Abstract: Provided is an operation method of a user equipment performing narrowband Internet of Things-based communication, the operation method including determining a delayed distance based on at least one of a channel characteristic and a channel estimation technique-related coefficient, estimating, based on a time axis, a channel of a target subframe using reference signals of subframes from a start subframe prior to the target subframe to an end subframe corresponding to a determined delayed distance after the target subframe, and decoding the target subframe based on the estimated channel.

Abstract: An operation method of a user equipment based on non-terrestrial network (NTN) communication includes: performing channel estimation of a first broadcast channel included in a first frame; performing initial channel estimation of system information included in the first frame; performing channel estimation of a second broadcast channel included in a second frame which is subsequent to the first frame; determining a first weight corresponding to the system information, a second weight corresponding to the first broadcast channel, and a third weight corresponding to the second channel; and calculating a channel estimate of the system information based on results of the channel estimation of the first broadcast channel, the initial channel estimation of the system information and the channel estimation of the second broadcast channel, and the first weight through the third weight.

Abstract: A wireless communication device and a channel estimating method thereof are provided. A wireless communication device includes an interlayer interference detector configured to receive a reference signal including a plurality of layers transmitted through a plurality of ports respectively connected to a plurality of antennas and to determine whether interlayer interference occurs based on the reference signal; and a channel estimator configured to estimate a channel matrix by executing an algorithm that is based on whether the interlayer interference occurs. The wireless communication device may decode a receive signal based on the estimated channel matrix.

Abstract: A wireless communication device and a channel estimating method thereof are provided. A wireless communication device includes an interlayer interference detector configured to receive a reference signal including a plurality of layers transmitted through a plurality of ports respectively connected to a plurality of antennas and to determine whether interlayer interference occurs based on the reference signal; and a channel estimator configured to estimate a channel matrix by executing an algorithm that is based on whether the interlayer interference occurs. The wireless communication device may decode a receive signal based on the estimated channel matrix.

Abstract: Disclosed is a system and a training sequence setting method for performing frame synchronization in a wireless communication system. A received signal is affected by a frequency offset due to an oscillator mismatch between the transmitter and the receiver, which is one of the main causes of performance degradation of frame synchronization. In a prior Constant Amplitude Zero Auto-Correlation (CAZAC) sequence, the larger the frequency offset becomes, the more conspicuously the performance degradation of the frame synchronization occurs. The proposed training is designed to maintain a prior CAZAC property during a differential detection so as to perform a differential detection-based frame synchronization sequence insensitive to the frequency offset. As a result of performance verification, the proposed training sequence indicates that its performance of the frame synchronization is irrespective of the frequency offset, and has a better performance than the prior CAZAC sequence and random sequence.

Abstract: Disclosed is a system and a training sequence setting method for performing frame synchronization in a wireless communication system. A received signal is affected by a frequency offset due to an oscillator mismatch between the transmitter and the receiver, which is one of the main causes of performance degradation of frame synchronization. In a prior Constant Amplitude Zero Auto-Correlation (CAZAC) sequence, the larger the frequency offset becomes, the more conspicuously the performance degradation of the frame synchronization occurs. The proposed training is designed to maintain a prior CAZAC property during a differential detection so as to perform a differential detection-based frame synchronization sequence insensitive to the frequency offset. As a result of performance verification, the proposed training sequence indicates that its performance of the frame synchronization is irrespective of the frequency offset, and has a better performance than the prior CAZAC sequence and random sequence.