Mobile terminal device and method for processing signals

1. A method for processing a receive radio signal, the method comprising:

receiving in a mobile device a receive radio signal;

equalizing the receive radio signal using a first equalizer to generate a first equalized receive radio signal;

equalizing the receive radio signal using a second equalizer to generate a second equalized receive radio signal;

calculating a second subtraction signal based on a second re-synthesized transmit signal;

subtracting the second subtraction signal from the second equalized receive radio signal to generate a second subtracted equalized receive radio signal;

re-synthesizing a transmit signal from the second subtracted equalized receive radio signal;

calculating a first subtraction signal based on the re-synthesized transmit signal; and

subtracting the first subtraction signal from the first equalized receive radio signal.

2. The method according to claim 1 ,

wherein calculating the first subtraction signal and/or the second subtraction signal based on the re-synthesized transmit signal comprises filtering the re-synthesized transmit signal using a filter representing a residual multipath response of a radio channel.

3. The method according to claim 1 ,

wherein the first subtraction signal and/or second subtraction signal represents a multipath interference contained in the first equalized radio signal.

4. The method according to claim 1 ,

wherein re-synthesizing the transmit signal comprises:

descrambling and despreading the equalized second receive signal to generate estimated transmit symbols; and

symbol detecting the transmit symbols; and

re-spreading and re-scrambling the symbols to transmit chips.

5. The method according to claim 1 ,

wherein the first equalizer and the second equalizer are each configured as a minimum mean squared error filter.

6. The method according to claim 1 ,

wherein the first equalizer is configured as a matched filter of a radio channel via which the receive radio signals are received, and

wherein the second equalizer is configured as a minimum mean squared error filter.

7. The method according to claim 1 ,

wherein the second equalizer is configured as minimum mean squared error filter; and

wherein the first equalizer and a filter representing the residual multipath response are configured jointly as minimum mean squared error filter.

8. The method according to claim 1 ,

wherein re-synthesizing the transmit signal from the second equalized receive radio signal comprises considering parts of the second equalized receive radio signal meeting a reliability criterion.

9. A receiver for a mobile radio communication device comprising:

one or more lower receive branches, comprising:

a second equalizer configured to equalize a receive radio signal to generate a second equalized receive radio signal;

a second filter configured to filter a second re-synthesized transmit signal to generate a second subtraction signal; and

a second subtractor configured to subtract the second subtraction signal from the second equalized receive radio signal to generate a second subtracted equalized radio receive signal;

wherein the one or more lower receive branches is either a lowest branch or an intermediate branch between the highest branch and the lowest branch; and

a re-synthesizer configured to re-synthesize a transmit signal from the second subtracted equalized receive radio signal;

a highest receive branch comprising:

a first equalizer configured to equalize the receive radio signal to generate a first equalized receive radio signal;

a first filter configured to filter the re-synthesized transmit signal to generate a first subtraction signal; and

a first subtractor configured to subtract the first subtraction signal from the first equalized receive radio signal.

10. The receiver according to claim 9 , wherein the one or more lower receive branches comprises:

a plurality of cascaded receive branches arranged between the lowest receive branch and the highest receive branch.

11. The receiver according to claim 10 ,

wherein the one or more receive branches of the plurality of cascaded receive branches further comprises a second re-synthesizer configured to re-synthesize a transmit signal from a linearly or non-linearly equalized receive radio signal of the preceding receive branch branches to generate the re-synthesized transmit signal.

12. The receiver according to claim 9 ,

wherein the subtraction signal represents a neighbor cell interference contained in a corresponding equalized signal.

13. The receiver according to claim 9 ,

each receive branch further comprising:

a descrambler/despreader configured to process each equalized signal to generate estimated transmit symbols; and

a symbol detector configured to detect the transmit symbols; and

re-spreading and re-scrambling the symbols to transmit chips.

14. The receiver according to claim 9 ,

wherein the re-synthesizer is configured to re-synthesize the transmit signal by considering parts of the second equalized receive radio signal meeting a reliability criterion.

15. The receiver according to claim 14 ,

wherein parts of the second equalized receive radio signal meeting a reliability criterion are parts of the second equalized receive radio signal that have been coded with a spreading factor exceeding a spreading factor threshold.

16. The receiver according to claim 9 ,

wherein each equalizer of each receive branch is configured to reconstruct noise contained in each respective receive branch, and wherein a subtractor of a succeeding receive stage is configured to subtract the reconstructed noise from an output of an equalizer of a succeeding stage.

17. The receiver according to claim 9 ,

wherein an equalizer coefficient computation for each equalizer of each receive branch is configured to ignore parts of the respective receive radio signal subtracted by a subtractor of the respective receive branch.

18. The receiver according to claim 9 ,

wherein each equalizer coefficient computation of each equalizer of the respective receive branch is configured to ignore parts of the respective receive radio signal subtracted by a subtractor of a preceding receive branch subtracts.

19. A mobile radio communication terminal device, comprising:

a receiver, comprising:

one or more lower receive branches, comprising:

a second equalizer configured to equalize a receive radio signal to generate a second equalized receive radio signal;

a second filter configured to filter a second re-synthesized transmit signal to generate a second subtraction signal;

a second subtractor configured to subtract the second subtraction signal from the second equalized receive radio signal to generate a second subtracted equalized radio receive signal; and

a re-synthesizer configured to re-synthesize a transmit signal from the second subtracted equalized receive radio signal to generate a re-synthesized transmit signal; and

a highest receive branch comprising:

a first equalizer configured to equalize the receive radio signal to generate a first equalized receive radio signal;

a first filter configured to filter the re-synthesized transmit signal of a preceding receive branch to generate a first subtraction signal; and

a first subtractor configured to subtract the first subtraction signal from the first equalized receive radio signal;

an application processor coupled to the receiver.