Frequency generator and associated method

A frequency generator for generating an oscillator clock according to a reference clock, the frequency generator being used in a frequency hopping system that switches a carrier frequency among a plurality of channels, the carrier frequency further carrying a modulation frequency for data transmission, the frequency generator comprising:

• a frequency hopping and modulation control unit, arranged for generating a current channel according to a channel hopping sequence;
• a calibration unit, arranged for sampling a phase error according to the reference clock, and generating an estimated DCO normalization value according to the current channel and the phase error obtained according to the oscillator clock and the reference clock;
• an oscillator tuning word (OTW) generator, arranged for generating an OTW according to the estimated DCO normalization value;
• and
• a digital-controlled oscillator (DCO), arranged for to generating the oscillator clock according to the OTW.

A method for controlling an digital-controlled oscillator (DCO) through an oscillator tuning word (OTW), wherein the DCO generates an oscillator clock according to a reference clock, the method is used for a frequency hopping system that switches a carrier frequency among a plurality of channels, the carrier frequency further carrying a modulation frequency for data transmission, and the method comprises:

• obtaining a channel hopping sequence, wherein the channel hopping sequence indicates a sequence of change of a current channel among the plurality of channels of the frequency hopping system;
• obtaining the current channel among the plurality of channels according to the channel hopping sequence;
• generating an estimated digital-controlled oscillator (DCO) normalization value at least according to the current channel, wherein the estimated DCO normalization value is a function of a frequency of the reference clock over a DCO gain, and the DCO gain is a function of a frequency of the oscillator clock over the OTW;
• and
• generating the OTW according to the estimated DCO normalization value.