Method for semi-statically adapting uplink multiple-input multiple-output transmission

1. A method for performing an uplink transmission with a wireless terminal device, comprising:

receiving, at the wireless terminal, from a base station an antenna precoding instruction;

receiving, at the wireless terminal, from the base station a representation of a transmit antenna adapter in an adapter transmission message;

modifying the antenna precoding instruction according to the representation of the transmit antenna adapter, wherein modifying the antenna precoding instruction comprises at least one of:

(i) re-indexing the transmit antenna, or (ii) covariance matrix-based pattern virtualization, wherein re-indexing the transmit antenna comprises using a permutation matrix having one entry in each column equal to 1 and remaining entries equal to 0;

and performing the uplink transmission according to the modified precoding.

2. The method of claim 1 , wherein the representation of a transmit antenna adapter is a bit field indicating the antenna adapter to be applied.

3. The method of claim 1 , wherein covariance matrix-based pattern virtualization comprises using the square root of a covariance matrix of a vector of channels corresponding to a link between each of a plurality of transmit antennas and a certain receive antenna.

4. The method of claim 1 , further comprising:

combining, by the user equipment, a precoding matrix indicated in the precoding instruction with an adapter matrix; and

if more than one non-zero entry is present in any row of the combined matrix, emitting a signal on a corresponding antenna, wherein the signal is a weighted superposition of two or more waveforms.

5. The method of claim 1 , further comprising:

receiving the transmit antenna adapter representation from the base station at a different interval than the antenna precoding instruction.

6. The method of claim 1 , wherein the modifying the antenna precoding instruction multiplies a precoding matrix representing the antenna precoding instruction by a unitary matrix to transform a set of physical antennas to a set of virtualized antennas via weighting the set of physical antennas according to the unitary matrix.

7. The method of claim 1 , wherein re-indexing transmit antenna is based on observed long term statistics of transmission performance.

8. The method of claim 1 , wherein re-indexing transmit antenna is based on an observed antenna correlation.

9. The method of claim 1 , wherein re-indexing transmit antenna is based on a criterion of minimal codeword distance.

10. A wireless terminal device for performing an uplink transmission, comprising:

a receiving unit adapted to receive from a base station an antenna precoding instruction;

one or more processors configured to:

receive from the base station a representation of a transmit antenna adapter in an adapter transmission message;

modify the antenna precoding instruction according to the representation of the transmit antenna adapter, wherein modifying the antenna precoding instruction comprises at least one of:

(i) re-indexing the transmit antenna, or (ii) covariance matrix-based pattern virtualization, wherein re-indexing the transmit antenna comprises using a permutation matrix having one entry in each column equal to 1 and remaining entries equal to 0;

and a transmitting unit adapted to perform uplink transmission according to the modified precoding.

11. The wireless terminal device of claim 10 , wherein the transmitting unit sends a transmit antenna adapter representation to the base station.

12. The wireless terminal device of claim 10 , wherein the receiving unit receives a transmit antenna adapter representation from the base station.

13. The wireless terminal device of claim 12 , wherein the transmit antenna adapter representation represents a modified antenna adapter.

14. The wireless terminal device of claim 12 , wherein the receiving unit receives the transmit antenna adapter representation from the base station at a different interval than the antenna precoding instruction.

15. The wireless terminal device of claim 10 , wherein the transmit antenna adapter configures a set of transmit antennas according to at least one of antenna index permutation or antenna pattern virtualization.

16. A non-transitory computer-readable medium storing a set of instructions executable by a processor for performing a method, comprising:

receiving, at the wireless terminal, from a base station an antenna precoding instruction;

receiving, at the wireless terminal, from the base station a representation of a transmit antenna adapter in an adapter transmission message;

modifying the antenna precoding instruction according to the representation of the transmit antenna adapter, wherein modifying the antenna precoding instruction comprises at least one of:

(i) re-indexing the transmit antenna; or (ii) covariance matrix-based pattern virtualization wherein re-indexing the transmit antenna comprises using a permutation matrix having one entry in each column equal to 1 and remaining entries equal to 0;

and performing the uplink transmission according to the modified precoding.

17. The medium of claim 16 , wherein covariance matrix-based pattern virtualization comprises using the square root of a covariance matrix of a vector of channels corresponding to a link between each of a plurality of transmit antennas and a certain receive antenna.

18. The medium of claim 16 , further comprising:

combining, by the user equipment, a precoding matrix indicated in the precoding instruction with an adapter matrix; and

if more than one non-zero entry is present in any row of the combined matrix, emitting a signal on a corresponding antenna, wherein the signal is a weighted superposition of two or more waveforms.