Probabilistic amplitude shaping including energy selection, composition determination, and amplitude symbol sequence determination

Patent metadata

Field	Value
Publication number	US-2025286757-A1
Application number	US-202219105020-A
Country	US
Kind code	A1
Filing date	Sep 1, 2022
Priority date	Sep 1, 2022
Publication date	Sep 11, 2025
Grant date	—

Abstract

This disclosure provides methods, devices and systems for encoding data for wireless communication to achieve an amplitude distribution. One implementation includes a method in which probabilistic amplitude shaping is constrained by an energy value and a sequence composition. The implementation may include three phases. In a first phase, the energy value is determined. In a second phase, the sequence composition is determined. In a third phase, the output sequence is determined as constrained by the sequence composition. The methods generate output sequences defining amplitude symbols that are used to encode data for transmission.

First claim

1 . A method for wireless communication by a wireless communication device, the method comprising:
generating a plurality (k) of information bits, wherein k is an integer greater than 1; performing an encoding operation on the plurality of information bits, the encoding operation including:
accessing a first plurality of cumulative sequence quantities, each cumulative sequence quantity of the first plurality of cumulative sequence quantities representing a quantity of symbol sequences of a length (n) and having at most a respective energy level;
processing the first plurality of cumulative sequence quantities, including selecting a first energy level based at least in part on the plurality of information bits and the first plurality of cumulative sequence quantities;
determining a composition of an output symbol sequence from among a first set of symbol sequences having the first energy level, including performing a plurality of iterations to identify a plurality of elements of the composition, a quantity of the plurality of iterations being related to a size of a symbol alphabet; and
determining the output symbol sequence, including determining a plurality (n) of amplitude symbols of the output symbol sequence based at least in part on the composition and the plurality of information bits, wherein n is an integer greater than 1; and
transmitting a wireless packet to at least one receiving device based on the output symbol sequence.

2 . The method of claim 1 , wherein each of the amplitude symbols is selected from the symbol alphabet having size m, the symbol alphabet defining a set of different amplitude symbols, wherein m is an integer greater than 1.

3 . The method of claim 1 , wherein selecting the first energy level comprises:
performing a first function on the plurality of information bits, the first function generating a first number; computing a set of ratios, wherein each of the ratios is associated with a respective one of the first plurality of cumulative sequence quantities; and determining that the first number corresponds to a first one of the ratios, the first one of the ratios corresponding to the first energy level.

4 . The method of claim 3 , wherein the first number comprises a dyadic number.

5 . The method of claim 1 , further comprising:
receiving a subsequent wireless packet from a transmitting wireless communication device, the subsequent wireless packet including information having a received symbol sequence of n amplitude symbols and a second energy level and defined by the symbol alphabet; and decoding the subsequent wireless packet, wherein decoding comprises: computing the second energy level, obtaining a second composition of the received symbol sequence by counting symbol occurrences within the subsequent wireless packet; performing a plurality (n) of decoding iterations, each decoding iteration including computing a plurality of transition probabilities and a decoding interval constrained by a prefix composition, and after n of the decoding iterations generating a binary expansion corresponding to a final decoding interval.

6 . The method of claim 1 , wherein identifying a first element (k m *) of the plurality of elements of the composition comprises:
calculating a first number based at least in part on the plurality of information bits; accessing a plurality of sequence quantities, each one of the sequence quantities defining a set of all sequences having a length n minus km, an energy having been reduced by an amount proportional to k m , and a symbol alphabet excluding a first amplitude symbol, and using k m as a variable over a range of possible candidates for k m *; accessing a plurality of binomial coefficients; computing a plurality of transition probabilities based on the sequence quantities and the binomial coefficients; and determining that a first one of the transition probabilities corresponds to the first number, the first one of the transition probabilities corresponding to the first element (k m *) of the plurality of elements of the composition.

7 . The method of claim 6 , further comprising:
generating a residual energy value in accordance with determining the first element (k m *) of the plurality of elements of the composition.

8 . The method of claim 6 , further comprising:
generating a residual length value in accordance with determining the first element (k m *) of the plurality of elements of the composition.

9 . The method of claim 6 , further comprising:
scaling the first number in accordance with determining the first element (k m *) of the plurality of elements of the composition.

10 . The method of claim 6 , further comprising:
performing a second iteration to determine a second element (k m−1 *) of the plurality of elements of the composition, including:
generating a residual energy value and a residual length value in accordance with determining the first element (k m *) of the plurality of elements of the composition;
calculating a second number based on the plurality of information bits;
accessing a second plurality of sequence quantities defining a set of all sequences having a second length of the residual length value minus k m−1 , a second energy equal to the residual energy value minus a second amount proportional to k m−1 , and a second symbol alphabet excluding the first amplitude symbol and a second amplitude symbol, using k m−1 as a variable over a range of possible candidates for k m−1 *;
accessing a second plurality of binomial coefficients;
computing a second plurality of transition probabilities based on the second plurality of sequence quantities and the second plurality of binomial coefficients; and
determining that a second one of the second plurality of transition probabilities corresponds to the second number, the second one of the transition probabilities corresponding to the second element (k m−1 *) of the plurality of elements of the composition.

11 . The method of claim 1 , wherein a first iteration of the plurality of iterations begins with a first subinterval of a first interval and defines a second subinterval, the first subinterval corresponding to the first set of symbol sequences, and the second subinterval corresponding to a second set of symbol sequences, the first subinterval having a length that is proportional to a first transition probability, the second set of symbol sequences corresponding to a reduction of the first set of symbol sequences to exclude ones of the symbol sequences that do not conform to a first element of the composition.

12 . The method of claim 11 , further comprising:
scaling a first number according to the reduction of the first set of symbol sequences, wherein the first number is computed using the plurality of information bits.

13 . The method of claim 11 , further comprising:
scaling the first subinterval to be a same size as the first interval.

14 . The method of claim 1 , wherein the encoding operation and the transmitting is performed by a user equipment (UE) or a wireless base station (BS).

15 . (canceled)

16 . A wireless communication device comprising:
at least one modem; at least one processor communicatively coupled with the at least one modem; and at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor in conjunction with the at least one modem, is configured to:
generate a plurality of information bits;
access a first plurality of cumulative sequence quantities, each cumulative sequence quantity of

Assignees

• Qualcomm Inc

Inventors

• Liu Wei
• Richardson Thomas Joseph
• Wu Liangming
• Xu Changlong
• Shental Ori
• Xu Hao

Classifications

• H04L2025/03611

  Iterative algorithms · CPC title

• H04L25/03343

  Arrangements at the transmitter end · CPC title

• H03M13/25

  Error detection or forward error correction by signal space coding, i.e. adding redundancy in the signal constellation, e.g. Trellis Coded Modulation [TCM] {(modulation codes H03M13/31)} · CPC title

• H04L1/0047

  Decoding adapted to other signal detection operation (in conjunction with sequence estimation or equalization H04L25/03286) · CPC title

• H04L1/0042

  Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape (H04L1/0067 takes precedence) · CPC title