Abstract: An apparatus and a method for manage network entry in a heterogeneous network (HetNet). In the method for network entry of a terminal in a HetNet, a base station access signal for network entry is transmitted to a serving base station. A response message is received from the serving base station. An uplink parameter is controlled based on an indication of the serving base station included in the response message. An access request message is generated and transmitted to the serving base station. A downlink response message including information regarding a selected serving base station is received from the serving base station. An access response message including information for network entry is received from the selected serving base station. A network entry procedure is performed with the selected serving base station.

Abstract: An apparatus and a method for ranging in a distributed antenna system are provided. A method for an operation of a Mobile Station (MS) in a distributed antenna system includes obtaining per-group ranging code configuration information indicating a ranging code allocation for each antenna port group, determining an antenna port group that the MS belongs to, and performing a ranging procedure by one of a plurality of ranging codes allocated to the antenna port group that the MS belongs to.

Abstract: Disclosed is a method and an apparatus for subchannel assignment for suppressing inter-antenna interference in an Orthogonal Frequency Division Multiplexing Access (OFDMA) system based distributed wireless communication system equipped with antennas that are randomly distributed in a geographical manner and can simultaneously communicate with multiple Subscriber Stations (SSs). The method includes selecting and obtaining access to distributed antennas which satisfy the data transmission rate that an SS requires and with which the SS can communicate; re-queuing a distributed antenna having the maximum transmitted power within the same cell in high priority; and assigning subchannels to the relevant distributed antennas in an order from the relevant distributed antenna having the high priority.

Abstract: An apparatus and a method for operating a Mobile Station (MS) in a wireless communication system are provided. The method includes receiving a threshold for a gap of an average Receive (Rx) power between a neighboring Base Station (BS) and a serving BS, transmitting to the serving BS, identification information of a BS having the average power greater than a first value, receiving information of a BS involving joint processing generated using information of the BS having the average power greater than the first value, feeding Precoding Matrix Index (PMI) information of the BS involving the joint processing, back to the serving BS, receiving information indicating a PMI operation mode of the MS, from the serving BS, and determining a PMI operation mode according to the information indicating the PMI operation mode of the MS.

Abstract: A method for mitigating interference by a femto Base Station (BS) in a wireless communication system including a macro BS is provided. The method includes receiving information about resources allocated for a channel measurement signal from the macro BS, measuring an UpLink (UL) power by detecting a channel measurement signal transmitted from at least one Mobile Station (MS) to the macro BS based on the received information, determining MSs whose UL powers are greater than or equal to a threshold, and transmitting identification information for the MSs to the macro BS.

Abstract: Disclosed is a device for allocating transmission power using a symbol error rate (SER) for orthogonal space-time block codes (OSTBC) in a wireless communication system. The device includes: a plurality of antennas, which are distributed geographically and independently linked to a central processing unit; a receiver to select an optimum subset of the SER performance, using a preset power allocation to each of available antenna subset combinations, and sending the selected subset to a transmitter; and a central processing unit to allocate power by applying an OSTBC symbol having a unit average power to the optimum subset from the receiver.

Abstract: An apparatus that adaptively allocates transmission power for beam-forming combined with orthogonal space time block codes in a distributed wireless communication system, the apparatus including: sub-arrays for beam-forming, which are geographically distributed and each of which includes a plurality of distributed antennas placed in random groups. A central processing unit provides predetermined combinable power allocation schemes according to subsets in a plurality of the sub-arrays, identifying performances of the schemes by using information on large-scale fading of each of the sub-arrays fed back from a receiving party, setting a subset having best performance as an optimal subset according to the identified performances, and performing power allocation according thereto.

Abstract: A calibration apparatus and a calibration method for multicell Multiple Input Multiple Output (MIMO) transmission in a multiple antenna system are provided. More particularly, an operating method of a Mobile Station (MS) for performing calibration for multicell MIMO transmission in a multiple antenna system includes negotiating a multi-Base Station (BS) joint processing with a BS, receiving a control message including information instructing multi-BS calibration for sounding based on the multi-BS joint processing, from the BS; when receiving the control message involving the multi-BS joint processing, generating a second sounding sequence by mapping estimated phases of downlink channels per subcarrier of BSs to a first sounding sequence allocated from the BS, and transmitting the second sounding sequence, including the phases of the downlink channels per subcarrier, over a sounding symbol interval with respect to each of the BSs involving the multi-BS joint processing.

Abstract: Provided is a device and a method for eliminating inter-cell interference in Multiple Input Multiple Output (MIMO) wireless communication system. The method for operating a user equipment for eliminating the inter-cell interference includes determining one or more optimum bands among bands not requested to be restricted from a neighboring cell, determining at least one of band and Precoding Matrix Index (PMI) to be requested to be restricted to the neighboring cell among the determined one or more optimum bands, and feeding back at least one of the band and PMI to be requested to be restricted to the neighboring cell to a serving base station.

Abstract: Disclosed is an apparatus and method for adaptively allocating transmission power for beamforming combined with orthogonal space-time block codes (OSTBC) in a distributed wireless communication system, the apparatus comprising: a plurality of sub-arrays for beamforming, which are geographically distributed and each of which comprises a plurality of distributed antennas placed in random groups; and a central processing unit for identifying performances of subsets by applying a predetermined power allocation scheme according to subsets which can be obtained by combining the sub-arrays, by means of a Nakagami fading parameter and information about large-scale fading of each of the sub-arrays, fed back from a receiving party, for determining a subset having a best performance as an optimal subset according to the identified performances, and for performing power allocation based on the subset set as the optimal subset.

