An apparatus and method for generating a Scheduling Assignment (SA), which reduces a probability of an incorrect action by a User Equipment (UE) in response to a reception of the SA, in a communication system wherein a base station transmits the SA being a first type or a second type and including at least one Information Element (IE). The method includes setting at least one bit in the at least one IE with a predetermined value, if the SA is of the second type; and setting any remaining bits in the at least one IE with arbitrary values.