Constellation shaping for multiple user multiple input multiple output

1 . An apparatus for wireless communication at a first wireless device, comprising:

at least one memory; and

at least one processor coupled to the at least one memory and, based at least in part on stored information that is stored in the at least one memory, the at least one processor is configured to:

receive an indication of a non-uniform distribution of symbols associated with at least one shaping operation associated with one or more layers of a quadrature amplitude modulated (QAM) multiple user multiple input multiple output (MU-MIMO) communication, wherein the one or more layers of the QAM MU-MIMO communication are associated with one or more additional wireless devices in a plurality of wireless devices, wherein each of the plurality of wireless devices is a co-scheduled wireless device associated with a layer of the QAM MU-MIMO communication, and wherein the first wireless device is included in the plurality of wireless devices;

receive, from a network node, the QAM MU-MIMO communication;

perform a demodulation of the QAM MU-MIMO communication based on the indication; and

output a result of the demodulation of the QAM MU-MIMO communication for at least one of a transmission to at least one other wireless device or a local storage at the first wireless device.

2 . The apparatus of claim 1 , wherein the at least one shaping operation is one of a probabilistic amplitude shaping operation or a geometric shaping operation, and wherein the indication of the at least one shaping operation comprises at least one of:

(1) a first single-bit indication of whether at least one layer of the QAM MU-MIMO communication is associated with a shaping operation,

(2) a second single-bit indication of whether a majority of layers of the QAM MU-MIMO communication are associated with the shaping operation, or

(3) one or more single-bit indications indicating whether the shaping operation is associated with a corresponding additional wireless device of the one or more additional wireless devices.

3 . The apparatus of claim 2 , wherein the indication indicates at least one of (1) that the at least one layer of the QAM MU-MIMO communication is associated with the shaping operation, (2) that the majority of layers of the QAM MU-MIMO communication are associated with the shaping operation, (3) that the shaping operation is associated with at least one of the one or more additional wireless devices, and the at least one processor is further configured to:

detect a distribution associated with the at least one shaping operation, wherein to perform the demodulation of the QAM MU-MIMO communication the at least one processor is configured to perform the demodulation based on the distribution associated with the at least one shaping operation, wherein the demodulation is configured to demodulate the QAM MU-MIMO communication based on the distribution associated with the at least one shaping operation; or

refrain from detecting the distribution associated with the at least one shaping operation, wherein to perform the demodulation of the QAM MU-MIMO communication, the at least one processor is configured to perform the demodulation that does not consider knowledge of the at least one shaping operation associated with at least one of the at least one layer of the QAM MU-MIMO communication, the majority of layers of the QAM MU-MIMO communication, or the one or more additional wireless devices.

4 . The apparatus of claim 3 , wherein the at least one shaping operation is at least one constellation shaping operation, and wherein the indication of the at least one shaping operation comprises information regarding at least one modulation and coding scheme (MCS) table associated with the one or more additional wireless devices.

5 . The apparatus of claim 4 , wherein to detect the distribution, the at least one processor is configured to detect the distribution based on the at least one MCS table.

6 . The apparatus of claim 2 , wherein the indication indicates at least one of (1) that the at least one layer of the QAM MU-MIMO communication is not associated with the shaping operation, (2) that the majority of layers of the QAM MU-MIMO communication are not associated with the shaping operation, (3) that the shaping operation is not associated with the one or more additional wireless devices, and the at least one processor is further configured to:

detect a modulation order associated with at least one of the at least one layer of the QAM MU-MIMO communication or at least one of the one or more additional wireless devices, wherein to perform the demodulation of the QAM MU-MIMO communication, the at least one processor is configured to perform the demodulation further based on the modulation order.

7 . The apparatus of claim 1 , wherein the indication of the non-uniform distribution of symbols associated with the at least one shaping operation comprises information regarding at least one of:

a shaping rate;

a shaping parameter;

a power scaling factor associated with the at least one shaping operation; or

at least one modulation and coding scheme (MCS) value associated with the at least one shaping operation for the one or more additional wireless devices.

8 . The apparatus of claim 1 , wherein the at least one processor is further configured to:

receive an additional indication of a scrambling sequence associated with at least one demodulation reference signal (DMRS) associated with the one or more additional wireless devices, wherein to perform the demodulation of the QAM MU-MIMO communication, the at least one processor is configured to perform the demodulation of the QAM MU-MIMO communication based on the at least one DMRS.

9 . The apparatus of claim 1 , wherein the indication of the at least one shaping operation comprises information regarding one or more of:

whether there are wireless devices that are co-scheduled with the first wireless device;

a number of co-scheduled layers of the QAM MU-MIMO communication;

a number of wireless devices of the one or more additional wireless devices; or

a set of time-and-frequency resources associated with co-scheduled QAM MU-MIMO communications with the one or more additional wireless devices.

