Method and apparatus for multiplexing data and control information in wireless communication systems based on frequency division multiple access
An apparatus for transmitting data in a frequency division multiple access based communication system is disclosed. The apparatus includes a symbol block generator for generating a symbol block in a predetermined symbol block period within one TTI when control information to be transmitted exists in the TTI, an FFT unit for performing FFT on the symbol block, and an IFFT unit for performing IFFT on signals output from the FFT unit and then transmitting the signals. The symbol block includes the control information and data to be transmitted. The TTI includes multiple symbol block periods.
1. An apparatus for receiving data in a frequency division multiple access based communication system, the apparatus comprising:
a Fast Fourier Transform (FFT) unit for receiving signals received during one symbol block period and for performing FFT on the signals;
an Inverse Fast Fourier Transform (IFFT) unit for performing IFFT on the signals output from the FFT unit, thereby restoring symbol blocks;
a control information demodulator/decoder for, when the symbol block period comprises a symbol block period in which data and control information are multiplexed, receiving modulation symbols corresponding to IFFT output indexes from among the symbol blocks and demodulating and decoding the modulation symbols, thereby outputting control information; and
a data demodulator/decoder for receiving modulation symbols corresponding to the other IFFT output indexes except for indexes corresponding to the control information from among the symbol blocks by using the control information, demodulating and decoding the received modulation symbols, and then outputting the data.
2. The apparatus as claimed in claim 1 , further comprising:
a channel estimator for generating channel estimation information by using pilot symbols output from the FFT unit when the symbol block period comprises a symbol block period comprising a pilot signal; and
a channel compensator for channel-compensating the symbol block comprising data and control information output from the FFT unit by using the channel estimation information and then outputting the symbol block to the IFFT unit.
3. The apparatus as claimed in claim 1 , further comprising:
a channel estimator for generating channel estimation information by using pilot symbols output from the IFFI unit when the symbol block period comprises a symbol block period comprising a pilot signal; and
a channel compensator for channel-compensating the symbol block comprising data and control information output from the FFT unit by using the channel estimation information and then outputting the symbol block to the IFFT unit.
4. The apparatus as claimed in claim 1 , further comprising:
a channel estimator for generating channel estimation information by using pilot symbols output from the IFFT unit when the symbol block period comprises a symbol block period comprising a pilot signal; and
a channel compensator for channel-compensating the symbol block comprising data and control information output from the IFFT unit by using the channel estimation information and then outputting the symbol block to the demodulator.
5. The apparatus as claimed in claim 1 , further comprising:
a channel estimator for generating channel estimation information by using pilot symbols output from the IFFT unit when the symbol block period comprises a symbol block period comprising a pilot signal; and
a channel compensator for channel-compensating the symbol block comprising data and control information output from the FFT unit by using the channel estimation information and then outputting the symbol block to the demodulator.
6. The apparatus as claimed in claim 1 , wherein the control information comprises at least one of modulation information, channel coding information, symbol number-related information, and FFT mapping information.
7. The apparatus as claimed in claim 1 , wherein, when the symbol block period comprises a symbol block period comprising data, the data demodulator/decoder receives symbol blocks comprising the data from the IFFT unit and then demodulates and decodes the symbol blocks, thereby outputting the data.
8. A method for receiving data in a frequency division multiple access based communication system, the method comprising:
receiving signals received during one symbol block period and performing Fast Fourier Transform (FFT) on the signals by an FFT unit;
restoring symbol blocks from the FFTed signals by an Inverse Fast Fourier Transform (IFFT) unit;
when the symbol block period comprises a symbol block period in which data and control information are multiplexed, receiving modulation symbols corresponding to IFFT output indexes from among the symbol blocks from the IFFT unit and demodulating and decoding the modulation symbols, thereby outputting control information; and
receiving modulation symbols corresponding to the other IFFI output indexes except for indexes corresponding to the control information from among the symbol blocks from the IFFT unit by using the control information, demodulating and decoding the received modulation symbols, and then outputting the data.
9. The method as claimed in claim 8 , further comprising:
generating channel estimation information by using pilot symbols output from the FFT unit when the symbol block period comprises a symbol block period comprising a pilot signal; and
channel-compensating the symbol block comprising data and control information output from the FFT unit by using the channel estimation information and then outputting the symbol block to the IFFT unit.
10. The method as claimed in claim 8 , further comprising:
generating channel estimation information by using pilot symbols output from the IFFI unit when the symbol block period comprises a symbol block period comprising a pilot signal; and
channel-compensating the symbol block comprising data and control information output from the FFT unit by using the channel estimation information and then outputting the symbol block to the IFFT unit.
11. The method as claimed in claim 8 , further comprising:
generating channel estimation information by using pilot symbols output from the FFT unit when the symbol block period comprises a symbol block period comprising a pilot signal; and
channel-compensating the symbol block comprising data and control information output from the IFFT unit by using the channel estimation information and then outputting the symbol block to the demodulator.
12. The method as claimed in claim 8 , further comprising:
generating channel estimation information by using pilot symbols output from the IFFT unit when the symbol block period comprises a symbol block period comprising a pilot signal; and
channel-compensating the symbol block comprising data and control information output from the FFT unit by using the channel estimation information and then outputting the symbol block to the demodulator.
13. The method as claimed in claim 8 , wherein the control information comprises at least one of modulation information, channel coding information, symbol number-related information, and FFT mapping information.
14. The method as claimed in claim 8 , wherein, during the receiving of modulation symbols, when the symbol block period comprises a symbol block period comprising data, symbol blocks comprising the data are provided from the IFFT unit and are then demodulated and decoded, whereby the data is output.