Radio resource management for uplink carrier aggregation in LTE-Advanced

Abstract

This paper investigates the uplink resource allocation problem in the context of Long-Term Evolution (LTE)-Advanced systems with carrier aggregation (CA) and dual-cluster scheduling. On one hand, these Rel'10 functionalities can increase the available transmission bandwidth and scheduling flexibility in uplink. On the other hand, they will introduce additional power back-off for the power amplifier in the user equipment (UE) with non-contiguous resource allocation. Taking into account that the uplink is inherently limited by the maximum transmission power of the UE, the assignment of uplink CA and/or dual cluster transmission for LTE-Advanced UEs has to be careful. A pathloss-threshold-based component carrier (CC) and cluster configuration algorithm is proposed to determine whether an LTE-Advanced UE should be configured with multiple CCs and/or dual cluster scheduling. An extended bandwidth-expansion-based packet scheduling algorithm is proposed for dual-cluster transmission, which tightly couples the bandwidth allocation and packet scheduling together to exploit the frequency domain diversity with low complexity. Simulation results show that with proper differentiation between power-limited and non-power-limited UEs, Rel'10 CA with dual-cluster scheduling can maintain similar coverage performance as in Rel'8 case while achieving substantial gains in median and peak user throughputs. Moreover, the proposed CC assignment algorithm achieves higher user throughput as compared to blindly assigning all UEs on all available CCs.

Optimal Virtualized Inter-Tenant Resource Sharing for Device-to-Device Communications in 5G Networks

“…where B RB is the LTE-based resource block bandwidth (180 kHz) and γ ink is expressed in power ratio. Lastly, even though we focus on the uplink scenario where communications happen according to the SC-FDMA principles, we herein consider that the RBs allocated per user can be non-adjacent ( [24]) as the evolution of LTE towards 5G systems will eventually enable fully non-contiguous allocation. Considering this, we will practically provide an upper bound of the D2Dbased rate performance.…”

A Novel Algorithm for Efficient Downlink Packet Scheduling for Multiple-Component-Carrier Cellular Systems

“…This research has addressed the two key aims of 5G systems: spectral efficiency [15][16][17][18][19][20] and energy efficiency [21][22][23][24][25]. The performance of both throughput and delay for elastic traffic in systems utilizing the mechanism of multiple-CC transmission was previously analyzed by Lei and Zheng [15].…”

“…Additionally, a method of minimizing packet transmission delay was proposed by Chung and Tsai [19], who described a quantized water-filling packet scheduling scheme with multiple-CC transmission. A study by Wang et al [20] presented a number of CC allocation schemes addressing uplink environments. In a 2013 study, the issue of how to configure users on a subset of CCs in order to provide energy-efficient transmissions was investigated by Sundaresan and Rangarajan [21], who specifically addressed the issue by considering both CC selection and packet scheduling.…”

“…However, while the first eight of these previous investigations (i.e., [15][16][17][18][19][20][21][22]) of multiple-CC BS packet scheduler designs made significant contributions to the literature, they did not address the issue of how systems deal with simultaneous RT and NRT traffic. Consequently, the previous studies may not meet ideal scheduler requirements, since RT and NRT traffic forms differ considerably from each other with regard to both required QoS levels and also traffic characteristics.…”

“…A range of key issues affecting multiple-CC BS packet scheduler designs have, however, been investigated in various studies published in recent years [15][16][17][18][19][20][21][22][23][24][25]. This research has addressed the two key aims of 5G systems: spectral efficiency [15][16][17][18][19][20] and energy efficiency [21][22][23][24][25].…”