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This paper demonstrates 300 GHz terahertz wireless communication using CMOS transmitter and receiver modules targeting beyond 5G (or 6G). In order to support OFDM, a self-heterodyne architecture is introduced, which effectively cancels inter-carrier-interference due to phase noise in multi-carrier modulation. Besides, to extend communication distance, the high-gain antenna of a 40 dBi Cassegrain antenna is designed. As a proof-of-concept, the paper successfully demonstrates real-time video transfer at a 10 m communication distance using 5G based OFDM at the 300 GHz frequency band.

We propose a convolutional neural network (CNN)which classifies the type and direction of a stationary object from the range-Doppler map acquired by a 79 GHz MIMO radar. The multi-class (21 classes)classification is performed by inputting the single frame range-Doppler map. We measured five kinds of objects oriented in four directions with the MIMO radar equipped with 32 virtual arrays of 4 TX and 8 RX from a distance of 5 m. The CNN with a small number of layers are proposed and range-Doppler maps of the selected virtual arrays are used for input. In the classification of 21 classes, the two convolution layer CNN achieves an accuracy of 92.2% by inputting four virtual arrays in the diagonal direction.

Millimeter-wave (mmw) frequency bands, especially 60 GHz unlicensed band, are considered as a promising solution for gigabit short range wireless communication systems. IEEE standard 802.11ad, also known as WiGig, is standardized for the usage of the 60 GHz unlicensed band for wireless local area networks (WLANs). By using this mmw WLAN, multi-Gbps rate can be achieved to support bandwidth-intensive multimedia applications. Exhaustive search along with beamforming (BF) is usually used to overcome 60 GHz channel propagation loss and accomplish data transmissions in such mmw WLANs. Because of its short range transmission with a high susceptibility to path blocking, multiple number of mmw access points (APs) should be used to fully cover a typical target environment for future high capacity multi-Gbps WLANs. Therefore, coordination among mmw APs is highly needed to overcome packet collisions resulting from un-coordinated exhaustive search BF and to increase the total capacity of mmw WLANs. In this paper, we firstly give the current status of mmw WLANs with our developed WiGig AP prototype. Then, we highlight the great need for coordinated transmissions among mmw APs as a key enabler for future high capacity mmw WLANs. Two different types of coordinated mmw WLAN architecture are introduced. One is the distributed antenna type architecture to realize centralized coordination, while the other is an autonomous coordination with the assistance of legacy Wi-Fi signaling. Moreover, two heterogeneous network (HetNet) architectures are also introduced to efficiently extend the coordinated mmw WLANs to be used for future 5 Generation (5G) cellular networks.

A 60GHz short-range wireless system offers new opportunities for achieving wireless high-definition video links and multi-Gb/s wireless data transfer. Recent works have realized a 60GHz transceiver by means of a cost-effective CMOS process [1-3], but using a 60GHz system in mobile terminals poses the difficult challenge of achieving low power consumption as well as small form factor. The publication [3] achieves a power consumption of less than 756mW, but uses a simple MAC protocol incompatible with global standards and also suffers from a limited distance of less than 4cm. This paper presents a fully integrated transceiver chipset based on WiGig/IEEE802.11ad standards targeting mobile usage. The chipset is developed for a single-carrier (SC) modulation, which is suitable for reduced power consumption as compared to using OFDM modulation. However, the SC modulation is sensitive to in-band amplitude variation, mainly made worse by the gain variation of analog circuits and multipath delay spread. In order to compensate for those gain variations, the proposed chipset employs built-in TX in-band calibration and an RX frequency domain equalizer (FDE). The proposed techniques can relax the requirement for high speed analog circuits, leading to less power consumption while minimizing the increase of hardware size.

This paper presents a newly developed arm-swinging dynamic phantom that can simulate human walking and running motions. The arm-swinging phantom has unique features, in that swinging of the right and left arms and the direction and speed of swing can be controlled independently, leading to excellent capability for replicating the variety of natural walking and running styles seen in the average human. Using the phantom, we have attempted to develop a dynamic channel characterization for BAN systems, such as shadowing properties and path loss characteristics, when the geometrical relationships between the arms and the human body change continuously due to the movement of the arms for both off-body and on-body situations. Assessments of communication quality, such as the signal bit error rate, were also conducted to gain useful knowledge of the way and the degree to which arm-swinging might impact the performance of body-attached BAN devices. Analytical results are also shown for the case where the combined outcome of shadowing and multipath fading emerge simultaneously when a human walks in a multiple radio wave propagation environment while swinging both arms.

This paper presents a study on adjacent channel interference in millimeter-wave small cell systems based on IEEE 802.11ad/WiGig. It includes hardware prototype development, interference measurements, and performance evaluation of an interference suppression technique. The access point prototype employs three RF modules with 120° beam steering capability, thus enabling 360° coverage. Using the developed prototype, interference measurements were performed and the packet error degradation due to adjacent channel interference was observed. To mitigate the performance degradation, an interference suppression technique using a two stream receiver architecture was applied. The subsequent measurements showed improvement in EVM and also expansion of the cell's coverage area, demonstrating the effectiveness of the applied technique for small cell systems using IEEE 802.11ad/WiGig.

This paper presents an LDPC decoder employing a column-parallel architecture that enables low-power and high-speed operation suitable for the 802.11ad standard. As compared to the conventional row-parallel architecture, the proposed architecture reduces the required memory size by 60% and also minimizes the number of pipeline stages for high throughput operation. Fabricated in 40nm LP CMOS technology, the prototype achieves high energy efficiency of 4.7pJ/bit/iteration for 6.16Gb/s while supporting all the modulation and coding schemes (MCS0 to MCS12) required for the 802.11ad single-carrier (SC) modulation.

This paper presents a 60GHz analog/digital beamforming transceiver that effectively suppresses interference signals, targeting WiGig/IEEE 802.11ad standard. A prototype has been built with 40nm CMOS analog front-ends as well as offline baseband digital signal processing. Measurement shows 3.1dB EVM advantage over the conventional two-stream diversity during a packet collision situation.