Patent ID: 8233522

Claim:
A decision feedback equalizer for a digital broadcasting, comprising: a filtering means for removing Inter-symbol Interference (ISI) from received signals to generate a filtered signal; a symbol detecting means for receiving the filtered signal from the filter and deciding a symbol of the filtered signal using a trellis decoding algorithm wherein the symbol detecting means uses a Trellis Coded Modulation (TCM) decoder whose Trace Back Depth (TBD) is 1 (TBD=1), wherein the symbol detecting means is configured to calculate the distance among four symbol pairs D i for i=0, 1, 2, 3 of a 8-vestigial sideband (VSB) symbol pair, D 0 =−7 or +1, D 1 =−5 or +3, D 2 =−3 or +5 and D 3 =−1 or +7 and the filtered signal y[k], wherein the symbol detecting means is configured to select a closest distance from among the four symbol pairs and then the symbol detecting means calculates a new accumulated absolute distance by adding a previous accumulated distance calculated before with a next closest distance at each next state in the trellis decoding algorithm, wherein the symbol detecting means is further configured to select the next state having a smallest of the new accumulated distance among each of the next states in the trellis diagram and gets a next symbol from a node transited into for the selected next state of the trellis diagram, and wherein the received filtered signal of the symbol detecting means is output from the same symbol detecting means; and an error calculating means for calculating an error signal based on the decided symbol of the symbol detecting means in order to update the filter coefficients.