Abstract:
The present invention relates to a transmitting apparatus using a spread-spectrum transmission scheme. The transmitting apparatus includes a precoder for precoding a data signal by performing a product operation between a first matrix and a diagonal matrix. The precoding outputs a signal responding to the input data by performing a product operation between the first matrix and the diagonal matrix. Such a transmitting apparatus obtains a maximum diversity gain.
Abstract:
The present invention relates to a method and apparatus for transmitting and receiving data. A data transmission method from a sender terminal to a receiver terminal in a MIMO system using a variable frequency band according to one embodiment of the present invention comprises: repeatedly generating a signal field depending on a frequency band that is applied to the transmission of a data frame; generating a data field including the data; generating a data frame including the signal field and the data field; and transmitting the data frame to the receiver terminal. The present invention is advantageous in that a signal field which is transmitted together with the data being transmitted from the sender terminal to the receiver terminal in the MIMO system can be sent more efficiently.
Abstract:
Disclosed is a method for configuring an uplink frame in an OFDMA based wireless communication system. The total band of the uplink frame is divided into a predetermined number of subcarrier groups. Subcarriers within the respective allocated subcarrier groups are allocated to the subchannel defined for a predetermined number of consecutive symbols defined by slots in the uplink frame. Pilot subcarriers are allocated by the unit of the predetermined number of symbols so as to allow channel estimation from among the allocated subcarriers. Accordingly, data subcarriers are allocated by minimizing collision with specific users of adjacent cells so as to enable channel estimation using preambles in a cellular system, and some positions of the data subcarriers are allocated for pilots, thereby allowing synchronous demodulation and improving frequency reuse rates.
Abstract:
Respective codewords of quantization codebooks corresponding to a number of data streams are selected based on channel information estimated by a received training symbol. A stream mode is selected among stream modes to determine a modulation method applied to each data stream. The data stream is detected by using the codeword corresponding to the quantization codebook of the data stream corresponding to the selected stream mode as a precode matrix, and the detected data stream is modulated. In this case, a receiving apparatus performs a feedback operation so that indexes of the selected stream mode and the codeword used as the precode matrix may be transmitted to the transmitting apparatus. The transmitting apparatus selects the number of transmitted data streams and the modulation method based on the transmitted index of feedback streams by the feedback operation.
Abstract:
The present invention relates to a method and apparatus for transceiving data. A method in which a transmitting terminal transmits data to a receiving terminal in a MIMO system according to one embodiment of the present invention comprises the following steps: generating a data field containing the data; generating a signal field containing information on the data field; generating a data frame containing the data field and the signal field; and transmitting the data frame to the receiving terminal. According to the present invention, an end of the frame being transmitted is accurately notified to the receiving terminal in a communication system in which the frame is transmitted using MIMO, thereby decoding the frame in a more efficient manner at the receiving terminal.
Abstract:
A transmitting apparatus and receiving apparatus of a multi-carrier system using multiple antennas is proposed. An LCF encoder (202) of the transmitting apparatus performs a liner precoding to input signals to be transmitted to a receiving apparatus using a liner complex matrix considering the number of multiple antennas and the number of subcarriers, and a subcarrier allocator (203) respectively allocates a subcarrier to the signals liner-precoded by the LCF encoder. A transmitter (205) respectively transmits the signals having a subcarrier allocated by the subcarrier allocator through the multiple antennas externally. A subcarrier de-allocator (208) of a receiving apparatus extracts a liner-precoded signal by de-allocating a subcarrier allocated to the received signal. An LCF decoder (209) outputs a bit reliability of the received signal to the liner-precoded signal extracted from the subcarrier de-allocator considering the number m of multiple antennas and the number n of subcarriers. A performance may be improved by using space diversity due to multiple antennas and a frequency diversity due to the OFDMA system and a complexity may be reduced and a hard decision value of a performance similar to the maximum likehood detection may be obtained by using a lattice reduction and a 2-branch Chase decoder.
Abstract:
Disclosed is a method for constructing a downlink frame in a mobile data communication system using an OFDMA method. To construct the downlink frame, a single preamble is arranged at the head of the downlink frame, and a plurality of data symbols are arranged following the preamble. Then, a plurality of pilot symbols are inserted between the data symbols over the downlink frame at a predetermined period. Accordingly, a channel variation can be rapidly tracked using the preamble and pilot symbols. Furthermore, interference between adjacent cells is minimized and averaged to make a frequency reuse rate be 1, such that arrangement of multiple cells can be easily designed.
Abstract:
Ein Verfahren zum Senden von Daten durch ein Sendeendgerät zu einem Empfangsendgerät in einem drahtlosen Kommunikationssystem enthält: Erzeugen eines ersten Erfassungsfelds, das Symbole enthält, die unter Verwendung eines BPSK-Datentons moduliert werden; Erzeugen eines zweiten Erfassungsfelds, das Symbole enthält, die in der Weise moduliert werden, dass ein geradzahliger Hilfsträger und ein ungeradzahliger Hilfsträger eine Phasendifferenz von 90 Grad besitzen; Erzeugen eines Datenpakets, das das erste Erfassungsfeld, das zweite Erfassungsfeld und die Daten enthält; und Senden des Datenpakets.
Abstract:
Die vorlegende Erfindung betrifft ein Verfahren und eine Vorrichtung zum Senden und Empfangen von Daten. Ein Datensendeverfahren von eine Sende-Endgerät zu einem Empfangs-Endgerät in einem MIMO-System unter Verwendung eines variablen Frequenzbands weist gemäß einer Ausführungsform der vorliegenden Erfindung folgendes auf: wiederholtes Erzeugen eines Signalfelds in Abhängigkeit von einem auf ein Senden eines Datenframes angewandten Frequenzband; Erzeugen eines Datenfelds, das die Daten enthält; Erzeugen eines Datenframes, der das Signalfeld und das Datenfeld enthält; und Senden des Datenframes zum Empfangs-Endgerät. Die vorliegende Erfindung ist diesbezüglich vorteilhaft, dass ein Signalfeld, das zusammen mit den Daten gesendet wird, die vom Sender-Endgerät zum Empfänger-Endgerät im MIMO-System gesendet werden, effizienter gesendet werden kann.
Abstract:
Die vorlegende Erfindung betrifft ein Verfahren und eine Vorrichtung zum Senden/Empfangen von Daten. Ein Verfahren, bei welchem ein Sende-Endgerät Daten zu einem Empfangs-Endgerät in einem MIMO-System sendet, gemäß einer Ausführungsform der vorliegenden Erfindung weist die folgenden Schritte auf: Erzeugen eines Datenfelds, das die Daten enthält; Erzeugen eines Signalfelds, das Information bezüglich des Datenfelds enthält; Erzeugen eines Datenframes, der das Datenfeld und das Signalfeld enthält; und Senden des Datenframes zum Empfangs-Endgerät. Gemäß der vorliegenden Erfindung wird ein Ende des Frames, der gerade gesendet wird, dem Empfangs-Endgerät in einem Kommunikationssystem genau mitgeteilt, in welchem der Frame unter Verwendung vom MIMO gesendet wird, um dadurch den Frame bei einem Empfangs-Endgerät auf eine effizientere Weise zu decodieren.