Noncoherent SIMO Transmission via MOCZ for Short Packet-Based Machine-Type Communications in Frequency-Selective Fading Environments

Massive machine type communication (mMTC) is expected to support the connections of billion devices, where a sporadic short packet transmission is a key feature for mMTC applications. Conventional pilot-based coherent schemes suffer from a huge resource overhead as the pilot occupies a large portion in the short packet transmission. To avoid the overhead and latency caused by pilot symbols and mitigate the adverse effect of wireless fading, we develop a noncoherent single-input multiple-output (SIMO) framework with modulation on conjugate-reciprocal zeros (MOCZ) for short packet transmission. A novel low-complexity noncoherent Viterbi-like detector is proposed, which can exploit diversity of receive antennas by jointly testing the zeros of the received MOCZ symbol over independent channel realizations. Simulation results demonstrate that the proposed detector can outperform the pilot-based OFDM systems and get better performance than the direct zero-testing detector for short packet transmissions in frequency-selective fading environments.