Abstract:
An apparatus and a method for improving the performance of an error correction code in response to the influence of error propagation are disclosed. A receiver of a mobile communication system, which transmits/receives data at a high speed by means of the plurality of transmission antennas and the plurality of reception antennas, estimates a transmission signal of a specific path from a first received signal according to a preset criterion, measures an error component for each symbol of the estimated transmission signal, performs an error correction for symbols having a corresponding error component exceeding a preset value, detects transmission data from all symbols through a predetermined signal reverse-processing procedure, reconstructs a transmission signal from the transmission data, subtracts the reconstructed transmission signal from the received signal to generate a second received signal, and repeats the above operations until transmission data of all paths are detected from the second received signal.
Abstract:
An apparatus and method for improving the performance of an error correction code against the effects of error waves in a Multi-Input Multi-Output (MIMO) communication system are provided. In a receiver of the MIMO communication system, a Minimum Mean Square Error (MMSE) receiver unit estimates transmitted signals from at least two paths using signals received at each of receive antennas, a signal deprocessor selects one of the estimated signals, stores the other estimated signal, assigns weighting values to the selected signal and a previous detected signal, combines the weighted signals, and detects transmitted data from the combined signal, a signal reproducer reproduces a transmitted signal from the detected transmitted data, and a subtractor updates the received signals by subtracting the reproduced transmitted signal from the received signals and provides them to the MMSE receiver unit.
Abstract:
An apparatus and a method capable of effectively allocating sub-carriers for a plurality of users and transmitting the sub-carriers to users through multiple antennas in an orthogonal frequency division multiplexing (OFDMA) mobile communication system are provided. A sub-carrier allocation method reduces transmission power by taking a desired bit rate and power budget into consideration. The sub-carriers are optimally allocated to each antenna, so that peak to average power ratio (PARR) is reduced and Quality of Service (QoS) is improved. The apparatus and the method are adaptable for multi-users and obtain space diversity gain through multiple antennas.
Abstract:
Disclosed is a data transmission/reception apparatus and method for minimizing decoding errors during high-speed packet transmission in a CDMA mobile communication system. When retransmitting data in the Hybrid Automatic Repeat Request (“H-ARQ”) technique, the data transmission/reception apparatus and method performs symbol mapping on coded bits to be retransmitted by allocating different reliabilities to the coded bits according to the number of retransmissions, thus resulting in an improvement of system performance.
Abstract:
A de-rate matching method and apparatus in a High Speed Downlink Packet Access (HSDPA) system are provided. In the de-rate matching apparatus and method, a collection buffer temporarily stores a received packet, a combining buffer stores the packet received from the collection buffer according to predetermined memory address information including information indicating the positions of bits punctured during the rate matching, a controller decodes high-speed shared common control channel (HS-SCCH) information including a predetermined hybrid automatic repeat request (HARQ) parameter received from the transmitter and provides overall control to de-rate matching between the collection buffer and the combining buffer, an address generator generates the memory address information based on the decoded HARQ parameter, an address buffer stores the memory address information, and a zero inserter initializes at least one of data stored at memory addresses of the combining buffer including memory addresses for the punctured, before the de-rate matching.
Abstract:
A data transmitting/receiving apparatus and method for improving the reliability of data bits in a CDMA mobile communication system. High-priority bits are mapped to a high-reliability bit position and low-priority bits, to a low-reliability bit position in symbols. Thus system performance is improved at a transmission.
Abstract:
An apparatus and method for assigning sub-carriers in an orthogonal frequency division multiplex (OFDM) system are disclosed. In the apparatus and method, data is transmitted through at least one transmit antenna. At least two sub-carriers in a predetermined frequency band are assigned to a user equipment (UE), for data transmission. A Node B groups sub-carriers available to the OFDM system into sub-carrier groups, each having at least two sub-carriers, transmits data to the UE on sub-carriers in the sub-carrier groups, selects at least one sub-carrier group for the UE based on channel condition information about each of the sub-carrier groups received from the UE, and assigns the selected sub-carrier group to the UE.
Abstract:
Disclosed is a method for transmitting data comprised of bits with higher priority and bits with lower priority output from a coder, using a high-order modulator in which a bit stream comprised of at least 3 bits represents one symbol and includes a first bit part with higher reliability and a second bit part with lower reliability. The method comprises modulating the bits with higher priority and the bits with lower priority such that the bits with higher priority are mapped to the first bit part and the bits with lower priority are also mapped to the first bit part at initial transmission; and modulating the bits with higher priority and the bits with lower priority such that the bits with higher priority are mapped to the second bit part and the bits with lower priority are mapped to the first bit part at retransmission.
Abstract:
An apparatus and a method for improving the performance of an error correction code in response to the influence of error propagation are disclosed. A receiver of a mobile communication system, which transmits/receives data at a high speed by means of the plurality of transmission antennas and the plurality of reception antennas, estimates a transmission signal of a specific path from a first received signal according to a preset criterion, measures an error component for each symbol of the estimated transmission signal, performs an error correction for symbols having a corresponding error component exceeding a preset value, detects transmission data from all symbols through a predetermined signal reverse-processing procedure, reconstructs a transmission signal from the transmission data, subtracts the reconstructed transmission signal from the received signal to generate a second received signal, and repeats the above operations until transmission data of all paths are detected from the second received signal.
Abstract:
An apparatus and method for transmitting control information in a mobile communication system are disclosed. The apparatus and method include selecting a pilot signal having different predetermined pilot patterns according to whether the data are received and the data contain an error, and inserting the selected pilot signal into a pilot field of a dedicated physical channel frame as control information and transmitting the dedicated physical channel frame.