Patent ID: 7477709

Claim:
An apparatus detecting a level value of a Viterbi decoder, comprising: the Viterbi decoder which generates a first binary signal; a binarization unit which generates a second binary signal from an input RF signal; and a channel identifier which detects a new level value of the Viterbi decoder based on the input RF signal and the first and second binary signals, wherein the channel identifier selects a level of the input RF signal based on the binary signals and detects the new level value by obtaining a mean value of the input RF signal of the selected level and a previous level value, wherein the binarization unit is a slicer, and comprises a run length compensator correcting a sign of the second binary signal generated by the binarization unit, and wherein the channel identifier comprises: a selection signal generator which generates a selection signal based on the binary signals; a level selector which selects the level of the input RF signal according to the selection signal and outputs the selected level; and a mean filter which generates the new level value based on the previous level value and the input RF signal of the selected level, and the selection signal generator generates a selection signal by multiplexing a signal obtained by delaying the output signal of the Viterbi decoder by a same number of clock signals as a number of taps of the Viterbi decoder.