Inha-industry Partnership Institute

Electronics and Telecommunications Research Institute

Intellectual Discovery Co., Ltd.

Kyung Hi Chang

Mun Geon Kyeong

Youn Ok Park

Yang Gi Kang

Zeeshan Kaleem

Hyung Rae Park

Manar Mohaisen

Eung Soon Shin

Tae Hyoung Sun

Bing Hui

Bon Tae Koo

Hyun Seo Oh

Young Seok Baek

Jae Hyeong Kim

Jong Hun Kim

Sang Jun Ko

Young Bum Kim

Yunpeng Li

Hong Sun An

Seong Rak Kim

Cheng Chao Liang

Kyu Hyun Kim

Jeong Ho Roh

Seung Won Kang

Hyung Gun Park

A method and apparatus for an interference-aware resource-sharing scheme for multiple D2D group communications is provided. The method for interference-aware resource-sharing scheme for multiple D2D communications includes initializing a D2D communication request and deciding the numbers of D2D pairs and CUEs, grouping D2D pairs according to the decided numbers of the D2D pairs and CUEs, selecting target CUEs for the grouped D2D pairs to share frequency resources, applying interference alignment to the D2D groups, updating the set of the CUEs and D2D pairs, and moving the rest of the D2D pairs to the orthogonal group.

Method and apparatus for interference-aware resource-sharing scheme for multiple D2D group communications underlaying cellular networks

There is provided a method for removing interference between a femto-cell and a macro-cell, comprising: allocating communication resources to a plurality of femto-cell user devices; receiving uplink signals between a plurality of the macro-cell user devices and a macro-cell base station from the plurality of the macro-cell user devices; detecting a high interference indicator (HII) from the uplink signals; deciding a macro-cell user device, which has transmitted the high interference indicator, as an interference subject user device; extracting channel state information (CSI) from the uplink signal received from the interference subject user device; and changing and allocating the communication resource allocated to the femto-cell user device based on the extracted channel state information.

Apparatus and method for mitigation/removal of interference between macro-cell and femto-cell

A power control system and method to mitigate interference in a heterogeneous network is provided. A power control method to mitigate interference may include: receiving a link connection request from a femto terminal; transmitting a downlink signal when the link connection request is allowed; receiving information of a macro terminal present around a femto base station; controlling a power of the downlink signal in response to a high interference indicator (HII) report being included in the received information of the macro terminal; and controlling the power of the downlink signal based on a priority of service while satisfying predetermined constraints, in response to the HII report in a state in which the power of the downlink signal is decreased up to a predetermined required power.

System and method to mitigate interference of 3GPP LTE heterogeneous network according to priority of service

A method and system to dynamically allocate a frequency based on a priority of quality of experience (QoE) is disclosed. A method to dynamically allocate a frequency may include: securing a predetermined frequency band and a bonus frequency band for a macrocell; allocating the predetermined frequency band and the bonus frequency band to a macro terminal located in the macrocell; allocating the bonus frequency band based on the priority of service in a subsequent time slot when a frequency band comprising the predetermined frequency band and the bonus frequency band is not allocated to the macro terminal.

System and method to allocate frequency dynamically based on priority of quality of experience (QoE) in 3GPP LTE heterogeneous network

There is provided a signal detecting method using constellation set grouping in a spatial multiplexing multiple input multiple output system. The signal detecting method includes dividing a set of candidate symbols, a constellation set into a plurality of subsets by grouping the constellation set; dividing a tree search process of a QR-decomposition with M-algorithm (QRDM) algorithm into a plurality of partial detection phases; and performing the plurality of divided partial detection phases in parallel or iteratively.

Adaptive QRD-M algorithm based signal detecting method by using constellation set grouping in spatial multiplexing multiple-input multiple-output system

Disclosed herein is a ranging apparatus and method. The ranging apparatus includes a correlation unit for correlating OFDMA reception signals with inverse fast Fourier transformed ranging codes, and outputting correlation result values. A threshold determination unit determines a threshold value depending on characteristics of the reception signals. A comparison unit estimates a delay time by selecting a maximum value from among the correlation result values, and detects a ranging code by comparing the maximum value with the threshold value, and then outputs and feeds back the ranging code and the delay time when the maximum value is equal to or greater than the threshold value. A weight multiplication unit delays the ranging code by the delay time, multiplies a weight by the delayed ranging code, and outputs a resulting value. A calculation unit subtracts the resulting value from the reception signals, and provides adjusted reception signals.

Ranging apparatus and method for improving ranging performance in OFDMA system

Provided is a method for retransmitting data based on antenna scheduling in a MIMO system to which a spatial multiplexing technique is applied. The method includes the steps of: (a) at a transmitter side, modulating an input packet into transmittable data to transmit to a receiver side; (b) at the receiver side, estimating channel values from the packet transmitted from the transmitter side, and selecting transmitting and receiving antennas for transmitting the next packet from the estimated channel values; (c) detecting whether an error is present in the packet or not, and transmitting a feedback signal to the transmitter side, the feedback signal including information on whether or not to transmit the packet and a list of the selected transmitting antennas; and (d) at the transmitter side, retransmitting the transmitted packet or transmitting the next packet through the transmitting antennas designated by the receiver side depending on the feedback signal.

