Innowireless Co., Ltd.

Kyeongmin Ha

Jinsoup Joung

Seunghwan Ji

Junwan Park

Cheoljin Lee

Jongmin Kim

Byungkwan Jang

Sunglyong Lim

Jaesung Lee

Yonghoon Lim

Joohyeong Lee

Daesung Yun

The present invention relates to an apparatus and a method for eliminating I/Q offset in a receiver of a SC-FDMA system which improves performance of the system by accurate measurement and cancellation of I/Q offset in a receiver of a SC-FDMA system operating in a 3GPP LTE uplink. An apparatus for eliminating I/Q offset in a receiver of the SC-FDMA system constituting the receiver of the SC-FDMA system includes: a linear interpolation channel estimation unit for estimating channel using demodulation reference symbol (DMRS) that is a training sequence (X) corresponding to the discrete Fourier transformed signal (Y) that has passed through frame sync acquisition, frequency compensation and cyclic prefix elimination; a signal regeneration/cancellation unit for calculating I/Q offset (D=Y&#x2212;Y') by subtracting the discrete Fourier transformed signal (Y) from the ideal discrete Fourier transformed signal (Y&#x2032;=H&#x2032;X) generated by using channel coefficient (H&#x2032;), that is an output of the linear interpolation channel estimation unit, and the DMRS that is the training sequence (X); and an I/Q offset measurement/cancellation unit for generating VQ offset-free signal (Y=Y&#x2212;D&#x2032;) by subtracting I/Q offset (D&#x2032;) having corrected phase and power of the VQ offset (D=Y&#x2212;Y&#x2032;) from the discrete Fourier transformed signal (Y).

Apparatus and method for I/Q offset cancellation in SC-FDMA system

Disclosed herein is a digital re-sampling apparatus. The digital re-sampling apparatus includes a sample buffer, a sample buffer control unit, a filter bank, a first delay bank, a fractional delay constant table, a combiner bank, and a second delay bank. The sample buffer temporarily stores an input sample in synchronization with an input sampling frequency. The sample buffer control unit controls writing and reading operations. The filter bank includes a number of digital filters equal to the number of stages, and filters the input sample. The first delay bank differentially delays a filter output value. The fractional delay constant table stores information about re-sampling time. The combiner bank includes a number of adders and multipliers, performs an operation, and outputs a re-sampled value. The second delay bank causes a delay so that output of each combiner can be synchronized with each output of the fractional delay constant table.

Digital re-sampling apparatus using fractional delay generator

A signal analysis apparatus of an LTE system includes a radio frequency reception unit for receiving a radio frequency signal of the LTE system and converting it into a signal of an intermediate frequency, a digital signal conversion unit for converting an analog signal, processed by the radio frequency reception unit, into a digital signal, a baseband conversion unit for converting the signal of the intermediate frequency into a baseband signal, a baseband signal simple analysis unit for decoding the baseband signal in real time in accordance with an LTE standard, a signal depository for storing the baseband signal, a baseband signal precision analysis unit for decoding and analyzing the baseband signal in accordance with the LTE standard and analyzing various items derived in the decoding process, two switching units for alternatively connecting the baseband conversion unit or the signal depository to the baseband signal simple analysis unit or the baseband signal precision analysis unit, and a control unit for controlling the switching units.

Signal analyzing apparatus for LTE system

Disclosed herein is a transmission/reception channel matching apparatus and method for a mobile communication terminal and a mobile phone test equipment. The apparatus includes mobile communication terminal-side terminals, transmission and reception terminals, a connection detection unit, a switching unit, and a control unit. The mobile communication terminal-side terminals are connected to the option pins of a serial communication port in a one-to-one correspondence. The transmission and reception terminals correspond to the transmission and reception channels of the mobile phone test equipment. The connection detection unit detects the state of connection between the mobile communication terminal-side terminals and the option pins. The switching unit connects the mobile communication terminal-side terminals to the transmission and reception terminals. The control unit automatically sets the transmission and reception channels of the mobile communication terminal and the transmission and reception channels of the mobile phone test equipment with reference to the state of the connection, and outputs the channel matching command.

