关键词: LDPC码, 嵌套结构, 编码

Abstract: This paper designs an adjustable rate LDPC with nesting structure.This code can use a differential encoder which is easy in circuit implementation.There are several codes with different rates because of the nesting structure in parity check matrix，so we can send different rate code in different channel condition to improve the system performance.This coding method is also suitable in the Automatic Repeat Request（ARQ） system.Simulation results indicate that these codes perform as well as regular low density parity check codes based on completely random matrix constructions.

Key words: Low-Density Parity-Check（LDPC） Code, nesting structure, encoding