• Jaume Nin Guerrero
  • Iván Ordás Villamandos
Orthogonal Frequency Division Multiple Access (OFDMA) is the access scheme chosen by 3GPP for downlink in its LTE UTRAN. As OFDMA can provide intra-cell orthogonality, the main interference in downlink is inter-cell interference, which can severely limit the throughput of users near the cell edge. Under limited traffic conditions, fractional load as interference control scheme can be considered, transmitting only in a subset of the available physical resource blocks (PRBs). The inter-cell interference can be reduced avoiding the overlapping of the resources. However, defining the set of PRBs to transmit in each cell is not a trivial operation. In this thesis, autonomous resource selection algorithms are developed to allocate these resources utilizing only the information available internally within each cell. The algorithms proposed are implemented on a system level simulator and tested for a constant and variable number of users, under both low and high loads. The best-performing algorithm demonstrates a significant reduction in inter-cell interference by means of overlapping avoidance and, thereby, a considerable improvement in SINR. Furthermore, a new method proposed allows dynamic adjustments on the cell load based on the instantaneous cell requirements estimated through the feedback of the users.
Publication date2007
Number of pages130
Publishing institutionAAU
ID: 13285257