Search

This article presents an 802.11ba-based wake-up radio (WUR) receiver that is fully integrated within an 802.11a/b/g/n/ac Wi-Fi transceiver. Low-cost integration is achieved with the WUR only occupying 0.13 mm2 while not adding any additional overhead to the Wi-Fi platform. The WUR consumes 667 $\mu \text{W}$ from 1.1-V Wi-Fi system supply. When measured from internal 0.6- and 0.9-V supplies, the receiver consumes 495 $\mu \text{W}$ . The receiver has a measured sensitivity of −92.6 dBm and can tolerate −40.5-dBm Wi-Fi adjacent channel blocker with 3-dB receiver de-sensitization. The WUR and Wi-Fi system co-operation is also demonstrated. The WUR receiver can operate when the Wi-Fi system is in sleep mode and can turn on Wi-Fi radio upon receiving 802.11ba-based wake-up packet.

An augmented-reality (AR) device which presents virtual volumetric images to switchable integrated spaces is proposed and demonstrated. A bi-focal geometric phase (GP) lens can project the integrated volumetric images to switchable integrated spaces by switching the polarization of them. For that purpose, a combination of GP lens and an active polarization switching device has been adopted. A demonstration of an AR display with switchable integrations is also provided to verify the proposed concept.

An augmented reality (AR) lightfield display can provide three-dimensional (3D) images at the locations of real objects. However, a conventional AR lightfield display has a few disadvantages in that its 3D resolution is poor and it is bulky in form owing to the use of an optical combiner or relay optics. In this paper, we propose a novel method to realize an AR lightfield display using a transparent display and an active pinhole array (APA) to enhance both the 3D resolution and visibility of real objects. An experimental demonstration verifies that the proposed method is appropriate for smart window applications.

This paper presents an 802.11g/n compliant wake-up radio solution that consists of an innovative on–off keying (OOK) emulating orthogonal frequency division multiplexing (OFDM) modulation scheme, and a fully integrated, highly scaled, ultra-low power wake-up receiver design in 14-nm FinFET CMOS technology requiring only a 32-kHz real-time clock reference. The receiver achieves −72-dBm sensitivity and +20 dBr adjacent channel interference (ACI) rejection at 10−3 bit error rate (BER) while consuming $95~\mu \text{W}$ . This receiver can be utilized along with any legacy Wi-Fi transmitter without changing any hardware.

Displays based on organic light-emitting diodes (OLEDs) are now widely used in mobile devices, in which they are major power consumers. The power drawn by an OLED display increases nonlinearly with sub-pixel intensities—thus reducing brightness saves appreciable power, but can displease users. This paper examines this tradeoff, and proposes a color blending scheme in which each frame is darkened in a way that reduces power consumption significantly while limiting the visual impact. The target lightness of frames is determined, in the LAB color space, from average intensities of the original frames; and these average values are in turn obtained by adaptive sampling, so as to reduce the computational overhead. An Android smartphone uses 12%–36% less power when running this scheme, compared to standard video playback, while a user evaluation suggested that reducing brightness to a certain extent can be largely unnoticed, or readily tolerated.

IEEE 802.11ah Task Group has been developing an amendment to the 802.11 standard to define sub-1-GHz license-exempt operation to support sensors and Internet of Things applications. This article presents an overview of major physical layer and MAC layer features of 802.11ah.

The IEEE 802.11ac amendment has been proposed to enhance the throughput of IEEE 802.11n beyond gigabit-per-second rates. In this article we present an overview of the most important features proposed in the 802.11ac amendment, including channel bonding mechanisms and multi-user MIMO.

In recent years, the unlicensed 60 GHz band has motivated the computer, wireless communications, and consumer electronics industries to develop wireless personal area network and wireless local area network standards that support wireless applications with multigigabit data rates. One of the technical challenges is managing interference between networks in a dense environment. In this article we first show the problem of interference in a dense environment and evaluate and compare PHY and MAC layer interference mitigation techniques in terms of performance and the level of co-ordination required among interfering networks.

This paper shows that a spatial diversity technique can maintain a stable link quality for a 60 GHz WLAN system in an indoor multi-path environment, which suffers from the human-induced shadowing. The 60 GHz spatial diversity technique is validated by simulations and experiments.

This paper is concerned about the demapping method using the pilots inserted in transmitter in COFDM (coded orthogonal frequency division multiplexing) system which is the standard transmission system of terrestrial digital TV in Europe. We have tested the demapping method of this paper under the standard Rayleigh and Rician fading channel and obtained better performance than conventional soft decision demapper.