Abstract: Disclosed is a method for receiving data that can reduce intersymbol interference (ISI) and interlink interference (ILI) occurring in a MIMO molecular communication system. An embodiment of the present invention provides a method for receiving data at a receiver in a MIMO molecular communication system, where the method includes: determining an enzyme inhibitor discharge stopping timepoint by using the distance between the antennas of the transmitter and the distance between the transmitter and the receiver; discharging an enzyme inhibitor, which is configured to deactivate an enzyme that is distributed around the receiver, and receiving a molecule transmitted from the transmitter; and stopping the discharge of the enzyme inhibitor according to the enzyme inhibitor discharge stopping timepoint, and where the enzyme is reactive to the molecule.

Abstract: Example embodiments are directed to methods of reducing interference in a communication system. In at least one example embodiment, a method includes first determining, by a first transmitter having a multi-directional antenna configured to produce a plurality of beams, at least one interference level of at least one interfering beam of a plurality of beams of at least one transmitter in the communication system, second determining a transmitting beam pattern based on the interference level, the transmitting beam pattern indicating a sequence of illuminating the plurality of beams at corresponding time slots, third determining a fractional frequency reuse pattern based on the transmitting beam pattern, and transmitting data based on the transmitting beam pattern and the frequency reuse pattern.

Abstract: A method and apparatus for a channel feedback by a signal transmitting device in a Multiple Input Multiple Output (MIMO) system are provided. The method includes transmitting a pilot in which a compression rate is reflected to a signal receiving device; receiving channel related information on a compressed channel from the signal receiving device; and performing a precoding based on the channel related information. The apparatus includes a transmitting unit configured to transmit a pilot to which a compression rate is reflected to a signal receiving device; a receiving unit configured to receive channel related information on a compressed channel from the signal receiving device; and a precoding unit configured to perform a precoding based on the channel related information.

Abstract: An apparatus and a method for feeding a channel back in a wireless communication system using multiple input multiple output antennas (MIMO) are provided. The method includes receiving a signal from a transmitter and configuring a channel matrix for the received signal, configuring a basis transformed sparse channel using a sparsifying basis function with respect to the channel matrix, selecting a channel part to be fed back to the transmitter from the transformed sparse channel, and creating a codebook by quantizing the selected channel part, and feeding a codebook index corresponding to the created codebook back to the transmitter.

Abstract: An apparatus and a method for feeding a channel back in a wireless communication system using multiple input multiple output antennas (MIMO) are provided. The method includes receiving a signal from a transmitter and configuring a channel matrix for the received signal, configuring a basis transformed sparse channel using a sparsifying basis function with respect to the channel matrix, selecting a channel part to be fed back to the transmitter from the transformed sparse channel, and creating a codebook by quantizing the selected channel part, and feeding a codebook index corresponding to the created codebook back to the transmitter.

Abstract: A method and apparatus for a channel feedback by a signal transmitting device in a Multiple Input Multiple Output (MIMO) system are provided. The method includes transmitting a pilot in which a compression rate is reflected to a signal receiving device; receiving channel related information on a compressed channel from the signal receiving device; and performing a precoding based on the channel related information. The apparatus includes a transmitting unit configured to transmit a pilot to which a compression rate is reflected to a signal receiving device; a receiving unit configured to receive channel related information on a compressed channel from the signal receiving device; and a precoding unit configured to perform a precoding based on the channel related information.

Abstract: Example embodiments are directed to methods of reducing interference in a communication system. A method includes receiving, by a transmitter, first and second quantized matrices from a mobile station. The first and second quantized matrices are based on an estimated channel matrix and an estimated interference matrix. The method further includes determining, by the transmitter, a transmission beamforming vector based on the first and second quantized values.

Abstract: Examples are generally described that include methods for selecting a transmit mode in a communications system. An example method may include calculating a first transmission rate for data in a multiple-input multiple-output mode of the communications system and calculating a second transmission rate for the data in a single-input multiple-output mode of the communications system. A mode may be selected from the group consisting of the multiple-input multiple-output mode and the single-input multiple-output mode based, at least in part, on an energy consumption of the first and second transmission rates. Data may be transmitted from a transceiver in the communications system using the selected mode.

Abstract: An apparatus and method are provided for beamforming in a MIMO wireless communication system. A base station includes a first calculator that repeatedly calculates downlink beamforming vectors of the user terminals to calculate the optimal beamforming vectors for the user terminals, a quantizer that quantizes the downlink beamforming vectors in order to transmit information of the downlink beamforming vectors, a control channel transmitter that feeds forward information of the quantized downlink beamforming vectors to the user terminals, a second calculator that calculates the final downlink beamforming vectors of the user terminals, and a beamforming transmitter that sums the beamformed TX signals of the user terminals and transmits the summed TX signals through a plurality of TX antennas.

Abstract: A base station is capable of transmitting a signal in a wireless communication network. The base station decides channel state information matrices of respective channels by determining a state of the channels corresponding to respective transmission antennas. The base station calculates transmission beam forming vectors for the respective transmission antennas by a combination of a dot product and a cross product of the channel state information matrices. Thereafter, the base station beam-forms signals for the respective transmission antennas by using the respective transmission beam forming vectors, and transmitting the beam-formed signals.

