Blind reconstruction of a helical scan interleaver

Abstract

Interleaving is a technique that is commonly used in wireless digital communication systems to overcome burst errors occurred in wireless channels. The interleaver rearranges a consecutive data pattern into a certain pattern without repeating or omitting any information bit. At the receiver, the deinterleaver, which has information of the interleaver, rearranges the interleaved data back into the original data. For an unknown interleaved signal, however, a receiver has to estimate the parameters of the interleaver to recover the original data. In this paper, we focus on a helical scan interleaver and reconstruct the blind interleaved data. In order to recover the blind original data from the interleaved data, we first analyze the unknown data stream based on the linearity of the information and redundant bits of a channel code. And then, we develop an algorithm, based on the Gaussian elimination which is used to detect the linearity of the channel code, to estimate three parameters, such as the helical scan interleaver period, the size of rows and columns of the deinterleaver matrix and the codeword length.