| 摘要 |
An apparatus and a method for calculating channel quality information per stream in an MIMO(Multiple Input Multiple Output) wireless communication system are provided to generate per stream CQI(Channel Quality Information) for a CL(Closed Loop) scheme in an MIMO wireless communication system. A receiving end includes a plurality of radio frequency receivers(302-1 to 302-N), an MIMO detector(304), a channel estimator(306), and a CQI generator(308). The RF receivers each convert an RF signal received via respective antennas to a baseband signal. The MIMO detector detects the transmit signals per stream from the received signals output from the RF receivers. The detection manner of the MIMO detector differs according to various implements. The CQI generator generates per stream channel quality information using the channel information output from the channel estimator. The CQI generator includes a channel transformer, an LR operator, a classifier, a first SER calculator, a second SER calculator, an SINR converter, a rate adder, and a CQI determiner. The channel transformer generates a list of the possible modulation combinations and scales the channel matrixes output from the channel estimator according to the modulation combinations. The classifier checks whether the lattice reduction matrixes corresponding to the modulation combinations are the unit matrix or not. When the lattice reduction matrix is the unit matrix, the classifier outputs information of the corresponding modulation combination to the first SER calculator. When the lattice reduction matrix is not the unit matrix, the classifier outputs information of the corresponding modulation combination to the second SER calculator. The first SER calculator calculates the upper boundary of the per stream SER in the first manner for the unit matrix. In doing so, how to calculate the upper boundary of the per stream SER differs depending on the detection scheme adopted for the signal detection. |
