Patent ID: 7428274

Claim:
A receiver of a frequency-modulated signal representing a digital signal comprising: a frequency translation unit comprising a single local oscillator including a divider, wherein the single local oscillator generates both a local oscillator signal and a reference signal, the reference signal having a frequency derived by the divider dividing a frequency of the local oscillator signal by a value, and a mixer circuit that multiplies the received frequency-modulated signal with the local oscillator signal to lower the frequency of the received frequency-modulated signal to provide a lowered-frequency signal; a digital demodulator to regenerate the digital signal from the lowered-frequency signal, wherein the frequency translation unit comprises counting means to determine the number of periods of the reference signal during a period of the lowered-frequency signal and wherein the digital demodulator comprises computation means to compute the period of the lowered-frequency signal from the number of periods of the reference signal; and wherein the duration of the period of the reference signal is variable and may take two possible values, T 1 and T 2 ; and further wherein the counting means comprises a first counter to count a number P of periods with a duration T 1 of the reference signal during a period of the lowered-frequency signal and a second counter to count a number Q of periods with a duration T 2 of the reference signal during a period of the lowered-frequency signal, and wherein the computation means of the digital demodulator computes the period of the lowered-frequency signal by adding the number of P periods and the number of Q periods.