1. A transmission method in a transmission apparatus using a light communication scheme and an encoding method of a low-density parity-check convolutional code (LDPC-CC) of a coding rate of ½ and a time-variant period of 3, the method comprising the steps of:obtaining a parity bit sequence from an information sequence including input data sequence and a bit sequence comprising a plurality of bits each bit having a value of 0, using first to third parity check polynomials that satisfy 0; and

transmitting, by a transmission circuitry in the transmission apparatus using the light communication scheme, a light communication signal generated by using the input data sequence and the obtained parity bit sequence, wherein:

the first parity check polynomial that satisfies 0 is represented by a first Equation of the following three Equations where

(a#1,1,1%3, a#1,1,2%3, a#1,1,3%3) is a combination of different values, and

(b#1,1%3, b#1,2%3, b#1,3%3) is a combination of different values;

the second parity check polynomial that satisfies 0 is represented by a second Equation of the following three Equations where

(a#2,1,1%3, a#2,1,2%3, a#2,1,3%3) is a combination of different values, and

(b#2,1%3, b#2,2%3, b#2,3%3) is a combination of different values;

the third parity check polynomial that satisfies 0 is represented by a third Equation of the following three Equations where

(a#3,1,1%3, a#3,1,2%3, a#3,1,3%3) is a combination of different values, and

(b#3,1%3, b#3,2%3, b#3,3%3) is a combination of different values;

the low-density parity-check convolutional code (LDPC-CC) is defined by periodical switching of the first to third parity check polynomials that satisfies 0 by the time-variant period of 3;

wherein:

Xj(D) is a polynomial representation of the information sequence Xj;

P(D) is a polynomial representation of the parity bit sequence;

a#k,1,1, a#k,1,2, and a#k,1,3 (where k=1, 2, 3) are integers (where a#k,1,1?a#k,1,2?a#k,1,3);

b#k,1, b#k,2, and b#k,3 (where k=1, 2, 3) are integers (where b#k,1?b#k,2?b#k,3); and

c % d indicates a remainder obtained by dividing c by d.