Abstract: Digital information is transmitted by generating coded signals in the form of pulses on the basis of binary digital information and decoding the coded signals into the binary digital information, the pulses being coded in the time domain and being of at least two distinctly different shapes with respect to their numerical amplitude variation along the time axis of the pulses, the pulses comprising two bits of information in each pulse having energy one, but coded in the way that one bit of information is in the polarity and one bit in the shape, or two bits are in the shape.