Motorola

About: Motorola is a company organization based out in Schaumburg, Illinois, United States. It is known for research contribution in the topics: Signal & Communications system. The organization has 27298 authors who have published 38274 publications receiving 968710 citations. The organization is also known as: Motorola, Inc. & Galvin Manufacturing Corporation.

Parametric process optimization to improve the accuracy of rapid prototyped stereolithography parts

Abstract: The functional requirements of a rapid prototyping system are speed and accuracy, and they are both functions of vendor defaulted and user selected manufacturing parameters. Accuracy is evaluated by dimensional errors, form errors and surface roughness of manufactured parts. A specially designed specimen with 20 dimensional, geometrical, and surface roughness features has been used in the inspection of RP manufacturing processes. In terms of Taguchi experimental design techniques, an orthogonal array of experiments has been developed which has the least number of experimental runs and desired process parameter settings. Using a 3-D coordinate measuring machine and surface profilometer, a series of measurements in evaluating the SLA parts quality has been conducted to find the functional relationships between the output part quality and input manufacturing process parameters. Two analysis tools, response surface methodology and Analysis of Variance (ANOVA), have been used to evaluate the SLA RP process and to perform the product optimization. The optimal setups of SLA manufacturing parameters for both individual features and a general part with various features have been concluded from this study.

Method and apparatus for selecting a serving transceiver

Abstract: A radio communication system selects a serving transceiver for a remote unit by generating and using a center of mass location estimation. The radio communication system collects uplink and downlink signal characteristics, including impaired signals caused by co-channel interference, from a set of transceivers, including those adjacent to and non-adjacent to the candidate transceiver and remote unit, to aid in the estimation of the remote unit's location within the radio communication system. Using the uplink and downlink signal characteristics, the radio communication system determines weighted coordinates related to predetermined coordinates and the signal characteristics which are used to produce a first and second center of mass coordinate estimation. The radio communication system then selects the serving transceiver to be the transceiver whose predetermined coordinates are closest to the first and second center of mass coordinate estimation.

A Wideband Spatial Channel Model for System-Wide Simulations

Abstract: A wideband space-time channel model is defined, which captures the multiple dependencies and variability in multicell system-wide operating environments. The model provides a unified treatment of spatial and temporal parameters, giving their statistical description and dependencies across a large geographical area for three outdoor environments pertinent to third-generation cellular system simulations. Parameter values are drawn from a broad base of recently published wideband and multiple-antenna measurements. A methodology is given to generate fast-fading coefficients between a base station and a mobile user based on the summation of directional plane waves derived from the statistics of the space-time parameters. Extensions to the baseline channel model, such as polarized antennas, are given to provide a greater variety of spatial environments. Despite its comprehensive nature, the model's implementation complexity is reasonable so it can be used in simulating large-scale systems. Output statistics and capacities are used to illustrate the main characteristics of the model

Wireless electrocardiograph system and method

Abstract: A method and system for wireless ECG monitoring is provided. An electrode connector, transmitter and receiver operate with existing electrodes and ECG monitors. The electrode connector includes connectors for attaching to disposable or reusable single electrodes. The transmitter transmits the signals from the electrodes to the receiver. The receiver passes the electrode signals to the ECG monitor for processing. ECG monitors used with an electrical conductor, for example wire connections to electrodes, are connected with the receiver, avoiding the purchase of a new monitor. Any legacy ECG monitor, including different ECG monitors, connects with the receiver using the ECG monitor's lead-wires. The ECG monitor operates as if directly connected to the electrodes without the problems discussed above associated with wires running from the ECG monitor to the patient.

Implementation experience with MANET routing protocols

Abstract: This paper outlines our experience with the implementation and deployment of two MANET routing protocols on a five node, four hop, network. The work was prompted by the lack of published results concerning the issues associated with the implementation of MANET routing protocols on actual wireless networks, as opposed to results of simulation experiments. We examined implementations of two distance vector MANET routing protocols and found a number of problems with both protocols during the course of our experiments. The most significant was that neither protocol could provide a stable route over any multi-hop network connection. The route discovery process of both protocols is fooled by the transient availability of network links to nodes that were more than one hop away. Packets transmitted over a fading channel cause the routing protocol to conclude incorrectly that there is a new one hop neighbor that could provide a lower metric (hop count) route to even more distant nodes. This can occur even when nodes are stationary, mobility resulted in even less route stability. We implemented a simple signal strength based neighbor selection procedure to test our assertion that fading channels and unreliable network links were the cause of the failure of the routing protocols. The result was that neighbor discovery and the filtering for neighbors with which nodes could communicate reliably enables the creation of reliable multihop routes. Based on our experiences, we outline several recommendations for future work in MANET research.