Telecommun Syst (2013) 52:1541–1547 DOI 10.1007/s11235-011-9521-5 Improving cell edge throughput for LTE using combined uplink power control Hristo Gochev · Vladimir Poulkov · Georgi Iliev Published online: 17 June 2011 © Springer Science+Business Media, LLC 2011 Abstract Uplink power control is used in 3GPP Long Term Evolution (LTE) systems to maximize the power of the de- sired received signals while limiting the interference. This paper analyzes two power control mechanisms, Fractional Power Control (FPC) and Interference Based Power Control (IBPC). A way of combining them is proposed in order to find an efficient algorithm to control the transmitted Power Spectral Density (PSD) in order to compensate poor channel conditions and thus to obtain better performance in terms of cell edge throughput. Keywords Cell capacity · Cell interference · Long Term Evolution · Uplink power control Abbreviations BS: Base Station CIBPC: Cell Interference Based Power Control eNB: Evolved NodeB LTE: Long Term Evolution FPC: Fractional Power Control OLPC: Open Loop Power Control PC: Power Control PG: Path Gain PL: Path Loss PRB: Physical Resource Blocks PSD: Power Spectral Density PUSCH: Physical Uplink Shared Channel SC-FDMA: Single-carrier Frequency Division Multiple Access H. Gochev · V. Poulkov ( ) · G. Iliev Faculty of Telecommunications, Technical University of Sofia, Sofia, Bulgaria e-mail: vkp@tu-sofia.bg SINR: Signal to Interference Noise Ratio SNR: Signal to Noise Ratio UE: User Equipment 1 Introduction Long Term Evolution (LTE) is considered to be the next major step in mobile radio communications and is intro- duced in 3GPP Release 8 [1]. LTE employs Orthogonal Frequency Division Multiplexing (OFDM) as its radio ac- cess technology, together with advanced antenna technolo- gies, such as Multiple Input Multiple Output (MIMO) tech- niques and beamforming. The main objectives behind this new technology are: reduced cost per bit; increased ser- vice provisioning—more services at lower cost with better user experience; flexible use of existing and new frequency bands; simplified architecture and open interfaces; reason- able terminal power consumption. The access scheme chosen for LTE uplink is Single Car- rier Frequency Division Multiple Access (SC-FDMA) [2]. Theoretically SC-FDMA provides intra-cell orthogonality meaning that the User Equipments (UE) within the same cell will not interfere with each other. This means that the main problem in LTE networks is inter-cell interference, es- pecially in the case when the frequency reuse factor is 1. Using such a scenario it is possible to reach a high spectral efficiency gain but at the same time a complex method for interference control is needed. As a result the uplink Power Control (PC) becomes crucial because it provides the re- quired Signal to Interference and Noise Ratio (SINR) for UEs in the outage of the cell, while keeping a predefined low level of interference cased by UEs to the neighboring cells [3].