The Relationship Between the Cyclic Wiener Filter and Fractionally Spaced Equalizers
Omar A. Yeste-Ojeda, Jesús Grajal · IEEE Transactions on Signal Processing · 2019
This paper presents a different interpretation of the cyclic Wiener filter (CWF) for digital (in-phase/quadrature) IQ-modulated signals, such as phase-shift keying (PSK) or quadrature amplitude modulations (QAM). We demonstrate that the CWF can be implemented as a multirate filter instead of the frequency-shift (FRESH) filter implementation found in the literature. The multirate implementation consists of a fractionally spaced equalizer (FSE) followed by a pulse shaping filter, thus establishing a direct relationship between the CWF and FSEs. Afterwards, the results from the study are applied to develop a simple blind adaptive algorithms for signal estimation, which are benchmarked against the most common CWF implementation based on FRESH filters.