Skip to main content
main-content

About this book

There have been recent advancements in wireless network technologies such as wireless virtualization to accommodate the exponential growth in demand, as well as to increase energy and infrastructure efficiencies. This SpringerBrief discusses the user-association and resource-allocation aspects in Virtualized Wireless Networks (VWNs) and highlights key technology innovations to meet their requirements. Various issues in practical implementation of VWNs are discussed along with potential techniques such as Massive MIMO, Cloud-Radio Access Network (C-RAN), and non-orthogonal multiple access (NOMA).

This SpringerBrief will target researchers and professionals working on current and next-generation wireless networks. The content is also valuable for advanced-level students interested in wireless communications and signal processing for communications.

Table of Contents

Frontmatter

Chapter 1. Introduction

The tremendous increase in multimedia applications and high-end communication devices like smart phones over the last decade has driven the capacity demand for the currently deployed wireless networks. As such, the future generation of wireless networks, e.g., fifth generation of wireless networks (5G), needs to address a number of challenges. First, with the proliferation of the high data-rate applications that have become ubiquitous nowadays, there should be a huge increase in the supported data rates by the next-generation networks. Secondly, with the advent of machine type communications (MTC) and the Internet-of-Things (IoT), the future network will need to support devices that are not only remotely controlled in real time but will also communicate with each other.

Tho Le-Ngoc, Rajesh Dawadi, Saeedeh Parsaeefard, Mahsa Derakhshani

Chapter 2. Bandwidth-Efficient Joint User-Association and Resource-Allocation in Multi-Cell VWN

This chapter addresses the user association and resource allocation problem in a multi-cell VWN where users belong to different slices with each slice requiring a minimum reserved rate from the network. We formulate a bandwidth-efficient joint user-association and resource-allocation scheme that assigns users to BS and allocates the sub-carriers and power to maximize the total achieved sum-rate of the network subject to the rate reservation per slices.

Tho Le-Ngoc, Rajesh Dawadi, Saeedeh Parsaeefard, Mahsa Derakhshani

Chapter 3. Power-Efficient Joint User-Association and Resource-Allocation in Multi-Cell VWN

This chapter addresses the power-efficient user-association and resource-allocation problem in a multi-cell VWN. With the aim of minimizing the total transmit power from the BS, we formulate a joint BS assignment, sub-carrier and power allocation problem subject to the slice isolation constraints. This problem is inherently a non-convex optimization problem. To tackle its computational complexity, we apply successive convex approximation (SCA) and complementary geometric programming (CGP) to convert the problem into a computationally efficient formulation and propose an iterative algorithm for solving the problem. Simulation results illustrate the performance enhancement of the VWN achieved through our formulation for different network scenarios.

Tho Le-Ngoc, Rajesh Dawadi, Saeedeh Parsaeefard, Mahsa Derakhshani

Chapter 4. Uplink Resource-Allocation in VWN with Massive-MIMO and Dynamic Pilot-Duration

In this chapter, we address the resource allocation problem in a VWN with massive MIMO at the BS. Specifically, we focus on the imperfect CSI estimation scenario in a massive MIMO VWN and formulate the resource allocation problem that jointly assigns sub-carrier, power, antenna and adaptive pilot duration to users with the aim of maximizing the total sum-rate of the system. An iterative algorithm is proposed that tries to dynamically assign these resources to users while maintaining the isolation constraints among slices. The proposed iterative algorithm is compared with the scenario where users have a fixed pilot duration to report their CSI information to the BS. The numerical results demonstrate that there is a significant improvement in the spectral efficiency of the VWN when using adaptive pilot duration compared to the situation with a fixed pilot duration.

Tho Le-Ngoc, Rajesh Dawadi, Saeedeh Parsaeefard, Mahsa Derakhshani

Chapter 5. User-Association and Resource-Allocation in a C-RAN-Based VWN

Although user association and dynamic resource allocation are the prime requirements in a VWN, the practical realization of these algorithms require coordination among BSs in order to obtain the knowledge about the channel conditions of users in all slices. To that end, C-RAN has been proposed to facilitate the collaboration among BSs by shifting the baseband processing of all BSs into the cloud. In this chapter, we address the issue of user association and resource allocation in a C-RAN-based VWN. Specifically, we formulate a resource allocation problem that jointly associates users to RRHs/BBUs and allocates the resources (power and antenna) in order to maximize the total sum-rate of the system. We evaluate the performance of the proposed scheme in both the imperfect and perfect CSI scenarios.

Tho Le-Ngoc, Rajesh Dawadi, Saeedeh Parsaeefard, Mahsa Derakhshani

Chapter 6. Resource Allocation in a NOMA-Based VWN

In this chapter, we consider the resource allocation problem in a NOMA-based VWN. Specifically, we formulate a power-efficient resource allocation problem in a NOMA-based VWN to find the optimal power allocation coefficients to users while maintaining the slice isolation requirements. By using various convexification approaches, we develop a computationally efficient algorithm that tries to minimize the total transmit power from the BS. The simulation results performed demonstrate that the proposed NOMA scheme significantly outperforms the OFDMA scheme in terms of the power efficiency.

Tho Le-Ngoc, Rajesh Dawadi, Saeedeh Parsaeefard, Mahsa Derakhshani

Chapter 7. Conclusion

In this brief, the problems of user-association and resource-allocation as well as their requirements in a VWN were discussed along with the various state-of-the-art techniques in order to meet the requirements. We considered various aspects, including massive MIMO, C-RAN, NOMA in studying the resource allocation problems in both the single-cell and multi-cell VWNs.

Tho Le-Ngoc, Rajesh Dawadi, Saeedeh Parsaeefard, Mahsa Derakhshani

Backmatter

Additional information