Patent ID: 7613103

Claim:
A turbo TCM decoder, comprising: means for converting a received signal to signal bits of QPSK mode by using an I-axis coordinate and a Q-axis coordinate on a constellation of the received signal; means for performing a phase sector quantization on the received signal by using the I-axis coordinate and the Q-axis coordinate; means for determining coded data by decoding the signal bits of QPSK mode; means for delaying the quantized signal from the phase sector quantization means; and means for determining un-coded data by using the delayed quantized signal and the determined coded data, wherein a relation of the I-axis coordinate and the Q-axis coordinate with a phase of the received signal is determined by a rotational transformation using the phase of the received signal, wherein said rotational transformation using the phase of the received signal is determined by: x′ =√{square root over (2)} cos(2(φ−φ)) y′ =√{square root over (2)} sin(2(φ−φ)), wherein x′ and y′ are coordinates of input symbols for converting the received signal to the signal bits of QPSK mode, φ is a phase rotation constant and φ is a phase of the received signal, and wherein said means for determining the coded data by decoding the signal bits of QPSK mode includes: a first decoding unit configured to decode the signal bits of QPSK mode; and a second decoding unit configured to decode an output of the first decoding unit.