Showing papers by "Motorola published in 1988"

Vehicle monitoring arrangement and system

Abstract: A vehicle monitoring system is described having an arrangement (14,16) installed within a vehicle, wherein the system includes an external data terminal for communicating information to a remotely located base station (12). The arrangement includes a plurality of communication modules (36), each being capable of communicating messages associated with performance of the vehicle; a data bus member (44) for electrically intercoupling the plurality of communication modules (36) and for receiving the communicated messages therefrom; a driver interface module (28) for transmitting messages to and for receiving messages from a vehicle operator; and a recorder (26) coupled to the data bus member (44) for recording information associated with performance of the vehicle which has been transmitted over the data bus member (44) by the plurality of communication modules (36), coupled to the driver interface module (28) via a second data bus member (30) for transferring messages therebetween. The external data port (24) is provided by the recorder (26) and is used for communicating messages with the base station (12), preferably over an RF link.

Trunked communication system with nationwide roaming capability

Abstract: Selected regional trunking systems are equipped with telephone interconnect capability and provided with local computers (106), which communicate with a national hub computer (110). At each selected trunking system, several IDs are reserved as ''roaming IDs'' to be temporarily assigned to roaming subscribers (112). When a subscriber determines that it has roamed into a new trunked system, it requests a roaming ID. A roaming ID is assigned and transmitted to the subscriber, which thereafter operates within the new trunked system using its roaming ID. The roaming assignment is also transmitted to the national hub computer (110) so that interconnect calls may be appropriately properly forwarded. The roaming subscriber (112) continues to operate under the assigned roaming ID until it roams out of the range of the current system and into yet another trunked system. In this way, the subscribers may roam from system to system.

Packet-switched cellular telephone system

Abstract: A unique packet-switched cellular telephone system includes a cellular switch (140) and base sites (110) for providing packet-switched data services to cellular data telephones (102). Cellular switch (140) includes packet access points (152, 153) coupled to a packet network and T1 span lines (160, 161) coupled to the landline telephone network. Base sites (110) are coupled to cellular switch (140) by T1 span lines (164, 165) in which all time slots are clear channels and one time slot is dedicated for common channel signalling. Multiple data calls are assigned to each packet-mode radi channel thereby conserving valuable radio channel spectrum. Data calls are handed off from one packet-mode radio channel to another on the basis of cellular data telephone movement, signal strength, and/or bit-error rate, or on the basis of radio channel data packet capacity, data packet traffic, and/or data packet throughout.

Self-centering electrode for power devices

Abstract: An improved means and method for forming leads to a power device is provided by use of a one-piece leadframe on which the die is mounted and a separate connecting clip between the leadframe and the bonding pad on the semiconductor die. The leadframe has an alignment dimple or groove for receiving a mating alignment feature on one end of the connecting clip. The other end of the connecting clip is located over the bonding pad on the die. Solder is placed between die and the leadframe and between the connecting clip and the bonding pad and between the mating alignment surfaces on the clip and leadframe. When the solder is liquid during assembly the die and clip float thereon and automatically align by surface tension so that the die is centrally located on the die flag, the connection point on the clup is centered on the bonding pad and the mating alignment surfaces on the clip and leadframe are engaged. The self-aligning process is dominated by the mating alignment regions on the connecting clip and leadframe which have a larger area and solder wetted periphery than the other regions being soldered.

Method for dynamically allocating data channels on a trunked communication system

Abstract: Disclosed is a method to dynamically allocate a number of data channels on a trunked radio system (100). The data activity is monitored during a predetermined time interval. If activity is above a predetermined maximum, an additional channel may be reserved for data use. Conversely, if data traffic is low, a data channel may be reallocated for voice message use. Moreover, should the amount of data traffic among the available data channels be unbalanced, the present method contemplates reassigning subscriber units (114 or 116) to the available data channels to balance the data traffic load, thereby providing superior access time and system performance.

