Communication precoding devices and methods

1. A communication device, comprising:

a transmitter device coupled to a plurality of communication connections and configured to transmit data over the plurality of communication connections, the transmitter device comprising a precoder, the precoder being adapted to jointly precode data to be transmitted via the plurality of communication connections, wherein the precoder is adapted to perform a first type of precoding for a first set of communication connections comprising receivers of a first type and a second type of precoding for a second set of communication connections comprising receivers of a second type, wherein the receivers of the second type are different from the receivers of the first type, and wherein the first type of precoding is different from the second type of precoding,

wherein the communication device is adapted for multicarrier communication, wherein the precoder is adapted to perform the first and second types of precoding for a first set of subcarriers of the multicarrier communication, and to perform a same type of precoding for all communication connections at least for a second set of subcarriers, and

wherein the first set of subcarriers consists of subcarriers having a frequency above a frequency threshold, and the second set of subcarriers comprises a set of subcarriers consisting of subcarriers below the frequency threshold.

2. The device of claim 1 , wherein the first set of subcarriers consists of subcarriers having a frequency below a further threshold, the further threshold being higher than the threshold, wherein for a third set of subcarriers consisting of subcarriers having frequencies above the further threshold, the transmitter is adapted to transmit data only on a part of the communication connections for subcarriers of the third set.

3. The device of claim 1 , wherein the first type of precoding comprises a modulo operation, and the second type of precoding omits the modulo operation.

4. The device of claim 3 , wherein the precoding comprises a feedback, wherein processing for at least one communication connection of the second set of communication connections is included in the feedback.

5. The device of claim 1 , wherein the precoder comprises a non-linear precoder for data to be transmitted via the first set of communication connections and a separate linear precoder for the second set of communication connections, wherein the non-linear precoder and the linear precoder each have a number of outputs equal to an overall number of communication connections in the first set and the second set, wherein outputs of the non-linear precoder and the linear precoder are combined.

6. The device of claim 1 , wherein the first type of precoding comprises non-linear precoding and the second type of precoding comprises linear precoding.

7. A communication device, comprising:

a transmitter device coupled to a plurality of communication connections and configured to transmit data over the plurality of communication connections, the transmitter device comprising a precoder, the precoder being adapted to jointly precode data to be transmitted via the plurality of communication connections, wherein the precoder is adapted to perform a first type of precoding for a first set of communication connections comprising receivers of a first type and a second type of precoding for a second set of communication connections comprising receivers of a second type, wherein the receivers of the second type are different from the receivers of the first type, and wherein the first type of precoding is different from the second type of precoding,

wherein the precoder is adapted to use the first type of precoding for the first set of communication connections during a first set of time slots of a time division duplexing scheme, and to use the second type of precoding during a second set of time slots different from the first set of time slots, and

wherein the transmitter is adapted to transmit to only the first set of communication connections during the first set of time slots and to transmit to all communication connections using the second type of precoding during the second set of time slots.

8. The device of claim 1 , the device further comprising a power spectral density scaling at an input of the precoder, wherein the device is adapted to modify the power spectral density scaling based on a power spectral density at an output of the precoder.

9. The device of claim 8 , wherein the adapting comprises estimating the power spectral density at the input of the precoder.

10. The device of claim 9 , wherein the estimating comprises at least one of a linear estimation or a quadratic estimation.

11. The device of claim 9 , wherein the adapting comprises adapting based on an optimization process.

12. A method, comprising:

transmitting data over a plurality of communication connections, and

jointly precoding data to be transmitted via the plurality of communication connections, wherein the jointly precoding comprises performing a first type of precoding for a first set of communication connections comprising receivers of a first type and a second type of precoding for a second set of communication connections comprising receivers of a second type, wherein the receivers of the second type are different from the receivers of the first type, and wherein the first type of precoding is different from the second type of precoding,

wherein the jointly precoding comprises a non-linear precoding for data to be transmitted via the first set of communication connections and a linear precoding for the second set of communication connections, wherein the non-linear precoding and the linear precoding each generate a number of outputs equal to an overall number of communication connections in the first set and the second set, wherein the method comprises combining the outputs of the non-linear precoder and the linear precoder.

13. The method of claim 12 , wherein the transmitting of data comprises a multicarrier communication, wherein jointly precoding further comprises performing the first and second types for a first set of subcarriers of the multicarrier communication, and performing a same type of precoding for all communication connections at least for a second set of subcarriers.

14. The method of claim 13 , wherein the first set of subcarriers consists of subcarriers having a frequency above a frequency threshold, and the second set of subcarriers comprises a set of subcarriers consisting of subcarriers below the frequency threshold, and

wherein the first set of subcarriers consists of subcarriers having a frequency below a further threshold, the further threshold being higher than the threshold, wherein the second set of subcarriers comprises a further set of subcarriers consisting of subcarriers having frequencies above the further threshold.

15. The method of claim 12 , wherein the first type of precoding comprises a modulo operation, and the second type of precoding omits the modulo operation, and wherein the second type of precoding comprises a feedback.

16. The method of claim 12 , further comprising determining a receiver type of each receiver of each communication connection of the plurality of communication connections prior to transmitting the data.