Performance analysis of user association strategy based on power-domain non-orthogonal multiple access in visible light communication multi-cell networks

Abstract

A multi-cell visible light communication (VLC) network with non-orthogonal multiple access (NOMA) introduces an inter-cell interference (ICI), which causes poor experience of overlap-area user association. In this study, we focus on the strategic analysis of user association in multi-cell NOMA-VLC networks and reveal the relationship between the performance of user association and visible-light cell deployment. First, we establish the model of power-domain NOMA in multiple cells of VLC. Second, when the principle of proximity access (PPA) considers channel attenuation, we present the violation of the principle of proximity access (VPPA) based on signal-to-interference-plus-noise ratio (SINR) and derive a closed-form sufficient condition for overlap-area users based on the visible light channels. Third, based on the sufficient condition, we perform the strategic analysis of user association in two cases, i.e., the scenario probability with different numbers of users and the probability of the ratio of channel gains with an edge user are deduced. In addition, we evaluate the performance of user association by the deployment of lighting angles and inter-cell distance. Finally, the simulation results indicate that the VPPA achieves better data rate performance than the PPA based on the sufficient condition. Furthermore, the probability distributions in numerical results show that the situations with the VPPA reach a certain scale of occurrence probability.

Model and Methodology to Characterize Phosphor-Based White LED Visible Light Communication Links

“…The parameters of LED1 and LED2 were obtained using the method described in [3] for a reference VLC channel with d 0 = 130 cm and perfect alignment between the LED and photodetector (θ = 0, φ = 0). The estimated parameters are indicated in Table 2, and their frequency responses are shown in Figure 6, where solid lines correspond to the measured frequency responses of LED1 and LED2, and dashed lines were obtained using Equation (9) with the extracted parameters. During measurements, the LEDs were biased with the corresponding I bias indicated in Table 1, and the modulating signal (v s ) amplitude was set to 900 mV pp to keep the signal in the linear zone.…”

“…The main limitation of phosphor-coated white LEDs for data transmission is their small modulation bandwidth: they usually have a dB frequency of a few MHz [ 2 , 3 ]. Therefore, to reach data rates of hundreds of Mb/s, as will be required in future data networks, it is necessary to develop advanced data transmission techniques, such as advanced modulations [ 4 , 5 , 6 ], multiple access techniques [ 7 , 8 , 9 ], LED non-linearity compensation [ 10 , 11 ] or the use of multiple LEDs for transmission [ 12 , 13 ]. Any new proposal, after being analytically developed and evaluated, requires validation with experimental measurements in a real VLC setup [ 14 ].…”

Vertical handover algorithm based on multi-attribute and neural network in heterogeneous integrated network

“…WLAN networks have relatively wide bandwidth and small coverage, while cellular series networks (such as current 3G/4G wireless networks) have relatively narrow bandwidth and wide coverage [12][13][14], so the integration of cellular series network and WLAN network can complement each other [15,16], giving full play to their respective strengths and restraining their limitations at the same time [17][18][19], in addition, with the birth of 5G technology, the integration between multiple networks with different architectures will make a revolutionary progress [20][21][22][23][24][25]. Therefore, the vertical handover algorithm should be considered with a variety of disturbing factors and a variety of candidate network types [26], and it is more suitable to be combined with intelligent algorithms [27]. The relevant neural network algorithms in the field of machine learning are now used in the design of this paper's algorithm [28][29][30][31][32].…”

“…Reference [18], reference [22], and reference [24] emphasized the application of 5G network technology, but failed to integrate perfectly with vertical handover algorithms in heterogeneous networks. Reference [26] considered factors related to inter-cell interference in communication activities, but the related theory was more complicated. Reference [27] introduced fuzzy logic algorithm into wireless positioning, and failed to combine related network environment factors.…”