Abstract: A method for triggering multicell MIMO schemes in a multiple antenna system includes transmitting, at a Mobile Station (MS), a first feedback information for single-cell closed-loop MIMO to a Base Station (BS); requesting, at the BS, Normalized Interference Power (NIP) feedback from the MS based on the first feedback information; feeding, at the MS, the NIP back to the BS; selecting, at the BS, a first NIP threshold and a second NIP threshold based on the NIP fed back from the MS; and requesting, at the MS, one of a first MIMO scheme and a second MIMO scheme by comparing the calculated first and second NIPs with the first NIP threshold and the second NIP threshold.

Abstract: A method and apparatus reduce overhead of feedback in a closed loop Multiple Input Multiple Output (MIMO) system. A controller feeds back the long-term Precoder Matrix Index (PMI) to a serving base station under direction of the serving base station when the long term PMI feedback transmission is required, generates a new codebook using the long term PMI, and determines a short term PMI from the new codebook. A feedback transmitter feeds back the short-term PMI to the serving base station.

Abstract: A Mobile Station (MS) apparatus and a Base Station (BS) apparatus, and methods for their operation in a wireless communication system, are provided. The method for operating the MS includes receiving Precoding Matrix Index (PMI) subset information from a BS, determining downlink channel quality of the BS, determining a PMI for the BS based on the PMI subset information and the determined downlink channel quality of the BS, and transmitting the determined PMI to the BS.

Abstract: A multiple antenna system including a mobile station and a base station are operable to perform a method for transmitting control information for interference mitigation. A Mobile Station (MS) can transmit control information for interference mitigation. The MS determines a first Precoding Matrix Index (PMI) and a second PMI for interference from an adjacent Base Station (BS). Based on a correlation level from correlation values between one of the first PMI and second PMI and the remaining PMIs in the codebook, the MS determines a level of a subset of PMIs, and feeds back information indicating the correlation level.

Abstract: A method for operating a Mobile Station (MS) in a Multiple Input Multiple Output (MIMO) wireless communication system is provided. The method includes measuring channel quality for a serving Base Station (BS), if the channel quality is less than a threshold, measuring interference power from one or more neighbor BSs, determining a Precoding Matrix Index (PMI) and a priority metric for each neighbor BS, and feeding back at least one of the PMI, a PMI type indicator, the priority metric, and the channel quality to the serving BS.

Abstract: Disclosed is a method and an apparatus for assigning a subcarrier to a subcell serviced by a Distributed Antenna System (DAS) employing an Orthogonal Frequency Division Multiplexing Access (OFDMA) scheme in a broadband wireless access system. The method includes dividing an overall frequency band into multiple subcarrier bands, assigning the multiple subcarrier bands to respective Base Stations (BSs) without overlap among the BSs adjacent to one another in assigning the multiple subcarrier bands corresponding to the divided overall frequency band to the respective BSs and dividing the assigned subcarrier bands and selectively assigning the divided subcarrier bands to multiple Remote Stations (RSs) connected with the BSs through optical fibers.

Abstract: Disclosed is a method and an apparatus for subchannel assignment for suppressing inter-antenna interference in an Orthogonal Frequency Division Multiplexing Access (OFDMA) system based distributed wireless communication system equipped with antennas that are randomly distributed in a geographical manner and can simultaneously communicate with multiple Subscriber Stations (SSs). The method includes selecting and obtaining access to distributed antennas which satisfy the data transmission rate that an SS requires and with which the SS can communicate; re-queuing a distributed antenna having the maximum transmitted power within the same cell in high priority; and assigning subchannels to the relevant distributed antennas in an order from the relevant distributed antenna having the high priority.

Abstract: A method for Symbol Error Rate (SER) approximation of an SER-based transmission power allocation operation for an Orthogonal Space Time Block Code in a DWCS equipped with multiple transmission Distributed Antennas (DA) geographically dispersed at random. The method for SER approximation includes the steps of: setting multiple combinable antenna subsets from the multiple DAs; selecting a quasi-optimal antenna subset Ag (1?g?2n?1) having a quasi-optimal power allocation weight wg based on predetermined power allocation, for each of the set multiple antenna subsets; and calculating an SER approximation value of the selected quasi-optimal antenna subset by applying a Probability Density Function (PDF) of a Signal-to-Noise Ratio (SNR) to the OSTBC SER having symbol constellation of a predetermined modulation scheme. The output of the SER approximation value can be output to a transmitter, or to a space-time encoder of a central processor for optimal power transmission.

Abstract: Disclosed is a system and a method for performing handover in a Worldwide interoperability for Microwave Access (WiMAX) mobile communication system supporting broadband wireless access. The system includes a plurality of Mobile Stations (MSs); at least one distributed antenna having the ability to perform simultaneous communications with the plurality of MSs; and a base station connected to the at least one distributed antenna through optical fibers for performing communications and handovers with the multiple MSs.

Abstract: A system and a method for forming a cell by using distributed antennas in a World interoperability for Microwave Access (WiMAX) mobile communication system supporting a broadband wireless access communication system. A virtual cell is formed with a specific Mobile Station (MS) as a central part of the virtual cell by using distributed antennas, which improves the transmission capacity and the performance of an overall network system without changing the structure of a backbone network and the interface of the overall network system. The system includes, multiple MSes; distributed antennas for perform simultaneous communications with at least one MS among the multiple MSes, and for forming one virtual cell by communicating with the multiple MSes; and a Base Station (BS), which is typically connected to the distributed antennas through optical fibers, for communicating with the MSes.