Abstract:
A method and apparatus for receiving data produced by mapping high-priority bits to a high-reliability bit position and low-priority bits to a low-reliability bit position in symbols, in a receiver in a mobile communication system. The apparatus includes a demodulator for demodulating the high-priority bits from the high-reliability bit position and the low-priority bits from the low-reliability bit position in the symbols; a position exchange for exchanging the position of the high-priority bits with the position of the low-priority bits in an original order if a transmitter has exchanged the bit positions; a controller for controlling the positions of the high-priority bits and the low-priority bits according to whether the transmitter has exchanged the bit positions; and a combiner for combining the high-priority bits and the low-priority bits with previously received same bits.
Abstract:
Disclosed is a data transportation/reception apparatus and method in a mobile communication system. The data transportation apparatus and method divides transport data bits into bits having higher priority and bits having lower priority, maps the bits having higher priority to bit positions having higher reliability, and maps the bits having lower priority to bit positions having lower reliability. The data reception apparatus and method demodulates received modulated symbols, divides the demodulated coded bits into two coded bit groups according to priority, deinterleaving the coded bit groups using different deinterleavers, and decodes the deinterleaved coded bits.
Abstract:
Provided is an apparatus and method for preventing successive failures in a call connection in a mobile communication terminal. When a call connection is attempted, a cell with the highest RX power is selected among cells and an RRC Connection Request message is transmitted from the mobile terminal to a BS of the selected cell. It is determined whether the mobile terminal receives an RRC Connection Accept/Reject message from the BS. If the mobile terminal receives an RRC Connection Reject message from the BS of the selected cell, it is determined whether the selected cell is able to perform the RRC connection by detecting a Connection Reject message frequency that is the number of times of rejection of an RRC connection request for a predetermined period. If the selected cell is not able to perform the RRC connection, a neighboring cell is reselected and an RRC Connection Request message is transmitted to the reselected neighboring cell.
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 method and apparatus for efficiently transmitting channel quality information on a radio channel in a mobile communication system are provided. The reporting cycle of channel quality information is changed adaptively according to time-varying characteristics associated with the Doppler frequency of a radio channel or the variation of the channel quality information. Therefore, the channel quality information is efficiently transmitted. Also, the decrease of unnecessary frequent information transmissions reduces an uplink interference power level and power consumption in user equipment (UE), as well.
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:
Disclosed are an apparatus and a method capable of preventing performance degradation during a channel decoding process. A bit interleaving is performed with respect to parity bits among coded bits output through a channel coding unit, thereby preventing a repetition period of the parity bits from matching a puncturing period for a rate matching. A bit de-interleaving is performed with respect to the parity bits during a channel decoding process, so that the parity bits have a repetition period identical to initial parity bits. Thus, the repetition period of the parity bits is not matched with the puncturing period for the rate matching, thereby preventing performance degradation during the channel decoding process.
Abstract:
Provided is a method for measuring a neighbor cell signal in a portable terminal includes acquiring a minimum required quality level value and a threshold for an intra-frequency measurement from received system information; calculating a measured cell quality value after the acquiring step; and commencing a neighbor cell signal measurement for an intra-frequency cell reselection when a value acquired by subtracting the minimum required quality level value from the measured cell quality value is less than or equal to a value acquired by adding the threshold and a certain signal strength value over a certain time. In the neighbor cell signal measurement for the cell reselection, the unnecessary neighbor cell signal measurement can be avoided to reduce the power consumption and extend the battery lifetime.
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:
An apparatus and method for estimating a decision boundary in symbol units in a mobile communication system. The method for estimating a decision boundary of reception symbols in a receiver of a mobile communication system includes the step of calculating a preliminary decision boundary for every symbol entered a decision boundary estimator; and reflecting the preliminary decision boundary calculated for every symbol in a previous symbol's decision boundary having been calculated in consideration of a channel environment until reaching the previous symbol, and calculating a new decision boundary for the entered symbol.