Spectrally-Efficient Modulation on Conjugate-Reciprocal Zeros (SE-MOCZ) for Non-Coherent Short Packet Communications
Aiman Asad Siddiqui, Ebrahim Bedeer, Ha H. Nguyen, Robert Barton
Abstract
This paper proposes a non-coherent communication scheme for short packet communications (SPCs), called spectrally-efficient modulation on conjugate reciprocal zeros (SE-MOCZ). The proposed SE-MOCZ scheme is realized by combining the recently-proposed MOCZ and faster-than-Nyquist (FTN) signaling. Specifically, the pulses carrying the polynomial coefficients of MOCZ are accelerated beyond the Nyquist limit to enhance the spectral efficiency. The spectral efficiency enhancement, however, comes at the expense of inter-polynomial-coefficient interference (IPCI), which increases the number of received complex zeros in the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$z$ </tex-math></inline-formula> -domain of the polynomial representing the received signal. We design a partial-complex-zeros-removal filter at the receiver to partially remove the pre-defined zeros due to the FTN signaling. Furthermore, we also optimize the radius of the transmit complex zeros in SE-MOCZ to improve the bit error rate (BER) performance. We propose a maximum likelihood (ML) detector for the proposed SE-MOCZ scheme. To strike a balance between the BER performance and computational complexity, we adopt a root-finding minimum distance (RFMD)-based detector. Simulation results clearly show the performance advantage of the proposed SE-MOCZ when compared to MOCZ for a wide range of operating parameters.