Showing papers by "Motorola published in 1985"

A two way personal message system with extended coverage.

Abstract: A communication system for carrying messages via a radio channel between one central site (100) of a plurality of central sites and a plurality of two-way remote data units (106). Each central site (100) has a radio coverage area (300) and each remote unit has a unique address and association with one of the central sites. When a message addressed to one of the remote units is received in a central site, a file (804) of remote unit addresses is searched to find the location and central site association of the remote unit to which the message is addressed. If an address match is found indicating that the remote transceiver is in the coverage area of the message-receiving central site, the addressed message is stored and transmitted in that site. If an address match is found indicating that the remote transceiver is in another central site, the addressed message is conveyed to that site for transmission.

Digital global positioning system receiver

Abstract: A digital receiver for GPS C/A-code signals is described. The GPS receiver of the present invention provides reception and tracking a plurality of satellites simultaneously, using four separate receiver channels. The GPS receiver of the present invention includes an analog front-end for selecting and frequency translating the received GPS signal. The GPS receiver further includes a highspeed digital signal processor for recovering the despread data of the GPS signal. The baseband signal is further processed by a general purpose digital signal processor for signal search, tracking, and data recovery operations, and a microprocessor provides overall receiver control, and interface with the operator of the GPS receiver.

Noise suppression system

Abstract: An improved noise suppression system (400) is disclosed which performs speech quality enhancement upon speech-plus-noise signal available at the input (205) to generate a clean speech signal at the output (265) by spectral gain modification. The noise suppression system of the present invention includes a background noise estimator (420) which generates and stores an estimate of the background noise power spectral density based upon pre-processed speech (215), as determined by the detected minima of the post-processed speech energy level. This post-processed speech (255) may be obtained directly from the output of the noise suppression system, or may be simulated by multiplying the pre-processed speech energy (225) by the channel gain values of the modification signal (245). This technique of implementing post-processed signal to generate the background noise estimate (325) provides a more accurate measurement of the background noise energy since it is based upon much cleaner speech signal. As a result, the present invention performs acoustic noise suppression in high ambient noise backgrounds with significantly less voice quality degradation.

The category concept: an extension to the entity-relationship model

Abstract: An enhanced version of the Entity-Relationship (ER) data model called the Entity-Category-Relationship (ECR) data model is presented. The principal extension is the introduction of the concept of a category. Categories permit the grouping of entities from different entity types according to the roles they play in a relationship, as well as the representation of ISA and generalization hierarchies. The structures of the ECR data model are defined, and a graphic representation technique for their display is presented. Language operations to define and use an ECR database are defined. Two realistic examples of the use of the ECR model for database design are demonstrated. The examples show how ECR structures can be directly mapped into relational and network structures. The definition of derived relationships on an ECR database gives the power to phrase higher order recursive queries in a first order query language.

Cellular voice and data radiotelephone system

Abstract: A data message transmission system for a cellular radiotelephone system provides protection against data loss caused by multipath fade and subscriber unit handoff. Data from data terminal equipment (801) to be transmitted is converted by a system data processor (805) and radio signalling interface (807) into a format compatible with radio transmission prior to transmission by a transceiver (809). The data is reconverted to its original format following reception. Handoff is accomplished by halting the data transmission prior to handoff and resuming data transmission after handoff. Call supervision occurs via busy-idle bit coding performed in radio signalling interface (807).

Automatic gain selector for a noise suppression system

Abstract: An automatic gain selector is disclosed for use with a noise suppression system which performs speech quality enhancement upon a noisy speech signal available at the input to generate a noise-suppressed speech signal at the output by spectral gain modification. The channel gain controller (240) of the present invention produces a modification signal (245), comprised of individual channel gain values, for application to a channel gain modifier (250). A particular gain table set is automatically selected from one of a plurality of gain tables (450) by a selector switch (470) and a noise level quantizer (440) in response to a multi-channel noise parameter, such as the overall average background noise level of the input signal. Then the individual channel gain values (455) are obtained from the particular gain table set in response to the individual channel signal-to-noise ratio estimate (235). Hence, each individual channel gain value is selected as a function of (a) the channel number, (b) the current channel SNR estimate, and (c) the overall average background noise level. The automatic gain selector further includes a gain smoothing filter (460) for smoothing these noise suppression gain factors on a per-sample basis thereby improving noise flutter performance caused by step discontinuities in frame-to-frame gain changes.

