US-20260128813-A1 - PROBABILISTIC SHAPING BASED ON BLOCK CODES

US20260128813A1US 20260128813 A1US20260128813 A1US 20260128813A1US-20260128813-A1

Abstract

Methods, systems, and devices for wireless communications are described. A transmitting device may support shaping of bits in block encoding schemes and a probabilistic shaping framework to generate shaped bits that include both information bits and shaping bits, without conveying extra information (e.g., in addition to the shaped bits) to a receiving device. The transmitter may use a decoder such as a polar decoder (e.g., a modem configured for both coding and decoding) to determine a set of shaping bits based on the information bits. The transmitting deice may also map information bits to frozen bit locations of the polar code, and the shaping bits to information bit locations of the polar, such that the encoded (e. g., shaped) bits from the polar encoder satisfy a target probability distribution.

Inventors

Wei Yang
Jing Jiang
Liangming WU

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260507
Application Date: 20221221

Claims (20)

1 . An apparatus for wireless communications at a first device, comprising: a processor; and memory coupled with the processor, the processor configured to: generate, based at least in part on a plurality of information bits, a plurality of shaping bits associated with shaping the plurality of information bits into a target probability distribution associated with a block encoding scheme; encode the plurality of information bits and the plurality of shaping bits according to the block encoding scheme to generate a plurality of shaped bits satisfying the target probability distribution; and output a message that is based at least in part on the plurality of shaped bits.
2 . The apparatus of claim 1 , wherein the processor is further configured to: determine the block encoding scheme associated with the target probability distribution for transmission of the message.
3 . The apparatus of claim 2 , wherein the processor is further configured to: communicate, with a second device, control signaling scheduling a transmission of the message and indicating the block encoding scheme, wherein the block encoding scheme is determined based at least in part on the control signaling.
4 . (canceled)
5 . (canceled)
6 . The apparatus of claim 1 , wherein the processor is further configured to: determine that the block encoding scheme is one of a polar coding scheme, a low-density generator matrix coding scheme, a convolution coding scheme, a turbo coding scheme, a Reed Muller coding scheme, an algebraic coding scheme, or any combination thereof.
7 . The apparatus of claim 6 , wherein the processor is further configured to: communicate control signaling indicating the block encoding scheme, wherein the block encoding scheme is determined based at least in part on the control signaling.
8 . The apparatus of claim 1 , wherein the processor is further configured to: determine a mapping of the plurality of information bits to a plurality of frozen bit locations and the plurality of shaping bits to a plurality of information bit locations, wherein the message is based at least in part on the mapping.
9 . The apparatus of claim 8 , wherein the processor is further configured to: communicate control signaling indicating the mapping, wherein the mapping is determined based at least in part on the control signaling.
10 . The apparatus of claim 1 , wherein the processor is further configured to: calculate a set of log likelihood ratio values based at least in part on the target probability distribution; and decode the set of log likelihood ratio values according to a decoding operation associated with the block encoding scheme to generate the plurality of shaping bits.
11 . The apparatus of claim 10 , wherein: a plurality of information bits are mapped to a plurality of frozen bit locations of the block encoding scheme, and the plurality of shaping bits are based at least in part on the set of decoded log likelihood ratio values.
12 . The apparatus of claim 10 , wherein the processor is further configured to: map a second plurality of information bits and at least one candidate shaped bit to a modulation symbol; determine a conditional distribution based at least in part on the target probability distribution; and determine a log likelihood ratio value for the at least one candidate shaped bit based at least in part on the second plurality of information bits and the conditional distribution associated with the modulation symbol, wherein the set of log likelihood ratio values is calculated based at least in part on determining the log likelihood ratio value for the at least one candidate shaped bit.
13 . (canceled)
14 . (canceled)
15 . The apparatus of claim 1 , wherein the processor is further configured to: generate the plurality of shaped bits using a joint decoder for the block encoding scheme and a channel encoding scheme based at least in part on the target probability distribution associated with the block encoding scheme and a second target probability distribution associated with the channel encoding scheme; and apply a channel encoding scheme to the plurality of shaped bits comprising the plurality of information bits and the plurality of shaping bits to generate a plurality of parity bits
16 . The apparatus of claim 15 , wherein the processor is further configured to: calculate a first set of log likelihood ratio values for the block encoding scheme based at least in part on the target probability distribution; and calculate a second set of log likelihood ratio values for the channel encoding scheme for the decoder associated with the channel encoding scheme, the second set of log likelihood ratio values based at least in part on the second target probability distribution corresponding to the plurality of parity bits, wherein the plurality of shaped bits are shaped based at least in part on the first set of log likelihood ratio values and the second set of log likelihood ratio values.
17 . (canceled)
18 . An apparatus for wireless communications, comprising: a processor; and memory coupled with the processor, the processor configured to: obtain, a message; and decode the message to generate a plurality of shaped bits satisfying a target probability distribution associated with a block encoding scheme, the plurality of shaped bits comprising a plurality of information bits and a plurality of shaping bits.
19 . The apparatus of claim 18 , wherein the processor is further configured to: determine the block encoding scheme associated with the target probability distribution for reception of the message.
20 . The apparatus of claim 19 , wherein the processor is further configured to: communicate, with a first device, control signaling scheduling a transmission of the message and indicating the block encoding scheme, wherein the block encoding scheme is determined based at least in part on the control signaling.

