Showing papers by "Theodore S. Rappaport published in 2010"

60 GHz Wireless: Up Close and Personal

Abstract: To meet the needs of next-generation high-data-rate applications, 60 GHz wireless networks must deliver Gb/s data rates and reliability at a low cost. In this article, we surveyed several ongoing challenges, including the design of cost-efficient and low-loss on-chip and in-package antennas and antenna arrays, the characterization of CMOS processes at millimeter-wave frequencies, the discovery of efficient modulation techniques that are suitable for the unique hardware impairments and frequency selective channel characteristics at millimeter-wave frequencies, and the creation of MAC protocols that more effectively coordinate 60 GHz networks with directional antennas. Solving these problems not only provides for wireless video streaming and interconnect replacement, but also moves printed and magnetic media such as books and hard drives to a lower cost, higher reliability semiconductor form factor with wireless connectivity between and within devices.

Analog Equalization for Low Power 60 GHz Receivers in Realistic Multipath Channels

Abstract: Multi-gigabit per second wireless network devices are emerging for personal area networks (PAN) in the 60 GHz band. Such devices are typically power hungry, largely due to the requisite high speed analog to digital converters (ADCs) that can consume from tens to hundreds of milliwatts of power. This paper studies the use of analog equalization before the ADC to reduce the required ADC resolution. We provide a novel analysis that uses a superposition model for multipath energy and derive a closed-form expression that relates ADC resolution to the channel state, and also the bit error rate (BER) for MQAM constellations. Simulations verify that analog equalization can reduce the link bit-error rate by up to several orders of magnitude, without increasing the number of quantization bits in the ADC.

Millimeter-Wave CMOS Antennas and RFIC Parameter Extraction for Vehicular Applications

Abstract: This paper reviews recent developments in vehicular radar at 60 GHz and above, with a focus on low cost integrated antennas. We investigate a number of radar and communication antenna systems that can be made inexpensively and in large volumes using standard CMOS semiconductor fabrication methods. As shown here, the electromagnetic characteristics of low cost CMOS processes are often not well understood when applied to mmWave and THz RF applications. Here, we describe several methodologies and measured results to understand electromagnetic behavior of integrated circuits and on-chip antenna performance in a 180nm CMOS process up to 67 GHz. By gaining understanding of the electrical characteristics of older, lower cost semiconductor CMOS processes, it becomes possible to design mmWave on-chip antennas and other passive devices at extremely low cost and with great reliability.

Analysis and Simulation of Adjacent Service Interference to Vehicle-Equipped Digital Wireless Receivers from Cellular Mobile Terminals

Abstract: This paper provides detailed analysis and simulation for exploring the impact of out-of-band emissions (OOBE) from adjacent wireless cellular services to receive-only digital mobile radio services. Based on an extensive analysis of interference from vehicles with mobile cellular users in realistic roadway conditions, we propose proper methods for determining out-of-band emission spectral masks that should be used in interference coordination in mobile to mobile interference conditions. Analysis for roadway and propagation conditions in various US cities resulted in the suggested interference protection masks. This work offers approaches that can be used to determine spectral masks to allow harmonious co-existence of mobile digital receivers with new cellular and fixed broadband mobile services that operate in adjacent spectrum bands.

Wireless communication system, and wireless communication method

Abstract: PROBLEM TO BE SOLVED: To provide site-specific performance prediction modeling for a digital data network depending upon a performance-based real-time wireless network feedback and visual display function. SOLUTION: A method is presented for determining optimal or preferred configuration settings for wireless or wired network equipment in order to obtain a desirable level of network performance. A site-specific network model is used with adaptive processing to perform efficient design and ongoing management of network performance, and the cost is obtained, and further equipment settings, locations and orientations are updated. Display and storage are performed in real time to enable iterative adaptation to any network regarding constantly varying traffic and interference conditions. Alarms provide rapid adaptation of network parameters, and alerts, and preprogrammed network shutdown actions may be taken autonomously. COPYRIGHT: (C)2011,JPO&INPIT

Analysis and Simulation of Adjacent Service Interference to Vehicle-Equipped Satellite Digital Radio Receivers From Cellular Mobile Terminals

Abstract: This paper provides detailed analysis and simulation for explol'ing the impact of out-of-band emissions (OOBE) of adjacent wireless services to the Sirius XM digital satellite radio service. Based on an extensive analysis of interference from vehicles with mobile cellular users in realistic roadway conditions, we propose proper methods for determining out of band emission spectral masks that should be used by new WCS cellular subscriber transmitters. in the 2.3 GHz band. Analysis for roadway and propagation conditions in various US cities resulted in the suggested masks. This work presents the first simulation of its ldnd and offers approaches that federal regulators may use to determine spectral masks that allow harmonious co-existence of existing mobile radio listeners with new cellular and fixed broadband mobile services in adjacent spectrum bands.