  Interference mitigation strategies are deemed to play a key role in the
context of the next generation (B4G/5G) of multicellular networks based on
orthogonal frequency division multiple access. Fractional and soft frequency
reuse (FFR, SFR) constitute two powerful mechanisms for intercell interference
coordination that have been already adopted by emerging cellular deployments as
an efficient way to improve the throughput performance perceived by cell-edge
users. This paper presents a novel optimal fifth-percentile user rate
constrained design for FFR/SFR-based networks that, by appropriately
dimensioning the center and edge regions of the cell, rightly splitting the
available bandwidth among these two areas while assigning the corresponding
transmit power, allows a tradeoff between cell throughput performance and
fairness to be established. To this end, both the cumulative distribution
function of the user throughput and the average spectral efficiency of the
system are derived assuming the use of the ubiquitous proportional fair
scheduling policy. The mathematical framework is then used to obtain numerical
results showing that the novel proposed design clearly outperforms previous
schemes in terms of throughput fairness control due to a more rational
compromise between average cell throughput and cell-edge ICIC.
