Patent application number | Description | Published |
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 |
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 |
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 |
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 |
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 |
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 |
20150140940 | APPARATUS FOR TRANSMITTING MULTIPLE STREAMS AND METHOD FOR TRANSMITTING MULTIPLE STREAMS - Disclosed is an apparatus for transmitting multiple streams, including: a polarized wave control unit generating non-orthogonal polarization information for three or more input streams; a polarized wave generating unit polarizing three or more input streams in a baseband based on the non-orthogonal polarization information to generate vertical and horizontal polarization components; and a polarized wave transmitting unit transmitting the plurality of vertical and horizontal polarization components through dual polarization antennas. | 05-21-2015 |
Patent application number | Description | Published |
20080209298 | Decoding Apparatus and Method Thereof - In a decoding apparatus in a portable Internet terminal, a channel encoded symbol received from a transmitter is decoded by one of a chase-combining scheme and a code-combining scheme selected based on an ID value of the subpacket indicating a start position of the symbol. In this case, the chase-combining scheme is partly used for the encoded symbol of the information bit. With such a mode, decoding can be performed at a low code rate. | 08-28-2008 |
20080287078 | Terminal and Method for Controlling Transmission Power - A terminal of a communication system includes a power amplifier, an open-loop power controller, a gain controller, a modulator, and a digital/analog converter. The power amplifier amplifies transmission power of a transmission signal. The open-loop power controller measures a received signal strength to control the transmission power, and increases a gain of the power amplifier according to the received signal strength. The gain controller sets a power concentration gain and applies the power concentration gain to the transmission signal when the gain of the power amplifier is maximized. The modulator modulates the transmission signal. The digital/analog converter converts an input signal to an analog signal. The gain controller applies the power concentration gain to the trans mission signal modulated by the modulator, and transmits the power concentration gain to the digital/analog converter. | 11-20-2008 |
20090225704 | UPLINK TILE INDEX GENERATION APPARATUS AND A UPLINK SUBCHANNEL ALLOCATION APPARATUS OF AN OFDMA SYSTEM - A tile index generation apparatus for allocating subchannels of a control channel and a diversity channel, a subchannel allocation apparatus for allocating subchannels of a diversity channel, and a subchannel allocation apparatus for allocating subchannels of an adaptive modulation coding (AMC) channel, which are used for an uplink of an orthogonal frequency division multiplexing access (OFDMA) system, are provided. With these subchannel allocation apparatuses, optimum designs for the uplink subchannel allocation in the OFDM scheme can be provided to a modulator of a subscriber station and a demodulator of a base station, and so the uplink subchannel allocation apparatus has a simple structure and an enhanced transmission speed. | 09-10-2009 |
20090231992 | METHOD FOR DESIGNING OPERATION SCHEDULES OF FFT AND MIMO-OFDM MODEM THEREOF - The present invention provides a method for designing operation schedules of a fast Fourier transform (FFT) and a multiple input multiple output orthogonal frequency division multiplexing modem (MIMO-OFDM modem) thereof. According to the present invention, an operation speed of an FFT operator is set up, a receiving symbol is arranged in an OFDM symbol duration in an FFT after receiving the symbol, a transmitting symbol is arranged in an OFDM symbol duration in the FFT schedule before transmitting the symbol, a transmitting/receiving symbol which has the same timing is inserted into an idle symbol duration of the FFT schedule, an FFT schedule which is good to be deleted is deleted, and symbols of the deleted FFT schedule are re-arranged in order to not have an error occur in transmitting/receiving timing. According to the present invention, the FFT operation and the IFFT operation are processed by one FFT/IFFT operator in the MIMO-OFDM modulation/demodulation apparatus, so that symbols to be modulated/demodulated may be properly scheduled, a minimum number of FFT/IFFT operators may be needed, and a delay of data processing may be minimized. | 09-17-2009 |
20100061223 | SUBCARRIER ALLOCATION APPARATUS AND METHOD, SUBCARRIER DE-ALLOCATION APPARATUS AND METHOD IN OFDM SYSTEM - A subcarrier allocating apparatus allocating data to be transmitted to a plurality of orthogonal subcarriers in an orthogonal frequency division multiplexing (OFDM) system, the apparatus including: a logical index generator ( | 03-11-2010 |