Recovering the output of an OFB in the case of instantaneous erasures in sub-band domain

Abstract

In this paper, we propose a method for reconstructing the output of an Oversampled Filter Bank (OFB) when instantaneous erasures happen in the sub-band domain. Instantaneous erasure is defined as a situation where the erasure pattern changes in each time instance. This definition differs from the type of erasure usually defined in literature, where e erasures means that e channels of the OFB are off and do not work at all. This new definition is more realistic and increases the flexibility and resilience of the OFB in combating the erasures. Additionally, similar to puncturing, the same idea can be used in an erasure-free channel to reconstruct the output, when sub-band samples are discarded intentionally in order to change the code rate. In this paper we also derive the sufficient conditions that should be met by the OFB in order for the proposed reconstruction method to work. Based on that, eventually we suggest a general form for the OFBs which are robust to this type of erasure.