Abstract: Provided is a method for generating, by a base station, a common signal commonly required for surrounding terminals of the base station in a massive multiple input multiple output (MIMO) system. The base station generates data commonly required for the surrounding terminals. The base station generates a plurality of beamforming vectors using a time-domain constant amplitude (TCA)-frequency-domain constant amplitude (FCA) sequence having a constant size in a time domain and a frequency domain. Further, the base station generates a plurality of antenna streams corresponding to the common signal by multiplying the plurality of beamforming vectors by the data.

Abstract: A transmitter generates a first precoding vector for a first virtual antenna port among a plurality of virtual antenna ports using a first sequence having a constant magnitude and a discrete Fourier transform (DFT) vector sequence in a time domain and a frequency domain. The transmitter generates a plurality of second precoding vectors for the remaining virtual antenna port, except for the first virtual antenna port of the plurality of virtual antenna ports by circular shifting the first precoding vector. The transmitter maps a plurality of first data streams for the plurality of virtual antenna ports to a plurality of physical antenna ports using the first precoding vector and the plurality of second precoding vectors.

Abstract: A transmitter generates a first precoding vector for a first virtual antenna port among a plurality of virtual antenna ports using a first sequence having a constant magnitude and a discrete Fourier transform (DFT) vector sequence in a time domain and a frequency domain. The transmitter generates a plurality of second precoding vectors for the remaining virtual antenna port, except for the first virtual antenna port of the plurality of virtual antenna ports by circular shifting the first precoding vector. The transmitter maps a plurality of first data streams for the plurality of virtual antenna ports to a plurality of physical antenna ports using the first precoding vector and the plurality of second precoding vectors.

Abstract: Provided is a method for generating, by a base station, a common signal commonly required for surrounding terminals of the base station in a massive multiple input multiple output (MIMO) system. The base station generates data commonly required for the surrounding terminals. The base station generates a plurality of beamforming vectors using a time-domain constant amplitude (TCA)-frequency-domain constant amplitude (FCA) sequence having a constant size in a time domain and a frequency domain. Further, the base station generates a plurality of antenna streams corresponding to the common signal by multiplying the plurality of beamforming vectors by the data.

Abstract: Disclosed are payload formatting and deformatting methods for burst data loss recovery. The payload formatting method according to an embodiment of the present invention includes: generating an XOR operation packet by performing an XOR operation on the basis of a base layer packet and any one of enhancement layer packets of a group of pictures (GoP), the GoP including the base layer packet and the enhancement layer packets; and adding the XOR operation packet to the GoP.

Abstract: Provided is a multi-dimensional layered modulation transmitting and receiving apparatus and method for stereoscopic three-dimensional (3D) video data. The transmitting apparatus may convert multi-dimensional data to a plurality of stream data by mapping the multi-dimensional data to a complex number plane, and may transmit the plurality of stream data by mapping the plurality of stream data to dimensions divided based on a time and a space, respectively. The receiving apparatus may determine a signal strength of received signal, a performance, a power mode, may determine a service image corresponding to the signal strength, the performance, the power mode, may determine a dimension corresponding to the service image, and may receive stream data of the determined dimension.

Abstract: In order to provide a three-dimensional (3D) video streaming service to a user terminal, user characteristic information including eyesight information of the left eye and the right eye of a user is received from the user terminal. Then, one of quality of a left image and that of a right image is improved in accordance with the eyesight information so that an image with improved quality is transmitted to the user terminal.

Abstract: Disclosed are a graceful degradation-forward error correction method and an apparatus for performing same. A graceful degradation-forward error correction method determines an encoding unit data group constituted by a predetermined number of time intervals for a data stream input in a time-sequential manner, determines a reference data group to be used in generating a parity frame in each time interval of the encoding unit data group, generates a parity frame using the determined at least one reference data group, and assigns the generated parity frame to at least one time interval from among a plurality of time intervals including time intervals constituting the encoding unit data group based on a predetermined rule. Thus, a lost packet can be recovered even when the packet of a continuous long interval is lost, and consequentially, a seamless service may be provided.

Abstract: Provided is a multi-dimensional layered modulation transmitting and receiving apparatus and method for stereoscopic three-dimensional (3D) video data. The transmitting apparatus may convert multi-dimensional data to a plurality of stream data by mapping the multi-dimensional data to a complex number plane, and may transmit the plurality of stream data by mapping the plurality of stream data to dimensions divided based on a time and a space, respectively. The receiving apparatus may determine a signal strength of received signal, a performance, a power mode, may determine a service image corresponding to the signal strength, the performance, the power mode, may determine a dimension corresponding to the service image, and may receive stream data of the determined dimension.

Abstract: Provided is a data transmission system using a vertical layer optimisation technique. A data transmission device predicts the buffer state of a data receiving device by using feedback information of a physical layer, and controls data transmission by referring to the predicted buffer state. The data transmission device can control the transmission of first data and second data such that the buffer state of the receiving device is within a preset range.

Abstract: Disclosed are payload formatting and deformatting methods for burst data loss recovery. The payload formatting method according to an embodiment of the present invention includes: generating an XOR operation packet by performing an XOR operation on the basis of a base layer packet and any one of enhancement layer packets of a group of pictures (GoP), the GoP including the base layer packet and the enhancement layer packets; and adding the XOR operation packet to the GoP.

Abstract: A method and an apparatus for providing video service according to example embodiments of the present invention are disclosed. The method for providing video service according to one example embodiment of the present invention comprises determining based on a predetermined reference whether it is necessary to set multiple bearers to provide the video service for a terminal, and when it is determined necessary to set the multiple bearers, setting an additional bearer, dividing a video source stream into a first stream and a second stream, assigning the first and second streams to a default bearer and the additional bearer, respectively, and transmitting the first and second streams to the terminal.

Abstract: Provided is a method of retransmitting and receiving a packet in heterogeneous network environment. A terminal and a relay base station receive a packet transmitted from a macro base station, and the relay base station informs the terminal of whether the packet is successively received or not. When the packet fails to be received, the terminal is configured to receive the erroneous packet again from at least one of the macro base station and the relay base station. The macro base station and the relay base station may be configured to retransmit the packet through joint processing JP) transmission, and the terminal may be configured to receive the JP transmission. Thus, the method allows the m optimization of a HARQ process and scheduling scheme to efficiently utilize a relay and radio resources, thereby leading to a maximum capacity and quality of wireless network.

Abstract: Provided are an apparatus and method for transmitting multimedia data in a wireless network. The apparatus and method receive multimedia data classified into at least one layer, and set different radio bearer channels for the respective at least one multimedia layer. Here, a service quality parameter is differentially applied to the respective set radio bearer channels, so that end-to-end quality of service (QoS) improvement is maximized.

Abstract: A transmitter that transmits data using a multiple antenna includes a multiple description coder that generates a plurality of descriptions by performing multiple description coding of the data, and a multiple input multi output (MIMO) transmitting unit that performs channel coding of the plurality of descriptions and that transmits a description in which channel coding is performed through the multiple antenna.

Abstract: An adaptive power control method for a CDMA mobile radio telephone system is disclosed which operates similarly to a fixed increment and decrement power control method in the portion where the slope of the channel signal due to a fading effect is steep when the transmission power of a mobile station is adjusted. In the portion where the slope of the channel signal is gentle, like the peak portion of the channel signal, the granular noise can be improved by using the Jayant's equations. In accordance with the present invention, the fading effect in the mobile radio channel can be efficiently compensated without giving much load to a forward link since a mobile station determines the variation of the backward channel signal by using the statistical characteristics of a power control command (1 bit) transmitted from a base station.