Abstract: A novel modulator converts a sequence of N'ary codes representative of an element P of a set (0, 1, 2, . . . , N - 1) into a sequence of 2N-phase carrier pulses, where N = 2.sup.n, n being a positive integer. A phase shift in the carrier signal between each carrier pulse and the next preceding one is selected from P.pi./N and (P + N).pi./N in compliance with a prescribed law of correlation between the N'ary codes in the sequence. Alternatively, the carrier signal is given in each carrier pulse a phase selected in the manner specified. For convenience of resorting to the prescribed correlation law, the N'ary code sequence may be converted into N trains, corresponding to the respective elements P, of three-level signals, 0 and .+-.1. In the train corresponding to a particular element, the three-level signals are successively produced with the prescribed correlation law, such as with resort to a bipolar or duobinary technique.

Abstract: A baseband signal switching arrangement for diversity reception in a PCM communication system is disclosed. The switching arrangement is characterized by the provision of a 1/n write-in frequency-dividing counter in each receiving channel to count clock signals in response to being reset by a frame signal and n buffer memory circuits for successively writing bit information of a received digital signal in response to the n frequency-divided outputs of the 1/n frequency-dividing counter. The switching arrangement further includes a 1/n read-out frequency-dividing counter which is adapted to successively read out memory outputs of one set of the n buffer memory circuits and a switching means for enabling the 1/n read-out frequency-dividing counter to selectively read out memory outputs of a given set of buffer memory circuits.