Flexible rate and punctured zigzag codes

Abstract

A generalized zigzag code is described where the code segments (each including one parity bit and information bits) of a block are not necessarily of uniform length. For coding rates in which the average code segment length is not an integer, all code segment lengths may be identical. The number of code segments depends on the coding rate and number of information bits in a block. At the encoder, parity bits are added to each string of information bits in a block to yield the code segments. For a punctured code, concatenated or not, the encoder may remove or not generate the punctured parity bits. At a decoder that operates at a rate different from the code rate of a received block, null parity bits are inserted. The received block has a number of code segments. The decoder increases the number of code segments by the addition of null parity bits, thereby reducing the coding rate to the rate of the decoder. Methods and apparatuses are detailed.