Frequency division multiplexed acknowledge back paging system

Abstract: An acknowledge back (ack-back) paging system (100) is provided which includes a central station (110) which transmits a group of message signals to a group of ack-back pagers (121, 122, ...) which are addressed as a group. The users of the group of addressed ack-back pagers indicate a response to their respective pagers thus providing ack-back data. The pagers in the group of addressed ack-back pagers (121, 122, ...) then simultaneously transmit back to the central station (110) their ack-back data on different frequency subbands, a different frequency sub-band being allocated to each of the pagers (121, 122, ...) in the group.

Tdma communications system with adaptive equalization

Abstract: Method and means for reducing multipath interference distortion in a time-division multiple access (TDMA) communications system. A transmitting station (100) formats one or more equalizer synchronization words with a first user's data word, time-multiplexes this formatted user message with at least one other user message, and transmits the combined signal. The receiving station (200) receives the transmitted TDMA signal in a receiver (220), de-multiplexes the first user message from the other user messages in the TDMA controller (240), and the equalizer (250) equalizes the time delay spread characteristics of the data word portion of the first user message (or a stored version of such) in response to this de-multiplexing. Performing the adaptive equalization process more than once per user time slot provides an even higher data throughput for the system. Storing the first user message in a data buffer (230) permits the adaptive equalization process to be performed in non-real time, thereby lowering the required signal processing data rate in any particular receiver.

Registration of radiotelephones in networked cellular radiotelephone systems

Abstract: Adjacent cellular systems (101-103) are interconnected to form a network providing telephone coverage to mobiles located throughout their combined coverage areas (111-113). Each networked cellular system (101-103) includes base sites (412, 414, 416) located in cells (402, 404, 406) and a control terminal (420) coupled by data and voice lines to the base sites, a telephone central office (422) and the other cellular systems. Each base site (412, 414, 416) includes a base site controller (950), a scanning receiver (910), signalling transceiver (912) and up to eight voice channel transceivers (901-908). As mobiles move about the networked coverage area (111-113), intrasystem handoffs are provided between cells of the same cellular system, and intersystem handoffs are provided between border cells of adjacent cellular systems. Mobiles are paged throughout the networked coverage area (111-113) in the paging area (121-136) in which the mobile last registered. Registration parameters are updated by the control terminal (420) and base sites (412, 414, 416) and sent to mobiles in the overhead message train. Mobiles automatically register in response to receipt of the overhead message train when moving between paging areas (121-136) according to the flow charts of Figures 5 and 6.

Nationwide display pager with location readout.

Abstract: A selective call receiver (Fig. 2) for receiving and displaying information in a nationwide communication system (Fig. 1) includes circuitry (40) to decode and process transmitted channel identification information. The receiver (Fig. 2) displays channel identification indicia in response to a user interrogation thereby confirming proper operation of the receiver (Fig. 2) on the system (Fig. 1) at the expected location.

Microcellular communications system using macrodiversity

Abstract: A cellular system employing time division messages transmitted from a plurality of radiators (407, 409, 411) in each cell is disclosed. A first electromagnetic signal at a particular frequency is transmitted during one time slot (903) from one of the plurality of radiators. A second electromagnetic signal at the same frequency is transmitted during another time slot (917) from a second one of the plurality of radiators. A remote unit (401,403) selects the best electromagnetic signal and communicates the selection to a cell controller (413), which selects a third time slot for transmission of a message from the radiator transmitting the best electromagnetic signal.

Colocated cellular radiotelephone systems

Abstract: An existing cellular system (X-system 102) is interconnected with another cellular system (M-system 101) via inter-office trunks (150) to add additional switching capacity for providing telephone coverage to mobiles located throughout their common coverage area. X-system (102) includes a control terminal (120) coupled by data and voice lines to base sites (121-124) and by out trunks to a telephone central office (110). M-system (101) includes a control terminal (420) coupled by data and voice lines to base sites (411-415) and by in trunks and out trunks to the telephone central office (110). M-system base sites (411-414) are colocated with corresponding existing X-system base sites (121-124). Paging/access channels are assigned to M-system base sites (411-414) for processing all incoming originations from mobiles and paging mobiles for all outgoing originations. Access-only channels are assigned to X-system base sites (121-124) for processing mobile originations transferred to X-system (102) by a directed retry message from M-system (101). M-system (101) shares the mobile origination traffic with X-system (102) by sending a directed retry message to a percentage of the originating mobiles.

