Impulsive noise suppression for robust timing recovery and iterative decoding

Abstract

The problem of baseband signal processing operations for coded communications systems employing iterative decoding in impulsive noise is treated. Prior to the decoder, such systems typically consist of a matched filter followed by a sampler that is controlled by a timing recovery algorithm to obtain soft channel outputs. This approach, however, performs poorly in the presence of impulsive noise. To overcome this problem, an impulse mitigation strategy derived from the myriad filtering framework is used to produce reliable symbol waveforms over a wide range of noise environments. This method proves to be fruitful in that all subsequent signal processing operations including symbol synchronization and iterative decoding are safe to process the symbol samples obtained hereafter, thereby retaining all their optimality and advantages