摘要:
A base station in a downlink of a wireless communication system requires downlink channel status information of terminals to transmit link-adaptive transmission to the terminals. This channel status information is generated as a terminal receives a reference signal to be transmitted via the downlink, and fed back to the base station through a control channel of the uplink. Therefore, an increase in the transmission cycle of the reference signal and the feedback cycle of the channel status information may increase a difference between the channel status having been fed back from a terminal to the base station and the channel status at the point when data is actually transmitted to the terminal, thereby causing inefficient link-adaptive transmission and deteriorating the system performance. The present invention thus provides a method and apparatus for designing an uplink periodic feedback structure for reducing the channel status difference in case a reference signal for the estimation of a downlink channel status is transmitted over a prolonged cycle, and distributing a feedback overhead of terminals in terms of the system.
摘要:
An initial access method of a user equipment (UE) and an apparatus performing the same are provided. The initial access method of a user equipment attempting access a macro cell base station in a network with which the macro cell base station and at least one Femto cell base station share, includes: receiving a cell ID from the macro cell base station or the Femto cell base station; transmitting an interference control request message to the Femto call base station when the received cell ID is a Femto cell ID; and receiving a macro cell ID provided from the macro cell base station when an interference control response message is received from the Femto cell base station to attempt an initial access. When a macro UE near to a Femto cell base station attempts to access a macro cell, it searches an ID of the macro cell through interference control from the Femto call base station to achieve initial access.
摘要:
A transmission method and apparatus utilizing Multiple-Input and Multiple-Output (MIMO) precoding based on Distributed Antenna Systems (DASs) are provided. The transmission method includes determining active antenna ports, for a User Equipment (UE) having multiple receive antennas, from among a plurality of Distributed Antenna Ports (DAPs) evenly placed in a service area; assigning a Multiple-Input and Multiple-Output (MIMO) mode to the UE and notifying the UE of the MIMO mode assignment; determining a signal precoding vector on a basis of feedback information for the MIMO mode received from the UE; and precoding a signal using the signal precoding vector and transmitting the precoded signal through the active antenna ports.
摘要:
The present invention relates to a method and apparatus for setting the transmission power of a terminal in a wireless communication system. Particularly, the initial transmission power by means of which the terminal transmits a signal via an uplink non-anchor carrier is determined by reflecting the transmission power by means of which the terminal has most recently transmitted a signal via an uplink anchor carrier and by reflecting the difference between channel environments of the uplink anchor carrier and the uplink non-anchor carrier, in a wireless communication system using a broadband formed by carrier aggregation. Consequently, the initial transmission power of the terminal is set as accurately as possible in the uplink non-anchor carrier, thereby preventing signal transmission delay and improving the reliability of received signals.
摘要:
A method is provided for allocating resources of a control channel in a mobile communication system using Orthogonal Frequency Division Multiplexing (OFDM). The method includes, when a time index and a frequency index of available Resource Elements (REs) are defined as l and k, respectively, dividing the available REs in a two-dimensional structure of (k, l); and time-first-allocating each RE to a plurality of RE groups while increasing the time index l for each frequency index k from an initial value up to a predetermined range.
摘要:
Feedback methods and apparatuses are provided for efficiently feeding back downlink Channel State Information (CSI) using limited information in a DAS-based wireless communication system. A method includes determining, by a receiver, a candidate Antenna Port (AP) set from among a plurality of APs; selecting an active AP set from the candidate AP set; and transmitting the candidate AP set, the active AP set, and the downlink CSI of active APs included in the active AP set
摘要:
A method and apparatus for transmitting a control channel in a base station for a wireless communication system. The base station transmits information including a number of channel elements constituting control channels, to a terminal; establishes a set of control channels that the terminal can receive, within the number of channel elements using an identifier (ID) of the terminal; and transmits control information to the terminal through a selected control channel among the control channels. The terminal is restricted to monitor only a proper number of control channels established without the need to monitor all control channels, thereby reducing reception complexity and avoiding unnecessary battery consumption.
摘要:
A method and apparatus for selecting and allocating antennas efficiently are provided. The method includes transmitting, to a User Equipment (UE), information indicating a configuration of a plurality of Channel Status Information Reference Signals (CSI-RSs) through UE specific signaling during an initial access attempt with the UE; receiving, from the UE, CSI-RS measurement results indicating configured CSI-RSs; transmitting CSI-RSs corresponding to a set of available distributed ports (D-ports) based on received signal strength information included in results of the CSI-RS measurement; and determining a CSI-RS of a selected D-port set for use in communications based on feedback information received from the UE.
摘要:
A method from transmitting data via multiple antennas. In this method, four information bits to be transmitted are multiplexed by using either one of a code division multiplexing scheme or a second code division multiplexing scheme combined with a real and imaginary multiplexing scheme, to generate a code division multiplexed symbol including four vectors. Then, the code division multiplexed symbol is repeatedly transmitted by alternatively applying two transmit diversity schemes via four transmission antennas.
摘要:
A method for transmitting and receiving a codebook subset restriction bitmap is provided. The Codebook Subset Restriction (CSR) bitmap transmission method of an evolved Node B (eNB) in transmission mode 9 for communication with 8 antenna ports includes generating a CSR bitmap including bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a User Equipment (UE). The CSR bitmap comprises 53 bits corresponding to a first codebook and 56 bits corresponding to a second codebook, the 53 bits corresponding to a first codebook comprise 16, 16, 4, 4, 4, 4, and 1 bits for layers 1, 2, 3, 4, 5, 6, 7, and 8, respectively, and the 56 bits corresponding to a second codebook comprise 16, 16, 16 and 8 bits for layers 1, 2, 3, and 4, respectively.