| Patent application number | Description | Published |
|---|
| 20080232437 | Base Station Transmitter For Mobile Telecommunication System, Method For That System - The present invention relates to a transmit diversity method of a mobile communication system and a base station transmitting apparatus using the same. A first code and a second code that is diversity-encoded from the first code are generated, and transmit symbols are spread with the first code and the second code. A first transmit symbol spread with the first code and a second transmit symbol spread with the second code are mapped to symbols in frequency and time domains in a frame and transmitted through antennas. Therefore, various diversity techniques can be provided to the mobile communication system, and the diversity technique is not restricted to symbols transmitted to the same mobile station and can also be applied to a 1-bit channel. | 09-25-2008 |
| 20080260055 | Apparatus for Creating, Demodulating, Transmitting and Receiving Othorgonal Frequency Division Multiplexing Symbol - The present invention relates to an orthogonal frequency division multiplexing (OFDM) signal transmitting and receiving device, in which a peak to average power ratio characteristic is improved without reducing a data D transmission speed. The OFDM signal transmitting device separates a digital modulated symbol as a real part and an imaginary part, and performs discrete cosine transform (DCT) and discrete sine transform (DST) operations respectively for real and imaginary part symbols, performs an inverse fast Fourier transform operation, and generates an OFDM symbol. The OFDM signal receiving device performs a fast Fourier transform operation for the OFDM symbol, and performs an inverse DCT operation and an inverse DST operation, performs a digital demodulating operation, and generates a final binary data symbol. | 10-23-2008 |
| 20080316913 | Method and Apparatus for Transmitting by Using Transmit Diversity at Dft Spread Ofdma - The present invention relates to a packet data transmission method in an OFDMA system and an apparatus thereof. The present invention provides a user packet data transmission method including generating a RACH burst for channel information estimation, selecting a first antenna among a plurality of antennas, transmitting the RACH burst through the first antenna to a base station, receiving a data transmission acceptance signal from the base station, in response to the RACH burst, transmitting user packet data through the first antenna when receiving a signal indicating that the data transmission is allowed, and selecting a second antenna that is difference from the first antenna and transmitting a RACH burst through the second antenna when receiving a signal indicating that the data transmission is not allowed, and a transmitting apparatus of a mobile station having the plurality of antennas. According to the present invention, the RACH burst and user packet data are transmitted by using a mobile station having a plurality of antennas in an LTE-applied OFDMA system, and therefore data transmission can be performed with a wide bandwidth and high data rate and a deep fading period that may occur during the data transmission can be reduced, thereby preventing call dropping and improving data transmission performance. | 12-25-2008 |
| 20090003478 | Method and Apparatus for Generating and Receiving Ofdm Symbol - The present invention provides an OFDM symbol generating apparatus. The OFDM symbol generating apparatus generates a plurality of weight-applied symbol groups by applying a plurality of weights to a digital modulation symbol group, and generates a plurality of IFFT symbol groups by performing an IFFT operation on the plurality of weight-applied symbol groups. Subsequently, an IFFT symbol group having the minimum PAPR is selected from among the plurality of IFFT symbol groups such that a characteristic of a PAPR can be improved without reducing data transmission speed. | 01-01-2009 |
| 20090161652 | APPARATUS FOR GENERATING DOWN LINK SIGNAL, AND METHOD AND APPARATUS FOR CELL SEARCH IN CELLULAR SYSTEM - The invention provides a method of generating a downlink signal and searching a cell on the basis of the downlink signal in an OFDM-based cellular system. The downlink signal includes a plurality of synchronization blocks each having a plurality of sub-frames, and a synchronization pattern composed of a combination of a cell group identification code for identifying a cell group and a frame synchronization identification code for indicating a frame start point is generated in each of the synchronization blocks. Different frame synchronization identification codes are allocated to the synchronization blocks. | 06-25-2009 |
| 20090196279 | TDM BASED CELL SEARCH METHOD FOR OFDM SYSTEM - Provided are a sync channel of a forward link, a common pilot channel structure, and an initial cell search method and an adjacent cell search method for handover in a cellular system using orthogonal frequency division multiplexing (OFDM). A cell search method in an OFDM cellular system in which a primary sync channel and a secondary sync channel are configured based on time division multiplexing (TDM) includes acquiring sync block synchronization and a primary sync channel sequence number using a primary sync channel symbol included in a frame received by a terminal, detecting a boundary of the frame and a scrambling code group using the sync block and a secondary sync channel symbol included in the frame received by the terminal, and acquiring a scrambling code using the primary sync channel sequence number and the scrambling code group, thereby reducing cell search time with low complexity. | 08-06-2009 |
