Abstract: An apparatus and method of generating a pseudo noise (PN) code is provided. The apparatus for generating the PN code includes: a memory device unit including a plurality of memory devices; an exclusive-OR (XOR) operation unit receiving output values of at least two memory devices among output values of the plurality of memory devices to output an XOR operation value with respect to the received output values; and a PN code generation unit generating the PN code based on an output value of the XOR operation unit.

Abstract: Disclosed is a wireless signal receiving apparatus, and more particularly, disclosed is a parallel automatic frequency offset estimation apparatus and method for tracking a frequency offset in an early stage by calculating, in parallel, frequency offsets of a received signal. The parallel automatic frequency offset estimation apparatus includes a receiving unit to receive a data frame; and a frequency offset estimation unit to calculate, in parallel, frequency and phase deviations at different bit intervals within a particular section of the received data frame, to add together the frequency and phase deviations to obtain a first sum of the frequency and phase deviations, and to add the first sum to a frequency phase deviation calculated for each bit after the particular section in the received data frame to obtain a second sum of the frequency and phase deviations.

Abstract: An active radio frequency identification (RFID) apparatus having an additional transmitter in addition to a single transmitter is provided. The active RFID apparatus includes a first transmitter including a first pseudo noise (PN) code generator to generate a direct sequence spread spectrum (DSSS) introduced by ISO/IEC (International Organization for Standardization/International Electrotechnical Commission) 24730-2 or ISO/IEC 18185-5 type B; and a second transmitter including a second PN code generator to perform an AND operation on an initial value and a fed back value and shift the resultant value of the AND operation, to perform an XOR operation on particular bits from among the shifted bits and to perform an XOR operation again on the shifted bits and the resulting value of the XOR operation to finally generate a PN code.

Abstract: An iterative tree search-based preceding method for a multi-user Multi-Input Multi-Output (MIMO) communication system includes determining a reference value of a cumulative branch metric of a candidate symbol, eliminating candidates having values that exceed the determined reference value of the cumulative branch metric of the candidate symbol, and registering values, which do not exceed the determined reference value of the cumulative branch metric of the candidate symbol, as entries, and selecting the least value from the values registered as the entries. Thereby, the method has low complexity and similar performance compared to an existing Sphere Encoding (SE) technique.

Abstract: Provided are a real-time locating systems, a reader, an RFID tag and a driving method of the RFID tag for locating. The locating system includes an RFID tag, a plurality of readers, and a location processor. The RFID tag outputs a first or second transmission message frame according to whether value added information exists. The readers are disposed at different locations, receive and analyze the first or second transmission message frame to transmit extracted information and reception time information corresponding to the extracted information to a location processor. The location processor analyzes the information which is extracted through the readers and the reception time information to calculate location information or the value added information related to the RFID tag.

Abstract: An apparatus and method of generating a pseudo noise (PN) code is provided. The apparatus for generating the PN code includes: a memory device unit including a plurality of memory devices; an exclusive-OR (XOR) operation unit receiving output values of at least two memory devices among output values of the plurality of memory devices to output an XOR operation value with respect to the received output values; and a PN code generation unit generating the PN code based on an output value of the XOR operation unit.

Abstract: Disclosed is a wireless signal receiving apparatus, and more particularly, disclosed is a parallel automatic frequency offset estimation apparatus and method for tracking a frequency offset in an early stage by calculating, in parallel, frequency offsets of a received signal. The parallel automatic frequency offset estimation apparatus includes a receiving unit to receive a data frame; and a frequency offset estimation unit to calculate, in parallel, frequency and phase deviations at different bit intervals within a particular section of the received data frame, to add together the frequency and phase deviations to obtain a first sum of the frequency and phase deviations, and to add the first sum to a frequency phase deviation calculated for each bit after the particular section in the received data frame to obtain a second sum of the frequency and phase deviations.

Abstract: An active radio frequency identification (RFID) apparatus having an additional transmitter in addition to a single transmitter is provided. The active RFID apparatus includes a first transmitter including a first pseudo noise (PN) code generator to generate a direct sequence spread spectrum (DSSS) introduced by ISO/IEC (International Organization for Standardization/International Electrotechnical Commission) 24730-2 or ISO/IEC 18185-5 type B; and a second transmitter including a second PN code generator to perform an AND operation on an initial value and a fed back value and shift the resultant value of the AND operation, to perform an XOR operation on particular bits from among the shifted bits and to perform an XOR operation again on the shifted bits and the resulting value of the XOR operation to finally generate a PN code.

Abstract: An iterative tree search-based preceding method for a multi-user Multi-Input Multi-Output (MIMO) communication system includes determining a reference value of a cumulative branch metric of a candidate symbol, eliminating candidates having values that exceed the determined reference value of the cumulative branch metric of the candidate symbol, and registering values, which do not exceed the determined reference value of the cumulative branch metric of the candidate symbol, as entries, and selecting the least value from the values registered as the entries. Thereby, the method has low complexity and similar performance compared to an existing Sphere Encoding (SE) technique.

Abstract: A signal detection apparatus and method using a modified stack algorithm in a Multi-Input Multi-Output (MIMO) system are provided. The signal detection method includes sorting signals received via antennas and channel coefficients for respective users in descending order, decomposing a channel matrix composed of the sorted channel coefficients into a unitary matrix and an upper-triangular matrix, determining the number of candidate symbol-sequences using the decomposed upper-triangular matrix, obtaining a signal vector for the antennas by using the sorted signals received via respective antennas and the unitary matrix, wherein the signal vector is proportional to the upper-triangular matrix, and detecting the determined number of candidate symbol-sequences by using a modified stack algorithm while expanding a stack structure for the obtained signal vector.