According to an example embodiment, a method of generating a soft decision value using an Analog-to-Digital Converter (ADC) having a given resolution may include receiving metric values calculated based on levels of a transmission signal and output levels of the ADC. Metric values corresponding to a level of a received signal may be selected from among the received metric values. A first maximum metric value may be detected from among the selected metric values when a transmission bit is a first level, and a second maximum metric value may be detected from among the selected metric values when the transmission bit is a second level. The soft decision value may be generated based on a difference between the first maximum metric value and the second maximum metric value.