Su-Ryong Jeong

Tens of Gbps support with mmWave beamforming systems for next generation communications

The recent strong demands for higher data rate support to cope with the explosive mobile data crunch has initiated research on the next generation (5G) wireless mobile communication technologies that could provide with drastic capacity increase. One of the promising candidates is to use wide spectrum in the mmWave bands, where a breakthrough to overcome the unfavorable channel properties needs to be preceded. In this paper, we propose a novel hybrid beamforming scheme that jointly combines RF beamforming and baseband precoding as a key enabling technique to make efficient use of mmWave channel. The link level simulation results show that the proposed scheme can almost achieve the optimal performance with noticeably reduced implementation complexity. Furthermore, system level simulation results are provided pointing out the possibility of tens of Giga-bits/sec data rate support with the proposed scheme.

Interference Level Control in Mobile WiMAX Uplink System

Interference over thermal noise (IoT) level control is crucial to system performance and link quality in interference limited scenarios, especially for cell edge users. This paper proposes a simple and novel technique for IoT control by adopting the concept of load control where load is defined as the total interference impacting on neighbor sectors. The proposed technique is able to control IoT level accurately and is very robust against impairments in practical implementations, while minimizing the required signaling overhead.

Transparent operation of Kronecker product based full dimension MIMO to exploit 2D antenna array

A concept of full-dimension MIMO (FD-MIMO) adopting 2-dimensional (2D) antenna array has been proposed with intent to cope with practical challenges of massive MIMO systems. In this paper, we investigate an FD-MIMO operation that can be transparently applied with current 3GPP LTE specifications, and propose a novel method that facilitates an accurate estimation of channel quality indicator (CQI) at base station (BS). We first introduce a feedback scheme in which horizontal and vertical dimension channel information are separately reported. To further improve accuracy of modulation and coding scheme (MCS) selection to maximize system throughput, we propose an enhanced feedback scheme that is helpful to more accurate CQI estimation at the BS. In the evaluation results, we show performance improvement of the proposed scheme over the conventional MIMO scheme.