## Abstract

Statistical-delay quality of service (QoS) provides bounded link-layer delay over wireless fading channels with a certain delay-bound violation probability. We propose statistical-delay-QoS-aware adaptive modulation (AM) and power allocation for a dual-channel coherent optical wireless communication system over the atmospheric turbulence fading channels. For given statistical-delay constraints and target bit-error-rate requirements, our proposed AM and power allocation maximize the effective spectral efficiency subject to the transmit-power constraints. We develop delay-QoS-aware adaptive transmission schemes by employing independent and joint channel optimizations subject to average transmit-power constraints. We also consider independent, joint, and successive channel optimizations for developing delay-QoS-aware adaptive transmission schemes subject to peak transmit-power constraints. Numerical results demonstrate that our proposed AM and power allocation significantly outperform the conventional adaptive transmission schemes in the strict statistical-delay constraints. Numerical results also depict superiority of the joint channel optimization in the strong turbulence fading and strict statistical-delay constraints.

© 2018 Optical Society of America

Full Article | PDF Article**More Like This**

I-Shyan Hwang, Jhong-Yue Lee, K. Robert Lai, and Andrew Tanny Liem

J. Opt. Commun. Netw. **4**(2) 99-107 (2012)

Ivan B. Djordjevic

J. Opt. Commun. Netw. **2**(5) 221-229 (2010)

Abhishek Dixit, Bart Lannoo, Goutam Das, Didier Colle, Mario Pickavet, and Piet Demeester

J. Opt. Commun. Netw. **5**(3) 240-253 (2013)