Engineering Commons^™

Design And Characterization Of A 1-Watt Driver Amplifier For Wireless Infrastructure, Chin-Leong Lim

Chin-Leong Lim

Variable gain amplifiers (VGA) find application in RF systems wherever the signal amplitude must be varied in reaction to a changing environment. Transmitters' driver stage utilize VGAs to conserve power under good propagation conditions and to minimize interference to adjacent sites. Cellular base-station receivers use VGAs in the 2nd/3rd stage LNA to prevent mixer/DAC overloading. Commercially available L-band VGA devices require 14 to 19 external components and have modest linearity-to-power consumption ratio (OIP3 / Pdc). To achieve the industry's lowest component count and best linearity-to-power ratio, we developed a highly integrated VGA module from 0.25 x 3900 um enhancement-mode Pseudomorphic …

Simulation Of Mc-Ds-Cdma-System Based On: Multi-Wavelets Transform Over Wireless Channel, Amean Al_Safi

Amean S Al_Safi

In this paper a scheme was proposed to improve the performance form the Bit Error Rate (BER) view point for Multicarrier-Direct-Sequence-Code Division Multiple Access (MC-DS-CDMA) system in wireless channel. The conventional MC-DS-CDMA-system is based on Fast Fourier Transform (FFT). The proposed system was based on Multi-Wavelet transform (MWT). Simulation results are done in three different types of channels. Simulation shows that the proposed system outperforms the conventional system in addition to a coded version of the conventional system. Also the MC-DS-CDMA-system which is based on MWT achieves better performance with the same loss in bandwidth than the MC-DS-CDMA-system based on …

Mass-Market Designed-For-Cellular Mmics Can Be Gainfully Adapted For Use In Niche Applications On Different Frequencies, Chin-Leong Lim

Chin-Leong Lim

Due to semiconductor manufacturers’ near exclusive focus on high growth markets such as cellular and wireless data, very little commercial RND resource is expended on developing Microwave Monolithic Integrated Circuits (MMIC) for the lower-volume traditional wireless services such as aviation and land mobile, etc. To circumvent the dearth of MMICs in those under-served market segments, we intend to show how off-the-shelf cellular MMICs can be leveraged into non-cellular applications. For this purpose, a MMIC originally conceived as a 900 MHz 0.5W driver amplifier is redeployed to two dissimilar applications: (i) a high linearity Low Noise Amplifier (LNA) for the 400~520 …

Software Engineering Education At Carnegie Mellon University: One University; Programs Taught In Two Places, Ray Bareiss, Mel Rosso-Llopart

Ray Bareiss

Teaching Software Engineering to professional master’s students is a challenging endeavor, and arguably for the past 20 years, Carnegie Mellon University has been quite successful. Although CMU teaches Software Engineering at sites world-wide and uses different pedagogies, the goal of the curriculum -- to produce world-class software engineers -- remains constant. This paper will discuss two of the most mature versions of Carnegie Mellon’s Software Engineering program -- the main campus program and its “daughter program” at the Silicon Valley Campus. We discuss the programs with respect to the dimensions of curriculum, how students work and learn, how faculty teach, …

Developing Software Engineering Leaders At Carnegie Mellon Silicon Valley, Ray Bareiss, Todd Sedano

Ray Bareiss

The Carnegie Mellon’s Silicon Valley Campus offers a master’s degree in Software Engineering, with technical and development management tracks, targeted at working software professionals in Silicon Valley. We believe the program to be unique in that it is entirely team-based and project-centered. Students learn by doing as they are coached just in time by faculty in the context of their work on authentic projects, and they are evaluated based on what they produce. In response to our interactions with an industry characterized by innovation and short project development timelines, the program evolved from one focused on “high ceremony” processes to …

Developing Software Engineering Leaders At Carnegie Mellon Silicon Valley, Ray Bareiss, Todd Sedano

Todd Sedano

The Carnegie Mellon’s Silicon Valley Campus offers a master’s degree in Software Engineering, with technical and development management tracks, targeted at working software professionals in Silicon Valley. We believe the program to be unique in that it is entirely team-based and project-centered. Students learn by doing as they are coached just in time by faculty in the context of their work on authentic projects, and they are evaluated based on what they produce. In response to our interactions with an industry characterized by innovation and short project development timelines, the program evolved from one focused on “high ceremony” processes to …

Building A Business On Open Source Software, Tony Wasserman

Tony Wasserman

For many years, free and open source software was exclusively associated with the research community, in contrast to the closed source products developed by commercial software vendors. Over the past decade, there has been a vast increase in the availability of open source software, growing from such projects as Linux and Apache. Open source software is being widely adopted in industry, which has led to numerous business opportunities for entrepreneurs and vendors. This activity is having a disruptive effect on the software industry that has affected even the largest software vendors. This paper describes the emergence of open source business, …

Vlsi Implementation Of High Resolution High Speed Low Latency Pipeline Floating Point Adder/Subtractor For Fft Applications, Rozita Teymourzadeh, Burhan Yeop Majlis, Mok Vh, Masuri Othman

Dr. Rozita Teymourzadeh, CEng.

Throughput And Delay In Wireless Sensor Networks Using Directional Antennas, Hong-Ning Dai

Hong-Ning Dai

Most of studies only consider that wireless sensor networks are equipped with only omni-directional antennas, which can cause high collisions. It is shown that the per node throughput in such networks is decreased with the increased number of nodes. Thus, the transmission with multiple short-range hops is preferred to reduce the interference. However, other studies show that the transmission delay increases with the increased number of hops.

In this paper, we consider using directional antennas in wireless sensor networks. We have found that using directional antennas not only can increase the throughput capacity but also can decrease the delay by …