Automatic background noise estimator for a noise suppression system

Abstract: An improved background noise estimator (320) is disclosed for use with a noise suppression system (300) for generating an estimate of the background noise power spectral density provided to noise suppressor (310), which performs speech quality enhancement upon the pre-processed speech-plus-noise signal available at the input to generate a clean post-processed speech signal at the output. Background noise estimator (320) utilizes an energy valley detector based upon post-processed speech to perform the speech/noise classification, and a noise spectral estimator based upon pre-processed speech to generate an estimate of the background noise power spectral density. As a result, the background noise estimate supplied to the noise suppressor is a more accurate measurement of the background noise energy, since it is performed during a more accurate determination of the occurrences of pauses in the speech.

Uniform emission backlight

Abstract: A backlight having lamps inserted into ends of a transparent member is disclosed. A top surface of the member is polished and contains an opaque section opposing the lamps. A bottom surface of the member is uniformly frosted so that variations in the average depth of surface irregularities are minimized.

Method of doppler searching in a digital GPS receiver

Abstract: An improved method of doppler searching in a digital GPS receiver is described. According to the principles of the present invention, an N-point fourier transform is performed on samples of a down converted GPS signal representing the entire range of Doppler-shifted GPS carrier frequencies. The magnitude of the square of each of the output samples is calculated to produce N power quantities, corresponding to N search frequencies. The power quantities for each of the N search frequencies are then summed to produce N quantities proportional to average power. The maximum of the N-power quantities indicates the presence of the corresponding GPS signal.

Hands-free control system for a radiotelephone

Abstract: PCT No. PCT/US85/01672 Sec. 371 Date Sep. 3, 1985 Sec. 102(e) Date Sep. 3, 1985 PCT Filed Sep. 3, 1985 PCT Pub. No. WO87/01546 PCT Pub. Date Mar. 12, 1987.An improved hands-free user-interactive control and dialing system is disclosed for use with a speech communications device. The control system (400) includes a dynamic noise suppressor (410), a speech recognizer (420) for implementing voice-control, a device controller (430) responsive to the speech recognizer for controlling operating parameters of the speech communications device (450) and for producing status information representing the operating status of the device, and a speech synthesizer (440) for providing reply information to the user as to the speech communications device operating status. In a mobile radiotelephone application, the spectral subtraction noise suppressor (414) is configured to improve the performance of the speech recognizer (424), the voice quality of the transmitted audio (417), and the audio switching operation of the vehicular speakerphone (460). The combination of noise processing, speech recognition, and speech synthesis provides a substantial improvement to prior art control systems.

Computer peripheral shock mount for limiting motion-induced errors

Abstract: A disk drive shock mount is provided which attenuates shocks and vibrations to a disk drive (1, FIG. 1). The mount comprises a cradle 20 which is affixed to the disk drive housing, and a mounting plate 10 which may be used to suitably secure the disk drive assembly 1 to the next higher level of assembly. Flexible, compressible vibration isolators 50 of rubber or plastic are used to couple the cradle to the mounting plate. Rigid pins 70 on the cradle mate with grommet-enclosed apertures 60, 61 in the mounting plate to limit the degrees of motion permitted between the cradle and the mounting plate.

Low cost integrated circuit bonding process

Abstract: A low cost process for bonding a plurality of integrated circuit die to a variety of die support frames using existing, readily available equipment. Tape automatic bonding (TAB) processes offer a number of new possibilities in the assembly and packaging of integrated circuits. However, the investigation of TAB techniques or the use of TAB techniques on low volume parts is prohibited by the high cost of "bumping" or putting interconnection balls on the chip or the tape leads. The process permits placing balls on the bonding pads of a plurality of die by a wire bonder, cutting off the wire, planarizing the balls, coating the planarized region with a conductive epoxy and then registering and bonding the die to corresponding conductive patterns on die support frames.

