Devices and methods for recursive block precoding

Patent metadata

Field	Value
Publication number	US-12418331-B2
Application number	US-202118026561-A
Country	US
Kind code	B2
Filing date	Sep 24, 2021
Priority date	Sep 29, 2020
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

A precoder for precoding a vector of information symbols to be sent to a plurality of users, the precoder includes a user ordering and grouping unit configured to group the plurality of users depending on one or more quality of service indicators and on modulation and coding parameters associated with the plurality of users, the user ordering and grouping unit being configured to divide a predefined upper triangular precoding matrix into a plurality of sub-matrices and to divide the vector of information symbols into a plurality of sub-vectors, each sub-vector comprising information symbols to be sent to a group of users, the sub-vectors being arranged according to an arbitrary order of the one or more quality of service indicators; a precoding unit configured to determine a perturbation vector according to the minimization of a transmit power metric, the perturbation vector comprising a plurality of perturbation sub-vectors, each perturbation sub-vector corresponding to a sub-vector of information symbols, the precoding unit being configured to determine an estimate of each perturbation sub-vector by applying a recursive search algorithm.

First claim

The invention claimed is:

1. A precoder for precoding a vector of information symbols, said vector of information symbols comprising information symbols to be sent to a plurality of users, wherein the precoder is configured to receive inputs from said plurality of users, said inputs comprising one or more quality of service indicators associated with each user and modulation and coding parameters associated with each user, the precoder comprising:
a user ordering and grouping unit configured to group said plurality of users depending on said one or more quality of service indicators and on said modulation and coding parameters, which provides two or more groups of users, the user ordering and grouping unit being configured to divide a predefined upper triangular precoding matrix into a plurality of sub-matrices and to divide said vector of information symbols into a plurality of sub-vectors, each sub-vector comprising information symbols to be sent to a group of users among said two or more groups of users, said sub-vectors being arranged according to an arbitrary order of the one or more quality of service indicators;
a precoding unit configured to determine a perturbation vector according to the minimization of a transmit power metric, said perturbation vector comprising a plurality of perturbation sub-vectors, each perturbation sub-vector corresponding to a sub-vector of information symbols, the precoding unit being configured to determine an estimate of each perturbation sub-vector by applying a recursive search algorithm, the precoding unit being configured to determine an elementary transmit power metric in association with each perturbation sub-vector from previously determined estimates of perturbation sub-vectors and to determine an estimate of a perturbation sub-vector by minimizing said elementary transmit power metric.

2. The precoder of claim 1 , wherein the precoder further comprises a processing unit configured to determine a diagonal matrix comprising diagonal components that depend on said modulation and coding parameters.

3. The precoder of claim 2 , wherein the processing unit is configured to determine said transmit power metric depending on said diagonal matrix, on said sub-vectors of information symbols and on said predefined upper triangular precoding matrix.

4. The precoder of claim 1 , wherein the precoding unit is configured to set to a null vector the perturbation sub-vector corresponding to the sub-vector of information symbols to be sent to the group of users having the lowest values of the one or more quality of service indicators.

5. The precoder of claim 1 , wherein said inputs further comprise channel state information.

6. The precoder of claim 1 , wherein each group of users is associated with an interval of values of the one or more quality of service indicators, each interval of values of the one or more quality of service indicators being defined by a first threshold and a second threshold of the one or more quality of service indicators, the users associated with values of the one or more quality of service indicators that belong to a same interval of quality of service indicators being included in a same group of users.

7. The precoder of claim 1 , wherein users included in a same group of users are associated with same modulation and coding parameters.

8. The precoder of claim 1 , wherein said diagonal matrix comprises diagonal components, each diagonal component corresponding to an information symbol to be sent to a user among said plurality of users and having a value that depend on the modulation and coding parameters associated with said user.

9. A method for precoding a vector of information symbols, said vector of information symbols comprising information symbols to be sent to a plurality of users, wherein the method comprises the steps of:
receiving inputs from said plurality of users, said inputs comprising one or more quality of service indicators associated with each user and modulation and coding parameters associated with each user;
grouping said plurality of users depending on said one or more quality of service indicators and on said modulation and coding parameters, which provides two or more groups of users;
dividing a predefined upper triangular precoding matrix into a plurality of sub-matrices;
dividing said vector of information symbols into a plurality of sub-vectors, each sub-vector comprising information symbols to be sent to a group of users among said two or more groups of users, said sub-vectors being arranged according to an arbitrary order of the one or more quality of service indicators;
determining a perturbation vector according to the minimization of a transmit power metric, said perturbation vector comprising a plurality of perturbation sub-vectors, each perturbation sub-vector corresponding to a sub-vector of information symbols, said perturbation vector being determined by determining an estimate of each perturbation sub-vector by applying a recursive search algorithm, an elementary transmit power metric being determined in association with each perturbation sub-vector from previously determined estimates of perturbation sub-vectors and an estimate of said perturbation sub-vector being determined by minimizing said elementary transmit power metric.

Assignees

• Inst Mines Telecom

Inventors

• Rekaya Ghaya
• Askri Aymen

Classifications

• H04B7/0452 Primary

  Multi-user MIMO systems · CPC title

• H04B7/063

  Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection · CPC title

• H04B7/0465

  taking power constraints at power amplifier or emission constraints, e.g. constant modulus, into account · CPC title

• H04B7/0456 Primary

  Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting · CPC title