Description

CROSS REFERENCE The present application is a 371 national phase filing of International PCT Application No. PCT/CN2022/140573 by YANG et al., entitled “PROBABILISTIC SHAPING BASED ON BLOCK CODES,” filed Dec. 21, 2022, which is assigned to the assignee hereof, and which is expressly incorporated by reference in its entirety herein. INTRODUCTION The following relates to wireless communications, including probabilistic shaping according to various encoding schemes. Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations, each supporting wireless communication for communication devices, which may be known as user equipment (UE). SUMMARY The described techniques relate to improved methods, systems, devices, and apparatuses that support probabilistic shaping based on block codes. A method for wireless communications at a first device is described. The method may include generating, based on a set of multiple information bits, a set of multiple shaping bits associated with shaping the set of multiple information bits into a target probability distribution associated with a block encoding scheme, encoding the set of multiple information bits and the set of multiple shaping bits according to the block encoding scheme to generate a set of multiple shaped bits satisfying the target probability distribution, and outputting a message that is based on the set of multiple shaped bits. An apparatus for wireless communications at a first device is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to generate, based on a set of multiple information bits, a set of multiple shaping bits associated with shaping the set of multiple information bits into a target probability distribution associated with a block encoding scheme, encode the set of multiple information bits and the set of multiple shaping bits according to the block encoding scheme to generate a set of multiple shaped bits satisfying the target probability distribution, and output a message that is based on the set of multiple shaped bits. Another apparatus for wireless communications at a first device is described. The apparatus may include means for generating, based on a set of multiple information bits, a set of multiple shaping bits associated with shaping the set of multiple information bits into a target probability distribution associated with a block encoding scheme, means for encoding the set of multiple information bits and the set of multiple shaping bits according to the block encoding scheme to generate a set of multiple shaped bits satisfying the target probability distribution, and means for outputting a message that is based on the set of multiple shaped bits. A non-transitory computer-readable medium storing code for wireless communications at a first device is described. The code may include instructions executable by a processor to generate, based on a set of multiple information bits, a set of multiple shaping bits associated with shaping the set of multiple information bits into a target probability distribution associated with a block encoding scheme, encode the set of multiple information bits and the set of multiple shaping bits according to the block encoding scheme to generate a set of multiple shaped bits satisfying the target probability distribution, and output a message that is based on the set of multiple shaped bits. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the block encoding scheme associated with the target probability distribution for transmission of the message. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, communicating, with a second device, control signaling scheduling a transmission of the message and indicating the block encoding scheme, where determining the block encoding scheme may be based o