Analysis of interference alignment for wireless communication with external interference

In order to better cope with the increasing levels of interference in wireless cellular systems, interference mitigation techniques that consider a certain degree of coordination/cooperation among cells have been recently employed, such as Joint Processing (JP) and Interference Alignment (IA). In this paper we evaluate the performance of different IA-based algorithms in the presence of uncoordinated external interference, with JP schemes used as a benchmark. Sum rate and Bit Error Rate (BER) results are presented for different external interference scenarios and it is shown that there is trade-off between IA and JP, and that for high external interference levels IA algorithms modified to handle this external interference can achieve better BER performances.