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.

Dual open and closed loop linear transmitter

Abstract: A linear transmitter includes an amplifier feedback loop for amplifying an input signal at a power amplifier. The feedback loop is operated in an open loop mode when the power amplifier is operating at a first operating point and is operated in a closed loop mode when the power amplifier is operating at a second operating point. The transmitter further includes an auxiliary loop coupled to the amplifier feedback loop that provides phase training for the feedback loop and power leveling when the feedback loop is operating open loop. Open loop phase training and power leveling is done during open loop transmission, without an associated training signal or training period. Stable closed loop operation can commence subsequently providing the higher power amplifier efficiency associated with the second operating point and maintaining off channel interference requirements.

A sense amplifier with an integral logic function

Abstract: A sense amplifier with an integral logic function for use in a circuit such as a tag cache portion of a microprocessor cache. In one form, the integral logic function is an exclusive-OR function. The sense amplifier senses a differential voltage developed between a differential pair of bit lines which are coupled to predetermined bit positions of a plurality of entries in a tag cache. While sensing the voltage, an exclusive-OR function is performed between the logic state of the sensed bit and a corresponding input address bit. If the input address bit matches the sensed bit, then a match signal is asserted. The value of the corresponding input address bit configures the circuit either to provide an output signal in a predetermined logic state if a true bit line signal voltage exceeds a complement bit line signal voltage, or to provide the output signal in the predetermined state if the complement bit line signal voltage exceeds the true bit line signal voltage.

Single sided capacitive force sensor for electronic devices

Abstract: A capacitive force sensor (100) includes a substrate (101) having at least one electrode pair (102,103) defining a capacitance disposed thereon. The substrate (101) is fixed relative to a first plate (106). A drive circuit (104) is configured to apply a voltage relative to a circuit ground (105) to the electrode pair (102,103). The first plate (106) is separated from a second plate (107) that is coupled to circuit ground (105) by a compliance member (108,109). The compliance member (108,109) is configured to oppose a compression force (110) while allowing the first plate (106) to physically move relative to the second plate (107). A capacitive detection circuit (111) is then configured to detect a change the capacitance when the compliance member (108,109) is compressed. The compression force (110) is then determined from the change in capacitance and the spring constant of the compliance member (108,109).

Mobility using IEEE 802.21 in a heterogeneous IEEE 802.16/802.11-based, IMT-advanced (4G) network

Abstract: Industry is defining a new generation of mobile wireless technologies, called in cellular terminology "fourth generation" or "4G." This article shows that a system combining extensions of two radio access technologies, IEEE 802.11 and IEEE 802.16, meets the ITU-R's "IMT-Advanced" or 4G requirements. The extensions are 802.16 m (100 Mb/s, 250 km/h) and 802.11VHT (1 Gb/s, low velocity). The focus of this article is to show how IEEE 802.21 (the emerging IEEE standard for media-independent handover services) supports ";seamless"; mobility between these two radio access technologies. This mobility integrates the two radio access technologies into one system. We conclude that an 802.11VHT + 802.16 m + 802.21 system is likely to be proposed to the ITU-R for IMT- Advanced 4G.

Energy efficient system design with optimum transmission range for wireless ad hoc networks

Abstract: In ad hoc networks, devices are required to self-organize themselves into a network without previously established infrastructure. The kind of ad hoc network we consider is made up of a multitude of relatively low mobility, short range, wireless devices, pervasively deployed throughout the environment. One of the most important design criteria for this type of network is energy efficiency. This paper looks at the energy efficiency aspect of the system design. Specifically, this paper looks at the optimum one-hop transmission distance that will minimize the total system energy. The analysis assumes that the individual devices do not have power control, but that the transmission range of all the devices as a group can be varied in the design stage. The results show that the optimum one-hop transmission distance is independent of the physical network topology, the number of transmission sources, and the total transmission distance. It only depends on the propagation environment and the device parameters. With this result, some system design trade offs can be made to minimize the total system energy. We discuss what these parameters are, how they interact with each other, and how they can be used to obtain an energy efficient wireless system. We also discuss the implications this result has for future developments of low bit rate, short range, and highly dense wireless devices for ad hoc networks.