The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 28, 1994
Filed:
Dec. 23, 1992
Juha Rapeli, Oulu, FI;
Nokia Mobile Phones Ltd., Salo, FI;
Abstract
The invention relates to a method, in which a phase modulated or frequency modulated signal can be directly generated with a PLL frequency synthesizer. With an interpolating synthesizer it is possible to create a very dense output frequency (f.sub.x) raster, so that the pulses received in the phase comparator (63) both from the reference signal (f.sub.o) branch and from the voltage controlled oscillator VCO (65) are lengthened in lengthening means (62, 69; 67, 68; k.sub.1, L+.DELTA.L; k.sub.2, L) by a desired amount. The numbers k.sub.1 and k.sub.2 are proportional to the amount of lengthening. When these integers now further are changed proportionally to the modulating signal, the change of the integers causes a change of the time difference of the pulses received by the phase comparator (63). This change of the time difference further causes a change in the output signal (f.sub.x) of the voltage controlled oscillator. The method is particularly well suited to provide digital quadrature phase modulation QPSK or quadrature amplitude modulation QAM, in which the shift from one carrier phase to another has a predetermined size and waveform as a function of time.