Abstract: A computing device (100) including a wireless packet data communications modem (101) used in conjunction with a computer (103) to provide untethered access to data bases and other computer users. A method is provided for controlling data transmission and reception using the wireless packet data communications modem (101) in tandem with the computer (103). Two-way communications is achieved using a small, low-cost, light-weight wireless packet data communications modem contained in a housing, integral to a computing device, or a removable housing conforming to a PCMCIA industry standard.

Abstract: A method and apparatus for mitigating error in a received communications signal includes an error mitigation unit (245) which receives and performs mitigation based on an error indication (e.g., a CRC) and a quality indication (QI). The error mitigation unit may include a magnitude adjuster (220) for adjusting the input signal value (e.g., an ADPCM nibble) when the QI is less than a threshold, and a soft correction unit (240) for, when the QI is above the threshold, either soft correcting nibble magnitudes or muting selective nibbles based on further signal information such as differential phase.

Abstract: A transceiver (10) in a first embodiment includes a zero intermediate frequency (ZIF) receiver (11), which achieves high throughput operation by reducing receiver latency time due to receiver response within a receiver pass band to carrier spectral components of a modulated carrier frequency. During a receive mode, a receiver local oscillator (LO) frequency is offset from the carrier frequency within the receiver pass band, preferably as determined by worst case errors in the carrier frequency and the LO frequency. During a transmit mode, the receiver LO frequency is modulated in such a way as to suppress the LO center frequency component in the modulated spectrum.

Abstract: A frequency-locked loop (100) employs a controllable oscillator (102) for generating an output signal having a frequency, optional sampler (104), coupled to oscillator (102), for sampling the frequency of the output signal, a divider (106), coupled to optional sampling circuit (104), for dividing the output signal frequency to generate a prescaled signal and a microprocessor (108), coupled between the divider 106 and oscillator (102), for comparing the prescaled signal to a reference signal and generating a control signal for correcting frequency shifts based upon the comparison. The control signal generated by microprocessor (108) is non-continuous. During that time when microprocessor (108) generates no control signals, power is removed from various frequency-locked loop circuitry.

Abstract: A data demodulator operating to recover symbols from a data signal including, an estimator, coupled to the data signal, for estimating a reference parameter, and a decision function that is responsive to the reference parameter and the data signal, for selecting a symbol for a symbol time from a set of predetermined symbols where the symbol is coupled to the estimator for updating the reference parameter when the symbol is representative of the reference parameter.

Abstract: A method for gauging battery charge in which current flowing from a battery (11) is integrated (25) and a charge counter counts charge. Voltage (Vb) across the battery is measured (16) and compared (26) with a voltage threshold (28). The counter (27) is reset to a predetermined value (29) when the measured voltage crosses the voltage threshold.

Abstract: A method for improved data communications in a wireless system is described. An enhanced access burst is provided having an additional logical information field, or alternately using one of a set of possible synch sequences indicative of supplementary information. Upon receipt of a system parameter indicating an enhanced access burst capability, the communication unit sends an appropriate enhanced access burst with the increased information. A reduction in system messaging is thus achieved, e.g., by avoiding the need to send the supplemental information via subsequent bursts.

Abstract: A method and apparatus for improved offset frequency estimation includes in a first embodiment a receiver (100) for coherent reception of a signal having known reference information, the receiver including an extractor (106) for extracting the reference information (107) from the signal, and an offset frequency estimator (110). The offset frequency estimator (110) includes a filter (121) for filtering the reference information and outputting a filtered reference sequence; a correlator (122, 124) for correlating the filtered reference sequence against a predetermined reference signal to form correlation values; and a peak detector (126) for determining an offset frequency estimate (131) from the correlation values. Other embodiments are also shown.

Abstract: A packet delivery method for assuring the delivery of packets in an wireless local area network (LAN) having a service access point (AP) and a plurality mobile user devices, said user devices in communication with each other and with the access point. The access point determines when a destination device is in the sleep mode of operation and stores data packets intended for that device in memory. Thereafter the access point determines when the destination device enters the active mode of operation, delivers the data packets to the destination device and informs the source device of delivery of the data packets to the destination device.

Abstract: In a data communication system (100) including infrastructure (101) arranged to communicate with a plurality of terminals (103) over a channel (109), a method of adaptable channel access practiced at a terminal (103) including determining an access priority value (303), responsive thereto ascertaining when the channel is available (305), and then executing a channel access attempt (307). The access priority value is determined with information received by the terminal or information available to the terminal.

Abstract: An electromagnetic shield providing for input/output signal paths includes: a carrier 101 having a shielding surface 103 that has electromagnetic shielding properties; a plurality of signal paths 107 mechanically coupled to the carrier 101; a plurality of filtering elements 109 corresponding to the plurality of signal paths 107 and electrically coupled, respectively, from the plurality of signal paths 107 to the shielding surface 103; and an enclosure 101 constructed from a material having electromagnetic shielding properties and having a perimeter edge 113 that is arranged and constructed to electrically couple the enclosure 111 to the shielding surface 103 at an interface so as to sandwich the plurality of filtering elements 109 between the perimeter edge 113 and the shielding surface 103 at the interface such that the plurality of signal paths 107 pass through the interface.