Code division multiplexed acknowledge back paging system

Abstract: An acknowledge back (ack-back) paging system is provided which includes a central station which transmits a group of message signals to an group of ack-back pagers which are addressed as a group. The users of the group of addressed ack-back pagers indicate a response to their respective pagers thus providing ack-back data. The pagers in the group of addressed ack-back pagers then simultaneously transmit back to the central station their ack-back signals using different respective pseudorandom codes, a different pseudorandom code being dynamically allocated to each of the pagers in the group.

Method and arrangement for a sigma delta converter for bandpass signals

Abstract: An improved apparatus and method for a sigma delta converter for bandpass signals is disclosed, suitable for use in mobile radio applications, between the front end and digital signal processing stages, that includes at least one bandpass filter, an n-level quantizer, an n-level digital-to-analog (D/A) converter, and a direct current (DC) feedback network. The sigma delta converter for bandpass signals may be configured in a second order or a fourth order embodiment and achieves analog-to-digital conversion of a signal having a non-zero frequency carrier or suppressed carrier with improved signal-to-noise ratio performance and with minimal quantization error. As a result, the sigma delta conversion occures earlier in a receiver chain and a dynamic range of about 95-98 dB is achieved.

Metallization scheme providing adhesion and barrier properties

Abstract: A titanium-tungsten-nitride/titanium-tungsten/gold (TiWN/TiW/Au) packaging interconnect metallization scheme is used to provide electrical contact to chip level interconnect metallization on a semiconductor substrate. The TiWN/TiW/Au packaging interconnect metallization scheme provides for good adhesion and barrier properties that withstand high temperatures and improve the reliability of the semiconductor chip. The TiWN layer provides good adhesion to the chip level interconnect metallization and the passivation layer. It also provides improved barrier properties to prevent the diffusion of other metal atoms through it. The TiW layer provides good adhesion to the gold metal layer. A gold bump may be electroplated to the gold layer and automatically bonded to a conductive lead of a tape in TAB packaging; or a wire bonded to the gold layer in conventional packaging.

High bit rate communication system for overcoming multipath

Abstract: A communication system for relatively high data bit rate RF communication overcomes multipath interference by employing relatively narrow beam antenna sectors and by selecting the best communication path established between two terminals, at least one of which has narrow beam antenna sectors. The communication path selection process includes determining the signal integrity of data communicated between the terminals. One implementation includes the narrow beam antenna sectors at each terminal.

Low power digital receiver

Abstract: A low power digital receiver (10) is provided that contemporaneously selects the lowest possible sampling signal frequency (34) (from a plurality of available sampling signals), and received signal level (28) to properly digitize (32) and recover a desired signal. Digitization is performed after the first IF using broadband stages (28, 30, and 32) that are temporarily enabled (44) to rapidly digitize the first IF signal. This, together with the low sampling rate, minimizes the power consumption of the receiver (10) thereby permitting portable and mobile digital receiver embodiments.

Method for entering digit sequences by voice command

Abstract: A user-interactive speech recognition control system is disclosed for recognizing a complete sequence of keywords (e.g., a telephone number such as 123-4567) via entering, verifying, and editing variable-length utterance strings (e.g., 1-2-3; 4-5; 6-7) separated by the user-defined placement of pauses. The device controller (120) utilizes timers (124) to monitor the pause time between partial-sequence digit strings recognized by the speech recognizer (110). When a string of digits is followed by a predetermined pause time interval, the recognized digits will be replied via the speech synthesizer (130). An additional string of digits can then be entered, and only the subsequent string will be replied after the next pause. Furthermore, the user has the flexibility to correct only the last digit string entered, or the entire sequence. Hence, if there is an error in only one digit, the erroneous digit string can be corrected without having to re-enter the entire digit sequence. The invention is well-suited to be used in a hands-free voice command dialing system for a mobile radiotelephone, wherein vehicular background noise may affect recognition accuracy.

