Patent application number | Description | Published |
20090052593 | LOG LIKELIHOOD RATIO CALCULATION METHOD, TRANSMIT SIGNAL DETECTION METHOD, AND RECEIVER - The present invention relates to a log-likelihood ratio calculation method, a transmitting signal detection method, and a receiver. The present invention estimates a channel on the basis of the received signal and rearranges a plurality of layers. Further, at the time of rearrangement of the layers, a symbol of a layer having the lowest reliability is considered for every constellation dot, and the successive interference for the remaining layers is removed corresponding to the constellation dots of the layer having the lowest reliability to set the transmitting symbol candidate vector. Furthermore, a log-likelihood ratio for every bit of the plurality of layers is calculated using the transmitting symbol candidate vector to decode the channel. | 02-26-2009 |
20090060069 | SIGNAL TRANSMITTING APPARATUS, METHOD THEREOF, AND INVERSE FAST FOURIER TRANSFORM APPARATUS FOR SIGNAL TRANSMITTING APPARATUS - The present invention relates to a signal transmitting apparatus, a method thereof, and an inverse fast Fourier transform (IFFT) apparatus for a signal transmitting apparatus. A signal transmitting apparatus according to an embodiment of the present invention receives data, and performs inverse fast Fourier transform (IFFT) on the data on the basis of a twiddle factor for shifting output data by the size of a cyclic prefix. In addition, the signal transmitting apparatus sequentially stores data corresponding to the size of the cyclic prefix starting with initial data among the transformed data, and generates an OFDM symbol on the basis of the stored data and the transformed data. According to the embodiment of the present invention, it is possible to efficiently reduce a time delay and a memory use amount when a cyclic prefix is added at a transmitting end, without changing the size of hardware and power consumption. | 03-05-2009 |
20090135947 | METHOD OF SELECTING CANDIDATE VECTOR AND METHOD OF DETECTING TRANSMISSION SYMBOL - The present invention relates to a method of detecting a candidate vector and a method of detecting a transmission symbol using the same. According to an embodiment of the present invention, in a multiple input multiple output (MIMO) system using spatial multiplexing (SM), a receiver selects candidate vectors corresponding to a layer located at a last row among a plurality of rearranged layers, and sequentially ranks constellation dots of a next layer for each of the selected candidate vectors. Then, a plurality of arbitrary constellation dots are selected from the ranked constellation dots, accumulated costs of the arbitrary constellation dots are calculated, and a candidate vector is selected in correspondence with a constellation dot having a minimal accumulated cost. Then, a new arbitrary constellation dot is selected in place of the constellation dot selected as the candidate vector, an accumulated cost of the selected arbitrary constellation dot is compared with accumulated costs of the other arbitrary constellation dots, and another candidate vector is selected. | 05-28-2009 |
20090135964 | METHOD OF CALCULATING LOG-LIKELIHOOD RATIO AND METHOD OF DETECTING TRANSMISSION SIGNAL - The present invention relates to a method of calculating a log-likelihood ratio and a method of detecting a transmission signal. According to the present invention, when a transmission symbol candidate vector is detected on the basis of a received signal, a threshold value and an ML metric of each transmission symbol candidate vector are calculated and the ML metric that is larger than the threshold value is updated by the threshold value. Further, a log-likelihood ratio of the transmission signal bit is calculated using the updated ML metric and the threshold value, and a transmission signal is detected using the log-likelihood ratio. | 05-28-2009 |
20090141786 | APPARATUS AND METHOD OF ESTIMATING SIGNAL-TO-NOISE RATIO - The present invention relates an apparatus and method of estimating a signal-to-noise ratio (SNR) of a received signal when the received signal has a timing offset. An apparatus for estimating a signal-to-noise ratio (SNR) according to an exemplary embodiment of the present invention includes a fast Fourier transform (FFT) unit that performs a fast Fourier transform on a received signal to convert the received signal into a frequency domain signal; a preamble selector that extracts a preamble from the frequency domain signal; a correlator that correlates the preamble to a preamble reference signal generated by a receiver to calculate a correlation value; an entire power estimator that calculates entire power; a noise power estimator that applies a differential demodulation method to the correlation value to remove a timing offset and calculate noise power; and an estimating unit that uses the entire power and the noise power to estimate the signal-to-noise ratio (SNR). | 06-04-2009 |
