摘要:
A method for selecting a relay mode depending on channel status of relay links in a multihop relay broadband wireless communication system and a Relay Station (RS) apparatus for supporting the method. When signals are received from a Base Station (BS) and a Mobile Station (MS), channel status values (e.g., eigenvalue, mutual information, and probability error) of relay links (BS-RS link and RS-MS link) are estimated using the received signals. The estimated channel status values are compared with a preset reference value. According to a result of the comparison, the relay mode for relaying the received signals is selected. Accordingly, the reliability of the relayed signal can be enhanced and the capacity of the signal link can be increased.
摘要:
An apparatus and method for controlling power in a multi-hop relay broadband wireless communication system are provided. A BS sends a signal to an RS and an MS to estimate distances between the BS, the RS and the MS. Upon receipt of signals from the RS and the MS, the BS measures ToAs of the received signals and detects time information included in the received signals, and calculates propagation delays between the BS, the RS and the MS based on the ToAs and the time information. The BS estimates the distances between the BS, the RS and the MS using the propagation delays, and controls transmission power according to the estimated distances.
摘要:
A frequency resource operating apparatus and method for transmitting and receiving data at a different hopping pattern speed according to a CSI in a BWA communication system are provided. In a method of transmitting and receiving data using CSI in a mobile communication system, a BS sets the CSI of an MS to an initial CSI and sends data to the MS according to the initial CSI. The MS sends a downlink CSI to the BS. The BS groups the MS based on the downlink CSI and sends data to the MS according to a hopping pattern for the group of the MS among hopping patterns preset for predetermined groups.
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 providing EPG in a digital broadcasting system, in which an EPG connecting unit connects EPG servers of digital broadcasting channels, a program information generating unit generates program information according to program characteristics of the digital broadcasting channels, and an EPG server generates EPG information using the generated program information, and combines the generated EPG information with EPG information of the broadcasting channels. Accordingly, the program information of different broadcasting channels can be searched without switching channels, and quality of the EPG service can be improved. Moreover, users can be allowed to personally configure the EPG, thereby providing the EPG according to characteristics of the users.
摘要:
A ranging apparatus in a communication system is provided. A terminal generates a ranging code for ranging with a base station, maps the ranging code to at least one sub-carrier so the ranging code is repeated in a time domain, generates a ranging signal so the mapped ranging code has a size of one symbol interval, and transmits the generated ranging signal to the base station. The base station receives a ranging signal, extracts a half signal of a valid symbol interval of the ranging signal, generates a valid symbol interval signal by repeating the extracted half signal of the valid symbol interval, restores a ranging signal using the valid symbol interval signal, and performs ranging using the ranging signal.
摘要:
Disclosed is a method and apparatus for completely recovering received data with high reliability using LDPC codes without short-sized cycles in a digital communication system using an error-correcting code. The method includes performing exponent conversion of a predetermined number of exponent matrixes stored in advance in a memory so as to generate new exponent matrixes based on the exponent conversion, and generating new LDPC codes using the new exponent matrixes.
摘要:
An apparatus and method for reducing pilot overhead in a broadband wireless communication system are provided. A data symbol mapper maps data symbols to be transmitted into subcarriers and detects values of the data symbols mapped into predefined subcarriers. A pilot generator determines masking codes for each pilot group by using the detected values of the data symbols and masks the determined masking codes into pilot symbols of the corresponding pilot group. A pilot symbol mapper maps the masked pilot symbols received from the pilot generator into subcarriers.
摘要:
A frequency overlay communication system that includes a first communication system for performing communication using a first frequency band being a preset bandwidth; and a second communication system for performing communication using a second frequency band being a second preset bandwidth, wherein the second frequency band includes the first frequency band.
摘要:
Disclosed are an apparatus and a method for efficiently transmitting data by constellation combination in a communication system. The method includes encoding and interleaving transmission data according to a predetermined encoding scheme, and dividing an interleaved signal into at least one signal interval corresponding to at least one modulation scheme; and transmitting data obtained by modulating at least one divided signal interval according to a modulation scheme corresponding to the divided signal interval, the data satisfying a predetermined data rate setup in a system by applying a preset modulation scheme to each divided signal interval.