Resource Allocation and Interference Management Techniques for OFDM-Based VLC Atto-Cells

Abstract

In this paper, a resource partitioning scheme combined with a new multi-carrier optical modulation technique for indoor visible light communication (VLC) system is proposed. In VLC systems, the coverage area is divided into multiple atto-cells. In each atto-cell, multiple LED arrays are used as access points (APs) serving the assigned users. The coverage area of APs might be overlapped to avoid service discontinuity for mobile users. The overlapped coverage zones result in co-channel interference (CCI). We develop a shared frequency reuse (SFR) technique combined with two resource allocation algorithms to minimize interference and maximize the system throughput. This technique divides the overall bandwidth into two parts: the shared and reused bands. The shared band serves the users in the interference area while the reused band serves users in the non-interfering area. Furthermore, we propose a new multi-carrier optical modulation technique called odd clipped optical-OFDM (OCO-OFDM). This technique applies the odd symmetry on the frequency-domain OFDM to enhance the spectral efficiency compared to the asymmetrical clipped optical OFDM (ACO-OFDM) which is currently used. Then we study and evaluate the system performance in terms of the signal-to-interference and noise ratio (SINR), total throughput, and the outage probability. The proposed system achieved total throughput of up to 800 Mbps with 40 dB SINR at the cell edge. Furthermore, the outage probability can be optimized to its minimum value when the receiver fieldof-view (FOV) is taken by 40 when the minimum SINR is 10 dB.

Secure Visible Light Communication System via Cooperative Attack Detecting Techniques

“…Ibrahim et al developed odd clipped optical orthogonal frequency-division multiplexing (OCO-OFDM) technology to propose a shared frequency reuse technology that can increase spectral efficiency while minimizing interference compared to conventional asymmetric clipped OFDM (ACO-ODM) technology. [15]. Shared frequency reuse technology reduces interference by dividing the entire bandwidth into shared or reused bands and providing services by dividing the interference and noninterference areas.…”

Ambient Light Effect on Receiver for Visible Light Communication Systems

“…In this sense, the visible light communication (VLC) technology that is one of the optical communication systems has received the much attention from many researchers to meet the exploding demand for both spectral band and high speed data sharing. Therefore, it is considered that the VLC is a significant candidate for future wireless optical systems since it can support the multiplexing techniques such as orthogonal frequency-division multiplexing (OFDM), code division multiple access (CDMA), time-division multiple access TDMA [1][2][3].…”

Hybrid NOMA-Based ACO-FBMC/OQAM for Next-Generation Indoor Optical Wireless Communications Using LiFi Technology

“…However, the conventional OFDM signal based on the Fourier Transform (FT) cannot be considered an effective solution for optical wireless communication because it does not meet the real and positive signal requirements. Modified variations of the conventional OFDM technique have been introduced to generate real and positive signals such as the asymmetrical clipped optical OFDM (ACO-OFDM), the dc-clipped optical OFDM (DCO-OFDM), and the odd-clipped optical OFDM (OCO-OFDM) [4] [5]. ACO-OFDM and DCO-OFDM are applying Hermitian symmetry to optical carriers to generate a real OFDM signal.…”