Effect of imperfect CSI on interference alignment in multiple-high altitude platforms based communicationSudheesh, P.G.; Sharma, Navuday; Magarini, Maurizio; Muthuchidambaranathan, PalanivelPhysical communication2018 / p. 336-342 : ill https://doi.org/10.1016/j.phycom.2017.11.002