Research On The Period Distribution Of Constacyclic Codes Over Finite Rings

Constacyclic codes over finite rings have always been an important research object in theory of error-correcting codes over rings.As an important parameter,the period distribution of codes has been widely studied.In this paper,we mainly study the period distribution of constacyclic codes over several classes of finite rings.The details are given as follows:On one hand,letλbe an element of order l in the unit group of the ringZ_pm,where gcd（p,l）=1.In this paper,the period distribution ofλ-constacyclic codes of length n overZ_{p m} is studied,where gcd（p,n）=1.By using a direct decomposition,the calculation formula of the period distribution ofλ-constacyclic codes of length n overZ_pm is given.On the other hand,by using the generator polynomials and the properties of period distribution,the period distribution of some（1+u）-constacyclic codes of length 2^s over F₂+uF₂ is given.