Antenna modulation method applicable to wireless transmitter and transmitter using the same

1. An data modulation method applicable to a transmitter comprising a plurality of antennas and a processing unit which is configured to execute functions comprising:

receiving a data segment represented by a bit stream;

converting the bit stream into a multi-dimensional coordinate comprising a first dimension and a second dimension;

generating a first vector having a plurality of first elements according to the first dimension of the multi-dimensional coordinate, wherein the number of the first elements and the number of the antennas are identical, the first elements comprises at least a first entry and a second entry, and at least one of the first entry and the second entry of the first vector is set to a first non-zero entry;

generating a second vector having a plurality of second elements according to the second dimension of the multi-dimensional coordinate, wherein the number of the second elements and the number of the antennas are identical, the second elements comprises at least a third entry and a forth entry, and at least one of the third entry and the forth entry of the second vector is set to a second non-zero entry, wherein absolute phase difference between the first non-zero entry and the second non-zero entry is greater than 0 degree;

generating a third vector having a plurality of third elements by summing the first vector and the second vector, wherein the number of the third elements and the number of the antennas are identical, the third elements comprises at least a fifth entry and a sixth entry, the fifth entry of the third vector map to the first antenna among the antennas, and the sixth entry of the third vector map to the second antenna among the antennas; and

activating at least one of the first antenna and the second antennas and emitting waveforms according to one or more non-zero entries of the third vector for transmitting the data segment during one signalling interval.

2. The method of claim 1 , wherein:

the bit stream comprises B bits; and

a signal constellation of the multi-dimensional coordinate is the 2 B -ary Quadrature Amplitude Modulation (QAM) constellation.

3. The method of claim 1 , wherein the step of generating the first vector having the first elements according to the first dimension of the multi-dimensional coordinate comprising:

setting at least one of the first entry and second entry to 1 in response to the value of the first dimension of the multi-dimensional coordinate.

4. The method of claim 1 , wherein the step of generating the second vector having the second elements according to the second dimension of the multi-dimensional coordinate comprising:

setting at least one of the third entry and the fourth entry to j in response to the second dimension of the multi-dimensional coordinate, wherein j is the imaginary number.

5. The method of claim 1 , wherein activating the at least one of the first antenna and the second antennas and emitting waveforms according to the one or more non-zero entries of the third vector for transmitting the data segment during one signalling interval comprising:

when the fifth entry of the third vector is a non-zero entry, activating at least one of the first antenna and the second antennas corresponding the fifth entry; and

when the sixth entry of the third vector is a non-zero entry, activating at least one of the first antenna and the second antennas corresponding the sixth entry.

6. The method of claim 1 , wherein after the step of activating the at least one of the first antenna and the second antennas and emitting waveforms according to the one or more non-zero entries of the third vector for transmitting the data segment during one signalling interval, the method further comprising:

transmitting at least one analog radio frequency signal by the activated antenna based on the one or more non-zero entries of the third vector, wherein when one of the non-zero entries comprising real value, the analog radio frequency signal corresponding to the non-zero entry comprising a first Binary Phase Shift Keying (BPSK) signal, and when one of the non-zero entries comprising imaginary value, the analog radio frequency signal corresponding to the non-zero entry comprising a second BPSK signal, wherein the first BPSK signal is orthogonal to the second BPSK signal.

7. The method of claim 5 , wherein each of the first entry of the first vector, the third entry of the second vector, and the fifth entry of the third vector corresponds to only the first antenna.

8. The method of claim 5 , wherein each of the second entry of the first vector, fourth of the second vector and the sixth entry of the third vector corresponds to only the second antenna.

9. The method of claim 5 , wherein each of the first entry of the first vector, the third entry of the second vector, and the fifth entry of the third vector corresponds to at least both the first antenna and the second antenna.

10. The method of claim 5 , wherein each of the second entry of the first vector, fourth of the second vector and the sixth entry of the third vector corresponds to at least both the first antenna and the second antenna.

11. A transmitter comprising:

an antenna array comprising a first antenna and a second antenna among a plurality of antennas;

a communication unit coupled to the antenna array for converting from a digital baseband signal to an analog radio frequency signal; and

a processing unit coupled to the communication unit and is configured for:

receiving a data segment represented by a bit stream;

converting the bit stream into a multi-dimensional coordinate comprising a first dimension and a second dimension;

generating a first vector having a plurality of first elements according to the first dimension of the multi-dimensional coordinate, wherein the number of the first elements and the number of the antennas are identical, the first elements comprises at least a first entry and a second entry, and at least one of the first entry and the second entry of the first vector is set to a first non-zero entry;

generating a second vector having a plurality of second elements according to the second dimension of the multi-dimensional coordinate, wherein the number of the second elements and the number of the antennas are identical, the second elements comprises at least a third entry and a forth entry, and at least one of the third entry and the forth entry of the second vector is set to a second non-zero entry, wherein the absolute phase difference between the first non-zero entry and the second non-zero entry is greater than 0 degree;

generating a third vector having a plurality of third elements by summing the first vector and the second vector, wherein the number of the third elements and the number of the antennas are identical, the third elements comprises at least a fifth entry and a sixth entry, the fifth entry of the third vector map to the first antenna among the antennas, and the sixth entry of the third vector map to the second antenna among the antennas; and

controlling the communication unit to activate at least one of the first antenna and the second antennas and emitting waveforms according to one or more non-zero entries of the third vector for transmitting the data segment during one signalling interval.

12. The transmitter of claim 11 , wherein:

the bit stream comprises B bits; and

a signal constellation of the multi-dimensional coordinate is the 2 B -ary Quadrature Amplitude Modulation (QAM) constellation.

13. The transmitter of claim 11 , wherein:

the processing unit sets at least one of the first entry and second entry to 1 in response to the value of first dimension of the multi-dimensional coordinate.

14. The transmitter of claim 11 , wherein:

the processing unit sets at least one of the third entry and the fourth entry to j in response to the second dimension of the multi-dimensional coordinate, wherein j is the imaginary number.

15. The transmitter of claim 11 , wherein:

when the fifth entry of the third vector is a non-zero entry, the processing unit controls the communication unit to activate at least one of the first antenna and the second antennas corresponding the fifth entry; and

when the sixth entry of the third vector is a non-zero entry, the processing unit controls the communication unit to activate at least one of the first antenna and the second antennas corresponding the sixth entry.

16. The transmitter of claim 11 , wherein:

the communication unit transmits at least one analog radio frequency signal by the activated antenna based on the one or more non-zero entries of the third vector, wherein when one of the non-zero entries comprising real value, the analog radio frequency signal corresponding to the non-zero entry comprising a first Binary Phase Shift Keying (BPSK) signal, and when one of the non-zero entries comprising imaginary value, the analog radio frequency signal corresponding to the non-zero entry comprising a second BPSK signal, wherein the first BPSK signal is orthogonal to the second BPSK signal.

17. The transmitter of claim 15 , wherein:

each of the first entry of the first vector, the third entry of the second vector, and the fifth entry of the third vector corresponds to only the first antenna.

18. The transmitter of claim 15 , wherein:

each of the second entry of the first vector, fourth of the second vector and the sixth entry of the third vector corresponds to only the second antenna.

19. The transmitter of claim 15 , wherein:

each of the first entry of the first vector, the third entry of the second vector, and the fifth entry of the third vector corresponds to at least both the first antenna and the second antenna.

20. The transmitter of claim 15 , wherein:

each of the second entry of the first vector, fourth of the second vector and the sixth entry of the third vector corresponds to at least both the first antenna and the second antenna.