Apparatus and method for transmission which encoding a message with space-time tubo code using feedback bit in mobile communication system

1. An apparatus for transmission encoding a message with space-time turbo code in digital mobile communication system having a plurality of transmit antennas, comprising:

a space-time turbo encoder encoding an input bit corresponding to the message with a space-time turbo code and generating a systematic bit and a punctured parity bit; and

a phase rotator rotating a constellation corresponding to the systematic bit and the punctured parity bit, respectively,

wherein the phase rotator rotates the constellation according to a feedback bit from a receive antenna so that phase difference between the channel gains of the plurality of transmit antennas would be at its largest.

2. The apparatus for transmission of claim 1 , wherein the number of the transmit antennas in the digital mobile communication system is two.

3. A method for transmission encoding a message with space-time turbo code in digital mobile communication system having a plurality of transmit antennas, comprising:

encoding the message for communication with space-time turbo code and generating a systematic bit and a punctured parity bit;

receiving a feedback bit reflecting a phase difference information of the channel gain between the plurality of transmit antennas from a receive antenna; and

rotating a constellation corresponding to the systematic bit and the punctured parity bit, respectively, according to a feedback bit so that the phase difference between the channel gains of the plurality of transmit antennas would be at its largest.

4. The method for transmission of claim 3 , wherein the number of the transmit antennas in the digital mobile communication system is two.

5. An apparatus for transmission encoding a message with space-time turbo code in digital mobile communication system having a plurality of transmit antennas, comprising:

a space-time turbo encoder encoding an input bit corresponding to the message with a space-time turbo code and generating a systematic bit and a punctured parity bit; and

an alternator selecting one of the plurality of transmit antennas for each of the systematic bit and the punctured parity bit; and

a phase rotator rotating a constellation corresponding to the systematic bit and the punctured parity bit, respectively,

wherein the alternator selects a transmit antenna with larger channel gain of the plurality of transmit antennas according to a first feedback bit being transmitted from a receive antenna and transmits the systematic bit corresponding to the rotated constellation through the selected transmit antenna, and

wherein the phase rotator rotates the constellation according to a second feedback bit from a receive antenna so that phase difference between the channel gains of the plurality of transmit antennas is at its largest.

6. The apparatus for transmission of claim 5 , wherein the number of the transmit antennas in the digital mobile communication system is two.

7. A method for transmission encoding a message with space-time turbo code in digital mobile communication system having a plurality of transmit antennas, comprising:

encoding an input bit corresponding to the message for communication with space-time turbo code and generating a systematic bit and a punctured parity bit;

receiving a first feedback bit reflecting information about the channel gain of the plurality of transmit antennas from a receive antenna;

selecting a transmit antenna with the largest channel gain from the plurality of transmit antennas according to the first feedback bit;

receiving a second feedback bit reflecting a phase difference information of the channel gain between of the plurality of transmit antennas from a receive antenna;

rotating a constellation corresponding to the systematic bit and the punctured parity bit, respectively, according to the second feedback bit so that the phase difference between the channel gains of the plurality of transmit antennas is at its largest; and

transmitting the systematic bit and the punctured parity bit corresponding to the rotated constellation through the selected transmit antenna and one of the other antennas, respectively.

8. The method for transmission of claim 7 , wherein the number of the transmit antennas in the digital mobile communication system is two.