20090147887 | METHOD OF CALCULATING SOFT VALUE AND METHOD OF DETECTING TRANSMISSION SIGNAL - The present invention relates to a method of calculating a soft value and a method of detecting a transmission signal. The present invention estimates a channel on the basis of a received signal and rearranges a plurality of data streams. Further, a plurality of substitute vectors are selected from the rearranged data streams and a metric corresponding to each of the substitute vector is calculated. Further, a threshold value is calculated from a metric calculated for each of the substitute vectors and a soft value of each bit of a transmission signal is calculated from the metric and threshold value corresponding to each of the substitute vectors. | 06-11-2009 |
20090147892 | METHOD AND APPARATUS FOR CANCELING INTERFERENCE - An apparatus for canceling interference includes a plurality of converters, a plurality of interference cancellation units, a plurality of variance detectors, and an output selecting unit. The plurality of converters converts a plurality of received signals to a plurality of frequency domain signals, respectively. The plurality of interference cancellation units cancel interference in the plurality of frequency domain signals using a plurality of interference cancellation schemes to generate a plurality of interference-canceled signals corresponding to the plurality of interference cancellation schemes, respectively. The plurality of variance detectors measure a plurality of amounts of residual interference corresponding to the plurality of interference-canceled signals, respectively. The output selecting unit selects a single interference-canceled signal with the least amount of residual interference from the plurality of interference-canceled signals, based on the plurality of amounts of residual interference. | 06-11-2009 |
20090147894 | METHOD FOR DETECTING TRANSMISSION SYMBOLS IN MULTIPLE ANTENNA SYSTEM - The present invention relates to a transmission symbol detection method in a multiple antenna system. In the present invention, when a channel matrix is estimated through channel estimation, a receiving side calculates a Q matrix and an R matrix through QR decomposition that is more simplified than a typical QR decomposition from an augmented channel matrix that includes the estimated channel matrix. In addition, the receiving side detects symbols having the minimum Euclidean metric by using the two matrixes, as transmission symbols. | 06-11-2009 |
20090154540 | METHOD AND APPARATUS FOR ESTIMATING CHANNEL IN MOBILE COMMUNICATION NETWORK - The present invention relates to a method and apparatus for estimating a channel in a mobile communication network. In particular, the present invention relates to a method of estimating a channel under a channel environment where interference between neighboring base stations exists in a mobile communication network using an orthogonal frequency division multiplexing (OFDM) method. In order to estimate a channel, one cluster is divided into two sub-clusters, and pilot sub-carrier signals included in at least one sub-cluster in an OFDM symbol direction are used. Therefore, it is possible to further improve performance as compared to a method of estimating a channel by using pilot sub-carriers included in one cluster. | 06-18-2009 |
20090157787 | ROW-VECTOR NORM COMPARISON METHOD AND ROW-VECTOR NORM COMPARISON APPARATUS FOR INVERSE MATRIX - Disclosed are a row-vector norm comparison method and a row-vector norm comparison apparatus for an inverse matrix. A row-vector norm comparison apparatus includes: an input matrix processing module that receives and combines constituent elements of a matrix; a cofactor operation module that multiplexes the combination result of the constituent elements to calculate factors constituting an adjoint matrix; a square calculation module that squares the calculated factors; a summation module that selects a predetermined number of factors among the squared factors and sums the selected factors to calculate the norms of row vectors in an inverse matrix; and a norm comparison module that outputs a comparison result of the calculated norms of the row vectors. A row-vector norm comparison method includes: combining constituent elements of a matrix to generates a plurality of combination results of the constituent elements; multiplexing the combination results to calculate factors constituting an adjoint matrix of the matrix; squaring the calculated factors and selectively summing the squared factors; and calculating the norms of row vectors in an inverse matrix and comparing the calculated norms of the row vectors. With this configuration, row-vector norm comparison for an inverse matrix can be performed with a design structure. Therefore, it is not necessary to use an existing complex operation method. In addition, low power consumption of the multiple antenna system can be achieved, and efficiency of the design structure can be improved. | 06-18-2009 |
