摘要:
An apparatus transmits header information in a wireless communication system using a plurality of channels. In the apparatus, upon receiving uncompressed header (UCH) information, a compressor generates compressed header (CH) information and additional information container (AIC) information by compressing the UCH information with a predetermined compression scheme. A transmitter transmits the CH information through a first channel among the plurality of channels, and transmits the AIC information through at least one of the plurality of channels except for the first channel.
摘要:
An apparatus and method for estimating and correcting an uplink frequency offset in an OFDM communication system are provided. A subscriber station (SS) once repeats an OFDM symbol including a ranging code allocated from a BS and transmits the repeated OFDM symbols to the base station (BS). The BS demodulates the two successive OFDM symbols received from the SS using the ranging code, sums the demodulated signal for each FFT window, and estimates the uplink frequency offset by multiplying the complex conjugate of a sum for a first FFT window by a sum for a second FFT window by the base station. The BS transmits a message including information about the frequency offset estimate to the SS. The SS then corrects the uplink frequency offset using the frequency offset information.
摘要:
An apparatus and method for SFBC coding and decoding in a communication system using a plurality of (N1) Tx antennas are provided. In a transmitter using Nt transmit antennas, a pre-coder pre-codes an input symbol sequence using a pre-coding matrix. The pre-coding matrix is produced by puncturing a unitary matrix in a predetermined method. An encoder generates a plurality of vectors by grouping the symbols of the pre-coded symbol sequence by twos, space-frequency maps each of the vectors by encoding each of the vectors in an Alamouti coding scheme, and provides each of the space-frequency mapped symbols to a predetermined OFDM modulator.
摘要:
An apparatus and a method for cell search in an orthogonal frequency division multiplexing-based mobile communication system using a multiple access scheme. The method includes the steps of: detecting a symbol boundary of an input reception signal; detecting a frame cell boundary after synchronizing with the detected symbol boundary; detecting a reference signal for each symbol interval in a preset search interval; and detecting a pattern of the detected reference signals and detecting a base station to which the terminal belongs.
摘要:
A method and system for transmitting/receiving data in a heterogeneous communication system. A terminal accesses a first controller of a first communication system supporting a first communication service to make a communication path to the first communication system. After making the communication path to the terminal, the first controller determines whether it is possible to provide the first communication service to the terminal over the first communication system. If it is not possible, the first controller transmits to an interworking unit a first request indicating that the terminal requires the first communication service over the second communication system. The interworking unit transmits a second request to a second controller of the second communication system in response to the first request, the second request indicating that the second controller provides the first communication service to the terminal. Upon receiving a response to the second request, the interworking unit controls the first controller to provide the first communication service to the terminal over the second communication system according to the response.
摘要:
A hybrid forwarding apparatus and method for cooperative relaying in an OFDM network are provided. In a hybrid forwarding apparatus in a relay terminal, a forwarding scheme selector selects a forwarding scheme for transmission. An amplify and forward (AF) block amplifies data received from the forwarding scheme selector, if an AF scheme is selected. A decode and forward (DF) block decodes and encodes data received from the forwarding scheme selector, if a DF scheme is selected. A multiplexer provides the output data of the AF block and the DF block to an OFDM modulator.
摘要:
An apparatus and method for signal detection in a Broadband Wireless Access (BWA) system are provided, in which in a transmitter, a first preamble sequence generator generates preamble sequences, a low-Peak-to-Average Power Ratio (PAPR) preamble sequence selector selects a first low-PAPR preamble sequence from among the generated preamble sequences, a preamble sequence copier copies the first low-PAPR preamble sequence at least once and outputs the first low-PAPR preamble sequence and the at least one copy, a complex conjugator generates preamble sequences orthogonal to the first low-PAPR preamble sequence and the at least one copy by calculating complex conjugates of the first low-PAPR preamble sequence and the at least one copy, and a second preamble sequence generator generates at least one second low-PAPR preamble sequence using the first low-PAPR preamble sequence.
摘要:
An apparatus and method for controlling amount of information to be fed back in a multiple antenna system in a multi-user environment. The apparatus includes a channel estimator which estimates channel values by using an input signal; a Singular Value Decomposition (SVD) operator which decomposes singular values from the estimated channel values; and a feedback determining unit which uses the singular values to compute channel capacity that can be obtained according to the amount of channel information to be fed back, and selects the channel information to be fed back by using the channel capacity.
摘要:
A method and system for allocating resources in a communication system including a first system having a use right for a plurality of frequency bands, and a second system having no use right for the plurality of frequency bands. The method includes acquiring first, second and third sensing informations indicating frequency bands available by a base station, a relay station and a mobile station belonging to the second system, among the plurality of frequency bands; and selecting a frequency band to be allocated for communications, based on the acquired sensing informations.
摘要:
A receiver and transmitter of a closed-loop MIMO antenna system using a codebook and a receiving and transmitting method thereof are provided. The receiver of the MIMO antenna system includes a window size decider and a beamforming weight selector. The window size decider stores a codebook with beamforming weights and selects the beamforming weights corresponding to a window size from the codebook, and the beamforming weight selector selects an optimal beamforming weight based on a current channel state among the beamforming weights outputted from the window size decider, and feeds back the selected optimal beamforming weight to a transmitter.