SCMA with Low Complexity Symmetric Codebook Design for Visible Light Communication

摘要

Sparse code multiple access (SCMA) is attracting significant researchinterests currently, which is considered as a promising multiple accesstechnique for 5G systems. It serves as a good candidate for the futurecommunication network with massive nodes due to its capability of handling useroverloading. Introducing SCMA to visible light communication (VLC) can provideanother opportunity on design of transmission protocols for the communicationnetwork with massive nodes due to the limited communication range of VLC, whichreduces the interference intensity. However, when applying SCMA in VLC systems,we need to modify the SCMA codebook to accommodate the real and positive signalrequirement for VLC.We apply multidimensional constellation design methods toSCMA codebook. To reduce the design complexity, we also propose a symmetriccodebook design. For all the proposed design approaches, the minimum Euclideandistance aims to be maximized. Our symmetric codebook design can reduce designand detection complexity simultaneously. Simulation results show that ourdesign implies fast convergence with respect to the number of iterations, andoutperforms the design that simply modifies the existing approaches to VLCsignal requirements.