Digital speech coder having improved vector excitation source

Abstract: An improved excitation vector generation and search technique (FIG. 1) is described for a code-excited linear prediction (CELP) speech coder (100) using a codebook of excitation code vectors. A set of M basis vectors Vm (n) are used along with the excitation signal codewords (i) to generate the codebook of excitation vectors ui (n) according to a "vector sum" technique (120) of converting the selector codewords into a plurality of interim data signals, multiplying the set of M basis vectors by the interim data signals, and summing the resultant vectors to produce the set of 2M codebook vectors. The entire codebook of 2M possible excitation vectors is efficiently searched by using the vector sum generation technique with the M basis vectors--without ever having to generate and evaluate each of the 2M code vectors themselves. Furthermore, only M basis vectors need to be stored in memory (114), as opposed to all 2M code vectors.

Communication system with adaptive transceivers to control intermodulation distortion

Abstract: A transceiver determines the signal quality of a desired signal and the strength of all received signals. When the signal quality of the desired signal is low, and the signal strength of all received signals is high, the receiver is adapted to operate in a higher current mode, thereby minimizing intermodulation distortion. Conversely, when the quality of the desired signal is low and the strength of all received signals is also low, or when the quality of the desired signal is above a threshold, the receiver operates in a lower current mode to conserve power and maximize battery lifetime. Also, when the transceiver adapts to operate in the higher current mode, a command is sent instructing a transmitting party to increase the quality of their message which may enable the listening transceiver to adapt (return) to a lower current mode.

Extendable antenna for portable cellular telephones with ground radiator

Abstract: An antenna for a portable cellular telephone includes a quarter-wavelength ground radiator and a helical coil capacitively coupled to an extendable half-wavelength radiator. The extendable half-wavelength radiator includes a metallic coil molded in plastic. The ground radiator includes a serpentined transmission line on a flexible circuit board. The helical coil and ground radiator are coupled by a transmission line to a duplexer. The duplexer couples transmitter signals from a radio transmitter to the antenna and receiver signals from the antenna to a radio receiver. The antenna may be advantageously utilized in any portable radio applications where small size and immunity to hand induced radiation losses are desired.

Acknowledge back pager with frequency control apparatus.

Abstract: An acknowledge back (ack-back) pager (121, 122, ...) is provided for use in a paging system (100) which includes a central station (110) which transmits a group of message signals to a group of ack-back pagers (121, 122, ...) which are addressed as a group. The users of the group of addressed ack-back pagers (121, 122, ...) indicate a response to their respective pagers thus providing ack-back data. The pagers (121, 122, ...) in the group of addressed ack-back pagers (121, 122, ...) then simultaneously transmit back to the central station (110) their ack-back data on different frequency sub-bands, a different frequency sub-band being allocated to each of the pagers, (121, 122, ...) in the group. The invention provides apparatus for controlling the frequency of the selected sub-band with very high accuracy.

Integrated circuit trench cell

Abstract: A multiple element integrated circuit trench cell (10) having at least one vertical field effect transistor (FET) (46) in a wall (17) of a trench (18) in a semiconductor substrate (12). The cell (10) further comprises a central load device (54) within the trench (18) which is electrically connected to the vertical FET (46). The central load device (54) may be an active load device, such as another field effect transistor, or a passive load device, such as a resistor. Additionally, a further FET (50) may be present in another wall (19) of the trench (18) or in a lateral orientation adjacent the trench (18) in the semiconductor surface (14). Two of these multiple element trench cells (10) may be interconnected in various configurations to form conventional static random access memory (SRAM) cells (56).

An analytical expression for Fermi level versus sheet carrier concentration for HEMT modeling

Abstract: A simple second-order analytical expression of Fermi-level variation with two-dimensional electron gas density in a high-electron-mobility transistor (HEMT) has been developed. This empirical expression was found to give better results near cutoff and in saturation than the linear approximation currently being used in many models. It can be used in the development of a more accurate charge control model and hence in the development of an improved analytical model for the HEMT. >

Application of statistical design and response surface methods to computer-aided VLSI device design

