JDP_V3_N4_RevP1 Anuja Mishra Sharad Mohan Shrivastava Pooja Sharma Prachi Agrawal Rahul Parganiha Journal on Digital Signal Processing 2322–0368 3 4 27 36 Mode-multiplexing, Multiple Input Multiple Output (MIMO), Digital Signal Processing (DSP), Coherent Communication, Multi-Mode Fiber The objective of this review paper is to make readers understand the key terms related to optical fiber specifically few mode fiber to help them carry out further research work. With the increasing demand for faster transmission systems, optical fiber communication system requirement is increasing day-by-day. As we know that the capacity limits of single mode fiber is almost reached its maxima, Space division multiplexing can be helpful for increasing the data rate requirement. This review paper, inferred the transmission of 6 spatial and polarisation modes, each carrying the quadrature-phase-shift-keyed channels over few-mode fiber keeping lower differential group delay. The detection of these channels is being carried out using coherent detection namely MIMO DSP. The 66 impulse response matrix representation of few-mode fiber is presented, revealing the coupling characteristics between the modes. October - December 2015 Copyright © 2015 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=3709