Transmission/reception channel matching apparatus and method for mobile communication terminal and mobile phone test equipment

Disclosed herein are an apparatus and method for synchronizing a signal analyzer. The apparatus includes an Analog-to-Digital Converter (ADC), a signal storage unit, a trigger signal generation unit, a signal acquisition control unit, a signal analysis unit, and a time error control unit. The ADC converts the input signal into a corresponding digital signal. The signal storage unit stores therein the digital signal received from the ADC. The trigger signal generation unit generates a trigger signal for each predetermined period. the signal acquisition control unit acquires the digital signal from a signal acquisition time point. The signal analysis unit calculates the start position of a frame from the digital signal. The time error control unit calculates a time error between the time point at which each trigger signal is generated and the start position of the digital signal, and sets a subsequent signal acquisition time point based on the calculated time errors.

Apparatus and method for synchronizing signal analyzer

Disclosed herein is a transmission/reception channel matching apparatus for a mobile communication terminal and a mobile phone test equipment. The transmission/reception channel matching apparatus includes a Printed Circuit Board (PCB), a Dual In-line Package (DIP) switch, and a fastening casing. The PCB includes mobile communication terminal-side terminals to be electrically connected to option pins provided in the serial communication connector of the mobile communication terminal, and transmission and reception terminals corresponding to the transmission and reception channels of the mobile phone test equipment for transmitting a transmission signal to the mobile communication terminal and receiving a reception signal from the mobile communication terminal. The DIP switch is provided with a plurality of switches, is combined with the PCB, and selectively connects the mobile communication terminal-side terminals to the transmission and reception terminals depending on ON/OFF information. The fastening casing accommodates the PCB so that part of the DIP switch is exposed to the outside.

Transmission/reception channel matching apparatus for mobile communication terminal and mobile phone test equipment

Disclosed herein is a method of acquiring Uplink (UL) synchronization for a mobile WiMax system analyzer. When a DL sub-frame is received, the method is performed on a Portable Subscriber Station (PSS) having a test mode function of creating a UL sub-frame through the mobile WiMax system analyzer having signal generating means configured to store the CID information in advance and signal analyzing means configured to receive and analyze the DL sub-frame. The method includes step (a) of the signal generating means continuously D/A converting, RF-modulating and outputting the DL sub-frame, step (b) of the signal analyzing means receiving the UL sub-frame, step (c) of the signal analyzing means continuously demodulating, A/D-converting and capturing the modulated UL sub-frame, and step (d) of the signal analyzing means acquiring UL synchronization by comparing the UL sub-frame with the data captured at step (c) using a time correlation technique.

Method of acquiring uplink synchronization for mobile WiMax system analyzer

Disclosed herein is a portable Internet analyzer (PIA) having a handover test function. The portable Internet analyzer includes a transmission unit, a reception unit, a switching unit, and a central control unit. The transmission unit encodes the various DownLink signals of a serving and/or target Base Station (stBS) using a preamble index, synthesizes the encoded signals, and sends the synthesized signals to a Portable Subscriber Station (PSS). The reception unit receives various UpLink (UL) signals from the PSS, and decodes the UL signals using the cell Parameters of the stBS. The switching unit selectively switches the transmission unit and the reception unit to the PSS. The central control unit generates various Media Access Control (MAC) messages to be sent to the PSS through the transmission unit in association with the handover test, analyzes handover test-related MAC messages received through the reception unit, and controls switching operation of the switching unit.

Portable internet analyzer having handover test function

Disclosed herein is a time synchronizing apparatus for a mobile WiMAX analyzer. The time synchronizing apparatus includes a Global Positioning System (GPS) receiver and a synchronization control unit. The GPS receiver outputs a GPS signal that is synchronized with the GPS time using information received from a GPS satellite. The synchronization control unit compares the GPS signal and a reference signal, which is generated using an internal clock, and controls synchronization according to the result of the comparison. The synchronization control unit includes an oscillator, a divider, an offset comparison unit and a processor. The oscillator outputs an oscillation signal having a predetermined frequency. The divider divides the oscillation signal into the reference signal. The offset comparison unit compares the differences between the GPS signal and the reference signal, and outputs the result value of the comparison. The processor controls the oscillation frequency of the oscillator until the result value satisfies a predetermined reference value.

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Seongnam, South Korea

Kyeongmin Ha