ABSTRACT
In interference-limited networks, such as code division multiple access (CDMA) networks, the energy efficiency (EE) is limited by the interference power level (Buzzi and Poor 2008; Meshkati et al. 2005; Souza et al. 2012a), since this forces all users to increase the transmission power in order to maintain their quality of service (QoS) quantified for example as the minimum acceptable information rate or the maximum tolerable symbol/frame error rate (SER/FER). This problem is worst at the cell edges, given the higher distance to the base station (BS), which further limits the EE. When the number of users increases, which directly affects the interference power level, the percentage of users transmitting at their maximum power increases, resulting in a reduction of the achievable EE, even when employing advanced multiuser detection (MuD) techniques (Meshkati et al. 2005; Souza et al. 2012b), which mitigate the UL interference.
