Amplitude-coherent detection (ACD) is an efficient detection scheme that received increased attention in the literature because it can be used for detecting M-ary amplitude shift keying signals (MASK) using a simple receiver structure, while maintaining low symbol error rate (SER). The ACD can be used for various wireless systems application where phase tracking is infeasible due to high levels of phase noise, or due to the lack of resources at the receiver side. In this article, the performance of ACD is considered over wireless Nakagami-m fading channels, where the detector is derived and its performance is compared with the coherent and non-coherent detection schemes. The performance of the ACD is evaluated when the receiver is equipped with N receiving antennas for different values of the fading factor m and the modulation order M. The obtained results show that the SER of the AC and coherent MASK detectors are comparable in the absence of phase noise, while the ACD substantially outperforms coherent detection in the presence of phase noise.