【摘要】 由Ｉｍａｉ与Ｈｉｒａｋａｗａ提出的多级编码方法，可用来构造具有任意大最小平方欧氏距离的分组调制（ＢＣＭ）码一个ＢＣＭ码的性能主要取决于构成它的各个成分码，恰当地选择成分码是构造一个好的ＢＣＭ码的关键，文章给出了一种新方法，通过选用不同长度的成分码来构造ＢＣＭ码，仿真结果表明用此方法构造出的ＢＣＭ码较传统的ＢＣＭ码在性能与复杂度上有明显的改善更多还原

【Abstract】 Multilevel coding technique proposed by and Hirakawa can be used to construct BCM code with arbitrarily large minimum squared Euclidean distance,The performance and complexity of a BCM code mainly depend on its component codes To construct good BCM codes ,a proper selection of component codes is of great importance The paper presents a new method to construct BCM codes in which variant length block codes are used as component codes. Simulation results show BCM codes constructed by this method have better performance and complexity than conventional ones更多还原