Circular $\theta$ -QAM: A Circle-Shaped QAM for Higher-Order Modulation

Abstract

This paper proposes M-ary circular θ-quadrature amplitude modulation (CTQAM) for M = 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">l</sup> , l ≥ 4, which is constructed by rearrangement of the signal points based on θ-QAM. We provide a construction method for the signal constellation of CTQAM and analyze the symbol and bit error performances of M-ary CTQAM in additive white Gaussian noise (AWGN) and Nakagami-m fading channels. Through computer simulations, we validate theoretical results.