Abstract: A precoder and a precoding method in a multiuser multi-antenna system are provided. The precoder includes a channel checker for determining a DownLink (DL) channel condition of terminals in a service coverage area, a pre-compensator for pre-compensating, for channel distortion, signals to be sent to the terminals when a nonlinear algorithm is selected based on the channel condition of the terminals, and an interference remover for canceling interference in a channel by multiplying the pre-compensated signals by inverse channels of the terminals, and for canceling interference between the terminals. Accordingly, the pre-equalization can be carried out without global channel state information, and an increase of the transmit power can be prevented in the permutation.

Abstract: A method for beamforming by a transmission device in a multiantenna multiuser communication system. The method includes grouping codebook indexes included in a codebook into codebook index combinations, and calculating a sum of transmission rate for each of the codebook index combinations; selecting a codebook index combination with a maximum sum of transmission rate as an optimal codebook index combination; and transmitting a codebook index corresponding to a particular reception device among codebook indexes included in the optimal codebook index combination, to the particular reception device.

Abstract: An apparatus and method for beamforming in a Multiple Input Multiple Output (MIMO) wireless communication system are provided. A Base Station (BS) includes a calculator for generating relational expressions between beamforming vectors of Mobile Stations (MSs) using channel information of each MS, for determining beamforming vector candidates of each MS from the relational expressions using generalized Eigen-analysis, and for selecting beamforming vectors for each MS from the beamforming vector candidates, and a plurality of Transmit (Tx) beamformers for performing Tx beamforming on dedicated pilot symbols to be transmitted to each MS using the beamforming vectors for each MS.

Abstract: A method of selecting beamforming vectors for a first transmitter and a first receiver communicating via a first communication link to reduce interference at a second transmitter and a second receiver communicating via a second communication link includes estimating a transmission null space for the second transmitter with respect to the first receiver and estimating a reception null space for the second receiver with respect to the first transmitter. The method further includes determining a first transmission beamforming vector for the first transmitter that falls within the estimated reception null space, and determining a first reception beamforming vector for the first receiver that falls within the estimated transmission null space.

Abstract: A multiple antenna system for using a relay station with multiple antennas is provided. The system includes a base station for determining encoded data processing procedure based on first and second channel state information, determining a relaying procedure of the relay station, and sending the relaying procedure to the relay station based on the first and second channel state information; wherein the encoded data is terminating to a mobile station; the relay station for receiving data and the relay procedure which the base station sent, converting and sending the data according to the relaying procedure, and sending the first channel state information to the base station as a measured state of channel which receives the data; and the mobile station for receiving the data which the relay station sent, and sending the second channel state information to the relay station as a measured state of channel which receives the data.

Abstract: A transmitter in a multiple input multiple output (MIMO) communication system is provided. The transmitter includes a multiplexer for multiplexing an input bit stream into a plurality of bit streams, and outputting the bit streams in parallel; a bit-order rearranger for reordering bits constituting the bit streams, which are output from the multiplexer in the same time period, and outputting the reordered bits as reordered bit streams; and a modulator for modulating the parallel reordered bit streams output from the bit-order rearranger according to their associated modulation schemes, and transmitting the modulated symbols via their associated antennas.

Abstract: Example embodiments are directed to methods of reducing interference in a communication system. A method includes receiving, by a transmitter, first and second quantized matrices from a mobile station. The first and second quantized matrices are based on an estimated channel matrix and an estimated interference matrix. The method further includes determining, by the transmitter, a transmission beamforming vector based on the first and second quantized values.

Abstract: Example embodiments are directed to methods of reducing interference in a communication system. In at least one example embodiment, a method includes first determining, by a first transmitter having a multi-directional antenna configured to produce a plurality of beams, at least one interference level of at least one interfering beam of a plurality of beams of at least one transmitter in the communication system, second determining a transmitting beam pattern based on the interference level, the transmitting beam pattern indicating a sequence of illuminating the plurality of beams at corresponding time slots, third determining a fractional frequency reuse pattern based on the transmitting beam pattern, and transmitting data based on the transmitting beam pattern and the frequency reuse pattern.

Abstract: Provided is an apparatus and method for transmitting/receiving data in a multi-user multi-antenna communication system. A data transmitting apparatus and method computes a RX filter or a TX filter for each user receiver in an improved scheme, selects a codebook correlating with the computed TX filter or the computed RX filter, and transmits an index of the selected TX filter codebook or an index of the selected RX filter codebook to a receiver. A data receiving apparatus and method receives the codebook index and detects a corresponding RX filter from the codebook by using the received codebook index.

Abstract: An apparatus and method for selecting at least two users to be serviced in SDMA in an SDMA wireless communication system are provided. All users are ordered according to a predetermined rule and all possible user combinations each having at least two users are created from the ordered users. An investigation limit number is set using the capacity of a jth user combination. Or a total investigation number is reduced by comparing the interference-reflected SNR decrements of users with an investigation threshold. Therefore, the computation volume for selecting SDMA users is decreased.