Transmitting apparatus, transmission method and signal generating apparatus

A signal generating apparatus that generates a first symbol to be transmitted by a first antenna and a second symbol to be transmitted by a second antenna in a common frequency band and common transmission time, the apparatus comprising:

• a first symbol generation section that outputs one point of a plurality of first signal points to the first antenna as a first symbol, the plurality of first signal points being arranged on an IQ plane based on a first mapping pattern;
• and
• a second symbol generation section that outputs one point of a plurality of second signal points to the second antenna as a second symbol, the plurality of second signal points being arranged on an IQ plane based on a second mapping pattern, wherein:
• a plurality of bits are allocated to each of the plurality of first signal points;
• a first bit set in the plurality of bits is allocated to a first position on the IQ plane;
• the plurality in first signal points are divided into four groups based on specific two bits of the plurality of bits;
• in each of the groups, the plurality of first signal points are arranged per first distance in a horizontal direction or in a vertical direction;
• a minimum distance between signal points in one of the four groups and signal points in a rest of the groups is a second distance which differs from the first distance;
• the plurality of bits are allocated to each of the plurality of second signal points;
• the first bit set in the plurality of bits is allocated to a second position on the IQ plane;
• and
• the second position and the first position are different.

A transmission method comprising:

• a first symbol generation step of selecting one point of a plurality of first signal points as a first symbol, the plurality of first signal points being arranged on an IQ plane based on a first mapping pattern;
• a second symbol generation step of selecting one point of a plurality of second signal points as a second symbol, the plurality of second signal points being arranged on the IQ plane based on a second mapping pattern;
• and
• a transmission step in which a first antenna transmits the first symbol and a second antenna transmits the second symbol in a common frequency band and common transmission time with the first symbol, wherein:
• a plurality of bits are allocated to each of the plurality of first signal points;
• a first bit set in the plurality of bits is allocated to a first position on the IQ plane;
• the plurality of first signal points are divided into four groups based on specific two bits of the plurality of bits;
• in each of the groups, the plurality of first signal points are arranged per first distance in a horizontal direction or in a vertical direction;
• a minimum distance between signal points in one of the four groups and signal points in a rest of the groups is a second distance which differs from the first distance;
• the plurality of bits are allocated to each of the plurality of second signal points;
• the first bit set in the plurality of bits is allocated to a second position on the IQ plane;
• the second position and the first position are different.