Resource Allocation in SVD-Assisted Optical MIMO Systems using Polynomial Matrix Factorization

摘要

Within the last years the multiple-input multiple-output (MIMO) technology has revolutionized the optical fiber community. Theoretically, the concept of MIMO is well understood and shows some similarities to wireless MIMO systems. The interference in any kind of broadband MIMO systems can be removed by applying a spatio-temporal vector coding (STVC) channel description and using singular value decomposition (SVD) in combination with signal pre- and post-processing. In this contribution a newly developed decomposition strategy namely polynomial matrix factorization channel description in combination with a SVD algorithm for polynomial matrices is analyzed and compared to the commonly used STVC SVD. This comparison points out the analogies and differences of both equalization methods. Furthermore, the bit error rate (BER) performance is evaluated and optimized by applying bit allocation schemes involving power loading. For our simulations the specific impulse responses of the (2x2) MIMO channel, including a 1.4 km multi-mode fiber and optical couplers at both ends, are measured for the operating wavelength of 1576 nm. Our results, obtained by computer simulation, show that polynomial matrix factorization such as polynomial matrix SVD could be an alternative signal processing approach compared to conventional SVD-based MIMO approaches in frequency-selective MIMO channels.