  We analyze nonbinary spatially-coupled low-density parity-check (SC-LDPC)
codes built on the general linear group for transmission over the binary
erasure channel. We prove threshold saturation of the belief propagation
decoding to the potential threshold, by generalizing the proof technique based
on potential functions recently introduced by Yedla et al.. The existence of
the potential function is also discussed for a vector sparse system in the
general case, and some existence conditions are developed. We finally give
density evolution and simulation results for several nonbinary SC-LDPC code
ensembles.
