Energy-efficient multi-cell resource allocation in cognitive radio-enabled 5G systems

Hengwei Lv,Qinmengying Yan,Pandong Li,Haijian Zhang

doi:10.1186/s13634-018-0599-8

Abstract

In this paper, we propose an energy-efficient resource allocation (RA) algorithm in cognitive radio-enabled 5th generation (5G) systems, where the scenario including one primary system and multiple secondary cells is considered. Because of the high spectrum leakage of traditional orthogonal frequency division multiplexing (OFDM), alternative modulation schemes regarded as the potential air interfaces in 5G are analyzed, e.g., filter bank-based multi-carrier (FBMC), generalized frequency division multiplexing (GFDM), and universal filtered multi-carrier (UFMC). Our objective is to maximize the whole energy efficiency of secondary system defined by the ratio of the capacity to the total power consumption subject to some practical constraints. The general formulation leads to a non-convex mixed-integer nonlinear programming problem with fractional structure, which is challenging to solve due to its intractability and significant complexity. Therefore, we resort to an alternate optimization framework to optimize the variables of subcarrier assignment and power allocation, where successive convex approximation (SCA) is employed so that the general formulation is finally transformed into a solvable convex problem. Numerical results validate the effectiveness of the proposed RA algorithm, and the comparison with some existing RA algorithms is conducted. In addition, the performance of using different 5G candidate waveforms in the energy-efficient RA algorithm is also presented and discussed.

Highlights

With the explosive growth of various communication services, more and more mobile terminals or users are seeking for accessing the communication networks
6 Conclusions This paper proposes an energy-efficient resource allocation algorithm aiming at solving the awkward nonconvex problem involving multiple cells with multiple secondary users (SUs) per cell
The heuristic subcarrier assignment and convex approximation are adopted to sequentially transform the non-convex form into a convex one

Summary

Introduction

With the explosive growth of various communication services, more and more mobile terminals or users are seeking for accessing the communication networks. It is quite difficult to solve the CR RA problem of multi-cell due to the complicated system structure and the existence of co-channel interference between different cells. To make this problem tractable, some RA algorithms have been developed. In [23], a distributed resource allocation scheme-based game theory, taking user fairness and priority into consideration, was proposed to solve the energy-efficient RA problem. 1.2 Contributions In this paper, we propose an energy-efficient RA algorithm for the scenario including one primary cell and multiple secondary cells.

System model and problem formulation

Heuristic subcarrier assignment

Conclusions