Abstract: A statistically oriented methodology for optimization and sensitivity analysis of VLSI process, device, and circuit design through computer simulation has been developed. Emphasis has been placed on maintaining a clear distinction between design synthesis and design analysis. Design analysis is viewed as a multiple input-output system resulting in a multiple-constraints-optimization problem. It is shown how simple graphic techniques or rigorous mathematical optimization can be performed within a constrained desirability space to determine optimal operating conditions. This leads directly to the concept of global input factors. Which affect a large number of the response variables, and specific input factors, which can be used to adjust the operating level of a small number of response variables. By using the derived empirical equations to desensitize the responses to variations in input factors, the proposed methodology can play a key role in designing for manufacturability. As proof of concept, the methodology has been applied to the optimization of a VLSI BIMOS technology, with satisfactory results. >

Rotatable contactless antenna coupler and antenna

Abstract: A rotatable contactless RF signal coupler (26), which couples RF signals between an antenna (24) and an RF signal processor in a portable radio, along with an antenna (24) capable of operating in two modes is described herein. Specifically, the signal coupler (24) includes a transformer that is primarily located within the hinge formed by the housing of the radio and a rotatable flip portion (18). Substantially constant inductive coupling is maintained in the coupler regardless of rotation. The antenna (24) is capable of operating in a narrow band and a wide band mode to afford antenna operation through varied conditions.

CMOS salicide process using germanium implantation

Abstract: A salicided twin-tub CMOS process using germanium implantation to retard the diffusion of the dopants, such as phosphorus and boron. Implantation of n+ and p+ dopants after titanium salicidation is employed to fabricate devices with low junction leakage and good short-channel effects. Also, the germanium dopant may be introduced before or after the formation of the refractory metal silicide formation, and may be implanted independently or together with the dopant whose diffusion in the silicon it will modify. The employment of germanium permits the use of a phosphorus implant through a relatively thick refractory metal silicide contact layer. If arsenic is implanted through the silicide layer to solve the deep junction problem, the silicide layer must be thin to permit the passage of the larger arsenic atoms typically stopped by the silicide. Thinner silicide layers have the disadvantage of higher sheet resistances.

Paging receiver capable of reminding a user of an important message event

Abstract: An electronic paging receiver (10) for reminding a user of an important event includes a time of day clock (64) for recording the time when a data message is received. The paging receiver computes a future alert time to remind the user of the receipt of the data message. Additionally, the user may enter a future alert time to generate a future alert. Further, the paging receiver (10) is capable of detecting a special time/date field in the received data message to automatically generate a future alert.

Miniature shield with opposing cantilever spring fingers

Abstract: A miniature shield with opposing cantilever spring fingers is disclosed. Shield walls, which may be part of a housing for electronic equipment, are designed to insert between a plurality of opposing cantilever spring fingers arranged in a "U"-shaped channel. Torque generated at the bottom of the "U"-shaped channel is minimized by the opposing cantilever spring fingers and enables the channel to be reflow soldered to an electronic circuit board.

Data processor with development support features

Abstract: A data processor (11) with development support features includes an alternate mode of operation in which instructions are received by means of an externally-controlled path. The connections used by the externally-controlled path are not shared by any system resources accessible to the data processor (11) in the normal mode of operation, but are used by other development support features in the normal mode. In a preferred embodiment, an integrated circuit microcomputer (10) includes such a data processor (11) as its CPU. The CPU (11) has access to on-chip peripherals and memory, in addition to off-chip peripherals (13,15) and memory (14), in both the normal and alternate modes of operation, by means of a parallel bus (12) which it operates as a bus master. In the alternate mode, the CPU receives instructions by means of a serial bus on which the CPU is a slave device.

Reuse groups for scan monitoring in digital cellular systems

Abstract: An improved TDMA radiotelephone cellular communication system employs an improved cell site scan monitoring technique. The technique includes monitoring radiotelephone calls, and tracking and recording their signal qualities. The records are used to maintain and determine which frequencies and which time partitions at the base site equipment are being utilized for radiotelephone communication. When a new call assignment is required at a cell site, it is assigned to a time partition of a base site equipment frequency in a frequency prioritized manner such that radiotelephone calls are concentrated within each frequency so as to reduce the number of frequencies carrying radiotelephone calls.