Spatial Multiplexing Based NR-U and WiFi Coexistence in Unlicensed Spectrum

Chen, Qimei; Xu, Xiaoxia; Jiang, Hao

doi:10.1109/vtcfall.2019.8891514

Cited by 8 publications

(7 citation statements)

References 14 publications

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“…With the increasing number of antennas, it is easier to experience independent channels across multiple users served by a gNB, and the classical linear precoding schemes (e.g., ZF) can obtain a good performance, still keeping the complexity low. The algorithm for user group selection with ZF is detailed in [44], [45], and [46]. However, those works [44,45,46] assumed Rayleigh fading channels, an assumption that fails in case of mmWave channels.…”

Section: Related Workmentioning

confidence: 99%

“…The algorithm for user group selection with ZF is detailed in [44], [45], and [46]. However, those works [44,45,46] assumed Rayleigh fading channels, an assumption that fails in case of mmWave channels. In [47] and [48], the authors proposed an algorithm for user subset selection by ZF, but they did not enforce semi-orthogonality across users as they address the problem of cancelling the interference by dirty paper coding.…”

Section: Related Workmentioning

confidence: 99%

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Analysis of spatial scheduling in downlink vehicular communications: Sub-6 GHz vs mmWave

Haghshenas¹,

Linsalata²,

Barbieri³

et al. 2022

ITU J-FET

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Vehicular communications are gaining a lot of attention for the delivery of enhanced mobility services that require multi-Gbps and low latency connections. In this paper, we focus on Infrastructure-to-Vehicle (I2V) communications where a gNB has to assign spatial resources to a number of connected vehicle users. To efficiently manage the scheduling, we compare the Zero Forcing (ZF) and Maximum Ratio (MR) precoding strategies by evaluating the effect of shifting from sub-6 GHz to millimeter wave (mmWave) frequencies in urban and highway mobility scenarios. We analyze the impact of the geometry of the environment and propagation characteristics at different frequencies in terms of number of users that can be served and spectral efficiency. To model the I2V channel, we integrate realistic traffic conditions generated by SUMO into an accurate channel model based on ray tracing software by WirelessInsite. By numerical results we demonstrate the degradation at mmWave compared to sub-6 GHz on the multiplexing gain. We show the higher efficiency of ZF compared to MR as the former is not limited by inter-user interference, especially in urban scenarios where the number of distinctive eigendirections in space is limited. On the other hand, highway mobility has a more uniform distribution of vehicles that can be conveniently explored by the ZF scheduling to serve more users. Lastly, we show the benefits of adopting a higher number of transmit antennas at mmWave jointly with efficient scheduling to achieve higher spectral efficiency.

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Section: Related Workmentioning

confidence: 99%

Section: Related Workmentioning

confidence: 99%

Analysis of spatial scheduling in downlink vehicular communications: Sub-6 GHz vs mmWave

Haghshenas¹,

Linsalata²,

Barbieri³

et al. 2022

ITU J-FET

View full text Add to dashboard Cite

show abstract

“…However, the system does not try to optimize for multiple RCLs or even multiple radio access points (RAPs). Optimally allocating multiple RCLs in one cluster to serve them over Orthogonal Frequency-Division Multiple Access (OFDMA) is described in [6]. The communication is based on one antenna array shared by 5G and WiFi.…”

Section: A Related Workmentioning

confidence: 99%

Towards the Optimal Pattern of Joint Beamforming, User Scheduling and Power Allocation in a multi-RAT Network

Mankowski

Vijayaraghavan

Alba

et al. 2022

2022 IEEE 19th Annual Consumer Communications &Amp; Networking Conference (CCNC)

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Multiple solutions for the coexistence of different radio access technologies operating in the same frequency band have been proposed for 5G and WiFi. Most solutions based on spatial division just consider a small amount of radio access points, one link direction, and/or a single radio access technology. As a consequence, the performance of these solutions on realistic wireless network deployments may be poor and difficult to estimate. This paper investigates the serving of multiple users by multiple radio access technologies with the objective of minimizing the interference among network nodes. This is done by jointly optimizing the beams and link directions as well as the transmission powers, so as to ensure fair and near-optimal throughput allocation over time. For this purpose, a generalized beam-gain model for small-scale antenna arrays is proposed. We evaluate our proposed solution for realistic network scenarios in order to show its effectiveness.

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“…It is obvious that coexistence and interference are usually the two important issues discussed in various researches within LTE-LAA and NR-U systems. Several solutions such as offloading [9], interferences control [10], beam-based transmission using directional antennas [11], network slicing and spatial multiplexing [12], hybrid channel access mechanism [13] had been proposed. Besides, to ensure fair operation in unlicensed spectrum with the coexistence between LTE-LAA and Wi-Fi systems, we note that several works used Markov chain as their analytical models [14] [15] [16] [17].…”

Section: Related Workmentioning

confidence: 99%

Applications of Intelligent Radio Technologies in Unlicensed Cellular Networks - A Survey

Huang¹,

Chen²

2021

KSII TIIS

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Demands for high-speed wireless data services grow rapidly. It is a big challenge to increasing the network capacity operating on licensed spectrum resources. Unlicensed spectrum cellular networks have been proposed as a solution in response to severe spectrum shortage. Licensed Assisted Access (LAA) was standardized by 3GPP, aiming to deliver data services through unlicensed 5 GHz spectrum. Furthermore, the 3GPP proposed 5G New Radio-Unlicensed (NR-U) study item. On the other hand, artificial intelligence (AI) has attracted enormous attention to implement 5G and beyond systems, which is known as Intelligent Radio (IR). To tackle the challenges of unlicensed spectrum networks in 4G/5G/B5G systems, a lot of works have been done, focusing on using Machine Learning (ML) to support resource allocation in LTE-LAA/NR-U and Wi-Fi coexistence environments. Generally speaking, ML techniques are used in IR based on statistical models established for solving specific optimization problems. In this paper, we aim to conduct a comprehensive survey on the recent research efforts related to unlicensed cellular networks and IR technologies, which work jointly to implement 5G and beyond wireless networks. Furthermore, we introduce a positioning assisted LTE-LAA system based on the difference in received signal strength (DRSS) to allocate resources among UEs. We will also discuss some open issues and challenges for future research on the IR applications in unlicensed cellular networks.

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Spatial Multiplexing Based NR-U and WiFi Coexistence in Unlicensed Spectrum

Cited by 8 publications

References 14 publications

Analysis of spatial scheduling in downlink vehicular communications: Sub-6 GHz vs mmWave

Analysis of spatial scheduling in downlink vehicular communications: Sub-6 GHz vs mmWave

Towards the Optimal Pattern of Joint Beamforming, User Scheduling and Power Allocation in a multi-RAT Network

Applications of Intelligent Radio Technologies in Unlicensed Cellular Networks - A Survey

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