Hiroyuki Motozuka

A 60GHz wireless transceiver employing hybrid analog/digital beamforming with interference suppression for multiuser gigabit/s radio access

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.

A 6.16Gb/s 4.7pJ/bit/iteration LDPC decoder for IEEE 802.11ad standard in 40nm LP-CMOS

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.

IEEE 802.11ad/WiGig based millimeter-wave small cell systems with adjacent channel interference suppression

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 cells coverage area, demonstrating the effectiveness of the applied technique for small cell systems using IEEE 802.11ad/WiGig.