www.astesj.com 222 A Novel Fair and Efficient Resource Allocation Scheduling Algorithm for Uplink in LTE-A Havva Esra Bilisik * , Radosveta Sokullu Engineering Faculty, Department of Electrical-Electronics Engineering, Ege University, 35040, İzmir, Turkey A R T I C L E I N F O A B S T R A C T Article history: Received: 28 August, 2018 Accepted: 30 October, 2018 Online: 10 November, 2018 With the introduction of new services and new more sophisticated mobile devices the radio network operators are faced with new challanges to increase the system performance. The most recent standards introduced by 3GPP for the new architectures of the Long Term Evolution network address these issues and outline possibilities for optimizing network performance and user QoS. A major instrument in that respect is the resource scheduling and allocation procedure. So far many different algorithms have ben proposed. Uplink resource allocation however is less covered, beacsue it poses additional constraints which make it difficult to balance the optimization between channel state information, system throughput and user perceived throughput. In this paper we propose a novel algorithm for resource allocation which balances the advantages of two previously suggested ones, specifically Round Robin and Best-CQI. We also define a new parameter, the user ratio, which allows us to explicitly quantify the trade-off between fairness, system throughput and user throughput for different channel conditions. Keywords: Long Term Evolution – A Uplink Transmission Radio Resource Allocation Algorithms Network Throughput User Fairness 1. Introduction In recent years the number of smart mobile devices as well as the number of various applications they support has increased in unprecedented proportions. In turn this has increased immensely the network traffic and has changed its characteristics posing many new challenges for the network engineers and network operators. A major instrument which regulates the relation between user demands and network traffic is the network adopted procedure for radio resource allocation, which is defined in the respective network standard. The Long-Term Evolution (LTE) standard proposed by 3GPP and its latest version Long Term Evolution – Advanced (LTE-A) are the most recent telecommunication standards introduced to meet increasing user demands in terms of high data rates and better quality of service. LTE provides flexible deployments allowing low latency and supporting up to 300 Mbps of data transmission in downlink and up to 75 Mbps throughput for uplink. [1, 2, 3] The standard defines two separate radio access methods for the transmission in the downlink (Base Station to user) and the transmission in the uplink (user to Base Station). Orthogonal frequency division multiple access (OFDMA), selected for the downlink is not suitable for uplink transmissions mainly due to its high Peak to Average Power Ratio (PAPR). Another multiplexing method, namely single carrier-frequency division multiple access (SC-FDMA) is proposed for the uplink [1, 2]. According to the LTE-A architecture, the Base Station known as “Evolved Node B (eNodeB)”, regulates the resource allocation process in both transmission directions. [2]. Functions and algorithms for allocating network resources for the downlink and the uplink are part of the Medium Access Control (MAC) layer at the eNodeB. Since this work is focused on uplink resource allocation, from here on the discussion will concentrate on the specifics of uplink transmission and resource allocation. In the uplink (UL) the modified, pre-coded form of the OFDMA known as SC-FDMA is adopted in order to reduce cell interference and Peak to Average Power Ratio (PAPR). It is well known that the user equipment’s (UE) battery life is quite limited so SC-FDMA fits well the major requirement for the access method used in the uplink - to be power efficient. However, despite its obvious advantages, there are some additional constraints which make it more difficult to allocate resources in the uplink than in the downlink. These constraints include above all singularity, contiguity, and transmit power constrains [5]. The constraint defined as “singularity” mandates that a given resource block (RB) can be allocated only to a single user. The constraint defined as “contiguity” implies that all RBs allocated to a given user must be contiguous. The third constrained, defined as “transmit power constraint” in its turn requires that the maximum transmit power ASTESJ ISSN: 2415-6698 * Havva Esra Bilisik, Email: bilisik.h@gmail.com Advances in Science, Technology and Engineering Systems Journal Vol. 3, No. 6, 222-232 (2018) www.astesj.com https://dx.doi.org/10.25046/aj030629