Method and apparatus for detecting preamble signal of random access channel in base station of wireless communication system

An apparatus for detecting a preamble signal of a random access channel in a base station, the apparatus comprising:

• memory, comprising one or more storage media, storing instructions;
• and
• one or more processors communicatively coupled to the memory,
• wherein the instructions, when executed by the one or more processors individually or collectively, cause the apparatus to:
• receive preamble symbols for a third time interval via the random access channel for each antenna to convert the preamble symbols into a preamble symbol unit, wherein the third time interval is a sum of a first time interval required for transmission of the preamble symbols forming a preamble body and a second time interval during which two or more preamble symbols are transmitted,
• perform first fast Fourier transform on symbols including the preamble symbols and the two or more preamble symbols,
• generate the same preamble sequence as a preamble sequence used in the preamble body,
• calculate symbol power of each of the preamble symbols using the preamble sequence with respect to the first fast Fourier-transformed symbols for each antenna,
• for each antenna, calculate a non-coherent sums by adding the calculated symbol power of each preamble symbol across all possible sequences of consecutive preamble symbols within the first time interval,
• combine the non-coherent sums calculated for the preamble symbols at the same position for each antenna,
• detect a maximum energy value among the combined non-coherent sums and a first delay value (DF) of the preamble symbols having the maximum energy value,
• calculate power using the preamble sequence for two consecutive preamble symbols in the preamble symbols received for the third time interval,
• estimate a second delay value (DT) of the preamble symbols using the power of the two consecutive preamble symbols, and
• determine whether a preamble is received using the second delay value and the maximum energy value.