| 20090232125 | CELL SEARCH METHOD, FORWARD LINK FRAME TRANSMISSION METHOD, APPARATUS USING THE SAME AND FORWARD LINK FRAME STRUCTURE - In a cellular system in which OFDM is used, a forward link synchronization channel, a common pilot channel structure, an initial cell searching method of a mobile station, and an adjacent cell searching method for handover are required. | 09-17-2009 |
| 20090252109 | METHOD FOR DEMODULATING BROADCAST CHANNEL BY USING SYNCHRONIZATION CHANNEL AT OFDM SYSTEM WITH TRANSMIT DIVERSITY AND TRANSMITTING/RECEIVING DEVICE THEREFOR - The present invention relates to a method for demodulating a BCH by using an SCH in an OFDM system with transmit diversity, and a transmitting apparatus and a receiving apparatus using the same. For this purpose, the present invention provides a transmit diversity transmission method for a transmitting apparatus of a base station that generates an SCH symbol and a BCH symbol, maps the SCH symbol and the BCH symbol to an OFDM signal, converts the OFDM signal into a time domain signal, and transmits the OFDM signal trough a selected antenna among a plurality of antennas. In addition, the present invention provides a method for demodulating a BCH by using an SCH to a mobile station that receives an OFDM signal from the base station, filters an SCH and a BCH from the OFDM signal, converts the OFDM signal to a frequency domain signal, calculates a channel estimation value by using the SCH and the BCH, and coherently demodulates the BCH. According to the present invention, coherent demodulation of a BCH can reduce a frame error generation probability, minimize a channel estimation error due to fading, reduce time for checking the number of antennas of the base station and time for demodulating the BCH, and reduce power consumption. | 10-08-2009 |
| 20090252332 | METHOD FOR GENERATING DOWNLINK FRAME, AND METHOD FOR SEARCHING CELL - The present invention relates to a method for generating a downlink frame includes: generating a first short sequence and a second short sequence indicating cell group information; generating a first scrambling sequence determined by a first synchronization signal; generating a second scrambling sequence determined by a first short sequence and a third scrambling sequence determined by a second short sequence; scrambling the first short sequence with the first scrambling sequence; scrambling the second short sequence with at least the second scrambling sequence; scrambling the second short sequence with the first scrambling sequence; scrambling the first short sequence with at least the third scrambling sequence; and mapping one second synchronization signal including the first short sequence scrambled with the first scrambling sequence and the second short sequence scrambled with at least the second scrambling sequence and another second synchronization signal including the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled with at least the third scrambling sequence in the frequency domain. | 10-08-2009 |
| 20090252333 | METHOD FOR GENERATING DOWNLINK FRAME, AND METHOD FOR SEARCHING CELL - The present invention relates to a method for generating a downlink frame includes: generating a first short sequence and a second short sequence indicating cell group information; generating a first scrambling sequence determined by a first synchronization signal; generating a second scrambling sequence determined by a group to which the first short sequence belongs, the wireless communication system using a plurality of short sequences and the plurality of short sequence being divided into a plurality of groups; scrambling the first short sequence with the first scrambling sequence; scrambling the second short sequence with at least the second scrambling sequence; and mapping a second synchronization signal including the scrambled first short sequence and the scrambled second short sequence in the frequency domain. | 10-08-2009 |
| 20090252334 | METHOD FOR GENERATING DOWNLINK FRAME, AND METHOD FOR SEARCHING CELL - The present invention relates to a method of generating a downlink frame. The method of generating the downlink frame includes: generating a first short sequence and a second short sequence indicating cell group information; generating a first scrambling sequence and a second scrambling sequence determined by the primary synchronization signal; generating a third scrambling sequence determined by the first short sequence; scrambling the first short sequence with the first scrambling sequence and scrambling the second short sequence with the second scrambling sequence and the third scrambling sequence; and mapping the secondary synchronization signal that includes the scrambled first short sequence and the scrambled second short sequence to a frequency domain. | 10-08-2009 |
