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Average channel capacity vs. aperture diameter

Effect of aperture averaging and spatial diversity on capacity of optical wireless communication systems over lognormal channels

Rahul Kaushik, Vineet Khandelwal, Roop Chand Jain


In this paper average channel capacity of optical wireless communication system with aperture averaging and diversity reception over lognormal channels is evaluated using a simple approximate closed form expression. The qualitative improvement in channel capacity is compared and investigated for various turbulence mitigation techniques: namely aperture averaging, diversity techniques such as maximal ratio combining and equal gain combining. Based on our study it has been found that aperture averaging gives reasonably improved performance as compared to both types of diversity reception beyond certain turbulence strength. However, irrespective of turbulence strength, substantial improvement in capacity may be achieved with array of direct detection receivers. Results obtained using the proposed expressions are in excellent agreement with those based on Monte Carlo simulations.


optical wireless communication; average channel capacity; aperture averaging; diversity reception; lognormal distribution

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