Abstract: The present invention is a technique of estimating the time and frequency response of at least one desired signal received by at least one antenna. The invention is an update formula for the time-invariant channel responses for multiple transmitting devices, called “Doppler channels”, that model the time-varying channel between each of the transmitting devices and each receiving device. Through use of the update formula, the time-varying channels of the multiple transmitting devices can be better tracked than with prior inventions.

Abstract: System (100) is coupled with power amplifier (106). Generation component (166) generates error signal (110) based at least in part on an input signal (144) for the system (100). The error signal (110) includes a phase component. The input signal (144) includes an envelope component. Modification component (130) modifies the phase component of the error signal (110) in response to the envelope component of the input signal to reduce variation of a phase component of the power amplifier output signal (194).

Abstract: A microelectronic package (10) comprises an integrated circuit component (12) mounted on a substrate (14) by solder bump interconnections (16) formed of a lead-free, tin-base solder alloy that contains a significant copper addition. A preferred solder is composed of a tin alloy containing between about 2 and 8 weight percent copper, preferably between about 3 and 5 weight percent. In the absence of lead, it is found that precipitation of copper-containing intermetallics of the type that adversely affect tin-lead solders is reduced. Moreover, the lead-free copper-tin solder alloy exhibits a high surface tension to reduce collapse of component toward the substrate during solder reflow.

Abstract: The remote unit (113) maintains a count of inserted blank scan lines generated by the remote unit (113) and uses this to maintain a fixed number of scan lines per page during facsimile transmission. More particularly, in the preferred embodiment of the present invention the remote unit (113) maintains a fixed number of lines per page by deleting scan lines comprising a predetermined set of characters from the actual facsimile transmitted, until the number of scan lines deleted from the facsimile is equal to the number of blank scan lines generated by the remote unit (113).

Abstract: Data delivery in GSM and UMTS co-existing networks is controlled by apparatus located within the network infrastructure which predicts the trajectory of a moving mobile station (26) requesting transmission or reception of data. By knowing the trajectory of the mobile station (26), the transmission can be made in an optimum manner by setting an appropriate transmission rate or delaying transmission until the mobile station (26) reaches a cell (18) able to accommodate faster data rates than its neighbours (17, 19). The trajectory prediction is based on a learning process whereby a large population of mobile stations' behaviour in a designated zone (5) is monitored over a period of time. Mobile stations with like behaviourial characteristics are grouped together. A mobile station (26) requesting a service for data transmission is matched to one of the recorded groups from which its trajectory can be predicted.

Abstract: The invention provides a method and apparatus for determining the direction of a signal such as for example a received radio signal in a cellular mobile communication system. At lest two antenna arrays (10, 12) are connected to associated processors (14, 16) for extracting the desired signal and two independent direction of arrival estimates are determined in associated direction estimators (18, 20). A similarity testing unit (22) determines the direction of arrival and the accuracy of this estimate from the difference between the two estimates. A feature of the invention is controlling the beam form of a downlink signal in response to the direction estimate and the determined accuracy.

Abstract: Rate assignment circuitry (102) detects when a data transmission begins and originally assigns an Orthogonal Variable Spreading Factor (OVSF) code corresponding to low data rate. Over time, a base station controller (101) determines when an OVSF code and/or a repetition rate should be changed (i.e., data rate increased or decreased). The OVSF code and/or the repetition rate is changed in order to gradually increase the data rate, up to a maximum allowable data rate. Once data transmission ceases for a period of time the OVSF code and/or the repetition rate is changed in order to gradually decrease the data rate, down to a lowest allowable data rate.

Abstract: A communication system (100) that includes base stations (103-109) comprising selection circuitry (207) is provided herein. The determination of a call anchoring base station (base station performing Code Division Multiple Access (CDMA) frame selection) is made based on the base station with a lowest mean work load. During communication with a remote unit (113), frames received by non-call anchoring base stations (105, 107) are backhauled to a switch (101). The switch (101) then sidehauls the frames to the call anchoring base station (103), where selection and call processing functions for the particular call takes place.

Abstract: Joint detection of data signals occurs in a code division, multiple access (CDMA) communication system as follows: A digital signal processor (315) first extracts a midamble portion of transmitted signal vectors and generates an estimate of the channel response corresponding to each user-antenna pair using a channel estimator (401). In the preferred embodiment, each user's transmission within the communication system comprises either the type-1 or type-2 burst with varying midamble and guard period durations. Next, a convolution processor (402) forms the convolution of the user signature sequence with the channel impulse response estimate associated with each user and each of the antennas (308)-(310). A detector (403) utilizes the set of vectors and creates a set of sub-system matrices and solves the sub-system matrices to extract symbol information from an individual remote unit's transmission. Finally, the detector (403) outputs symbol information for subsequent infrastructure processing.

Abstract: A method and apparatus for handoff to a rescue channel is introduced without the need to send and receive handoff control messages. In the preferred embodiment of the present invention, coordination of the rescue procedure at the infrastructure and mobile station is provided first by disabling the mobile transmitter followed by subsequent detection of signal loss and frame erasures at the serving cells, then by enabling the mobile transmitter followed by subsequent detection of signal by a rescue cell, and finally by enabling the rescue cell channel transmitter followed by subsequent detection and reception of signal and frames by the mobile.

Abstract: In a wireless communications system using orthogonal transmit diversity, wherein the orthogonal transmit diversity signal is produced by a transmitter having first and second radio frequency diversity signals for transmitting from first and second transmit diversity antennas, a radio frequency sample signal that represents the sum of the first and second radio frequency diversity signals is produced. The radio frequency sample signal is then down-converted to produce a down-converted signal having first and second components corresponding to the first and second radio frequency diversity signals, respectively. Thereafter, a first time reference of the first radio frequency diversity signal is recovered from the first component. Finally, a characteristic of the second component that is indicative of a difference in delay between the first and second radio frequency diversity signals is measured using the first time reference.

