Method and apparatus for producing mobile radio signals
A method and device are provided for producing mobile radio signals, which utilize a direct conversion receiver, at least one first and one second local oscillator and one regenerative divider for processing signals according to different mobile radio standards. For generating the intermediate frequency for transmission according to at least one of the mobile radio standards, a division by four in addition to a division by three of the oscillator frequency is also possible.
1. A method for producing mobile radio signals with a direct conversion receiver that processes signals conforming to a plurality of different mobile radio standards, the method comprising the steps of:
respectively providing local oscillator signals via at least one first and one second local oscillator;
producing, during transmission, an intermediate frequency for a first mobile radio standard or a second mobile radio standard using a regenerative divider by dividing the second local oscillator signal by three;
producing, during transmission, an intermediate frequency for a third mobile radio standard using a divider that divides the second local oscillator signal by four;
IQ-modulating the respective intermediate frequency; and
delivering the resulting modulated signal jointly with one of the respective local oscillator signals to at least one of an offset PLL and a mixer.
2. The method for producing mobile radio signals as claimed in claim 1 , wherein the first mobile radio standard is the Global System for Mobile Communications (GSM) standard, and the second mobile radio standard is the Universal Mobile Telecommunications System (UMTS) standard.
3. The method for producing mobile radio signals as claimed in claim 2 , wherein the third mobile radio standard is the Digital Cellular System (DCS) standard.
4. An apparatus for producing mobile radio signals for a plurality of different mobile radio standards, comprising:
a direct conversion receiver;
at least one first and one second local oscillator for respectively producing local oscillator signals;
a regenerative divider that produces an intermediate frequency during transmission for a first mobile radio standard or a second mobile radio standard by dividing the second local oscillator signal by three; and
a divider that produces an intermediate frequency during transmission for a third mobile radio standard by dividing the second local oscillator signal by four;
an IQ-modulator for modulating the intermediate frequencies; and
at least one of an offset phase-locked loop (PLL), for processing a modulated signal jointly with one of the respective local oscillator signals, and a mixer, for mixing a modulated signal with one of the respective local oscillator signals.
5. An apparatus for producing mobile radio signals as claimed in claim 4 , wherein the first mobile radio standard is the Global System for Mobile Communications (GSM) standard, and the second mobile radio standard is the Universal Mobile Telecommunications System (UMTS) standard.
6. An apparatus for producing mobile radio signals as claimed in claim 4 , wherein the third mobile radio standard is the Digital Cellular System (DCS) standard.