20100124301 | METHOD FOR RE-ORDERING MULTIPLE LAYERS AND DETECTING SIGNAL OF WHICH THE LAYERS HAVE DIFFERENT MODULATION ORDERS IN MULTIPLE INPUT MULTIPLE OUTPUT ANTENNA SYSTEM AND RECEIVER USING THE SAME - Disclosed are a method for re-ordering multiple layers and detecting signals and a receiver using the same to be able to exert performance approaching a maximum likelihood scheme while having lower complexity than that of the maximum likelihood scheme in a multiple input multiple output (MIMO) antenna system in a form where each layer is modulated and transmitted with different modulation orders. | 05-20-2010 |
20100135438 | SIGNAL DETECTION METHOD AND RECEIVER - Disclosed is a method of detecting signals at a receiver of a communication system with a multiple input multiple output antenna. With the signal detection method, a square of the distance between a received signal vector and a channel status-considered transmission symbol vector is calculated first, and the square of the distance is then classified into first and second components. The first component is minimized to calculate a plurality of first soft symbol estimates. A solution set of the first component is calculated on the basis of the plurality of first soft symbol estimates. The second component is minimized to calculate a plurality of second soft symbol estimates. A solution set of the second component is calculated on the basis of the plurality of second soft symbol estimates. A final solution set is calculated by doing the sum of the first component solution set and the second component solution. | 06-03-2010 |
20100142654 | METHOD AND APPARATUS FOR SIGNAL DETECTION BASED ON MMSE IN MIMO COMMUNICATION SYSTEM - In a multi-input multi-output communication system receiving signals transmitted through a plurality of transmission antennas by using a plurality of reception antennas, a matrix determining a position of a symbol to be detected from a received signal is calculated at a first symbol detection step, and from the subsequent step, a matrix at the current step is acquired through a simple relationship from the matrix calculated at the previous step to determine a position of a symbol to be detected. | 06-10-2010 |
20100142656 | APPARATUS AND METHOD FOR SIGNAL DETECTION USING LOG LIKELIHOOD RATIO - A method for signal detection using a log likelihood ratio in a multi-input multi-output communication system includes reconfiguring the signals received through the reception antennas on the basis of channel characteristics and acquiring candidate groups for each transmission symbol by acquiring a signal constellation of one quadrant with respect to signals generatable for each transmission symbol and signal constellations for the remaining quadrants on the basis of the reconfigured signals. | 06-10-2010 |
20100142661 | DEVICE FOR GAIN CONTROL AND METHOD FOR RECEIVING SIGNAL - The present invention relates to a device for gain control and a method for receiving a signal. The device for gain control according to the present invention includes a map interpreter that detects beamforming symbol periods in wireless signals, a power calculator that calculate the average power of the beamforming symbol periods in response to outputs of the map interpreter, a gain calculator that calculates gain control signals on the basis of the output signals of the power calculator, and a switch that outputs gains from the gain control signals, in which the wireless signals are corrected on the basis of the gains. | 06-10-2010 |
20100157982 | TRANSMITTER AND METHOD FOR TRANSMITTING AND RECEIVING OF VOICE DATA FOR VOIP SERVICE - Provided are a transmitting apparatus and voice data transmitting and receiving methods for providing VoIP services. When a call is started and an analog signal including a voice signal is input, the transmitting apparatus divides the analog signal into a plurality of voice data packets for transmission. Here, the plurality of voice data packets are generated by sampling with different phases in the same frequency. In addition, the transmitting apparatus inserts a time indication bit that is changed every transmission period into each of the voice data packets and transmits the voice data packets, and distinguishes voice data corresponding to a current transmission period based on the time indication bit. | 06-24-2010 |
20100246548 | BASE STATION, METHOD FOR MANAGING CELL, METHOD FOR DETECTION SIGNAL, TERMINAL AND METHOD FOR TRANSMITTING SIGNAL THEREOF - A base station according to an exemplary embodiment of the present invention includes: a receiver receiving environment information of a first terminal from the first terminal positioned at a cell boundary and receiving usable resource information from a neighbor base station; a resource allocator allocating a resource to the first terminal on the basis of the usable resource information; and a transmitter transmitting information on the resource allocated to the first terminal to the neighbor base station. | 09-30-2010 |
