A short example MATLAB script for producing a M-OCK signal followed by a simplistic decoder. Assumes perfect synchronisation.
This is a short and (overly) simple example for producing a bandlimited M-OCK signal and subsequently demodulating the received signal. This example uses hardcoded m-sequences to demonstrate a K7 16-OCK signal. Perfect synchronisation is assumed in this example, although the paper referenced below does explore synchronisation structures as well as the associated receiver structures. For further information please read the associated paper dx.doi.org/10.1109/OCEANS-Genova.2015.7271500. If you should make use of this research/software then cite as below.

B. Sherlock, C. C. Tsimenidis and J. A. Neasham, “Signal and receiver design for low-power acoustic communications using m-ary orthogonal code keying,” OCEANS 2015 – Genova, Genoa, 2015, pp. 1-10. doi: 10.1109/OCEANS-Genova.2015.7271500