# US 10,320,521 B2 · Modulator and modulation method using non-uniform 16-symbol signal constellation for low-density parity check codeword having 2/15 code rate

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,320,521 B2
- Document ID: US10320521B2
- Status: Granted
- Kind: B2
- Application number: 15/368,287
- Filed: 2016-12-02
- Published: 2017-03-23
- Granted: 2019-06-11
- Earliest claimed: 2014-02-13
- Assignees: Electronics and Telecommunications Research Institute
- Applicants: Electronics and Telecommunications Research Institute
- Inventors: Sung-Ik Park; Sun-Hyoung Kwon; Jae-Young Lee; Heung-Mook Kim; Nam-Ho Hur
- Web page: https://patentgrep.com/patent/US10320521B2

## CPC

- H04L 1/0041: {Arrangements at the transmitter end}
- H03M 13/1102: {Codes on graphs and decoding on graphs, e.g. low-density parity check [LDPC] codes}
- H03M 13/1148: {Structural properties of the code parity-check or generator matrix}
- H03M 13/116: {Quasi-cyclic LDPC [QC-LDPC] codes, i.e. the parity-check matrix being composed of permutation or circulant sub-matrices}
- H03M 13/1185: {wherein the parity-check matrix comprises a part with a double-diagonal}
- H03M 13/255: {with Low Density Parity Check [LDPC] codes}
- H03M 13/2778: {Interleaver using block-wise interleaving, e.g. the interleaving matrix is sub-divided into sub-matrices and the permutation is performed in blocks of sub-matrices}
- H03M 13/2792: {Interleaver wherein interleaving is performed jointly with another technique such as puncturing, multiplexing or routing}
- H03M 13/616: {Matrix operations, especially for generator matrices or check matrices, e.g. column or row permutations}
- H03M 13/6552: {DVB-T2}
- H04L 1/0058: {Block-coded modulation}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C)

## Abstract

A modulator and a modulation method using a non-uniform 16-symbol signal constellation are disclosed. The modulator includes a memory and a processor. The memory receives a codeword corresponding to a low-density parity check (LDPC) code having a code rate of 2/15. The processor maps the codeword to 16 symbols of the non-uniform 16-symbol signal constellation on a 4-bit basis.

## Claims

### Claim 1

A digital broadcasting method, comprising:
generating a codeword corresponding to a low-density parity check (LDPC) code having a code rate of 2/15 by encoding information bits;
interleaving the codeword on a bit group basis;
performing 16-symbol mapping using 16 symbols of a non-uniform 16-symbol signal constellation on a 4-bit basis after interleaving the codeword, the 16 symbols being for the LDPC code having the code rate of 2/15;
adjusting at least one of amplitude and phase of a carrier in accordance with the 16-symbol mapping to generate a modulated signal; and
broadcasting, by an antenna, a transmission signal based on the modulated signal over a physical channel,
wherein the 16 symbols are defined as shown in the following Table:
TABLE
w
Constellation
0
0.7062 + 0.7075i
1
0.7075 + 0.7062i
2
0.7072 + 0.7077i
3
0.7077 + 0.7072i
4
−0.7062 + 0.7075i
5
−0.7075 + 0.7062i
6
−0.7072 + 0.7077i
7
−0.7077 + 0.7072i
8
0.7062 − 0.7075i
9
0.7075 − 0.7062i
10
0.7072 − 0.7077i
11
0.7077 − 0.7072i
12
−0.7062 − 0.7075i
13
−0.7075 − 0.7062i
14
−0.7072 − 0.7077i
15
−0.7077 − 0.7072i.

### Claim 2 (depends on 1)

The digital broadcasting method of claim 1, wherein the 16 symbols have non-uniform distances therebetween, and comprise a first group of four symbols of a 1st quadrant, a second group of four symbols symmetric to the four symbols of the first group with respect to an imaginary axis, a third group of four symbols symmetric to the four symbols of the first group with respect to an origin, and a fourth group of four symbols symmetric to the four symbols of the first group with respect to a real axis.

### Claim 3 (depends on 2)

The digital broadcasting method of claim 2, wherein a vector corresponding to four symbols w0, w1, w2, and w3 of the first group is w, a vector corresponding to four symbols w4, w5, w6 and w7 of the second group is −conj(w) (conj(w) is a function that outputs conjugate complex numbers of all elements of w), a vector corresponding to four symbols W12, W13, W14 and W15 of the third group is −w, and a vector corresponding to four symbols w8, w9, w10 and w11 of the fourth group is conj(w).

### Claim 4 (depends on 3)

The digital broadcasting method of claim 3, wherein amplitudes of real and imaginary components of two of the four symbols of the first group are symmetric.

### Claim 5 (depends on 4)

The digital broadcasting method of claim 4, wherein the four symbols of the first group are w0, w1, w2, and w3, |real(w0)|=|imaginary(w1)| (real(i) is a function that outputs a real component of i, imaginary(i) is a function that outputs an imaginary component of i, and i is an arbitrary complex number), |real(w1)|=|imaginary(w0)|, |real(w2)|=|imaginary(w3)|, and |real(w3)|=|imaginary(w2)|.