Multi-hphase coded signals are constant-envelope sinusoids whose phase varies in a piecewise linear manner driven by cyclically chosen slopes. The transmission of these over a Gaussian noise channel with Viterbi decoder is simulated. Decoded error events are of two types normal and long, but in either case only a few bit errors are caused; events are empirically independent, they do not propagate, and their frequency is that predicted by signal space theory. Power gain compared to MSK modulation varies from1.5dB at bit error rate0.05to4dB at0.0001.