Abstract: Disclosed is a V-BLAST system for a MIMO communication system. In the V-BLAST system for a MIMO communication system, a pseudo inverse matrix calculator receives a channel transfer function matrix including channel information and produces a cofactor matrix and a determinant for a pseudo inverse matrix. A norm & minimum calculator calculates a minimum index for the cofactor matrix outputted from the pseudo inverse matrix calculator, a weight vector selector selects a row vector having the minimum index and calculates a transposed matrix for the row vector; an adder adds the transposed matrix to a received input symbol, and a subtractor subtracts the determinant to the output. A demapper performs a determined function operation to the output and produces estimated information.

Abstract: Disclosed is an apparatus for performing both FHT (Fast Hadamard Transform) and FFT (Fast Fourier Transform). This apparatus determines the phase coefficients as constantly “1” when performing the FHT, and changes the input order of input data to a reverse order of bits when performing the FFT. In addition, the apparatus, which can process a plurality of input data sets simultaneously, classifies the received signals into multi-path signals and multi-antenna signals, thus processing the multi-path signals separately from the multi-antenna signals, or directly processes multi-antenna signals.

Abstract: Provided is a normalizing apparatus for adaptive beamforming by performing a normalizing process which uses a normalized least mean square (NLMS) algorithm that produces a weight vector for adaptive beamforming, in a smart antenna receiver. For the normalizing process, the normalizing apparatus includes a multiplication operation means that performs a multiplication operation, and a division operation means that performs a division operation using mathematic calculations based on binary logarithm principles, and using addition and subtraction operations.

Abstract: There is provided an adaptive loop gain control circuit for a voltage-controlled oscillator (VCO). The adaptive loop gain control circuit for a voltage-controlled oscillator (VCO) includes a detected voltage generating unit which generates a detected voltage signal according to changes in an operating voltage and an operating temperature, and a control circuit unit which outputs an oscillation control current signal according to the detected voltage signal and an input control voltage signal. The adaptive loop gain control circuit for a voltage-controlled oscillator (VCO) compensates for an oscillation control current according to changes in operating voltage and temperature and compensates for the gain of a phase locked loop (PLL) system, thereby ensuring high operating stability in the PLL circuit.

Abstract: Provided is a normalizing apparatus for adaptive beamforming by performing a normalizing process which uses a normalized least mean square (NLMS) algorithm that produces a weight vector for adaptive beamforming, in a smart antenna receiver. For the normalizing process, the normalizing apparatus includes a multiplication operation means that performs a multiplication operation, and a division operation means that performs a division operation using mathematic calculations based on binary logarithm principles, and using addition and subtraction operations.

Abstract: The present invention reduces complexity of computation as about 40% comparing to the conventional depth first tree search method. A method for searching an algebraic codebook in algebraic code excited linear prediction (ACELP) vocoding using a depth first tree method, includes the steps of: a) searching branches of predetermined levels to predict a branch in which optimum pulse is located; b) choosing a predetermined number of branches according to the search result of the step a) and removing residual branches; and c) searching the chosen branches and choosing optimum algebraic code.

Abstract: There is provided an adaptive loop gain control circuit for a voltage-controlled oscillator (VCO). The adaptive loop gain control circuit for a voltage-controlled oscillator (VCO) includes a detected voltage generating unit which generates a detected voltage signal according to changes in an operating voltage and an operating temperature, and a control circuit unit which outputs an oscillation control current signal according to the detected voltage signal and an input control voltage signal. The adaptive loop gain control circuit for a voltage-controlled oscillator (VCO) compensates for an oscillation control current according to changes in operating voltage and temperature and compensates for the gain of a phase locked loop (PLL) system, thereby ensuring high operating stability in the PLL circuit.

Abstract: A region searcher, a method of driving the same, and a code searcher using the same are disclosed. When a predetermined region is iteratively searched, the energy value corresponding to the same hypothesis location value is stored by using a searcher having divided two buffers, thereby the implementation complexity thereof can be remarkably reduced, without using a simple memory.

Abstract: A multipath searching apparatus for searching a short-delay multipath in a spread spectrum communications system and a method thereof are provided.

Abstract: In the apparatus and method for separating carrier of multicarrier wireless communication receiver system, each carrier separation is performed after a quantization in a wireless communication receiver system such as a received multicarrier CDMA (Code Division Multiple Access) etc., to thereby reduce the whole number of quantizers and separate multicarrier from a received signal.

Abstract: The present invention relates to a tuning circuit, more specifically to a tuning circuit for continuous-time filter capable of making exact the Gm value to minimize the variation of the cutoff frequency due to the variation of process in the Gm-C type of continuous-time filter.

Abstract: A nibble inversion and block inversion code coding and decoding method and a coding and decoding apparatus for the same.

Abstract: A CMOS high frequency variable gain amplifier with maximum high frequency operation and wide variable gain characteristics that is formed from an amplifier having a plurality of variable gain amplifier cells connected in series for continuously enabling wide gain variation; and a control voltage generator for generating and outputting the control voltage of the variable gain amplifier cells. By using both the saturation region and the linear region of input differential transistors constituting the variable gain amplifier cells in order to obtain wide gain variation characteristics, it is possible for the variable gain amplifier to operate in the saturation region when the input signal is small to obtain a high gain and to operate in the linear region when the input signal is large to obtain minimum distortion and a low gain. Also, it is possible for the gain to have the characteristics in the form of an exponential function to the gain control voltage.

Abstract: An improved data retiming circuit which is capable of more effectively retiming an externally inputted data by using a plurality of clocks from a voltage controlled oscillator of a phase-locked loop.

Abstract: The present invention relates to a fault detection and automatic recovery apparatus of write-read pointers in FIFO. While storing effective data in a register in writing performance, the apparatus does not unconditionally enable a FULL.sub.-- FLAG signal allotted to the register but confirms the relation of write-read pointers at that time and the EMPTY.sub.-- FLAG signal of a register at which the read pointer is situated and detects the error of FIFO. By selectively enabling the FULL.sub.-- FLAG signal of the register according to the result of detection, it automatically restores the FIFO functions without unnecessary re-initialization or the discontinuation of data transmission attributable thereto.