20100272205 | METHOD FOR DETECTING SIGNAL, DEVICE FOR DETECTING SIGNAL, AND RECEIVING DEVICE - The present invention relates to a method for detecting a signal, a device for detecting a signal, and a receiving device. A method for detecting a signal according to the present invention is a method for detecting a signal from a receiving device in a communication system including a multi-output multi-input antenna, including: estimating a channel matrix of a signal received from a plurality of receiving antennas; generating at least one channel matrix groups by aligning the channel matrix and generating at least one transmitting signal group by aligning a transmitting signal to be estimated to correspond thereto; determining a first candidate vector in consideration of all constellation points for a first layer of the at least one transmitting signal group; determining a second candidate vector in consideration of all constellation points for a second layer of the at least one transmitting signal group; generating a final candidate vector including the first candidate vector and the second candidate vector; and calculating a soft output using the final candidate vector. | 10-28-2010 |
20110103521 | METHOD AND APPARATUS FOR DECOMPOSING RECEIVED SYMBOL SIGNAL MODULATED WITH BIT REFLECTED GRAY CODE IN BIT INFORMATION - Disclosed is a method and apparatus for composing a received symbol signal modulated with a bit reflected Gray code into bit information. According to an embodiment of the present invention, a positive integer of the received symbol signal having bits is assigned according to the Gray mapping rule, and a sign is determined. A value that is indicative of an arrangement of the bits constituting the received symbol signal is calculated. A boundary value in at least one bit group consisting of the bits constituting the received symbol signal is acquired, and a difference from an absolute value of the received symbol signal is calculated. The received symbol signal is converted into information per bit using a value of the received symbol signal based on the positive integer and the determined sign, the value that is indicative of the bit arrangement, and the difference from the absolute value. Therefore, it is possible to reduce complexity in bitwise decomposition for an iterative decoder inevitably used in a receiver. | 05-05-2011 |
20110141962 | METHOD AND APPARATUS FOR DEMODULATING MULTICAST SIGNAL - An apparatus for demodulating signals received from a plurality of base stations including a serving base station and a neighbor base station determines start timings of a serving cell signal transmitted from the serving base station and neighbor cell signals transmitted from the neighbor base stations, and verifies whether or not the neighbor cell signals that are earlier than the serving cell signal are provided on the basis of the determined start timings. Next, the apparatus selects a section where the reception energy of the symbol has the maximum level among symbols corresponding to signals of frames corresponding to the signals, respectively, as a demodulation section, and demodulates a multicast signal including the received signals on the basis of the selected demodulation section. | 06-16-2011 |
20110286500 | SYNCHRONIZATION DEVICE AND METHOD OF RADIO-FREQUENCY REPEATER - A synchronization method of a radio repeater includes: using a first signal, a second signal, and a received signal including the first signal and the second signal to calculate correlation values of the first signal and the second signal; using the first signal correlation value, the second signal correlation value, and the power value of the received signal to output normalized correlation values; subtracting the normalized correlation value of the first signal and the normalized correlation value of the second signal; and detecting a start interval of the second signal based on the subtraction result and outputting a synchronization signal to synchronize the radio repeater. | 11-24-2011 |
20120230216 | COMMUNICATION METHOD - A mobile station and a base station communicate with each other using a frame including one or more downlink subframes and one or more uplink subframes. The base station begins the transmission of a data burst in a subframe corresponding to a downlink subframe index. The mobile station transmits feedback for the data burst to the base station in a subframe corresponding to an uplink subframe index. If the frame uses a time division duplex scheme, the uplink subframe index is determined by at least using the downlink subframe index and the parameter value. | 09-13-2012 |