Dual conversion FM receiver using phase locked direct conversion IF

Abstract: A receiver for frequency modulated signals, having down-conversion to a baseband, zero intermediate frequency for selectivity, followed by up-conversion to a non-zero IF for amplification, limiting, and demodulation. A phase-lock loop locks the frequency of the down-conversion source to the center frequency of the signal coupled to the baseband IF, converting the signal to precisely zero frequency. This avoids the beat note often found in direct conversion systems. The phase-lock loop additionally provides inherent demodulation of the FM signal. The received FM signal is coupled to the baseband IF through a radio frequency amplifier for improved sensitivity and local oscillator isolation, or through a first IF comprising a mixer, local oscillator, filter, and amplifier.

Intelligent write in an EEPROM with data and erase check

Abstract: A memory provides a byte program mode which avoids unnecessary erase and program cycles. If a byte is to be programmed, the new data to be written is first compared to the existing data in the byte. If the old data is the same as the new data, there is no need to do a conventional erase/program cycle. In such case the memory does not perform the erase and reprogram which saves much time and avoids decreasing the life of the floating gate transistors in the byte. Even if the old data is not the same as the new data, the byte may already be in the erased state. In such case the erase cycle is skipped and programming is begun.

Thermal management in semiconductor device packaging

Abstract: Thermal management at device level packaging involves efficient and cost-effective removal of dissipated thermal energy from the device to assure its reliable performance over the long term. In the context of very high levels of integration of future ICs, thermal management will mean making such devices possible close to the natural limits set by thermal physics. This paper will present trends in important parameters and discuss solutions through examples.

Full duplex speakerphone for radio and landline telephones

Abstract: A full duplex speakerphone employing adaptive filters and having application in radiotelephone systems. To cancel acoustic feedback echo of the receive signal, a representation of the receive signal generated via an A/D converter (601) and an adaptive filter (301) is subtracted by a summer (303) from the transmit signal generated by the speakerphone microphone (115). Adaptive filter receive signal representation coefficients employed in the receive signal adaptive filter (301) are modified when the receive signal is detected in a land party signal detector (225). Likewise, to cancel electronic echo of the transmit signal, a representation of the transmit signal generated via an A/D converter (605) and an adaptive filter (305) is subtracted from the receive signal by a summer (307). The adaptive filter transmit signal representation coefficients employed in the transmit signal adaptive filter (305) are modified when the transmit signal is detected.

AN XxY BIT ARRAY MULTIPLIER/ACCUMULATOR CIRCUIT

Abstract: An XxY bit array multiplier/accumulator circuit (10), where X and Y are integers, for adding an input number having (X+Y) bits to an (X+Y) bit product of an X bit number and a Y bit number. Modified Booth's algorithm is implemented with an array structure which maintains a regular and systematic structure. The array structure uses adders (13) and multiplexers (12) in a predetermined column and row arrangement. Propagation delay is minimized while utilizing the modified Booth's algorithm by using a sum skipping technique and by using inverting logic properties of adders. Sign bit extension is provided by additional logic circuitry (14) and signed/unsigned modes of operation (15) are provided.

Simulcast transmitter apparatus having automatic synchronization capability

Abstract: A simulcast transmitter apparatus having automatic synchronization capability is disclosed which utilizes a signal readily available from any one of a number of available master timing sources to maintain a constant, uniform time delay to the transmitter via its interconnect link, even though the time delay corresponding to this interconnect link is susceptible to variation. Each interconnect link may consist of a phone line or other radio link which exhibits a relatively fixed, but unstable, delay. Each base station includes at least a transmitter and an adaptive-delay device which operates as a remotely-adjustable delay network upon receipt of a resync signal from a central controller to readjust and automatically maintain a uniform amount of time delay to each transmitter in the base stations. A master timing signal receiver, such as a suitable radio navigation receiver, is coupled to a suitable fixed delay network and provides the reference sync signal for each remotely-sited base station throughout the designated geographical area. This transmitter is therefore able to be compensated for varying amounts of delay caused by utilizing alternate links which may be necessary to maintain system reliability while overcoming inclement weather, interference, or other equipment difficulties.

