Load Dependent Interference Margin for Link Budget Calculations of OFDMA Networks

Link budget calculations are essential in the planning of wireless networks to get a reliable estimate of maximum cell radius and guaranteed signal to interference plus noise ratios at the cell border. In future networks using orthogonal frequency division multiple access, the interference introduced by co-channel cells depends on the amount of subcarriers utilized in the interfering as well as in the considered cell. If distributed subcarrier allocation is applied, frequency diversity and interference averaging effects can be obtained. A method is derived in this paper to consider load dependent margins for interference from co-channel cells in the link budget calculation. This margin makes the estimation of the maximum cell radius more accurate.