Method and apparatus for retransmitting data based on antenna scheduling in MIMO system

Provided is a method for dynamic resource allocation of uplink and downlink in an OFDMA/TDD cellular system. The method for dynamic resource allocation of uplink in an OFDMA/TDD cellular system includes the steps of determining the number of sub-channels which can be allocated to each user through an FLR algorithm; performing channel allocation for a first frame through a round-robin algorithm in which channel information is not needed; performing dynamic channel allocation for a next frame through uplink channel information measured by uplink channel sounding; and performing power control. The method for dynamic resource allocation of downlink in an OFDMA/TDD cellular system includes the steps of selecting a user through a GPF algorithm; performing dynamic channel allocation through an ASA algorithm so as to perform a FASA algorithm for obtaining a multiuser diversity gain; and performing dynamic power allocation through an improved CHC algorithm, in consideration of a data rate provided to each user and a channel state.

Method for dynamic resource allocation of uplink and downlink in OFDMA/TDD cellular system

The present invention relates to a system for canceling co-channel interference (CC) in a cellular orthogonal frequency division multiplexing (OFDM) system. The system canceling co-channel interference (CCI) in a cellular orthogonal frequency division multiplexing (OFDM) system comprises a mobile station (MS) receiver including a feedback generation unit for generating a feedback to a base station (BS) so as to control a transmission power of the transmitting frame of the BS, and a maximum likelihood estimation (MLE) CCI cancellation unit for canceling CCI signals arriving from neighbor cells; and a BS transmitter including a closed-loop power control unit for controlling the transmission power of the transmitting frame according to the feedback received from the MS such that received power of desired signal at the MS receiver is different from that of an interferer signal.

System and method for co-channel interference cancellation in cellular OFDM systems

Provided are a synchronization apparatus and method for improving timing estimation performance in an OFDM-FDMA/CDMA/TDMA system, which can correctly estimate symbol timing through a more correct timing metric using a guard interval of a preamble. The synchronization apparatus includes an auto-correlator for calculating an auto-correlation value of a received signal and a signal delayed by a predetermined time, a power detector for calculating power of the received signal, a timing metric/normalizer for normalizing the auto-correlation value by dividing the auto-correlation value by the calculated power to obtain a timing metric, and a peak detector for finding a peak value of the timing metric to estimate a frame starting position and an initial symbol timing. The auto-correlator calculates an auto-correlation length as long as a length of a guard interval, considering the preamble characteristic that the patterns are repeated in the time domain. The initial symbol timing is set to a position determined by adding the position where the timing metric has a peak value to the length of the guard interval and subtracting the maximum value of the expected channel delay spread from the result value.

Synchronization apparatus and method for improving timing estimation performance in OFDM-FDMA/CDMA/TDMA system

In the hardware-efficient demodulator for a CDMA adaptive antenna array mechanism of a mobile radio communication system, a correlators bank receives digital baseband signals received through an antenna array of a base station and computes correlation values with a local code sequence. A beamformer receives the digital baseband signals and the correlation values from the correlators bank and calculates beamforming weight vectors. A searchers bank receives the digital baseband signals and calculates an initial acquisition and reliable timing information for a multipath search by a common work with the beamformer, which uses a beamforming algorithm. A beamforming complex multiplier for a finger performs a complex multiplication for the beamforming weight vectors and the digital baseband signals, and sums up them. A finger bank receives output signals from the beamforming complex multiplier, executes a code tracking for an alignment between a transmission code and a phase by each multipath on the basis of the multipath search timing information to then provide the timing information of the multipath tracking to the correlators bank, and outputs signals of dispreaded multipath through a time alignment based on each path. A multipath combiner performs a multipath combination for the output signals of the finger bank on a time base and outputting it.

Hardware-efficient demodulator for CDMA adaptive antenna array systems

This invention relates to a method and apparatus for increasing the performance of searcher by using the array antenna when the signal to interference plus noise ratio is low. The two-dimensional searcher performs the spatial-filtering to reduce the noise and interference components and then correlates the spatial-filtered signal with a pseudo noise (PN) code to thereby detect the incoming signals and acquire the corresponding code timings. Furthermore, the two-dimensional searcher can be used to increase the performance of a finger beamformer in two ways. One is to use searcher beamforming weight as initial finger beamforming weight to increase the convergence speed in the adaptive beamforming algorithms. The other is to reduce an amount of computation in the angle of arrival estimation algorithms by calculating the azimuth power spectrum only for the specific angle range.

Method and apparatus for searcher beamforming in CDMA base station system using array antenna

A sectored antenna system to optimize the distance between adjacent sensors of an array antenna in a CDMA mobile communication system in which success rate of softer handoff and antenna gain is increased and power consumption of terminals may be evenly distributed. In the CDMA mobile communication system, a cell is divided into a number of sectors. A sector antenna system comprising a number of linear array antennas, in which distance between the antenna sensors is determined in consideration of overlapping angle of beams to supply softer handoff is provided. The system also includes carrier demodulators, matched filters, a weight vector estimator, weight vector multipliers, weight vector combiners, parallel demodulators, and a signal combiner.

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Seoul, South Korea

Kyung Hi Chang