EP0398688A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Procedure for forming frequencies of a digital radio telephone
Assignee: Nokia Oyj
•
Filing: 1990-05-16
•
Granted: —
•
Expires: 2010-05-16
Abstract
Abstract The present invention concerns a procedure with which the frequencies required in a digital radio telephone based on time division multiplex channelling, in particular in radio telephone for the gsm system, in transmission and receiving can be formed. According to the procedure, the mixer frequencies (FTx1, FTx2; FRx1, FRx2) used in the transmitter (Tx) and the receiver (Rx) of the radio telephone are formed by means of a synthesiser (2) and a basic oscillator (1) commmon to both of them, from the frequency whereof (Fp) also the clock frequency for the logic of the radio telephone and the RF reference frequency to the synthesiser (2) being produced by means of division.
Inventors
- 👤 Raimo Ikonen
- 👤 Pekka Lonka
- 👤 Pekka Mikkola
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 13:38
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/16; H04; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/403; H04B1/405
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
114 words
A procedure by which the frequencies required in a digital radio telephone, in particular in a radio telephone of the gsm system, based on time division multiplex channelling (TOMA), in transmission and receiving can be formed, characterized in that the mixer frequencies (f Tx1 , f Tx2 ; f Rx1 , f Rx2 ) used in the transmitter (Tx) and the receiver (Rx) of the radio telephone are formed by means of a synthesiser (2) and a basic oscillator (1) common to both of them, from the frequency whereof (fp) are formed, using division, also the clock frequency for the logic of the radio telephone, and the RF reference frequency for the synthesiser (2).
Claim 2
Dependent Claim
114 words
A procedure by which the frequencies required in a digital radio telephone, in particular in a radio telephone of the gsm system, based on time division multiplex channelling (TOMA), in transmission and receiving can be formed, characterized in that the mixer frequencies (f Tx1 , f Tx2 ; f Rx1 , f Rx2 ) used in the transmitter (Tx) and the receiver (Rx) of the radio telephone are formed by means of a synthesiser (2) and a basic oscillator (1) common to both of them, from the frequency whereof (fp) are formed, using division, also the clock frequency for the logic of the radio telephone, and the RF reference frequency for the synthesiser (2).
Claim 3
Dependent Claim
156 words
Procedure according to claim 1, in which the received signal is transferred to an intermediate frequency in one mixer of the receiver (Rx), and the signal to be transmitted is transferred to the transmission frequency in another mixer of the transmitter, characterized in that the mixer frequency (f Rx2 , f Tx2 ) of both of said mixers is generated with the same synthesiser (2) in that during the transmission time interval the synthesiser (2) generates the second mixer frequency (f Tx2 ) of the transmitter (Tx), and subsequent to the transmission time interval the synthesiser (2) moves for 7 MHz in the frequency, being tuned to the receiving channel corresponding to the transmission frequency and generates, throughout the receiving time interval, a mixer frequency of the second mixer of the receiver (Rx), and subsequent to the receiving time interval, moves once again upwards for 7 MHz in the frequency to wait for another transmission period.
Claim 4
Dependent Claim
117 words
Procedure according to claim 1, in which a received signal is transferred from an intermediate frequency to an audio frequency in a first mixer of the receiver (Rx), and a transmission signal from the microphone is transferred to the first mixing frequency in the first mixer of the transmitter (Tx), characterized in that the fixed mixer frequency (f Rx1 , f Tx1 ) of both of said mixers is produced by means of one basic oscillator (1), its frequency (fp) being the first mixer frequency (f Rx1 ) of the receiver (Rx) and the second harmonic frequency (2 x f p ) whereof being the mixer frequency (f Tx1 ) of the first mixer of the transmitter.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.