Device for processing radio transmission data with digital predistortion

1. A device for processing data which is to be transmitted by radio, with the data to be transmitted being in the form of a digital baseband signal, the device comprising:

a filter unit configured to receive the digital baseband signal at a chip rate and to perform a pulse shaping and oversampling of the digital baseband signal to produce a pulse shaped and oversampled digital baseband signal at a sampling rate that is greater than the chip rate;

a predistortion unit configured to receive the pulse shaped and oversampled digital baseband signal of the filter unit and to perform a predistortion of the pulse shaped and oversampled digital baseband signal, wherein the predistortion unit comprises: a multiplication unit for multiplication of the pulse shaped and oversampled digital baseband signal by predistortion coefficients, and a first memory for storage of the predistortion coefficients; and

a control unit configured to receive the digital baseband signal at the chip rate and to control the predistortion unit as a function of the digital baseband signal, the control unit comprising: a second memory in which amplitude values have been stored in advance of processing the data which is to be transmitted by radio; and addressing logic configured to select amplitude values from the second memory as a function of the digital baseband signal such that the selected amplitude values correspond to amplitude values of the pulse shaped and oversampled digital baseband signal generated by the filter unit, the addressing logic being clocked at the chip rate, wherein the predistortion coefficients are selected from the first memory based on amplitude values selected from the second memory.

2. The device according to claim 1 , wherein the digital baseband signal and the baseband signals which are produced from it are complex signals.

3. The device according to claim 1 , further comprising:

a digital/analogue converter unit configured to convert the predistorted baseband signal.

4. The device according to claim 3 , further comprising:

a further filter unit configured to low-pass filter the analogue baseband signal.

5. The device according to claim 1 , further comprising:

a modulator unit with an oscillator configured to modulate a radio-frequency carrier, with the baseband signal, in particular via an intermediate frequency.

6. The device according to claim 5 , further comprising:

an amplifier unit configured to amplify the modulated radio-frequency signal with a variable gain, the gain being controllable in analogue form or being digitally programmable.

7. The device according to claim 5 , further comprising:

a power amplifier configured to amplify the modulated radio-frequency signal.

8. A transmitting device configured to send data by radio, with the data to be transmitted being in the form of a digital baseband signal, the transmitting device comprising:

the device according to claim 1 .

9. The device according to claim 1 , further comprising:

a power control unit configured to supply a multiplier value corresponding to a desired power level, wherein the first memory supplies to the multiplication unit predistortion coefficients selected by addresses generated by multiplying the amplitude values selected from the second memory by the multiplier value.

10. A method for processing of data to be transmitted by radio, with the data to be transmitted being in the form of a digital baseband signal, the method comprising:

pulse shaping and oversampling the digital baseband signal via a filter unit configured to receive the digital baseband signal at a chip rate to produce a pulse shaped and oversampled digital baseband signal at a sampling rate that is greater than the chip rate;

storing predistortion coefficients in advance in a first memory;

selecting, at the chip rate, amplitude values from a second memory as a function of the digital baseband signal, wherein the amplitude values have been stored in the second memory in advance of processing of the data to be transmitted by radio and correspond to amplitude values of the pulse shaped and oversampled digital baseband signal generated by the filter unit;

selecting the predistortion coefficients from the first memory for predistortion as a function of the amplitude values selected from the second memory; and

multiplying the pulse shaped and oversampled digital baseband signal by the selected predistortion coefficients to predistort the pulse shaped and oversampled digital baseband signal via a predistortion unit configured to receive the pulse shaped and oversampled digital baseband signal.

11. The method according to claim 10 , wherein the digital baseband signal and the baseband signals which are produced from it are complex signals.

12. The method according to claim 10 , wherein the predistorted digital baseband signal is converted to an analogue baseband signal.

13. The method according to claim 10 , wherein a radio-frequency carrier is modulated with the baseband signal via an intermediate frequency.

14. The method according to claim 13 , wherein the modulated radio-frequency signal is amplified with a variable gain, the gain being controllable in analogue form or being digitally programmable.

15. The method according to claim 13 , wherein the modulated radio-frequency signal is amplified by a power amplifier.

16. A method for transmission of data by radio, with the data to be transmitted being in the form of a digital baseband signal, using the method for processing the digital baseband signal according to claim 10 .

17. The method according to claim 10 , wherein addressing of the first memory is controlled by addresses generated by multiplying the amplitude values selected from the second memory by a multiplier value corresponding to a desired power level.