| 20090252335 | METHOD FOR GENERATING DOWNLINK FRAME, AND METHOD FOR SEARCHING CELL - The present invention relates to a method of generating a downlink frame. The method of generating the downlink frame includes: generating a first short sequence and a second short sequence indicating cell group information; generating a first scrambling sequence and a second scrambling sequence determined by the primary synchronization signal; generating a third scrambling sequence determined by the first short sequence and a fourth scrambling sequence determined by the second short sequence; scrambling the first short sequence with the first scrambling sequence and scrambling the second short sequence with the second scrambling sequence and the third scrambling sequence; scrambling the second short sequence with the first scrambling sequence and scrambling the first short sequence with the second scrambling sequence and the fourth scrambling sequence; and mapping the secondary synchronization signal that includes the first short sequence scrambled with the first scrambling sequence, the second short sequence scrambled with the second scrambling sequence and the third scrambling sequence, the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled by the second scrambling sequence and the fourth scrambling sequence to a frequency domain. | 10-08-2009 |
| 20090252336 | METHOD FOR GENERATING DOWNLINK FRAME, AND METHOD FOR SEARCHING CELL - The present invention relates to a method of generating a downlink frame. The method of generating the downlink frame includes: generating a first short sequence and a second short sequence indicating cell group information; generating a first scrambling sequence and a second scrambling sequence determined by the primary synchronization signal; generating a third scrambling sequence determined by a short sequence group-a wireless communication system uses a plurality of short sequences and the plurality of short sequences are grouped into a plurality of short sequence group-to which the first short sequence is assigned; scrambling the first short sequence with the first scrambling sequence and scrambling the second short sequence with the second scrambling sequence and the third scrambling sequence; and mapping the secondary synchronization signal that includes the scrambled first short sequence and the scrambled second short sequence to a frequency domain. | 10-08-2009 |
| 20090257409 | METHOD FOR GENERATING DOWNLINK FRAME, AND METHOD FOR SEARCHING CELL - The present invention relates to a method for generating a downlink frame including generating a first short sequence and a second short sequence indicating cell group information, generating a first scrambling sequence determined by the first synchronization signal, generating a second scrambling sequence determined by the first short sequence, scrambling the first short sequence with the first scrambling sequence, scrambling the second short sequence with at least the second scrambling sequence, and mapping a second synchronization signal including the scrambled first short sequence and the scrambled second short sequence in the frequency domain. | 10-15-2009 |
| 20090279513 | METHOD FOR TRANSMITTING SIGNAL AND METHOD FOR RECEIVING SIGNAL - A sector transmitter maps a synchronization channel and a broadcast channel to be on a time axis adjacent to each other, and applies the same bandwidth and the same transmission diversity to the synchronization channel and the broadcast channel. A mobile station estimates a plurality of channel statuses for a plurality of sectors from a synchronization channel signal, and acquires broadcast channel information from a broadcast channel signal using the plurality of estimated channel statuses. As a result, the mobile station can receive a broadcast channel with high reception quality while having low complexity. | 11-12-2009 |
| 20100020901 | METHOD AND APPARATUS FOR TRANSMITTING SIGNAL IN COMMUNICATION SYSTEM - When a plurality of sectors transmit the same signal in a communication system, the same signal is transmitted after a weight is applied to the same signal. At this time, defective reception of the same signal in a terminal may be reduced by setting a weight pattern differently according to a symbol transmission time and a sector number | 01-28-2010 |
| 20100034301 | METHOD FOR GENERATING AND TRANSMITTING DOWNLINK FRAME - A downlink frame generation device arrange a plurality of synchronization channel symbols and a plurality of broad-casting channel symbols in a common bandwidth of a system so that the symbols may neighbor each other on the time axis. The downlink frame generation device applies a precoding vector to the synchronization channel symbols and the broadcasting channel symbols to generate a plurality of downlink frames corresponding to a plurality of antennas. The precoding vector is variable by a sector for transmitting a plurality of downlink frames and a subframe in which a plurality of synchronization channel symbols are positioned. The precoding vector is independent of an index of a subcarrier. | 02-11-2010 |
| 20100046432 | METHOD FOR TRANSMITTING SIGNAL AND INFORMATION ON ANTENNA, AND METHOD FOR ESTIMATING THE NUMBER OF ANTENNAS - A base station applies frequency switching transmission diversity and a preceding vector to a synchronization channel and applies a space-frequency block coding and a preceding vector to a broadcast channel. The base station controls the synchronization channel and the broadcast channel to be positioned adjacent each other and then generates and transmits a downlink frame. The base station includes partial information on the number of antennas in the synchronization channel, and other information thereon in the broadcast channel. | 02-25-2010 |
