Power characteristic of a radio transmitter
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsKarl Gösta Sahlman, Hans Eriksson
Life of this patent
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Abstract
The present invention relates to radio transmission of bursts in for example a TDMA cellular radio system. The burst starts with a ramping up period, ends with a corresponding ramping down ramping down period and with the pay-load information therebetween. The ramp form is created in a ramp generator (13) which gives a multiplication value to multiply the digital information to be transmitted in multipliers (15, 16). The multiplied values are converted into analogue form and amplified before being transferred to the antenna (21). Output power and temperature of the transmitting equipment are measured (22, 23) and used to update the output power levels during the next burst.
Claims26
A method of creating an output power level characteristic of a radio information signal transmitted under supervision of a digital control circuit, DCC (10), in the form of a burst (s1-e4) beginning with a ramping up period (s1-s4), ending with a corresponding ramping down period (e1-e4) and with the actual pay-load message (t1-t6) signal therebetween and wherein the information signal originates from a digital signal which is converted into an analogue form and amplified for transmitting purposes, characterised in the following steps,
- generating a digital ramp function (R) based on the desired slope of said ramping up and down periods and with a substantially flat portion in between,
- combining the ramp function (R) and the information signal (s1-e4) while still in their digital form.
A transmitter system for transmitting radio signals in the form of bursts under the supervision of a digital control circuit DCC (10) wherein each burst (s1-c4) starts with a ramping up period and ends with a corresponding ramping down period with the actual payload message signal in between, including a source (14) for digital information to be sent, a digital to analogue converter (17, 18;
- 43), a modulator (19;
- 41), an amplification stage (20) and an antenna (21) characterised in that the transmitter system further includes
- a ramp generator (13) which generates a ramp function based on the desired ramping up and down slopes and with a substantially flat portion in between and
- a combining device (15, 16) connected to the information source (14) and the output of the ramp generator (13) which combines the digital information with the rampfunction (R).
Dependencies are inferred from the claim text.