  Channel adaptive signalling, which is based on feedback, can result in almost
any performance metric enhancement. Unlike the radio frequency (RF) channel,
the optical wireless communications (OWCs) channel is fairly static. This
feature enables a potential improvement of the bidirectional user throughput by
reducing the amount of feedback. Light-Fidelity (LiFi) is a subset of OWCs, and
it is a bidirectional, high-speed and fully networked wireless communication
technology where visible light and infrared are used in downlink and uplink
respectively. In this paper, two techniques for reducing the amount of feedback
in LiFi cellular networks are proposed, i) Limited-content feedback (LCF)
scheme based on reducing the content of feedback information and ii)
Limited-frequency feedback (LFF) based on the update interval scheme that lets
the receiver to transmit feedback information after some data frames
transmission. Furthermore, based on the random waypoint (RWP) mobility model,
the optimum update interval which provides maximum bidirectional user equipment
(UE) throughput, has been derived. Results show that the proposed schemes can
achieve better average overall throughput compared to the benchmark one-bit
feedback and full-feedback mechanisms.