| 20100061322 | METHOD FOR ALLOCATING CODE TO CELLS AND PLANNING CELLS IN OFDM CELLULAR SYSTEM - A piece of user equipment (UE), which has received more than two synchronization codes at the same time, has a problem in that the UE may not confirm the synchronization codes due to an increase in inter-signal interference. As a result, the UE may not acquire a primary scrambling code (PSC). A method of transmitting a forward synchronization signal in a wireless communication system includes: each base station existing in a wireless communication system generating a frame according to a predetermined unit of frame timing by using a same external clock signal; and allocating different offsets to frames of adjacent base stations by using the external clock signal so that forward link common channels included in the frames do not overlap each other, and transmitting the frames. In addition, a method of allocating a cell code suitable for an OFDM cellular system, a forward link frame transmitting method, a method of setting timing between cells, and a method of setting timing between a base station and a mobile station can be derived. | 03-11-2010 |
| 20100067613 | METHOD AND APPARATUS FOR TRANSMITTING UPLINK SIGNAL, AND METHOD AND APPARATUS FOR GENERATING UPLINK SIGNAL IN COMMUNICATION SYSTEM - When a terminal generates an uplink signal in a communication system, the terminal hops a sequence for differentiating itself from another terminal with time. The terminal generates the uplink signal by multiplying a transmission symbol by a sequence of a transmission time corresponding to the transmission symbol. | 03-18-2010 |
| 20100104001 | RECEIVER AND RECEIVING METHOD FOR SCALABLE BANDWITH - Provided are a receiver and a receiving method for a scalable bandwidth in a mobile station of an Orthogonal Frequency Division Multiplexing (OFDM) system. The receiving method includes the steps of: (a) filtering a received RF signal; (b) oscillating a frequency according to a center frequency control signal to output a local oscillation frequency; (c) down-converting the filtered RF signal by using the local oscillation frequency; (d) scalable-filtering the down-converted signal while adjusting a bandwidth according to a bandwidth control signal; (e) controlling gain of the scalable-filtered signal; (f) converting the gain-controlled analog signal into a digital signal by using a sampling frequency matching with a corresponding bandwidth according to an ADC control signal; and (g) demodulating the converted digital signal, outputting the center frequency control signal, the bandwidth control signal, and the ADC control signal according to control information received from an upper layer. | 04-29-2010 |
| 20100157877 | METHOD AND APPARATUS FOR ALLOCATING SEQUENCE TO SYNCHRONIZATION CHANNEL FOR NODE IDENTIFICATION IN WIRELESS COMMUNICATION SYSTEM - Provided is an apparatus for allocating a sequence to a synchronization channel for a node identification (ID), the apparatus including: a base node sequence generator to generate a base sequence that is a sequence for a node ID of a base node; a relay node sequence generator to generate a relay sequence that is a sequence for a node ID of a relay node by transforming the base sequence; a baseband signal generator to generate a baseband signal by mapping the base sequence or the relay sequence to a frequency domain and a time domain; and a transmitter to transmit the baseband signal. | 06-24-2010 |
| 20100158088 | PORTABLE APPARATUS AND METHOD OF MEASURING WIRELESS CHANNEL AND MULTIPLE ANTENNA CORRELATION - A portable apparatus of measuring a wireless channel and a multiple antenna correlation, the apparatus including: a Radio Frequency (RF) unit to control a frequency of a signal to be measured, to broadcast the signal to be measured through multiple transmission antennas, to control a frequency of a received signal, and to send the received signal to the baseband unit, the received signal being received through multiple receiving antennas; and a baseband unit to generate and transmit, to the RF unit, the signal to be measured, to measure wireless channels for each of the multiple transmission antennas and wireless channels for each of the multiple receiving antennas based on the received signal output from the RF unit, to calculate a correlation for each of the multiple transmission antennas, and to calculate a correlation for each of the multiple receiving antennas based on the wireless channels for each of the multiple transmission and receiving antennas. | 06-24-2010 |
| 20100159854 | METHOD AND APPARATUS FOR ADAPTIVELY CONTROLLING RECEIVED POWER OF MULTI-ANTENNA RADIO CHANNEL MEASUREMENT EQUIPMENT - Provided is an apparatus for adaptively controlling a received power of a multi-antenna radio channel measurement equipment, the apparatus including: a plurality of antennas to receive a measurement signal; a switch unit comprising a plurality of switches to input the measurement signal; a switch control unit to control the plurality of switches of the switch unit to sequentially input the measurement signal; a reception (Rx) attenuator to adjust a Received Signal Strength Indication (RSSI) of the measurement signal; an Rx AGC control unit to control the Rx attenuator to adaptively adjust the RSSI of the measurement signal; a timing control unit to generate a reference timing signal for the switch control unit and the automatic RSSI control unit; and a digital baseband control unit to collect and store information associated with the measurement signal. | 06-24-2010 |
