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In this paper we provide an overview of the technologies being developed for the beyond 3G systems that will be standardized in 3GPP2. We show how the system is being designed to support the varying QoS demands of the services that will be anticipated in a beyond 3G system. Preliminary simulation results are provided that show the increased spectral efficiency over present wireless networks
This paper analyzes the capacity and overhead of using the IEEE 802.16e worldwide interoperability for microwave access ("WiMAX") for last mile wireless backhaul transport. It first analyzes the WiMAX overhead size using 802.16e WiMAX as backhaul. Second, both WiMAX backhaul downlink and uplink capacity analysis are presented. Lastly, an EVRC VoIP bearer traffic efficiency analysis in an...
This paper introduces a simple spatial filtering model that can be used in the design of closely spaced patch array elements. The model predicts that the mutual coupling reduction can be significant if a single patch element is divided into smaller sections. A system composed of two patch elements separated in a traditional fashion is compared to another system developed using the presented model...
The race to 4G has already started with an increasing involvement of all cellular industry. With the increasing variety of technologies targeting 4G, and actors in competition, the migration to 4G appears to be a complex thing. This paper presents the expected market requirements for 4G, explains the complexity of future technology landscape, with an emphasis on the standards in competition, and spectrum...
Simulations were performed based on a model developed in ADS to demonstrate the effects of non-linear cosine transfer function in non-contact vital sign detection. Harmonics and intermodulation effects have been analyzed theoretically and demonstrated by simulation. It is shown that in contrast to the observation from simple linear approximation that detection sensitivity always increases with carrier...
Slot-line resonator (SLR) with parallel line (PL) microstrip feeding structure is proposed to design a compact ultra-wideband bandpass filter (UWBBPF) with extended upper stopband. Simulation results are validated by fabrication. Measurements show that, maximum insertion loss is 1.2 dB within the ultra-wide passband, minimum return loss is better than 10 dB and maximum passband group delay variation...
Low cost antennas based on image guide lines have been developed to address the needs for car collision avoidance radars. These developed antennas are suitable for beam steering and can easily operate above 60 GHz within the mm-wave wireless band
Many wireless applications require planar antennas but with monopole-like, vertically polarized radiation, a design challenge that cannot be easily achieved by using conventional microstrip patch or other types of printed antennas. In addition, while there have been significant advances in design of low-profile printed patch-type antennas in the frequency ranges of L-band and above, the patch antennas...
Municipal wireless broadband networks are changing the fundamental economics and performance of delivering fixed and mobile broadband services to residential, municipal and enterprise customers. This discussion reviews the motivation driving municipal deployments in major metropolitan areas such as Philadelphia, San Francisco and New Orleans. Citywide wireless networks leveraging mesh Wi-Fi technology...
In this talk, an overview of enormous potential of improving spectral utilization by using cognitive radio is presented. The current main focus on cognitive radio design is to research and develop adaptive radio access technologies, that have lead to many challenges in physical layer, medium access control (MAC) layer and cross layer design. Moreover in the talk, research scopes and challenges that...
Interferences due to the hostile environment (e.g. jammer) and the multi-user access are critical factors affecting performance of the wireless sensor networks. In this paper, we study a hybrid frequency hopping/time hopping-pulse position modulated (FH/TH-PPM) UWB for wireless sensor networks in hostile environment with partial-band (PB) tone interference. FH and TH are both used to get as much diversity...
Recent MIMO applications have noticeably magnified the importance of multi antennas. Antenna engineers are therefore constantly challenged with the temptation to search for optimum designs. In recent years, evolutionary optimization (EO) techniques are finding growing applications to the design of electromagnetic systems of increasing complexity. Among various EO's, nature inspired techniques such...
This paper addresses a fundamental issue regarding electrically small antennas. In conventional cases electrically small antennas suffer the fundamental limit of high Q and can not be used for broadband radiation. However, by integrating high-speed switch devices on the antenna, it is found that the bandwidth limit on the radiation can be overcome. This is because the high-Q value associated with...
We describe a low-power voltage amplifier that is suitable for RF (radio frequency) receivers in a WSN (wireless sensor network). Since a sensor node has a strict energy budget in a WSN, it often enters itself into a standby mode when no communication is required, and hence a standby power have to be suppressed as well as an active power in order to maximize a lifetime of a WSN. For this sake, it...
An efficient on-chip antenna structure in CMOS technology for system in package integration is presented. The antenna consists of a slot radiator on the top metal layer of the technology coupled to a rectangular dielectric resonator above the slot. The cavity backed slot configuration is used to isolate the antenna from the substrate. This configuration blocks the antenna interference through the...
Transmit adaptive beamforming can be applied on the subcarriers of an OFDM system to obtain a coherent processing gain at the receiver. The IEEE 802.16e-2005 standard for mobile broadband wireless access contains signaling strategies that facilitate the use of downlink adaptive beamforming which leverages time-division duplex (TDD) channel reciprocity. Using these strategies, Motorola Labs has developed...
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