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The 5G NR system starts with Release 15 and includes Release 16. The NR system has added physical channels identical to LTE and physical channels for duplication in high-speed and high-frequency environments. In this paper, the characteristics of PDCCH physical channel in LTE and NR system are compared and the implementation of NR PDCCH is discussed.

Large scale connection is one of the main goals of 5G mobile communication. The NB-IoT system achieves this goal using only very narrow bandwidth. NB-IoT systems can also work together without affecting existing LTE systems. In this paper, we compared the inband-mode and the guardband-mode of the NB-IoT system using the BER performance curve.

Massive connectivity is one of the major goals of 5G mobile communications. The NB-IoT system achieves this goal using only a very narrow bandwidth. The NB-IoT system can also work together without affecting existing LTE systems. In this paper, we analyze the interferences of guardband NB-IoT system from the LTE system when they coexist.

In this paper, we present hybrid ARQ techniques to improve the throughput performance in high speed packet transmission such as Internet or multimedia services. In order to evaluate the performance of the three different types of hybrid ARQ schemes, systemized link level simulations based on WWW traffic model are considered. In this paper, we also consider the simulated performance for an average link throughput and a normalized packet delay to compare the hybrid ARQ with link adaptation scheme in GPRS.

In this paper, we considered the received signal of the wideband CDMA systems using turbo code in the multipath channel environments, and analyze the performance of the system. This study is to analyze the performance for the variable system bandwidth according to the number of branches of rake receiver by passing the received signal through a rake receiver with a turbo code in Rayleigh fading channel environments. For the design of receiver in wideband CDMA systems, we presented the efficient parameters for the number of iterative decoding and the number of branches of rake receiver.

In this paper, the performance of a wireless communication system based on the TD-CDMA transmission technique is analyzed. In this paper, we present simulation results for the performance of a turbo coded TD-CDMA system with QPSK over Rayleigh fading channel model. And the system performance employing the simple averaging channel estimation is compared to the ideal case with the perfect channel estimation.

A novel mobile Internet access system based on the OFDM transmission technique is proposed and its performance is analyzed via computer simulations. Especially, OFDM is considered in combination with the TDMA/TDD scheme for a cellular mobile communication system. We present simulation results for the performance of a convolutional turbo coded OFDM/TDD system with QPSK, 16QAM, and 64QAM over ITU-R channel models. The performance of the proposed system employing pilot tone assisted channel estimation is compared to the ideal case with perfect channel estimation.

We considered a sequential decoding algorithm which enables fast decoding and retransmission in TD-CDMA systems. In addition, we propose an improved FANO algorithm, which adopts the competition path in order to reduce the number of revisit nodes. The conventional FANO algorithm suffered from the drawback of much more revisit nodes. Furthermore, we analyze the performance of the TD-CDMA system with the proposed sequential decoding scheme over a wideband multipath channel.

This paper is concerned about peak-to-average power ratio (PAPR) reduction technique on orthogonal frequency division multiplexing (OFDM) systems. First, we analyze PAPR statistical characteristics with fast Fourier transform (FFT) size and modulation order on OFDM systems. The result is that PAPR statistical characteristic is almost same for any sufficiently large size of FFT (>64) and types of modulation schemes. Next, the bit error rate (BER) performance and the power spectral density (PSD) of OFDM systems over clipping ratio (CR) are studied and simulated. The result is that BER performance goes a little bad but PAPR reduction effect is very large. Finally, we propose adaptive clipping technique for PAPR reduction on OFDM systems by modulation order.