Inter-Band Interference Cancellation Based on Complex ICA for 100Gbit/s/λ Non-Orthogonal m-CAP NGFI-II Fronthaul Data Transmission

Abstract

Next generation fronthaul interface (NGFI) has been adopted as the mobile fronthaul (FH) transportation solution of the next generation (NG) mobile network, which requires high bandwidth and architecture flexibility. Spectral efficiency (SE) is a key performance indicator that worth discussion for NG mobile FH. In this paper, a novel inter-band interference (IBI) cancellation method based on complex independent component analysis (ICA) is proposed in non-orthogonal multiband CAP (NO-m-CAP) system. The interfering distortion caused by spectral overlapping between adjacent sub-bands in non-orthogonal multi-band CAP is mitigated by the proposed method, and the overall SE has been improved. As a proof of concept, an experimental demonstration of 100Gb/s/λ NGFI-II data transmission over 25km SSMF is carried out. Simple intensity modulator at central unit (CU) and a coherent detection at distributed unit (DU) are applied to achieve high-performance, low-cost and flexible mobile FH data transmission. A maximum SE improvement of 15% is obtained with the proposed method for both 4-band and 8-band assuming a 7% HD-FEC limit. Flexible data rate allocating, from 12.5Gb/s to 100Gbps with a bandwidth granularity of 12.5Gb/s, is also demonstrated.