Abstract: A method and apparatus is provided for facilitating coherent communication reception. A received reference symbol coded spread spectrum communication signal is despread with a spreading code to derive a stream of reference samples and a stream of data samples. The channel response is estimated by utilizing the stream of reference samples. An offset frequency detector determines an offset to be applied to the received signal via a frequency locked loop, while a timing control compensates for slow timing drift and fast fading based on power estimates derived from the stream of reference samples and/or the stream of data samples. A rate estimator determines the rate at which the information was encoded, and the rate information is used to optimize the timing control, frequency offset detector and channel estimator. Thus an improved detection of estimated data symbols from the stream of received data samples is provided.

Abstract: A peripheral card (109) having an adaptive PCMCIA compliant interface including either an adaptive card present or card configuration function that includes a peripheral apparatus (209) arranged and constructed to operate in conjunction with a host computer (101) over a PCMCIA compliant interface, and an interface logic (205), coupled to the peripheral apparatus (209) and to a PCMCIA peripheral port (201), for interfacing the peripheral apparatus to the PCMCIA peripheral port (201), the interface logic further adaptively providing a card present signal at the PCMCIA peripheral port (201) when the peripheral apparatus (209) and the interface logic (205) expects the PCMCIA peripheral port (201) to be activated by the host computer (101) or alternatively adaptively providing configuration information pertaining to the peripheral apparatus to the host computer.

Abstract: A PCMCIA card having independent functionality and alternatively arranged to operate in conjunction with a host computer, that includes a peripheral apparatus (109) having an integral CPU (125), a power source (129), and a power supply (127) for exhibiting an independent operating state; and an interface function (121) integral with and coupled to said peripheral apparatus (109), said interface function arranged and constructed to couple said peripheral apparatus to the host computer (101) over a PCMCIA compliant interface and initiate a dependent operating state at said peripheral apparatus (109).

Abstract: A multi compartment electromagnetic energy shield (100) arranged for assembly to a mounting surface (203) of a carrier (201), the multi compartment electromagnetic energy shield includes an enclosure (101) and a partition (103) having electromagnetic shielding properties. The enclosure includes a first surface (405) and a first and a second side wall (105, 107) each extending from the first surface (405) to the mounting surface (203) of the carrier (201) after the assembly to the mounting surface of the carrier. The partition (103)including a mounting edge (305) and being arranged and constructed to electromagnetically divide the enclosure into multiple compartments (111, 113). The partition further captivated by the first and the second side wall (105, 107) in a free floating manner such that the mounting edge coincides with the mounting surface (203) after assembly to the mounting surface of the carrier (201).

Abstract: An apparatus (100) utilizes a shift register (107) to select which of multiple synthesizers (115, 117) is to receive programming information. This allows multiple synthesizers (115, 117) to be programmed based on input from a single programing line group (102). The number of devices that can be programmed is limited by the number of parallel outputs available from the shift register (107).

Abstract: An interface device (102) and corresponding method for coupling a peripheral controller (117) to a host computer (100), the interface device including an emulated universal asynchronous receiver transmitter (UART) (113) for the host computer. The interface device further includes a plurality of registers (203), preferably a control (215), status (227), and data register, such as a multi-register data buffer (401), corresponding to the registers of a UART, a host computer port (112), preferably compatible with a PCMCIA standard, that includes an address map for the plurality of registers (203), a peripheral controller port (114) providing an address mapped parallel interface to the plurality of registers (203), and control logic (207) for providing status signals, including UART status signals, to the host computer port and to the peripheral controller port.

Abstract: A communication system (100) employs a method (600) and apparatus (101) for conveying a communication signal between a communication unit (105) and a base site (101) that services a sectorized coverage area (103). The communication unit (105) transmits an uplink communication signal (113) to the base site (101). The base site (101) receives (603) the uplink communication signal (113) and determines (605) an approximate location of the communication unit (101) within a first portion (111) of a sector (108) of the sectorized coverage area (103). A downlink communication signal is then transmitted (609, 613) to the communication unit (105) based on the approximate location of the communication unit (105) using an antenna structure that produces a beamwidth (117) narrower than an angular width of the sector (108).

Abstract: A method and apparatus for packet alignment in a simulcast system includes a communications controller (310) having a vocoder and an input/output (I/O) processor (313) controlling the vocoder (311), the I/O processor having a timing alignment control (315) and a packet counter (314) for inserting timing alignment tags in voice/data packets and adjusting packet numbering and timing based on alignment requests from a master radio communication unit. The communications controller is coupled to radio communication units (330, 340, 350), each having a packet buffer (331) and an alignment processor (332) which includes a packet number detector (333) for detecting the transmission timing tag and sending a request for a packet numbering adjustment to the communications controller and a timing alignment detector (334) for comparing a receive time of the first information packet and a predetermined preferential receive time and for sending a timing alignment request to the communications controller.

Abstract: A high frequency transition (10) from a microstrip transmission line (57) to an MMIC coplanar waveguide (41) is provided. The microstrip transmission line (57) is representative of that typically encountered in a high frequency RF module on a first substrate (11). The MMIC coplanar waveguide (41) is representative of that encountered in low cost MMICs fabricated on a semiconductor substrate (56). An interface (15) couples the microstrip transmission line (57) to a mode converter (16). Mode converter (16) provides impedance mismatch compensation and coplanar waveguide propagation mode conditions for a connector coplanar waveguide (34) which connects from the first substrate (11) to the semiconductor substrate (56). An impedance transformer (40) provides additional impedance mismatch compensation on the semiconductor substrate (39) to complete the transition.