Sparse code multiple access (SCMA) has recently emerged as one of the most favorable multiple access schemes for 5G networks, which allows overloading with a large number of users so as to enable massive connectivity. In this paper, we design a hardware framework of a uplink system for SCMA. First, we propose a unified quantization scheme based on density evolution optimization which is independent of signal-to-noise ratios (SNR). Second, we apply a fast convergence message passing algorithm (FC-MPA) in SCMA multiuser detection, in which the function nodes updating and variable nodes updating are processed synchronously so as to make the FC-MPA converge about 2 times faster than standard MPA. Finally, based on FC- MPA, we design a pipelined decoding structure for SCMA so as to increase throughput. FPGA results demonstrate that the fix- point performance achieve a near floating-point performance for different SNR and the pipelined hardware structure we design is feasible.