Modulation method and apparatus for signal transmission and reception in mobile communication system

1. A method of signal transmission for a transmitter device in a mobile communication system, the method comprising:

identifying a modulation scheme for data transmission;

identifying a level for quadrature amplitude modulation (QAM) based on the identified modulation scheme;

identifying a amplitude and phase of a carrier wave based on the QAM level and data to be transmitted; and

identifying, when the identified modulation scheme is a first scheme, a length of sequences based on channel information, selecting a sequence according to the data to be transmitted among sequences of the identified length, and generating modulated symbols corresponding to the data to be transmitted based on the selected sequence, the amplitude of the carrier wave and the phase of the carrier wave.

2. The method of claim 1 , further comprising modulating, if the identified modulation scheme is a second scheme, the data to be transmitted based on the amplitude of the carrier wave and phase of the carrier wave.

3. The method of claim 1 , further comprising receiving information related to the signal-to-interference-plus-noise ratio (SINR) of a channel from a receiver device, and wherein the identifying of the modulation scheme comprises identifying QAM as the modulation scheme if the SINR is greater than or equal to a threshold value.

4. The method of claim 1 , further comprising:

interleaving the modulated symbols; and

scrambling the modulated symbols on a subcarrier basis to generate scrambled subcarriers.

5. The method of claim 4 , further comprising:

identifying fading effect of the scrambled subcarriers; and

mapping transmission resources of the subcarriers such that fading effect of the subcarriers corresponds to each other.

6. A method of signal reception for a receiver device in a mobile communication system, the method comprising:

receiving, from a transmitter device, a signal;

identifying the modulation scheme of the received signal;

identifying a sequence corresponding to the received signal from a sequence set used to modulate the received signal based on the modulation scheme and a correlator associated with the sequence set, wherein a length of the sequence set is associated with channel information between the receiver device and the transmitter device; and

demodulating the received signal based on the identified sequence and the log likelihood ratio (LLR) corresponding to the received signal.

7. The method of claim 6 , further comprising:

identifying the interleaving scheme applied to the received signal; and

deinterleaveing the received signal based on the interleaving scheme.

8. The method of claim 6 , further comprising:

identifying the scrambling scheme on a subcarrier basis applied to the received signal; and

descrambling the received signal on a subcarrier based on the scrambling scheme.

9. A transmitter device in a mobile communication system, comprising:

a transceiver configured to transmit and to receive a signal; and

at least one processor configured to:

control the transceiver,

identify a modulation scheme for data transmission,

identify a level for quadrature amplitude modulation (QAM) based on the identified modulation scheme,

identify an amplitude and phase of a carrier wave based on the QAM level and data to be transmitted, and

identify, when the identified modulation scheme is a first scheme, a length of sequences based on channel information, selecting a sequence according to the data to be transmitted among sequences of the identified length, and generate modulated symbols corresponding to the data to be transmitted based on the selected sequence, the amplitude of the carrier wave and the phase of the carrier wave.

10. The transmitter device of claim 9 , wherein the at least one processor is further configured to modulate, if the identified modulation scheme is a second scheme, the data to be transmitted based on the amplitude of the carrier wave and phase of the carrier wave.

11. The transmitter device of claim 9 ,

wherein the at least one processor is further configured to receive information related to the signal-to-interference-plus-noise ratio (SINR) of a channel from a receiver device, and

wherein the identifying of the modulation scheme comprises identifying QAM as the modulation scheme if the SINR is greater than or equal to a threshold value.

12. The transmitter device of claim 9 , wherein the at least one processor is further configured to:

interleave the modulated symbols, and

scramble the modulated symbols on a subcarrier basis to generate scrambled subcarriers.

13. The transmitter device of claim 12 , wherein the at least one processor is further configured to:

identify fading effect of the scrambled subcarriers, and

map transmission resources of the subcarriers such that fading effect of the subcarriers corresponds to each other.

14. A receiver device in a mobile communication system, comprising:

a transceiver configured to transmit and receive a signal; and

at least one processor configured to:

control the transceiver to receive, from a transmitter device, a signal,

identify the modulation scheme of the received signal,

identify a sequence corresponding to the received signal from a sequence set used to modulate the received signal based on the modulation scheme and a correlator associated with the sequence set, wherein a length of the sequence set is associated with channel information between the receiver device and the transmitter device, and

demodulate the received signal based on the identified sequence and the log likelihood ratio (LLR) corresponding to the received signal.

15. The receiver device of claim 14 , wherein the at least one processor is further configured to:

identify the interleaving scheme applied to the received signal, and

deinterleave the received signal based on the interleaving scheme.

16. The receiver device of claim 14 , wherein the at least one processor is further configured to:

identify the scrambling scheme on a subcarrier basis applied to the received signal, and

descramble the received signal on a subcarrier based on the scrambling scheme.