Dynamic Multiple Access Configuration in Intelligent Lifi Attocellular Access Points

Abstract

The exponential growth in the global demand for wireless connectivity calls for efficient and reliable management of the available wireless resources. Light fidelity (LiFi) harnesses the vast untapped wireless transmission resources in the infrared spectrum and visible light spectrum to create ultra-dense wireless networks which support user mobility, multiuser access, and handover. Various multiuser access (MA) protocols have been developed to meet the varying system requirements, including orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) schemes. While NOMA, on the one hand, allows for significant enhancement in the achievable data rates, its performance may be severely degraded under particular conditions such as a large number of connected users or users existing in highly symmetrical locations. OMA, on the other hand, provides better link reliability in such scenarios but at the expense of decreased spectral efficiency. Therefore, there is a need to enable a degree of intelligence in the LiFi access point (AP) to facilitate real-time configuration of the MA protocol. To this end, this paper develops a novel cross-layer design framework for dynamic multiple access selections (DMAS) in intelligent LiFi APs. The developed framework runs at LiFi attocell system level and can be configured to cater for various system requirements in terms of sum data rate, average outage probability, and fairness. The obtained results show that DMAS introduces an effective solution for multiuser resource allocation by achieving better satisfaction of the system requirements compared to the static configuration of a single MA scheme.INDEX TERMS Light fidelity, visible light communications, multiuser access, OMA, NOMA, MAC protocol, LiFi intelligence.

Performance analysis of a low-complexity nonorthogonal multiple access scheme in visible light communication downlinks using pulse modulations

“…[21], the combination of NOMA and Orthogonal Frequency-Division Multiple Access (OFDMA) was proposed in the downlink and uplink of VLC networks, and the corresponding Bit-Error Rate (BER) performance was studied experimentally. Later, Abumarshoud et al proposed the intelligent dynamic multiple access selection scheme, which could realize an adaptive configuration of the available multiple access modes, including OMA, NOMA, and hybrid OMA/NOMA [22] . Furthermore, how to group users in VLC systems must be addressed.…”

Rate-Splitting Multiple Access: Unifying NOMA and SDMA in MISO VLC Channels

“…Moreover, user grouping based on users' locations was proposed in [75] in order to reduce the interference in multi-cell VLC networks, where users in each group are served by only one access point using NOMA. On the other hand, the authors in [85] proposed a hybrid OMA/NOMA scheme for attocellular VLC based on a smart transmitter that can select dynamically the adequate MA technique according to the environment conditions. Finally, the authors in [86] proposed an efficient user pairing for the cases of having odd and even number of users.…”

Random-Access NOMA in URLL Energy-Harvesting IoT Networks With Short Packet and Diversity Transmissions

“…4 From a practical perspective, this can be performed by feeding the random number generators with the same seed [45]. 5 Orthogonal preamble transmissions are used in RA-LTE, and defined in 3GPP RA [46], [47]. 6 The preamble phase enables the BS to detect the stronger/weaker nodes within each cluster in order to determine the SIC decoding order.…”

“…Lemma 2: The transition probabilities of X n are obtained as given by (5), in which J αi,m (d) is defined as…”

“…Particularly, NOMA has been shown to be superior to the conventional OMA schemes in terms of capacity and transmission latency [4]. Thus, NOMA has been proposed for new emerging applications, such as LiFi access-points [5], device-to-device communications [6], wireless power transfer [7], mobile edge computing [8], and many others [9]. In turn, incorporating NOMA into IoT networks is envisioned to be a promising solution for high spectral-efficiency and massive connectivity requirements [10].…”