Systems and methods for reducing complexity in modulation coding scheme (MCS) adaptation

An apparatus comprising:

• a processor;
• and
• a computer readable storage medium storing programming for execution by the processor, the programming adapted to efficiently assign transmission parameters in a wireless communications network, and including instructions to:
• select users for an initial user group in the wireless communications network;
• compute initial modulation coding schemes (MCSs) for users in the initial user group, wherein the instruction to compute the initial MCSs for the users in the initial user group includes instructions to perform an initial QR decomposition operation for the initial user group;
• add a new user to the initial user group to obtain a new user group in the wireless communications network;
• compute a new MCS for the new user in the new user group, wherein the instruction to compute the new MCS for the new user includes instructions to calculate the new MCS directly using information obtained from the initial QR decomposition operation and without performing a QR decomposition operation for the new user group;
• and
• communicate the new MCS to a transmitter in the wireless communications network.

A method for efficiently assigning transmission parameters in a wireless communications network, the method comprising:

• selecting users for an initial user group in the wireless communications network;
• performing QR decomposition on an initial Hermitian matrix (HH) associated with the initial user group to obtain an initial unitary matrix (Q) and an initial upper triangular matrix (R);
• adding a new user to the initial user group to obtain a new user group in the wireless communications network, the new user group associated with a new Hermitian matrix (H1H);
• performing modulation coding scheme (MCS) adaptation for the new user group, wherein performing MCS adaptation for the new user group includes:
• computing a last column (r1) of a new upper triangular matrix (R1) corresponding to the new Hermitian matrix (H1H) directly from at least the initial unitary matrix (Q) and the initial upper triangular matrix (R), thereby obtaining the new upper triangular matrix (R1) without performing QR decomposition on the new Hermitian matrix (H1H);
• and calculating MCSs for users in the new user group in accordance with the new upper triangular matrix (R1);
• and
• communicating the MCSs to at least one transmitter in the wireless communications network.

An apparatus comprising:

• a processor;
• and
• a computer readable storage medium storing programming for execution by the processor, the programming adapted to efficiently assign transmission parameters in a wireless communications network, and including instructions to:
• select users for an initial user group in the wireless communications network;
• perform QR decomposition on an initial Hermitian matrix (HH) associated with the initial user group to obtain an initial unitary matrix (Q) and an initial upper triangular matrix (R);
• add a new user to the initial user group to obtain a new user group in the wireless communications network, the new user group associated with a new Hermitian matrix (H1H);
• perform modulation coding scheme (MCS) adaptation for the new user group, wherein the instructions to perform MCS adaptation for the new user group includes instructions to compute a last column (r1) of a new upper triangular matrix (R1) corresponding to the new Hermitian matrix (H1H) directly from at least the initial unitary matrix (Q) and the initial upper triangular matrix (R), thereby obtaining the new upper triangular matrix (R1) without performing QR decomposition on the new Hermitian matrix (H1H), and to predict MCSs for users in the new user group in accordance with the new upper triangular matrix (R1);
• and
• communicate the MCSs to at least one transmitter in the wireless communications network.

A method for efficiently assigning transmission parameters in a wireless communications network, the method comprising:

• adding a first new user to an initial user group to obtain a first new user group in the wireless communications network, the first new user group associated with a first new Hermitian matrix (H1H);
• computing a first new unitary matrix (Q1) and a first new upper triangular matrix (R1) corresponding to the first new Hermitian matrix (H1H);
• adding a second new user to the initial user group to obtain a second new user group in the wireless communications network, the second new user group associated with a second new channel matrix (H2);
• computing a second new unitary matrix (Q2) and a second new upper triangular matrix (R2) corresponding to the second new Hermitian matrix (H2H);
• adding both the first new user and the second new user to the initial user group to obtain a third new user group in the wireless communications network, the third new user group associated with a third new channel matrix (H12);
• performing modulation coding scheme (MCS) adaptation for the third new user group, wherein performing MCS adaptation for the third new user group includes:
• computing a last column (r12) of a third new upper triangular matrix (R12) corresponding to the third new channel matrix (H12) directly from at least the first new unitary matrix (Q1), the first new upper triangular matrix (R1), the second new unitary matrix (Q2), and the second new upper triangular matrix (R2), thereby obtaining the third new upper triangular matrix (R12) without performing QR decomposition on the third new Hermitian matrix (H12H);
• and
• predicting MCSs for users in the new user group in accordance with the third new upper triangular matrix (R12);
• and
• communicating the MCSs to at least one transmitter in the wireless communications network.