Abstract: A properly modulated carrier signal exits transmission circuitry (201) and enters a first and a second mixer (203, 205). The modulated carrier is mixed with a first and a second function by the first and the second mixers (203, 205). The functions are generated by a first and a second signal generator (207, 209). The mixed signals exit the mixers (203, 205), and are amplified (via amplifiers 211-213), to be radiated by an antenna (211). The antenna (221) comprises two orthogonal antenna elements (215, 217), that are in close proximity with one another (although not in contact). One of the mixed signals is radiated on a first element (215), and the other mixed signal is radiated on the second element (217). The resulting signal transmitted from the antenna (221) is the original carrier signal having the plane of polarization constantly changing. Thus a reflected signal emitted an instance earlier cannot interfere with a wave currently emitted.

Abstract: A current mode of operation is provided to a Walsh spreader (203), and based on the current mode of operation, the Walsh spreader (203) either varies a Walsh code at a symbol rate, or holds the Walsh code constant. During multi-carrier transmission a first symbol within a data stream (210) is spread with a first Walsh code, while symbols immediately preceding and following the first symbol are spread by a another, differing Walsh code. The sequence of Walsh codes exiting the spreader (201) is further scrambled by a pair of Pseudo-Noise (PN) codes (224) that are held constant for three Walsh code periods during multi-carrier transmission, and are not held constant during direct-spread transmission.

Abstract: In a method for wireless data communication between a base station and a subscriber unit in a wireless communication system, groups of symbols of an input data stream are commutated to produce a plurality of commutated data streams. The plurality of commutated data streams are then transformed to produce a plurality of transformed data streams. Next, each transformed data stream is spread with a selected one of a plurality of spreading codes to produce a plurality of antenna signals. Finally, each of the plurality of antenna signals is transmitted using a selected one of a plurality of spaced apart antennas, wherein the plurality of spaced apart antennas are spaced apart to provide transmit diversity. In one embodiment, the transform is a space-time transform.

Abstract: A method for determining failure modes of a transceiver (100) includes applying a control signal (121) to a transmitter (130) of transceiver (100). The power level of a transmit signal (131) is proportional to a predetermined voltage level of control signal (121), and is detected by a detector (132) which correspondingly produces a transmit power level indicator (133). A portion of transmit signal (131) is coupled to produce a coupled transmit signal (111) which is received by a receiver (110) of transceiver (100). Receiver (111) produces a receive signal strength indicator (112) corresponding to the power level of coupled transmit signal (111). Voltage levels of received signal strength indicator (112), transmit power level indicator (133) and predetermined voltage level of control signal (121) are stored in a memory means 125, and compared in a controller 126 to determine failure modes of receiver (110) and transmitter (130).

Abstract: In a wireless code-division multiple access (CDMA) system (100), a talkgroup (101) of subscriber units is provided. A sub-talkgroup (102) of subscriber units, forming a part of the talkgroup is assigned at least one inbound channel (416-417). The talkgroup is assigned outbound channels (415). Members of the sub-talkgroup may simultaneously transmit voice information (410-411) using the at least one inbound channel, which voice information is summed (412) and re-transmitted to the talkgroup using the outbound channels. Voice information is summed so that an individual talker receives summed voice information without the individual subscriber's voice content. Subscriber units in the sub-listengroup are allowed to transmit voice information only after requesting, and receiving, an additional inbound channel.

Abstract: A communication system provides a method and apparatus for interleaving data symbols of a block of data symbols (301) having data symbols from B(1) to B(n). The method and the accompanying apparatus include dividing block of data symbols (301) into a plurality of groups of data symbols (303 and 304). Each of the plurality of groups of data symbols (303, 304) includes data symbols equal in number to a fraction of data symbols B(1) through B(n), such as ½ and ⅓, such that the total number of data symbols in plurality of groups of data symbols (303, 304) substantially equals “n” data symbols. An interleaved block of data symbols (106) is formed by an alternating selection of data symbols from plurality groups of data symbols (303, 304). The alternating selection from each of plurality of groups of data symbols (303, 304) is according to either a forward addressing or a backward addressing mapping.

Abstract: The first frame of a paging slot (405) contains a portion of every page's (401-404) address. Likewise, the second, third, and fourth frames of the slot (405) contain a second, third, and fourth portion from each of the paging addresses. Address information is organized in the atomic frames of the slot (405) in such a way that the information in the earliest frame gives the mobile a high probability that it can determine that no messages directed to it are present in the slot. After receiving a first frame, a mobile station uses known partial address comparison techniques to determine if the mobile station has a page pending.

Abstract: A system for generating a short-range wireless data communication link through an over-the-air channel on a predetermined radio frequency (RF) carrier. The system integrates conventional RF techniques into a low-power and low-cost system for establishing short-range wireless data communication. The system generates short-range wireless data communication links between a transmitting unit (500) that transmits an operating signal carrying data, and a receiver unit (1000) that receives the operating signal without a synthesizer or a heterodyne scheme.

Abstract: Transferring communication within a communication system (100) occurs as follows: During communication with a serving base station (101), a handover candidate list (110) is provided to the remote unit (113). The list (110) comprises a set of neighboring base stations (102) that are capable of supporting the service requirements of the remote unit (113) and does not include any neighboring base station (111) that are incapable of supporting the current service required by the remote unit.