A new geometric shaping technique, referred to as coset shaping, is proposed and analyzed for coded QAM and PAM signaling. This method can be applied to both information and parity bits without introducing additional complexity. It is shown that, as the error-correcting code length and the modulation order grow, the gap to capacity of the proposed shaping scheme can be made arbitrarily small. A Gallager-type bound is provided together with numerical results, including performance comparisons for the shaping scheme combined with short and mid-length binary-coded, as well as nonbinary LDPC-coded QAM signaling

翻译：提出并分析了一种称为陪集成形的新型几何成形技术，用于编码QAM和PAM信号传输。该方法可同时应用于信息位和校验位，且不引入额外复杂度。研究表明，随着纠错码长度和调制阶数的增加，所提成形方案与信道容量的差距可任意缩小。本文给出了Gallager型界及数值结果，包括该成形方案结合短码/中长码二进制编码及非二进制LDPC编码QAM信号的性能对比。