FOERFARANDE OCH/ELLER ANORDNING FOER DEMODULERING AV EN BIPHASE-SIGNAL

The invention relates to a method and/or a device for demodulating a binary coded phase-modulated signal (biphase signal). It is provided to determine the period of time (T) passing between each two successive level jumps of an incoming biphase signal, to generate or extract a clock frequency (B) approximately corresponding to the bit rate of the biphase signal with the aid of a clock generator, the clock period (1/B) of which clock frequency is compared with the period of time (T) between each two level jumps, and to determine the logical value of the biphase signal with the aid of an interrogating circuit controlled by the clock frequency (B), and to output a signal corresponding to the logical value, whenever a value of between 1/4 and 3/4 of 1/B was determined twice in succession for the period of time (T) immediately before, or whenever a value of between 3/4 and 5/4 of 1/B has been determined for the period of time (T) immediately before. In addition, a signal identifying a disturbance can be output or the output can be muted if a value of less than 1/4 of 1/B or greater than 5/4 of 1/B has been determined as the period of time (T). The invention makes it possible to recover the original data with sufficient reliability in a relatively simple manner when a biphase signal is present.