| 20110009138 | METHOD FOR GENERATING DOWNLINK FRAME, AND METHOD FOR SEARCHING CELL - The present invention relates to a method of generating a downlink frame. The method of generating the downlink frame includes generating a first sequence and a second sequence for identifying cell groups; generating a first scrambling sequence and a second scrambling sequence that are one-to-two mapped to the sequence number of the primary synchronization signal; scrambling the first sequence with the first scrambling sequence and scrambling the second sequence with the second scrambling sequence; and generating a secondary synchronization signal including the scrambled first sequence and second sequence and mapping the secondary synchronization signal to a frequency domain. | 01-13-2011 |
| 20110044256 | METHOD FOR GENERATING DOWNLINK SIGNAL, AND METHOD FOR SEARCHING CELL - An apparatus for generating a downlink signal and a cell search apparatus are disclosed. An apparatus for generating a downlink signal generates a downlink signal by one unique cell identification code group and a plurality of frame synchronization identification sequences, generates a downlink signal by a plurality of unique cell identification code groups and a plurality of frame synchronization identification sequences, or generates a downlink signal by a plurality of unique cell identification code groups and one frame synchronization identification sequence. A cell search apparatus obtains frame synchronization and identifies cells through a frame synchronization identification sequence and a unique cell identification code group. | 02-24-2011 |
| 20110058528 | SYMBOL TIMING SYNCHRONIZATION OBTAINING METHOD AND APPARATUS ROBUST TO FREQUENCY OFFSET IN CELL SEARCH OF WIRELESS COMMUNICATION SYSTEM - Disclosed is a symbol synchronization obtaining apparatus robust to a frequency offset in a cell search of a wireless communication system. The symbol synchronization obtaining apparatus robust to a frequency offset in a cell search of a wireless communication system may include a sequence generator to generate a base sequence for obtaining the symbol synchronization, a synchronization pattern generator to generate a modified sequence based on the base sequence, and to generate a synchronization pattern by combining the modified sequence and the base sequence, a frequency mapping unit to perform mapping of transmission information to a time area and a frequency area, based on the synchronization pattern, for generating a transmission frame, and a transmitting unit to transmit the transmission frame. | 03-10-2011 |
| 20110063026 | PRE-DISTORTION APPARATUS OF POWER AMPLIFIER AND METHOD THEREOF - A pre-distortion apparatus of a power amplifier includes: a pre-distortion unit configured to generate a pre-distorted signal of an input signal by calculating a magnitude of the input signal and outputting a complex correction coefficient corresponding to the calculated magnitude of the input signal, and provide the generated pre-distorted signal as an input of the power amplifier; and a complex correct coefficient update unit configured to generate an error signal by comparing an output signal of the power amplifier with the input signal and updating the complex correction coefficient to minimize a magnitude of the generated error signal, wherein the pre-distortion unit provides a constant bias value corresponding to the magnitude of the input signal as a bias of the power amplifier while updating the complex correction coefficient. | 03-17-2011 |
| 20110124287 | METHOD AND DEVICE FOR ESTABLISHING COMMUNICATION LINK BY SELECTING OBJECT FROM SCREEN - A method for establishing a communication link of a first communication device by selecting a target from a screen includes: selecting a second communication device for establishing a communication link on a screen of the first communication device; transmitting a request for a communication link including information regarding the establishment of a link on the basis of the first communication device required for establishing a communication link to the selected second communication device; receiving a communication link response including information regarding the establishment of a communication link on the basis of the second communication device required for establishing a communication link from the second communication device; and establishing a communication link between the first communication device and the second communication device by using the information regarding the establishment of a link on the basis of the first communication device and the information regarding the establishment of a link on the basis of the second communication device. | 05-26-2011 |
| 20110149947 | CELL SEARCH METHOD, FORWARD LINK FRAME TRANSMISSION METHOD, APPARATUS USING THE SAME AND FORWARD LINK FRAME STRUCTURE - A method of and an apparatus therefor searching a cell in a mobile station of a communication system in which a plurality of cells are grouped into a plurality of cell groups, and each cell group includes at least two cells. The method includes detecting a primary synchronization signal and a secondary synchronization signal from a received signal, and identifying a cell based on a combination of the primary synchronization signal and the secondary synchronization signal. The secondary synchronization signal is related to the cell group to which the mobile station belongs and the primary synchronization signal is related to the cell to which the mobile station belongs within the cell group. | 06-23-2011 |
