Abstract:
일실시예에 따르면, 각 셀의 기지국 또는 송신부에서 다른 셀의 간섭을 고려하지 않고 주파수 대역에 대응하는 송신부에 송신 전력을 할당할 수 있다. 다음으로, 우선권이 부여된 주파수 대역에 대응하는 수신부에 미리 정해진 목표 전송량이 전송되하도록 빔포밍 벡터를 생성할 수 있다. 다음으로, 채널 피드백이 부정확할 경우의 간섭을 고려하여 송신 전력을 조절할 수 있다. 일실시예에 따르면, 제1 셀부터 우선권을 갖는 수신기에 미치는 간섭을 고려하여 송신 전력을 결정하고 앞선 과정에서 할당된 전력과 비교하여 남는 전력을 다른 주파수 대역으로 넘겨줘 총 전송량을 높일 수 있다.
Abstract:
본 발명은 DSTTD(Double Space Time Transmit Diversity) 시스템에서 수신신호를 검출하는 방법에 있어서, 잡음 에너지와 기준 부반송파에게 제1범위에 포함된 인접 부반송파들이 미치는 간섭의 에너지 합인 제1계수를 계산하고, 상기 제1계수를 적용한 제1Unbiased-MMSE(Minimum Mean Squared Error) DF(Decision Feedback)방식을 사용하여 상기 기준 부반송파로부터 수신된 제1신호를 검출하는 과정과, 상기 제1신호에서 상기 기준 부반송파를 기준으로 전후 미리 결정된 인접 부반송파들의 수인 제2범위를 사용하여 상기 기준 부반송파에게 상기 제2범위에 포함된 인접 부반송파들이 미치는 간섭의 에너지 합인 제2계수를 계산하고, 상기 제2계수가 적용된 제2Unbiased-MMSE DF방식을 사용하여 상기 기준 부반송파로부터 수신된 제2신호를 검출하는 과정을 포함하며; 상기 제1범위는 신호를 검출하고자 하는 기준 부반송파로부터 간섭이 미리 정해진 기준 이상인 간섭을 갖는 부반송파들의 수임을 특징으로 한다. 신호 검출, 이중 시공간 송신 다이버시티, 직교주파수 멀티플렉싱, 다중 안테나
Abstract:
PURPOSE: Secure transmission amount calculation method and system using a relative distance variable in a wireless network in which a secure section exists are provided to calculate more realistic secure transmission amount by considering a relative distance between receiver and tapping node based on a transmitter. CONSTITUTION: A secure transmission amount calculation system determines a relative distance variable based on a radius of secure region and a distance between transmitter and receiver (401). The secure transmission amount calculation system determines optimal electric power distribution variable in a closed form (402). The secure transmission amount calculation system calculates a secure transmission amount by finding the optimal electric power distribution variable (403). [Reference numerals] (401) Determine a relative distance variable; (402) Determine an optimal electric power distribution variable; (403) Determine optimal secure transmission amount; (AA) Radius of a secure region(d_zone); (BB) Distance between a transmitter and a receiver(d_R); (CC) Secure transmission amount is closed; (DD) Disperse channel electric power; (EE) Secure transmission amount
Abstract:
PURPOSE: A transceiving method in a multiple antenna system for reducing necessary computational complexity in selection or the quantization of a coding word is provided to remove interference between multi users by quantizing error. CONSTITUTION: A transmitter receives a codebook index from a plurality of terminals(300). The transmitter selects the k terminal of a plurality of terminals(302). The transmitter generates the precoder matrices P put through to the codebook index of the selected terminal(304). The transmitter performs precoding(306). The transmitter transmits the transmission signal of which the precoding is performed for the first time slot(308).
Abstract:
A method for transmitting and receiving data including an impulse symbol for estimating a channel in a MIMO(Multiple Input Multiple Output) OFDM(Orthogonal Frequency Division Multiplexing) and an IP(Impulse Postfix) OFDM system of an MIMO method are provided to improve channel estimation performance by using an orthogonal impulse in each channel. An IP OFDM system of an MIMO method includes a transmitter. A serial to parallel transform unit(101) converts the serially inputted data symbol to the parallel data symbol. An STBC/SFBC encoder(102) encodes the parallel data symbol inputted from the serial to parallel converter through one of STBC(Space-Time Block Coded) or SFBC(Space-Frequency Block Coded) method and comprises the signal. An IFFT(Inverse Fast Fourier Transform) unit(103) performs IFFT of data encoded in the STBC/SFBC encoder and converts the data into the signal in a time axis. A parallel to serial transform unit(104) converts data transformed in the IFFT unit into the serial data. An IP insertion unit inserts the impulse symbol for estimating the channel into a guard interval in a time axis of the data converted to the time domain.
Abstract:
A low-complexity signal detection apparatus based on the UITS in an MIMO system and a method thereof are provided to make easy combination with different tree search algorithms possible. A detector forms a tree structure corresponding to the degree of modulation by applying the QR decomposition to a channel matrix(203), determines the number of candidate symbols according to an SNR(Signal-to-Noise Ratio)(205), separates the whole tree depth into the first tree depth and the rest tree depth(207), and then determines candidate symbols as many as the number determined in the first tree depth(209).
Abstract:
A method for predicting a wireless channel in a wireless communication system, and an apparatus thereof are provided to accurately calculate the beamforming or precoding weight of a transmitter through the prediction of a downlink channel using the Kalman filter in a TDD system. A method for predicting a wireless channel in a wireless communication system comprises the following steps of estimating the current uplink channel; predicting the current uplink channel from an estimated predetermined previous uplink; and predicting the next downlink channel from the uplink channel prediction. The process of predicting the current uplink channel from the estimated previous uplink is implemented by the following steps. The predetermined previous uplink channel predictive value is filtered to predict the current uplink channel. A parameter for correcting the predicted uplink channel is calculated. The uplink channel value is corrected by using the parameter.