10 . The apparatus of claim 1 , wherein the at least one processor is further configured to: receive a second transmission along with the QAM MU-MIMO communication, wherein the second transmission is associated with the one or more additional wireless devices.

11 . The apparatus of claim 1 , wherein to receive the indication of the at least one shaping operation, the at least one processor is configured to: receive the indication, at least in part, via a second stage DL control information (DCI) of a multi-stage DCI procedure.

12 . The apparatus of claim 1 , wherein the at least one processor is further configured to:

transmit, for the network node, at least one of a first additional indication that the first wireless device is capable of performing a demodulation based on the indication of the at least one shaping operation or a second additional indication of whether the first wireless device is capable of performing a blind detection of at least one of a modulation and coding scheme (MCS) or a parameter associated with the at least one shaping operation.

13 . The apparatus of claim 1 , wherein to perform the demodulation of the QAM MU-MIMO communication, the at least one processor is configured to perform a non-linear demodulation of the QAM MU-MIMO communication that estimates an interference associated with the one or more layers of the QAM MU-MIMO communication based on the indication of the non-uniform distribution of the symbols.

14 . An apparatus for wireless communication at a network node, comprising:

at least one memory; and

at least one processor coupled to the at least one memory and, based at least in part on stored information that is stored in the at least one memory, the at least one processor is configured to:

output, for a first wireless device, an indication of a non-uniform distribution of symbols associated with at least one shaping operation associated with one or more layers of a quadrature amplitude modulated (QAM) multiple user multiple input multiple output (MU-MIMO) communication, wherein the one or more layers of the QAM MU-MIMO communication are associated with one or more additional wireless devices in a plurality of wireless devices, wherein each of the plurality of wireless devices is a co-scheduled wireless device associated with a layer of the QAM MU-MIMO communication, and wherein the first wireless device is included in the plurality of wireless devices;

generate, based on a first shaping operation associated with the first wireless device and the at least one shaping operation, a set of symbols for the QAM MU-MIMO communication; and

output, for transmission to the plurality of wireless devices, the QAM MU-MIMO communication.

15 . The apparatus of claim 14 , wherein the indication of the at least one shaping operation comprises at least one of (1) a first single-bit indication of whether at least one layer of the QAM MU-MIMO communication is associated with a shaping operation, (2) a second single-bit indication indicating whether a majority of layers of the QAM MU-MIMO communication are associated with the shaping operation, or (3) one or more single-bit indications indicating whether the shaping operation is associated with a corresponding additional wireless device of the one or more wireless devices.

16 . The apparatus of claim 14 , wherein the at least one shaping operation is at least one constellation shaping operation, and wherein the indication of the at least one shaping operation comprises information regarding at least one modulation and coding scheme (MCS) table associated with the one or more additional wireless devices.

17 . The apparatus of claim 14 , wherein the indication of the non-uniform distribution of symbols associated with the at least one shaping operation comprises information regarding at least one of:

a shaping rate;

a shaping parameter;

a power scaling factor associated with the at least one shaping operation; or

at least one modulation and coding scheme (MCS) value associated with the at least one shaping operation for the one or more additional wireless devices.

18 . The apparatus of claim 14 , wherein the at least one processor is further configured to:

output, for the first wireless device, an additional indication of a scrambling sequence associated with at least one demodulation reference signal (DMRS) associated with the one or more additional wireless devices, wherein the scrambling sequence is associated with a demodulation of the QAM MU-MIMO communication at the first wireless device.

19 . The apparatus of claim 14 , wherein the indication of the at least one shaping operation comprises information regarding one or more of:

whether there are wireless devices that are co-scheduled with the first wireless device;

a number of co-scheduled layers of the QAM MU-MIMO communication;

a number of wireless devices of the one or more additional wireless devices; or

a set of time-and-frequency resources associated with co-scheduled QAM MU-MIMO communications with the one or more additional wireless devices.

20 . The apparatus of claim 14 , wherein the at least one processor is further configured to: transmit a second transmission along with the QAM MU-MIMO communication, wherein the second transmission is associated with the one or more additional wireless devices, and wherein to output the indication of the at least one shaping operation, the at least one processor is configured to output the indication, at least in part, in association with a second stage DL control information (DCI) of a multi-stage DCI procedure.

21 . The apparatus of claim 14 , wherein the at least one processor is further configured to:

receive, from the first wireless device, at least one of a first additional indication that the first wireless device is capable of performing a demodulation based on the indication of the at least one shaping operation or a second additional indication of whether the first wireless device is capable of performing a blind detection of at least one of a modulation and coding scheme (MCS) or a parameter associated with the at least one shaping operation.