Method of forming transistors with poly-sidewall contacts utilizing deposition of polycrystalline and insulating layers combined with selective etching and oxidation of said layers

Abstract: Improved bipolar transistors having minimum base-collector and collector-substrate junction area are formed by using multiple polycrystalline (e.g. doped poly silicon) layers to make lateral contact to a pillar shaped single crystal device region. The lateral poly silicon contacts are isolated from each other and the substrate and extend to the upper surface of the device for external connections. The structure is made by depositing two dielectric-poly layer sandwiches, etching and oxidizing part of the poly silicon layers to provide isolated overlapping poly silicon regions, etching a first hole through both poly silicon regions to the substrate, etching a second hole to the lower poly silicon layer, and filling the first and second holes with single and poly-crystalline silicon, respectfully. A sidewall oxide is formed at the periphery of the top of the single crystal pillar for defining the emitter location without additional masking.

Single-chip microcomputer having a program register for controlling two EEPROM arrays

Abstract: A single-chip microcomputer comprises at least two separate and independent electrically erasable programmable read only memories (EEPROMs) on-board which may be independently programmed, erased and read. Each part of the split EEPROM has its own data bus and address bus. Programming and erasing is controlled by a program register which has separate bits for configuring and latching the data and address buses of a selected EEPROM array, for providing programming voltage to the array of choice and for choosing between programming and erasing the selected array. The split EEPROM provides versatility to the user in allowing one part of the EEPROM to be programmed while the program stored in another part of the EEPROM or RAM may be read and utilized. In addition, test time and effort of the microcomputer may be considerably reduced.

Simulcast transmission system having automtic synchronization

Abstract: An improved simulcast transmission system having automatic synchronization is disclosed which utilizes a signal from any one of a number of readily available master timing sources to maintain a constant, uniform time delay to a multiplicity of transmitters even though the time delay corresponding to an included individual interconnect link is susceptible to variation. This simulcast system includes a central controller for controlling, via an interconnect link, the operation of each transmitter located at a plurality of base station sites. This central controller includes a master timing signal receiver and periodically outputs a resynchronization command via the interconnect link to the base stations. Each interconnect link may consist of a phone line or other radio link which exhibits a relatively fixed, but unstable, delay. Each base station includes at least a transmitter and an adaptive-delay device which operates as a remotely-adjustable delay network upon receipt of a resync signal from the central controller to readjust and automatically maintain a uniform amount of time delay to each transmitter in the base stations. A master timing signal receiver such as a suitable radio navigation receiver is coupled to a suitable fixed delay network and provides the reference sync signal for each remotely-sited base station throughout the designated geographical area. This simulcast system is therefore cable to compensate for varying amounts of delay caused by utilizing alternate links which may be necessary to maintain system reliability while overcoming inclement weather, interference, or other equipment difficulties.

High density IC module assembly

Abstract: An electronic module (50) having a high density of silicon IC chips (42) is provided by mounting the chips (42) in tapered through-holes in a silicon substrate (41), filling the edge gaps (43g) between the chips and the substrate with a glass (43f) so that the chips (42), the filler glass (43f), and the substrate (41) have a smooth upper surface (41u) adapted to receive monolithic interconnections (46) formed by planar metallization methods. The resulting assembly (40) is enclosed in a housing (50) also formed substantially from silicon, which contains electrically isolated pins (54) for contacting the input-output electrodes of the assembly (40). Preferential etching is used to form the through-holes in the substrate (41) as well as various alignment means on the substrate (41) and other parts of the housing (50) so that they are self-aligning during assembly. Improved performance, reliability, and low cost is obtained.

Multichannel telephone system

Abstract: A multi-channel RF telephone system that utilizes a dedicated channel status monitor to develop a list of available communications channels, and a common channel transceiver to transmit this list to the telephones. The telephones select a channel to use from this list by sequentially accessing the list a number of times based upon, at least in part, an identification number uniquely assigned to the telephone in question. If the selected channel is in fact unavailable, the telephone can update the list it maintains independently.

Alarm system having alarm transmitter indentification codes and acoustic ranging

Abstract: An alarm system for sensing an alarm condition within a relevant alarm area includes one or more portable alarm units for sensing an alarm condition. Each alarm unit includes a radio frequency transmitter for identifying the alarm unit and a secondary, audio, transmitter for defining the relevant alarm area. The system also includes a plurality of transponders. Each transponder includes a primary receiver for receiving a radio message from an alarm unit and a secondary receiver for receiving an audio signal from the alarm unit. A real-time clock in each transponder provides the elapsed time between receipt of a primary and receipt of the secondary alarm signals. The alerted transponders then transmit to a control unit a transponder address code, an alarm unit identification code and an elapsed time indicia. Based on the address code or codes and the minimal elapsed times detected by the control unit, the relevant alarm area can be determined.

