A method for operating a random access channel (RACH) by a base station (BS) performing beamforming with at least one receive chain includes broadcasting RACH configuration information; and receiving an RACH signal with at least one receive chain, wherein the RACH configuration information includes threshold information to divide an RACH groups into a first group and a second group. A BS for operating a RACH by performing beamforming with at least one receive chain in a communication system, the BS comprising a controller configured to broadcast RACH configuration information and control at least one receive chain to receive an RACH signal, wherein the RACH configuration information includes threshold information to divide RACH groups into a first group and a second group. Other embodiments including a user equipment are also disclosed.