A system including an input module, a first gain module, a second gain module, and a preamble estimation module. The input module is configured to receive an input signal from a station. The input signal includes (i) a first preamble sequence, and (ii) subcarriers. The first gain module is configured to, based on the input signal, generate first channel gain values. Each of the first channel gain values is for a respective one of the subcarriers. A second gain module is configured to, based on the first channel gain values, generate second channel gain values. A preamble estimation module is configured to estimate the first preamble sequence based on (i) the first channel gain values, and (ii) the second channel gain values.