Dynamic Resource Allocation for Virtualized Wireless Networks in Massive-MIMO-Aided and Fronthaul-Limited C-RAN

We investigate the problem of sum-rate maximization of a secondary link of full-duplex generalized frequency division multiplexing (GFDM) radios operating over a spectrum hole, which is surrounded by two active primary adjacent channels. Thus, the secondary transmissions must be below an adjacent channel interference (ACI) threshold. In-band distortions and several interference terms are also caused by phase noise, in-phase (I) and quadrature (Q) imbalance, carrier frequency offset (CFO) and the nonlinear power amplifier (PA). Analog domain and digital domain self-interference (SI) cancellation is also considered. We study the two cases of two independent oscillators for local transmitter and receiver and one common shared oscillator. We derive the powers of residual SI, desired signal, interference signal and noise, signal-to-interference-plus noise ratio (SINR) and the power spectral density (PSD) of the transmit signal. By using successive convex approximations, we solve the sum-rate maximization problem. Finally, we show that in full-duplex radios under certain RF impairments, GFDM may double the sum rate compared to that of orthogonal frequency division multiplexing (OFDM). INDEX TERMS Full-duplex radios, generalized frequency division multiplexing (GFDM), cognitive radio, spectrum hole, radio frequency (RF) impairments, rate optimization.

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“…• The resulting problem is solved via common CVX tool [37]. All the theoretical derivations are verified with simulation results.…”

Section: B Work Contributionsmentioning

confidence: 99%

“…To write fractional terms of (46) in the form of posynomial functions, the arithmetic-geometric mean approximation (AGMA) can be used [37]. In this method, a fraction of two posynomial functions,…”

Section: Sum Rate Maximizationmentioning

confidence: 99%

Cognitive GFDM Full-Duplex Radios With RF Impairments and ACI Constraints

Mohammadian

Tellambura

2020

IEEE Open J. Commun. Soc.

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“…Laying optical fiber to connect the RRUs to their host BBU is impossible in city centres of some countries [25]. Thus wireless backhauling/fronthauling [26]- [30], relying on massive MIMO [4] and mmWave [5], [30], has recently emerged as a promising solution for 5G networks due to its flexibility and cost-efficiency [23], [31], [32]. Park et al [31] proposed a partially centralized C-RAN based on massive MIMO schemes, while Parsaeefard et al [32] allocated resources by appropriately adjusting the parameters of the RRU, BBU and fronthaul as well as the power allocated to UDs.…”

Section: A Related Workmentioning

confidence: 99%

Boosting Fronthaul Capacity: Global Optimization of Power Sharing for Centralized Radio Access Network

Zhang

Chen

Guo

et al. 2019

IEEE Trans. Veh. Technol.

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The limited fronthaul capacity imposes a challenge on the uplink of centralized radio access network (C-RAN). We propose to boost the fronthaul capacity of massive multipleinput multiple-output (MIMO) aided C-RAN by globally optimizing the power sharing between channel estimation and data transmission both for the user devices (UDs) and the remote radio units (RRUs). Intuitively, allocating more power to the channel estimation will result in more accurate channel estimates, which increases the achievable throughput. However, increasing the power allocated to the pilot training will reduce the power assigned to data transmission, which reduces the achievable throughput. In order to optimize the powers allocated to the pilot training and to the data transmission of both the UDs and the RRUs, we assign an individual power sharing factor to each of them and derive an asymptotic closed-form expression of the signal-to-interference-plus-noise for the massive MIMO aided C-RAN consisting of both the UD-to-RRU links and the RRU-to-baseband unit (BBU) links. We then exploit the C-RAN architecture's central computing and control capability for jointly optimizing the UDs' power sharing factors and the RRUs' power sharing factors aiming for maximizing the fronthaul capacity. Our simulation results show that the fronthaul capacity is significantly boosted by the proposed global optimization of the power allocation between channel estimation and data transmission both for the UDs and for their host RRUs. As a specific example of 32 receive antennas (RAs) deployed by RRU and 128 RAs deployed by BBU, the sum-rate of 10 UDs achieved with the optimal power sharing factors improves 33% compared with the one attained without optimizing power sharing factors.

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“…Provisioning of wireless resources is optimally adapted to the actual needs of operators and subscribers. By exploiting centralized network intelligence, real-time resource allocation can be implemented in order to adapt to network conditions and user needs [46].…”

Section: Cloud-ranmentioning

confidence: 99%

Realizing 5G vision through Cloud RAN: technologies, challenges, and trends

Pliatsios

Sarigiannidis

Goudos

et al. 2018

J Wireless Com Network

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Achieving the fifth-generation (5G) vision will introduce new technology innovations and substantial changes in delivering cutting-edge applications and services in current mobile and cellular networks. The Cloud Radio Access Network (C-RAN) concept emerged as one of the most compelling architectures to meet the requirements of the 5G vision. In essence, C-RAN provides an advanced mobile network architecture which can leverage challenging features such as network resource slicing, statistical multiplexing, energy efficiency, and high capacity. The realization of C-RAN is achieved by innovative technologies such as the software-defined networking (SDN) and the network function virtualization (NFV). While SDN technology brings the separation of the control and data planes in the playground, supporting thus advanced traffic engineering techniques such as load balancing, the NFV concept offers high flexibility by allowing network resource sharing in a dynamic way. Although SDN and NFV have many advantages, a number of challenges have to be addressed before the commercial deployment of 5G implementation. In addition, C-RAN introduces a new layer in the mobile network, denoted as the fronthaul, which is adopted from the recent research efforts in the fiber-wireless (Fi-Wi) paradigm. As the fronthaul defines a link between a baseband unit (BBU) and a remote radio unit (RRU), various technologies can be used for this purpose such as optical fibers and millimeter-wave (mm-wave) radios. In this way, several challenges are highlighted which depend on the technology used. In the light of the aforementioned remarks, this paper compiles a list of challenges and open issues of the emerging technologies that realize the C-RAN concept. Moreover, comparative insights between the current and future state of the C-RAN concept are discussed. Trends and advances of those technologies are also examined towards shedding light on the proliferation of 5G through the C-RAN concept.

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Dynamic Resource Allocation for Virtualized Wireless Networks in Massive-MIMO-Aided and Fronthaul-Limited C-RAN

Cited by 46 publications

References 27 publications

Cognitive GFDM Full-Duplex Radios With RF Impairments and ACI Constraints

Cognitive GFDM Full-Duplex Radios With RF Impairments and ACI Constraints

Boosting Fronthaul Capacity: Global Optimization of Power Sharing for Centralized Radio Access Network

Realizing 5G vision through Cloud RAN: technologies, challenges, and trends

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