Imran Shafique Ansari

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Abstract—In this work, the performance analysis of a dualhop relay transmission system composed of asymmetric radiofrequency (RF)/free-space optical (FSO) links with pointing errors is presented. More specifically, we build on the system model presented in [1] to derive new exact closed-form expressions for the cumulative distribution function, probability(More)
The probability distribution function (PDF) and cumulative density function of the sum of L independent but not necessarily identically distributed gamma variates, applicable to maximal ratio combining receiver outputs or in other words applicable to the performance analysis of diversity combining receivers operating over Nakagami-m fading channels, is(More)
Error performance is one of the main performance measures and the derivation of its closed-form expression has proved to be quite involved for certain communication systems operating over composite fading channels. In this letter, a unified closed-form expression, applicable to different binary modulation schemes, for the bit error rate of dual-branch(More)
Starting with the double generalized Gamma (GG) model to describe turbulence-induced fading in free-space optical (FSO) systems, we propose a new unified model that accounts for the impact of pointing errors and type of receiver detector. More specifically, we present unified closed-form expressions for the cumulative distribution function, the probability(More)
The probability density function (PDF) and cumulative distribution function of the sum of L independent but not necessarily identically distributed Gamma variates, applicable to the output statistics of maximal ratio combining (MRC) receiver operating over Nakagami-m fading channels or in other words to the statistical analysis of the scenario where the sum(More)
In this letter, the secrecy performance of the classic Wyner’s wiretap model over generalized-K fading channels is studied. The closed-form expressions for the average secrecy capacity, secure outage probability, and the probability of strictly positive secrecy capacity are derived. The new expressions provide a unified form, which can handle several of the(More)