22 . The apparatus of claim 14 , wherein the at least one shaping operation is one of a probabilistic amplitude shaping operation or a geometric shaping operation.

23 . The apparatus of claim 14 , wherein the first shaping operation and each shaping operation of the at least one shaping operation is a same shaping operation.

24 . The apparatus of claim 14 , wherein the first shaping operation and the at least one shaping operation are different shaping operations.

25 . A method of wireless communication at a first wireless device, comprising:

receiving an indication of a non-uniform distribution of symbols associated with at least one shaping operation associated with one or more layers of a quadrature amplitude modulated (QAM) multiple user multiple input multiple output (MU-MIMO) communication, wherein the one or more layers of the QAM MU-MIMO communication are associated with one or more additional wireless devices in a plurality of wireless devices, wherein each of the plurality of wireless devices is a co-scheduled wireless device associated with a layer of the QAM MU-MIMO communication, and wherein the first wireless device is included in the plurality of wireless devices;

receiving, from a network node, the QAM MU-MIMO communication;

performing a demodulation of the QAM MU-MIMO communication based on the indication; and

outputting a result of the demodulation of the QAM MU-MIMO communication for at least one of a transmission to at least one other wireless device or a local storage at the first wireless device.

26 . The method of claim 25 , wherein the at least one shaping operation is one of a probabilistic amplitude shaping operation or a geometric shaping operation, and wherein the indication of the at least one shaping operation comprises at least one of (1) a first single-bit indication of whether at least one layer of the QAM MU-MIMO communication is associated with a shaping operation, (2) a second single-bit indication of whether a majority of layers of the QAM MU-MIMO communication are associated with the shaping operation, or (3) one or more single-bit indications indicating whether the shaping operation is associated with a corresponding additional wireless device of the one or more additional wireless devices.

27 . The method of claim 26 , wherein the indication indicates at least one of (1) that the at least one layer of the QAM MU-MIMO communication is associated with the shaping operation, (2) that the majority of layers of the QAM MU-MIMO communication are associated with the shaping operation, (3) that the shaping operation is associated with at least one of the one or more additional wireless devices, the method further comprising one of:

detecting a distribution associated with the at least one shaping operation, wherein the demodulation of the QAM MU-MIMO communication is further based on the distribution associated with the at least one shaping operation, wherein the demodulation is configured to demodulate the QAM MU-MIMO communication based on the distribution associated with the at least one shaping operation; or

refraining from detecting the distribution associated with the at least one shaping operation, wherein the demodulation of the QAM MU-MIMO communication does not consider knowledge of the at least one shaping operation associated with at least one of the at least one layer of the QAM MU-MIMO communication, the majority of layers of the QAM MU-MIMO communication, or the one or more additional wireless devices.

28 . The method of claim 25 , wherein the indication of the non-uniform distribution of symbols associated with the at least one shaping operation comprises information regarding at least one of:

a shaping rate;

a shaping parameter;

a power scaling factor associated with the at least one shaping operation;

at least one modulation and coding scheme (MCS) value associated with the at least one shaping operation for the one or more additional wireless devices;

whether there are wireless devices that are co-scheduled with the first wireless device;

a number of co-scheduled layers of the QAM MU-MIMO communication;

a number of wireless devices of the one or more additional wireless devices; or

a set of time-and-frequency resources associated with co-scheduled QAM MU-MIMO communications with the one or more additional wireless devices.

29 . The method of claim 25 , wherein performing the demodulation of the QAM MU-MIMO communication comprises performing a non-linear demodulation of the QAM MU-MIMO communication that estimates an interference associated with the one or more layers of the QAM MU-MIMO communication based on the indication of the non-uniform distribution of the symbols.

30 . A method of wireless communication at a network node, comprising:

outputting, for a first wireless device, an indication of a non-uniform distribution of symbols associated with at least one shaping operation associated with one or more layers of a quadrature amplitude modulated (QAM) multiple user multiple input multiple output (MU-MIMO) communication, wherein the one or more layers of the QAM MU-MIMO communication are associated with one or more additional wireless devices in a plurality of wireless devices, wherein each of the plurality of wireless devices is a co-scheduled wireless device associated with a layer of the QAM MU-MIMO communication, and wherein the first wireless device is included in the plurality of wireless devices;

generating, based on a first shaping operation associated with the first wireless device and the at least one shaping operation, a set of symbols for the QAM MU-MIMO communication; and

outputting, for transmission to the plurality of wireless devices, the QAM MU-MIMO communication.