We investigate a quality-of-service-aware and energy-aware adaptive power allocation scheme for a point-to-point and line-of-sight optical wireless communication system employing the coherent detection and polarization multiplexing. The proposed power allocation scheme minimizes the average transmit power and provides the delay aware quality-of-service guarantee through maintaining a required effective capacity over the fading channels. The power allocation scheme is formulated as a convex optimization problem, and using the sub-gradient method, a fast convergent algorithm for the optimal power allocation is proposed. Numerical results demonstrate the advantages of the proposed power allocation algorithm in terms of the energy saving for the case of having strict statistical delay constraints.
['Md. Zoheb Hassan', 'Victor C. M. Leung', 'Md. Jahangir Hossain', 'Julian Cheng']
QoS-aware and energy-aware adaptive power allocations for coherent optical wireless communications