A method for efficiently assigning transmission parameters in a wireless communications network, the method comprising:

• selecting users for an initial user group in the wireless communications network, wherein an initial channel matrix (H) corresponds to the initial user group and a transmitter;
• performing QR decomposition on an initial Hermitian matrix (HH) associated with the initial user group to obtain an initial unitary matrix (Q) and an initial upper triangular matrix (R);
• inverting the upper triangular matrix (R) to obtain an initial inverted upper triangular matrix (R−1);
• adding a new user to the initial user group to obtain a new user group in the wireless communications network, the new user group associated with a new Hermitian matrix (H1H);
• performing modulation coding scheme (MCS) adaptation for the new user group, wherein performing MCS adaptation for the new user group includes:
• computing a new unitary matrix (Q1) and a new upper triangular matrix (R1) corresponding to the new Hermitian matrix (H1H);
• computing a last column (s1) of a new inverted upper triangular matrix (R1−1) corresponding to the new upper triangular matrix (R1) directly from at least the new unitary matrix (Q1) and a last column (r1) of the new upper triangular matrix (R1), thereby obtaining the new inverted upper triangular matrix (R1−1) without performing matrix inversion on the new upper triangular matrix (R1);
• and predicting MCSs for users in the new user group in accordance with the new inverted upper triangular matrix (R1−1);
• and
• communicating the MCSs to at least one transmitter in the wireless communications network.

An apparatus comprising:

• a processor;
• and
• a computer readable storage medium storing programming for execution by the processor, the programming adapted to efficiently assign transmission parameters in a wireless communications network, and including instructions to:
• select users for an initial user group in the wireless communications network, wherein an initial channel matrix (H) corresponds to the initial user group and a transmitter;
• perform QR decomposition on an initial Hermitian matrix (HH) associated with the initial user group to obtain an initial unitary matrix (Q) and an initial upper triangular matrix (R);
• invert the upper triangular matrix (R) to obtain an initial inverted upper triangular matrix (R−1);
• add a new user to the initial user group to obtain a new user group in the wireless communications network, the new user group associated with a new Hermitian matrix (H1H);
• perform modulation coding scheme (MCS) adaptation for the new user group, wherein the instructions to perform MCS adaptation for the new user group includes instructions to compute an new unitary matrix (Q1) and a new upper triangular matrix (R1) corresponding to the new Hermitian matrix (H1H), to compute a last column (s1) of a new inverted upper triangular matrix (R1−1) corresponding to the new upper triangular matrix (R1) directly from at least the new unitary matrix (Q1) and a last column (r1) of the new upper triangular matrix (R1), thereby obtaining the new inverted upper triangular matrix (R1−1) without performing matrix inversion on new upper triangular matrix (R1), and to predict MCSs for users in the new user group in accordance with the new inverted upper triangular matrix (R1−1);
• and
• communicate the MCSs to at least one transmitter in the wireless communications network.

A method for efficiently assigning transmission parameters in a wireless communications network, the method comprising:

• adding a first new user to an initial user group to obtain a first new user group in the wireless communications network, the first new user group associated with a first new Hermitian matrix (H1H);
• and
• computing a first new inverted upper triangular matrix (R1−1) corresponding to the first new Hermitian matrix (H1H);
• adding a second new user to the initial user group to obtain a second new user group in the wireless communications network, the second new user group associated with a second new channel matrix (H2);
• computing a second new inverted upper triangular matrix (R2−1) corresponding to the second new Hermitian matrix (H2H);
• adding both the first new user and the second new user to the initial user group to obtain a third new user group in the wireless communications network, the third new user group associated with a third new channel matrix (H12);
• performing modulation coding scheme (MCS) adaptation for the third new user group, wherein performing MCS adaptation for the third new user group includes:
• computing a third new unitary matrix (Q12) and a third new upper triangular matrix (R12) corresponding to the third new Hermitian matrix (H12H);
• computing a last column (s12) of a third new inverted upper triangular matrix (R12−1) corresponding to the third new upper triangular matrix (R12) directly from at least the first new inverted upper triangular matrix (R1−1), a last column (s12) of the second new inverted upper triangular matrix (R2−1), the third new Hermitian matrix (H12H), and the third new unitary matrix (Q12), thereby obtaining the third new inverted upper triangular matrix (R12−1) without performing matrix inversion on the third new upper triangular matrix (R12);
• and
• predicting MCSs for users in the third new user group in accordance with the third new inverted upper triangular matrix (R12−1);
• and
• communicating the MCSs to at least one transmitter in the wireless communications network.