Patent ID: 8107563

Claim:
A receiving apparatus for estimating symbols of a receiving signal vector including a plurality of symbols in a multiple input and multiple output (MIMO) system, the receiving apparatus comprising: a QR decomposing means for calculating a single (Q) matrix vector and an upper triangle (R) matrix vector for the receiving signal vector; a first symbol estimation means for estimating predetermined symbols of the plurality of symbols using the calculated Q matrix vector and R matrix vector; a log likelihood ratio (LLR) calculating means for calculating log likelihood ratios of unit bits for the estimated symbols; a decoding means for decoding the estimated symbols from the first symbol estimation means using the calculated log likelihood ratios calculated by the LLR calculating means; an interference removing means for receiving a decoded signal that is decided using the calculated log likelihood ratios and removing interference from the receiving signal vector; and a second symbol estimation means for linearly estimating remaining symbols of the plurality of symbols excluding the predetermined symbols using the interference removed signal produced by the interference removing means, wherein the decoding means further decodes the estimated remaining symbols from the second symbol estimation means, and outputs the decoded estimated symbols from the first and second symbol estimation means.