El-Khatib, RafahMacris, Nicolas2017-01-242017-01-242017-01-24201610.1109/ITW.2016.7606833https://infoscience.epfl.ch/handle/20.500.14299/133426WOS:000386639100050We consider spatially coupled systems governed by a set of scalar density evolution equations. Such equations track the behavior of message-passing algorithms used, for example, in coding, sparse sensing, or constraint-satisfaction problems. Assuming that the "profile" describing the average state of the algorithm exhibits a solitonic wave-like behavior after initial transient iterations, we derive a formula for the propagation velocity of the wave. We illustrate the formula with two applications, namely Generalized LDPC codes and compressive sensing.text::conference output::conference proceedings::conference paper