expression for the BER for BPSK and square M-QAM. Results are validated by means of comparison with simulations.
The capacity with probabilistic delay constraint CDt,epsiv expresses the maximum source rate that may be supported in a wireless system with a probability epsiv of exceeding certain delay bound Dt. In a previous paper by the authors (see Proc. IEEE GLOBECOM, November 2007), CDt,epsiv was calculated for a Rayleigh channel carrying a constant rate flow. In this work, the potential of the effective...
The use of finite state Markov chains (FSMC) for the simulation of the Rayleigh channel has been generalized in the last years. Several parameters influence the construction of the chain. The chain can be defined in terms of the complex channel response, the envelope of the received signal or the Signal to Noise Ratio. Moreover the partition method has to be selected among various options. This paper...
Resource allocation techniques are determinant to achieve high spectral efficiency in wireless systems and to provide QoS guarantees and fairness to the system users. In this work, several scheduling algorithms are evaluated over a packetized multiuser adaptive OFDMA system with spatial diversity MIMO. Multiuser capacity and fairness are assessed for different channel-aware and/or QoS-aware user multiplexing...
A wireless resource allocation algorithm based on utility functions is presented. Distinct utility functions dependent on the specific traffic class and the numerical QoS requirements are combined and maximised, so that different treatment is provided to each data flow. This approach is applied to allocate subcarriers and slots of an adaptive OFDMA scheme for services with heterogeneous QoS requirements...
We present an adaptive modulation policy that provides delay-throughput balance for data packet transmission over flat fading channels. The proposed policy is based on uninterrupted data transmission (zero-outage) and achieves low packet-delay while satisfies certain average BER constraints. Such delay and BER control is not an obstacle to achieve an average spectral efficiency close to that obtained...
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