Achievable data rate of coordinated multi-point transmission for visible light communications

Abstract

This paper studies the sum data rate that a Visible Light Communication (VLC) system with multiple users can achieve when phosphor-converted white LED panels are used to provide illumination and communication simultaneously. Three different transmission schemes based on Asymmetrically Clipped Optical Orthogonal Frequency Division Multiplexing (ACO-OFDM) are considered to allocate the communication resources in each transmission point: Frequency Reuse (FR), Joint Transmission Coordinated Multi-Point (JT-CoMP), and a Hybrid combination of them. Since phosphor-converted white LEDs have a larger modulation bandwidth for blue optical wavelengths rather than green-yellow-red ones, the performance of each transmission method is also evaluated using a visible and/or blue light optical filter in front of the Photodetector (PD). When the transmission points apply FR, strong inter-cell interference results in high variability of the achievable data rate at different locations. On the other hand, when JT-CoMP is applied, a more homogeneous data rate coverage is achieved, reducing the peak data rate in the inner parts of the cells but improving notably the data rate in cell-edge areas.

Visible Light Communication System in Presence of Indirect Lighting and Illumination Constraints

“…The illuminance and data rate performance of the VLC system with (in)direct illumination is evaluated in a small office scenario with dimension 5 [m] × 5 [m] × 3 [m], similar to the one presented in [7]. The receiver lies on a desk of height h desk = 0.85 [m] that takes random locations on the room, and collects the optical signal that is irradiated by the PC-LED lamp placed on the center of the room at variable height h lamp , pointing either downwards (direct illumination) or upwards (indirect illumination).…”

Throughput Enhancement of the Edge User Equipments Based on the PowerBandwidth Tradeoff in the Optical Attocell Networks

“…Wang and C. Zhang analyzed the interference management at the expense of proposing a coalition formation framework in the VLC context in which the APs are set to self-organize into cooperation coalitions for interference cancellation by using orthogonal time or frequency domain .Finally, A.A.Dowhuszko and A.I. Pérez-Neira in [19] proposed three different transmission schemes in terms of allocating the communication resources , while the data rate was compared with each transmission method. As aforementioned, co-channel interference (CCI) is one of the main issues that impacts the user performance in an optical attocell network which is caused by using the same subcarrier in neighboring APs at the same time.…”

Capacity enhancement of an indoor visible light communication system using cooperative transmission

“…Because the LEDs with a wide semiangle at half power provide better illumination in some places of the room [4], the illumination areas overlap on the receiver plane; this also helps to meet the illumination requirements throughout the room [2,9], which is 300-1500 lx for offices [8,9], and to implement the multiple-input single-output (MISO) or multipleinput multiple-output (MIMO) scheme in the VLC system. When multiple LEDs are used for data transmission, the LEDs can not only cooperate to transmit data [7], but they can also coordinate their transmissions [14] to increase the capacity of the system or decrease the probability of outage [15] as well as link blockages [1,15]. When the LEDs simultaneously transmit unique data over the same frequency resources applying a frequency reuse scheme [14] and the different signals fall within the PD's physical area [16], the interference between adjacent LEDs known as co-channel interference (CCI) occurs at the receiver side [6,17].…”

“…When multiple LEDs are used for data transmission, the LEDs can not only cooperate to transmit data [7], but they can also coordinate their transmissions [14] to increase the capacity of the system or decrease the probability of outage [15] as well as link blockages [1,15]. When the LEDs simultaneously transmit unique data over the same frequency resources applying a frequency reuse scheme [14] and the different signals fall within the PD's physical area [16], the interference between adjacent LEDs known as co-channel interference (CCI) occurs at the receiver side [6,17]. CCI affects the communication link quality due to the signal-to-interferenceplus-noise ratio (SINR) decreasing [6] as CCI increases.…”