Abstract: A process for transmitting digital signals, in which the digital data are coded differentially in symbols of a symbol period T.sub.s (2.1, 2.2), the symbols transmitted with the Q component being delayed by T.sub.s /2, relative to those of the I component, to achieve a time-staggering. A cross interference of the I and Q components, occurring on the receiver end and caused by the differential coding nd the time staggering, is resolved with a trellis decoder (10), for example. As a result, a differential offset QPSK process achieved on this basis combines the advantages of DQPSK and OQPSK procedures.

Abstract: In a signal transmission method, a sequence of equally distributed statistically uncorrelated symbols having a symbol duration T.sub.S is converted, in a transmitter, into a frequency baseband signal by means of a given CPM method, the frequency baseband signal is transmitted to a signal receiver by means of a carrier oscillation and the receiver is synchronized with respect to the frequency baseband signal. The signal receiver is synchronized in such a manner that, in a number N of time windows the starting times of which are displaced by an integral multiple of the symbol duration T.sub.S referred to a given reference time t.sub.R and the length of which in each case corresponds to the symbol duration T.sub.S, the frequency baseband signal is sampled in a number K of subintervals (1A, 1B, 1C, 2A, . . . ) per time window, dispers ions (.sigma..sub.A, .sigma..sub.B, .sigma..sub.C) are calculated for sampled values from subintervals (1A, 2A, 3A, . . . ) corresponding to one another and a sampling time T.sub.

Abstract: In a method for clock synchronization of a signal receiver, the demodulated received signal is sampled in each of the subintervals over N time windows having in each case K subintervals (1A . . . 4C). In each case, the dispersion is calculated for the sampled values of N corresponding subintervals and the K dispersion values obtained are compared with each other. The optimum sampling time is derived from the position in time of the minimum dispersion value.