Duplex interconnect/dispatch trunked radio system

Abstract: A dispatch trunked radio system which provides duplex or simplex telephone interconnect communications to subscriber units. The system allows duplex capable trunked system subscriber units (102), (104) to establish a full duplex communication link with conventional land based telephone interconnect service in accordance with a method which unifies the operation of the trunked system subscriber units (102), (104), a plurality of trunk system repeaters (106), a trunked system central control unit (110), and a telephone interconnect control unit (352). The method of the present invention also provides improved trunked system performance by allowing simultaneous transmission and reception of channel controlling information.

Shortened wideband decoupled sleeve dipole antenna

Abstract: A shortened wideband decoupled sleeve dipole antenna is disclosed in which a helically wound upper radiating element and an inductively loaded lower radiating sleeve element reduce the linear size of the antenna. Substantial decoupling is provided by a helically wound feed coaxial transmission line within the sleeve element. A matching network at the antenna feed point provides capacitive reactance above the antenna resonant frequency and inductive reactance below the antenna resonant frequency such that an impedance match between the feed coaxial transmission line is obtained at frequencies above and below the resonant frequency and dual-band performance may be obtained.

Portable battery powered electrical apparatus with improved battery pack protected against inadvertent short circuit of the battery terminals

Abstract: An improved portable battery powered electrical device is disclosed which includes a battery pack having normally inactivated battery terminals so that inadvertent short circuiting thereof will not produce an undesirable high amplitude short current thereacross. A normally open switch interrupts the current path in the battery pack which is actuated to energize such battery terminals only when the battery pack is fully interconnected and mated to the associated portable housing. Fuse means are included to prevent the use of unauthorized battery packs without the foregoing safeguard provisions.

Switchless external antenna connector for portable radios

Abstract: A portable radio transceiver and mobile mount housing are disclosed which utilize a switchless connector for connecting the portable unit to an external antenna which is electrically coupled to the mobile mount. In the preferred embodiment, the portable radio is equipped with an internal antenna which is either coupled to an electrical contact on the exterior of the portable unit adaptable to making electrical contact with a similar contact on the inside of the mobile housing when the portable radio is inserted therein. The internal antenna in the portable unit is shielded by the metallic mobile mount housing which obviates the need to disconnect the same. In one embodiment the contact disposed on the portable unit exterior is connected to a predetermined point on the internal antenna for impedance matching with the external antenna when the portable unit is inserted into the mobile mount housing. Similar switchless contacts can also be utilized for connecting the portable unit to external microphones, speakers, battery chargers and the like.

Stress-Induced Deformation of Aluminum Metallization in Plastic Molded Semiconductor Devices

Abstract: Plastic encapsulation of large semiconductor chips has resulted in increased stress-related failures such as cracked passivation, metal deformation and delamination, cracked chips, cracked packages, and parameter shifts. The large mismatch in the coefficient of thermal expansion between the silicon chip and the plastic encapsulant is felt to be the major contributor to these failures. In an effort to minimize stress problems, many mold compound manufacturers have modified their formulations and epoxy resin chemistries. As a result, many "low-stress" mold compounds have been introduced in recent years. A procedure was developed for screening encapsulation plastics for mechanical stress on semiconductor chips. The method involves temperature cycling of molded packages containing unpassivated test chips. The degree of deformation of the metallization is used as a measure of stress on the chip. Several semiconductor grade epoxy mold compounds were evaluated with this procedure. Many of the newer low-stress epoxy formulations gave metal deformation equal to or greater than the standard formulations. One of the materials, however, yielded no observable metal deformation under the test conditions. Metal deformation is a result of shear stress acting at the chip surface, with the direction of the deformation being toward the center of the chip. Microscopic cross-sectional analysis of temperature cycled packages revealed microcracks in the plastic which appeared to have initiated at the chip edge. In most cases, the cracks were about 400/ \mu m long and thus did not reach the package surface. The microcracks appear to promote metal deformation, since they reduce the restrictions on plastic movement at the chip surface. SEM analysis was employed to determine the topography of the deformed aluminum stripes. The effects of chip size, aluminum line width, number of temperature cycles, and post-cure conditions were also determined.