1. A method, executed by a memory controller, for estimating read levels of a nonvolatile memory, the method comprising: reading voltages stored by memory cells of a page space within the nonvolatile memory to which pilot signals of a predetermined symbol are programmed; identifying the number of memory cells whose voltages, read from the page space, are less-than/greater-than a read-voltage applied in reading the voltages stored by the memory cells; and estimating a voltage to be applied for reading data stored in the page space based upon the identified number of memory cells, wherein the pilot signals are mapped to a meta data area of the page space and the mapped pilot signals are programmed into the page space.