Junaid AHMED, Sarmad SOHAIB, Faqir-Najam Ul-HASSAN

Sum rate enhancement and interference alignment for MIMO channels

Interference alignment (IA) is a cooperative technique used for multiple-input, multiple-output (MIMO) interference channels to confine the interference to a reduced signal space of the receiver. IA helps all nodes of the network to achieve half of the degree of freedom that can be achieved if there were no interference. In this paper an iterative alternating minimization algorithm is presented, which aims at providing the higher sum rate along with IA for more than three users having complete channel state information. In each iteration of the algorithm precoders and decoders are calculated to align interference in a reduced interference subspace. The precoders are then further improved for sum rate enhancement by scaling with suitable weights to increase the signal power of the desired signal. The simulation results show that the proposed algorithm achieves significant increase in average sum rate and also minimizes the overall interference as compared to conventional IA algorithms at low signal-to-noise ratio.

PDF

___

[1] Gomadam K, Cadambe VR, Jafar SA. Approaching the capacity of wireless networks through distributed interference alignment. In: Global Telecommunications Conference; 2008. pp. 1-6.
[2] Peters SW, Heath RW. Interference alignment via alternating minimization. In: International Conference on Acoustics, Speech and Signal Processing; 2009. pp. 2445-2448.
[3] Cadambe VR, Jafar SA. Interference alignment and degrees of freedom of the K-user interference channel. IEEE T Inform Theory 2008; 54: 3425-3441.
[4] Santamaria I, Gonzalez O, Heath R, Peters SW. Maximum sum-rate interference alignment algorithms for MIMO channels. In: Global Telecommunications Conference; 2010. pp. 1-6.
[5] Ganesan A, Rajan BS. On precoding for constant K-user MIMO Gaussian interference channel with finite constellation inputs. IEEE T Wirel Commun 2014; 13: 4104-4118.
[6] Li S, Li F, Li C, Huang Y, Zhu W, Yang L. Hierarchy precoder design for multi-cell multiuser multiple-input multiple-output wireless networks with interference alignment. IET Signal Process 2016; 10: 218-226.
[7] Wang H, Song R, Leung SH. Throughput analysis of interference alignment for a general centralized limited feedback model. IEEE T Veh Technol 2016; 65: 8775-8781.
[8] Anand K, Gunawan E, Yetis CM, Guan YL. Finite-SNR precoder designs for the interference relay channel without CSI at the transmitters. IEEE T Commun 2015; 63: 4754-4767.
[9] Tresch R, Guillaud M, Riegler E. On the achievability of interference alignment in the K-user constant MIMO interference channel. In: Proceedings of the IEEE/SP Workshop on Statistical Signal Processing; 2009. pp. 277- 280.
[10] Maddah-Ali MA, Motahari AS, Khandani AK. Communication over MIMO X channels: interference alignment, decomposition, and performance analysis. IEEE T Inform Theory 2008; 54: 3457-3470.
[11] Schmidt DA, Shi C, Berry RA, Honig ML, Utschick W. Minimum mean squared error interference alignment. In: Conference Record of the Asilomar Conference on Signals, Systems and Computers; 2009. pp. 1106-1110.