20120275355 | METHOD AND APPARATUS FOR RESOURCE ALLOCATION AND METHOD AND APPARATUS FOR RECEIVING RESOURCE ALLOCATION INFORMATION SIGNAL - A method of allocating a resource by a base station is provided. The base station allocates a plurality of radio resources for transmitting a plurality of data bursts to a plurality of subframes in one frame, respectively, and generates a resource allocation information signal including allocation information on the plurality of radio resources. The base station transmits the resource allocation information signal to a mobile station through one subframe. | 11-01-2012 |
20120327882 | BASE STATION, MOBILE STATION, MIMO FEEDBACK RECEIVING METHOD, AND MIMO FEEDBACK TRANSMITTING METHOD - A mobile station receives a MIMO feedback mode bitmap and information on a MIMO feedback period. The mobile station estimates channel information corresponding to at least one MIMO feedback mode indicated by the MIMO feedback mode bitmap. The mobile station generates a MIMO feedback including the MIMO feedback mode bitmap and the channel information corresponding to the at least one MIMO feedback mode indicated by the MIMO feedback mode bitmap. The mobile station transmits the MIMO feedback at the advent of the MIMO feedback period. | 12-27-2012 |
20130004185 | OPTICAL REPEATER AND SIGNAL RELAY METHOD THEREOF - An optical repeater in a mobile communication system includes a main hub unit (MHU) and a plurality of repeaters connected to a plurality of access points of the MHU, respectively. Each of the repeaters receives subcarrier information and a signal transmitted from a base station, as optical signals, through the MHU or a different repeater connected thereto, processes only a signal corresponding to a subcarrier allocated to a terminal which has accessed according to the subcarrier information, and transmits the processed signal to the terminal which has accessed. Also, each of the repeaters maps a signal of the terminal which has accessed to a subcarrier allocated to the terminal which has accessed, and transmits the same to the MHU or a different repeater connected thereto. | 01-03-2013 |
20130121248 | WIRELESS BASE STATION AND METHOD OF PROCESSING DATA THEREOF - A clustering wireless base station includes a group digital processor including a plurality of digital units (DU) and a plurality of remote radio frequency units (RRU) that are connected to the group digital processor through a transport network and that are installed in each service target area. In this case, each DU includes a decoder that decodes upward data that is received from the each DU, and each RRU includes an encoder that encodes downward data from the each DU. | 05-16-2013 |
20130308464 | METHOD AND APPARATUS FOR ADJUSTING HARQ TIMING - A method for adjusting a hybrid automatic repeat request (HARQ) timing is provided. A base station adjusts a HARQ timing of a mobile station according to a system environment, and transmits radio resource allocation information including the adjusted HARQ timing information to the mobile station. The mobile station adjusts HARQ timing according to HARQ timing information, and transmits a HARQ signal according to the adjusted HARQ timing. | 11-21-2013 |
20140003416 | METHOD AND APPARATUS FOR ACQUIRING UPLINK AND DOWNLINK SYNCHRONIZATION BETWEEN A PLURALITY OF BASE STATIONS AND A TERMINAL IN A COOPERATIVE COMMUNICATION NETWORK | 01-02-2014 |
20140301495 | SYSTEM FOR TRANSMITTING AND RECEIVING MULTI-INPUT MULTI-OUTPUT AND METHOD FOR TRANSMITTING AND RECEIVING MULTI-INPUT MULTI-OUTPUT USING THE SAME - Provided is a method for transmitting and receiving multi-input multi-output in a wireless backhaul network, including: selecting at least one pair of dual-polarized transmitting antennas to be activated among pairs of dual-polarized transmitting antennas of a transmitter; transmitting a signal through the selected pairs of dual-polarized transmitting antennas; and receiving, by pairs of dual-polarized receiving antennas of a receiver, the signal transmitted from the transmitter. | 10-09-2014 |
20140355521 | INTELLIGENT MULTIPLE ACCESS COMMUNICATION CONTROL APPARATUS AND METHOD - An intelligent multiple access communication (MAC) control apparatus and method are disclosed. The intelligent MAC control apparatus includes a connection control unit, a resource management unit, a session control unit, a flow control unit, and a determination unit. The connection control unit connects at least one Radio Access Technology (RAT) and a wireless network. The resource management unit collects RAT information including information about available resources and radio state of the RAT. The session control unit checks the QoS of at least one connection target service. The flow control unit determines the priority of the connection target service, and selects a preferential connection target service. The determination unit determines a connection RAT for performing the preferential connection target service based on the QoS and the RAT information. | 12-04-2014 |