Demodulator having rotation means for frequency offset correction

A demodulator for angle modulated signals having a carrier frequency, the demodulator comprises:

• a demodulation channel provided with a local oscillator and with a channel output for supplying a representation of angle modulated signals;
• a frequency error detection means coupled to the channel output for deriving a local oscillator frequency error signal;
• and
• a frequency error correction means having two inputs and an output for providing the frequency error corrected angle modulated signals, one input whereof is coupled to the channel output, whereas its other input is coupled to the frequency error detection means;
• wherein the frequency error correction means are embodied as complex plane rotation means for providing complex angle modulated signals by complex plane rotation of a representation of said angle modulated signals in response to said local oscillator frequency error signals;
• and
• wherein the frequency error detection means are coupled to the channel output through coupling to the output of the frequency error correction means, and wherein the frequency error detection means comprises a series arrangement of an overdeviation detector and an up/down counter having a counter output which is coupled to the other input of the frequency error correction means.