METHOD (VARIANTS) AND APPARATUS (VARIANTS) FOR TRANSFORMATION WITH REDUCING FREQUENCY OF RECEIVED SIGNAL, RECEIVING DEVICE AND MACHINE-READABLE CARRIER FOR SAVING PROGRAMM MODULE FOR IMPLEMENTATION OF THE METHOD

摘要

A carrier recovery method and apparatus using multiple stages of carrier frequency recovery are disclosed. A receiver uses multiple frequency generation sources to generate earner signals used to downconvert a received signal. An analog frequency reference (114) having a wide frequency range and coarse frequency resolution is used in conjunction with a digital frequency reference (110) having a narrow frequency range and fine frequency resolution. The multiple carrier signals are multiplied by a received signal to effect a multi-stage downconversion, resulting in a baseband signal. A frequency tracking module (108) measures the residual frequency error present in the baseband signal. The measured residual frequency error is then used lo adjust the frequencies of the carrier signals generated by the multiple frequency generation sources (114 and 110) through a processor