We propose an enhanced physical random access channel (PRACH) preamble detector which efficiently identifies non-orthogonal preambles while suppressing the noise rise. The proposed PRACH preamble detector reconstructs preambles from the received signal and efficiently utilizes them to improve the detection performance. Through simulations, we verify that the proposed detector successfully detects the desired preambles while suppressing the undesired noise rise, and, thus, it can detect 10 non-orthogonal preambles simultaneously with an extremely low mis-detection probability lower than 10−5, while achieving a false alarm probability of approximately 10−3.