Communication method for preventing signal collision in peer aware communication system and apparatus for transmitting/receiving using the method

1. A receiving apparatus in a peer aware communication system, comprising:

a receiver for receiving a signal;

a block signal eliminator for eliminating a block signal from the received signal, wherein the block signal informs of channel occupation and is transmitted through an interval in which a message signal including a preamble signal is not transmitted; and

a received signal processor for processing the received signal from which the block signal is eliminated,

wherein the received signal processor includes:

a block signal channel for estimating a channel of the block signal based on the received signal to obtain a channel estimate of the block signal,

a block signal regenerator for estimating a block signal values of the block signal in a time domain and regenerating the block signal based on the channel estimate of the block signal and the block signal value of the block signal in a time domain,

a delay processor for delaying and outputting the received signal, and

a signal eliminator for subtracting the regenerated block signal from the delayed received signal to eliminate the block signal from the received signal.

2. The receiving apparatus of claim 1 , wherein a subcarrier for the block signal is different from a subcarrier for the preamble signal.

3. The communication method of claim 1 , wherein transmission power of the block signal is equal to or higher than that of data.

4. A communication method in a peer aware communication system, comprising: receiving, by a receiving apparatus, a signal transmitted from a transmitting apparatus with a block signal that informs of channel occupation and is transmitted from another transmitting apparatus through an interval in which a message signal including a preamble signal is not transmitted from said another transmitting apparatus;

regenerating, by the receiving apparatus, the block signal based on the received signal; and

subtracting, by the receiving apparatus, the regenerated block signal from the received signal to eliminate the block signal from the received signal.

5. The communication method of claim 4 , wherein a subcarrier for the block signal is different from a subcarrier for the preamble signal.

6. The communication method of claim 4 , wherein the block signal is transmitted in a case in which the peer aware communication system and other systems using different communication standards coexist in an unlicensed band.

7. The communication method of claim 4 , further comprising:

generating, by the transmitting apparatus, a preamble signal; and

transmitting, by the transmitting apparatus, the preamble signal with subcarriers satisfying a predetermined condition.

8. The communication method of claim 7 , wherein the subcarriers satisfying a predetermined condition include an even-numbered subcarrier except for predetermined subcarriers among subcarriers included within a predetermined range.

9. The communication method of claim 8 , wherein the subcarrier for the block signal includes the predetermined subcarriers.

10. The communication method of claim 9 , wherein at least two of the predetermined subcarriers are used for transmitting the block signal.

11. The communication method of claim 9 , wherein in the transmitting of the preamble signal, the preamble signal is transmitted through a discovery channel in a frequency domain, wherein

among the entire subcarriers included in symbols that are used in transmitting the preamble signal on the discovery channel, the subcarriers satisfying the predetermined condition are used for transmitting the preamble signal and the predetermined subcarriers are used for transmitting the block signal.

12. The communication method of claim 4 , wherein the regenerating of a block signal includes:

estimating a channel of the block signal based on the received signal to obtain a channel estimate of the block signal;

estimating a block signal values of the block signal in a time domain; and

regenerating the block signal based on the channel estimate of the block signal and the block signal value of the block signal in a time domain.

13. The communication method of claim 4 , wherein the subtracting the regenerated block signal includes:

delaying the received signal by a predetermined number of samples; and

subtracting the regenerated block signal from the delayed received signal to eliminate the block signal from the received signal.

14. The receiving apparatus of claim 4 , wherein transmission power of the block signal is equal to or higher than that of data.