Motorola Corporation

Anthony P Van Den Heuvel

Michael D Kotzin

Kenneth J Crisler

Lawrence M Mohl

Bradley Michael Hiben

Paul H Gailus

Richard A Comroe

Terry Michael Schaffner

Robert L Epsom

Daehyoung Hong

Jona Cohn

Arun Sobti

Allen L Davidson

Ronald H Chapman

Nicholas William Whinnett

John Stephen Ruppel

Dennis J Derfiny

Mark R Poulin

Theodore Saltzberg

Nihat S Edguer

Anthony J Sarli, Jr

A wireless device ( ) selectively opreates near protected sites ( ) including equipment at least intermittently using an operating frequency. The wireless device upon detecting a beacon signal from a beacon system ( ) ascertains interference parameters. The interference parameters are used to control operation of the wireless device to prevent harmful interference with the equipment at the protected site. The operation is selectively altered depending upon the interference parameters ascertained. The wireless device can be intelligently controlled from a control system ( ).

Wireless device, control system and methods for protected sites with operation according to interference parameters

A method and apparatus is provided for creating a composite waveform. This composite waveform is created by coding a plurality of input digital information signals. Subsequently, the plurality of coded input digital information signals are communicated over a communication medium to a digital combiner. The digital combiner combines the plurality of coded input digital information signals. Finally, the digitally combined information signal is spectrally shaped to form a composite waveform. These composite waveform creation principals may be applied to digitally encoded voice subbands in a subband coding system as well as channel information in a direct sequence code division multiple access (DS-CDMA) communication system transmitter.

Method and apparatus for creating a composite waveform

A bulletin board communication resource provides a message to communication units regarding available communication systems in a particular geographic area. The bulletin board resource also supports registration of the communication unit with one or more of these systems as selected by the communication unit.

Bulletin board resource for communication system access

A radio communication system includes a central station such as a repeater for transmitting FM signals to a plurality of radios. The repeater 11 is capable of receiving both analog speech FM signals and compressed voice signals. This permits the use of energy efficient transmission schemes by some of the radios operating in the system while permitting use of both types of transmission by the various remote radios.

Two way radio communication system

A TDM cellular communication (100) system includes a plurality of repeaters (102) each providing communication coverage for a cell site. A plurality of communication units communicate with the repeaters. The communication units are handed off from one cell site to another by measuring the range of the communication units from the repeaters. If the range exceeds a predetermined range the received signal quality of the adjacent cell site repeaters are measured. An available cell site which provides the best received signal quality is selected by the communication unit for hand off.

Handoff method for a cellular system

A harmonic signal is created from a limited spectral representation of a voice signal. The harmonic signal is combined with the at least a portion of the limited delayed spectral signal to provide a reconstructed speech signal having perceptually improved audio quality.

Speech quality improvement for voice coders and synthesizers

An RF communications system that can determine when a requesting subscriber unit comprises a TDM capable unit, and when it doesn't. Channel assignments are based upon this determination. The system also includes repeaters that can translate communications in a TDM format as transmitted by a TDM capable unit into non-TDM format for subsequent transmission to a non-TDM capable unit, and vice versa.

TDM/FDM communication system supporting both TDM and FDM-only

According to the invention, an information signal, such as a information signal, is sampled, quantized and processed digitally through an information encoder. Digitally processed samples produced by the encoder are modulated onto a communication channel to create channel symbols having a magnitude of modulation proportional to a characteristic of a respective digitally processed sample. Both a radio frequency (RF) transmission embodiment, and a wireline embodiment are provided. In a final aspect of the present invention, encryption is provided to ensure communication privacy.

Spectrally efficient method for communicating an information signal

A communication system that provides TDM and FDM communications between communication units. At least two control slots are provided in each TDM frame window to provide communication control information such as channel assignment information.

Multiple control slot TDM/FDM communication system

In a digital communication system, a residual signal is generated, encoded, and combined with an encoded information signal in a manner that does not appreciably degrade the encoded information signal. The information contained within the residual signal may be used by the receivers to improve the quality of the recovered signal. The residual signal is modulated such that it may only be recovered when the signal-to-noise ratio is sufficiently high. In this way, the quality of the recovered signal improves with increased signal-to-noise ratio.

Quality improvement for a digitally transmitted information signal

An improved arrangement and method for use in a radio communication system is disclosed which makes possible mobile radio channel assignments on narrower channel spacings with a minimum amount of adjacent channel interference or splatter occurring at an included base station receiver. In a first embodiment, the mobile radios modify at least one transmission parameter, such as maximum allowable deviation, a given amount of transmitter output power, and a modulation limiting bandwidth, if a processed value of receive signal strength exceeds at least one predetermined threshold value. The processed value of receive signal strength is taken from a plurality of sampled and stored receive signal strength values in the mobile radio. By determining that the processed value of receive signal strength exceeds a predetermined threshold value, the mobile radio is able to adaptively control the amount of splatter caused at the base station, thus keeping the amount of splatter within acceptable levels. In a second embodiment, the improved arrangement and method incorporated in a mobile radio progressively adapts the transmission parameters upon determining that the processed value of receive signal strength exceeds a first, a second, and a third threshold value to effect reduced maximum allowable deviation only, reduce the maximum allowable deviation and power output only, or to reduce the maximum allowable deviation, power output, and modulation limiting bandwidth upon exceeding one, two, or all of these threshold values. Moreover, in each of these embodiments, the base station includes apparatus and a method for compensating the level and bandwidth of recovered audio by sensing the relative level of received signal strength in the base station receiver.

Adaptive splatter control

An improved mounting system for surface mounted components is described. The mounting system of the present invention provides preparations for surface mounted components and the printed circuit substrate which render the resultant assembly highly resistant to stresses which occur due to thermal cycling. The printed circuit substrate is conditioned by removing selected areas of media surrounding the points of attachment between the surface mounted component and the printed circuit media. In addition, a spacing element is disposed between the surface mounted component and the printed circuit media to promote the formation of a virtual lead during assembly.

Mounting system for stress relief in surface mounted components

A variable impedance synthesis circuit is provided for generating a selected impedance, whether real or complex, at a predetermined port. The variable impedance synthesis circuit exhibits the selected impedance in response to control signals applied thereto.

Variable impedance synthesis apparatus

Apparatus is provided for inhibiting the generation of intermodulation products in a radio frequency amplifier coupled to a circulator. A control circuit generates a control signal exhibiting indicia of the amount of isolation provided by the circulator. The control signal is provided to a variable impedance synthesis circuit coupled to the circulation isolation port such that the impedance synthesis circuit exhibits the appropriate impedance to maximize circulation isolation. Intermodulation is thus minimized.

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Arlington Heights, IL, United States of America

Anthony P Van Den Heuvel