Self-Organizing Interference Management for LTE

Fourth generation cellular systems are currently being developed and deployed. Long Term Evolution (LTE) is one such 4G system and is an evolution of the 3GPP UMTS Standard [1][8]. These systems target significantly higher sector capacities and higher per user data rates compared to third generation systems. LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) in the Downlink (DL) and Single Carrier Frequency Division Multiple Access (SC-FDMA) in the Uplink (UL) as the Physical Layer radio access technology. OFDMA has been selected as it provides high spectral efficiency and robust performance in mobility and fading scenarios. Additionally, SC-FDMA provides a low peak to average power ratio. In LTE, the total system bandwidth is divided into a number of orthogonal sub-carriers. Information is transmitted by modulating each of these sub-carriers. Further, time is divided into slots consisting of a number of OFDM symbols and users are scheduled to transmit on an assigned set of subcarriers on specific time slots. Scheduling can be either persistent or semi-persistent or non-persistent.