Adaptive Interference Alignment with CSI Uncertainty

• Published in: IEEE transactions on communications 2013-02, Vol.61 (2), p.792-801
• Main Authors: Baile Xie, Yang Li, Minn, H., Nosratinia, A.
• Format: Article
• Language: English
• Subjects: Algorithm design and analysis; Applied sciences; Bit error rate; bit error rate (BER); bit loading; Detection, estimation, filtering, equalization, prediction; Exact sciences and technology; Information, signal and communications theory; Interference; Interference alignment; Loading; MIMO; Multiplexing; Signal and communications theory; Signal to noise ratio; Signal, noise; spatial multiplexing; SVD; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Teletraffic; Transmission and modulation (techniques and equipments); Vectors
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2012.121112.110589

Interference alignment (IA) is known to significantly increase sum-throughput at high SNR in the presence of multiple interfering nodes, however, the reliability of IA is little known, which is the subject of this paper. We study the error performance of IA and compare it with conventional orthogonal transmission schemes. Since most IA algorithms require extensive channel state information (CSI), we also investigate the impact of CSI imperfection (uncertainty) on the error performance. Our results show that under identical rates, IA attains a better error performance than the orthogonal scheme for practical signal to noise ratio (SNR) values but is more sensitive to CSI uncertainty. We design bit loading algorithms that significantly improve error performance of the existing IA schemes. Furthermore, we propose an adaptive transmission scheme that not only considerably reduces error probability, but also produces robustness to CSI uncertainty.