Abstract—Interference alignment (IA) is an emerging technique which can suppress the interference effectually and provides a means to approach the channel capacity in the multiple-input and multiple-output (MIMO) networks. However, little work has concentrated on the bandwidth efficiency of IA systems, which is undoubtedly important especially in the current situations of spectrum scarcity. In this paper, a novel IA scheme is proposed, which leverages the advanced continuous phase modulation (CPM) to increase the bandwidth efficiency. Due to the continuity of the information-bearing phase, the proposed CPM-IA scheme exhibits low sidelobe and rapid spectrum rolloff. Moreover, a low-complexity pulse amplitude modulated (PAM) decomposition algorithm is applied to CPM-IA scheme, which can reduce the number of matched filters without much performance degradation. In addition, a novel spatial-frequency domain (SFD)-CPM-IA scheme is proposed to mitigate the interference that the traditional IA cannot handle when the IA feasibility condition cannot be satisfied. The proposed SFD-CPM-IA scheme inherits the high bandwidth efficiency of CPM-IA, and can accommodate many more users to communicate simultaneously.

Index Terms—Interference alignment, bandwidth efficiency, continuous phase modulation, pulse amplitude modulated (PAM) decomposition, spatial-frequency domain, bit error rate (BER)

Cite: Zhilu Wu, Lihui Jiang, Guanghui Ren, and Gangyi Wang, "A Novel High Bandwidth Efficiency Interference Alignment Scheme Based on Continuous Phase Modulation," Journal of Communications, vol. 10, no. 4, pp. 268-275, 2015. Doi: 10.12720/jcm.10.4.268-275