Innowireless Co., Ltd.

Byung Kwan Jang

Jin Soup Joung

Yong Hoon Lim

Joo Hyeong Lee

Provided is a method of calibrating a power for a multiple input and multiple output-orthogonal frequency division multiplexing transmitter having a plurality of antennas via a measurement equipment, the method including: receiving a cyclic delay diversity (CDD) signal simultaneously output from the transmitter to obtain a starting point of a frame of a corresponding signal; performing a fast Fourier transform on a sample proceeded from the starting point by an extent of a maximum CDD delay; calculating a channel coefficient; calculating a channel impulse response and a power of the channel impulse response; converting CDD delay values of each antenna into values in units of samples by using a sampling rate in the channel impulse response; mapping a peak point position of the channel impulse response to each antenna using CDD delay sample values; and simultaneously performing a power calibration of each antenna based on each peak point power.

Method of calibrating power for MIMO-OFDM transmitter

An apparatus for efficiently and simply measuring an error vector magnitude (EVM) of a physical hybrid automatic repeat request (ARQ) indicator channel (PHICH) in a long term evolution (LTE) system. The apparatus includes an overall PHICH group data extraction unit configured to extract all PHICH group data from a received signal in a first subframe, an overall PHICH group analysis unit configured to detect orthogonal sequences and acknowledgement/negative acknowledgement (ACK/NACK) bits used in respective PHICH groups by analyzing all resources of the extracted PHICH group data, an ideal PHICH group sequence generation unit configured to generate an ideal PHICH group sequence using the detected ACK/NACK bits and orthogonal sequences, and an EVM measurement unit configured to measure an EVM of a PHICH using the ideal PHICH group sequence and the received signal.

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Gyeonggi-do, South Korea

Byung Kwan Jang