User Satisfaction-Based Scheduling Algorithm for Uplink Transmission in Long Term Evolution System

With low Peak-to-Average Power Ratio (PAPR), Single Carrier ¡V Frequency Division Multiple Access (SCFDMA) is adopted by 3GPP to be the uplink access method of the LTE system. SC-FDMA allocates continuous Resource Blocks (RBs) to each subscriber to reduce PAPR. However, the continuous RB allocation degrades the flexibility in resource allocation. How to efficiently allocate radio resource in the SCFDMA scheme has been a critical issue. This paper proposes a scheduling algorithm concerning user satisfaction in LTE uplink radio resource allocation. The proposed algorithm is a generalization and an improvement of the well-known Mean Enhanced Greedy (MEG) scheduling algorithm. The simulation results show that the proposed algorithm achieves not only higher user satisfaction degree but also better fairness between subscribers than the MEG scheduling algorithm and a related algorithm, called the Recursive Maximum Expansion (RME) algorithm, no matter the desired uplink transmission rates among subscribers are the same or not.

I. Introduction

The 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) system is one of the major candidates of the fourth generation (4G) wireless communication technologies. Along with evolution toward the new generation, LTE adopts the Orthogonal Frequency Division Multiplexing Access (OFDMA), which is inherently robust to time dispersion, as the downlink multiple-access scheme. The OFDMA has flat frequency selective channel fading in frequency domain by multi-carrier modulation and obtains multi-user diversity gain. However, OFDMA exhibits high Peak-to-Average Power Ratio (PAPR) [1] and is not suitable for mobile User Equipments (UEs) that are powered by batteries and equipped with simple power amplifiers. The 3GPP, thus, adopts the Single Carrier - Frequency Division Multiple Access (SC-FDMA) [7], which has lower PAPR and higher power efficiency, in the uplink of the LTE system.