Low-complexity DFT-pair carrier acquisition

When the maximum frequency offset to be acquired is a small fraction of the symbol-rate, a DFT-pair based carrier acquisition method (a frequency-domain analog of the early-late gate synchronizer) provides low-complexity frequency-offset acquisition using a modest number of symbols. Several new modulation and coding standards (e.g., DVB-S2, allowing receivers to operate at lower Eb/N0's) require that this DFT-based acquisition scheme be modified in order to allow acquisition at a range of signal-to-noise ratios. As the signal-to-noise ratio is unknown, an intuitively appealing method, explored in this paper, takes the smaller of the two DFT bins as the bin with more noise.