Abstract: A method of analyzing a circuit having at least one structural loop within a channel connected component first requires that the circuit be at least partly notionally split into its constituent channel connected components (100). The structural loops within a channel-connected component are then detected and a pair of temporary boolean variables is inserted at a break point in each structural loop in the channel-connected component at an internal input. The channel connected component is then analyzed utilizing the pairs of temporary boolean variables at the break points in order to obtain a pair of boolean equations at each break point representing the functionality of the channel connected component at that break point to produce a system of boolean equations for the break points within the channel connected component (101). The system of boolean equations is then solved to produce a result that indicates whether the channel connected component has oscillatory, combinational or sequential behavior.

Abstract: A direct digital synthesizer (200) includes a first accumulator (202) that acts as the frequency accumulator in order to generate the desired average frequency. A second accumulator (204) acts to generate a phase correction at each overflow, with the input into the phase correction accumulator (204) being a function of the input frequency. The clock signal of the phase correction accumulator (204) is the overflow signal (208) of the frequency accumulator (202). With this configuration, the frequency accumulator (202) generates the timing, and the phase correction accumulator (204) generates the interpolation value. The use of the two accumulators (202, 204) as described, eliminates the need to use a multiplier in the design which is a high current consumption device.

Abstract: A method 400, phone 203, radio transmitter 205, and communication system 200 including a nonsystematically shortened code encoder 202 having an input 204 adapted to receive input digital signals having a number of bits, the nonsystematically shortened code encoder 202 is adapted to produce encoded shortened code digital signals in accordance with the input digital signals. The communication system further including a nonsystematically shortened code decoder 208 adapted to receive the encoded shortened code digital signals, wherein the nonsystematically shortened code decoder 208 is adapted to produce an estimate of the input digital signals and an error detection flag.

Abstract: A direct modulation phase lock loop (PLL) a voltage controlled oscillator (VCO) (114). A divider (118) has a first divider input coupled to the VCO and a second divider input to receive a modulation inducing divisor sequence. A phase detector (102) has a first detector input coupled to the divider to receive the output thereof, and a second detector input to receive a reference input. A tuning circuit (306, 406) is coupled to the phase detector and the VCO, the tuning circuit responsive to a variable DC reference potential such that the tuning circuit has a frequency response that is constant over the modulation bandwidth whereby the PLL is a type 1 PLL with low modulation distortion.

Abstract: A wireless subscriber unit (30) contains an advertisement manager (56). The advertisement manager (56) is programmed to assign an advertisement icon (54) to a message indicator (46) on the display (42) of the wireless subscriber unit (30). Assignment of the advertisement icon (54) to the message indicator (46) associated with a message (26) may be based on a predetermined algorithm in the advertisement manager (56), or based on a notification received from the wireless communication system (10).

Abstract: A housing (101) for a portable two-way radio (100) includes a first aperture (107) located substantially at one end of the housing (101) for engaging an first attachment apparatus such as a belt clip (201). A second aperture (111) is located substantially at the opposite end of the radio housing (101) for engaging a second attachment apparatus. The first aperture (107) and the second aperture (111) are used with the belt clip (201) such that the clip may be secured within either the first aperture (107) or second aperture (111) for attachment to a user's body or other object. The attachment of the belt clip (201) is unique in that it can be bent without being disengaged from its associated aperture.

Abstract: A radio (100) includes a receiver circuitry (106) for use in conjunction with a tunable antenna (101). The radio includes a controller (122) which may be a digital signal processor. The controller (122) controls various radio functions including tuning of the antenna (101), measurement of the quality of received signals, and generation of a test signal. The radio is capable of generating a test signal on a desired frequency, which is radiated within the radio, received at the antenna (101) and then processed by receiver circuitry (106). Its quality is then measured and used to control the tuning of the antenna (101). The test signal generated by the controller (122) can be mixed up to the desired frequency by using one or more of the local oscillator signals of the radio.

Abstract: A VCO (Voltage Controlled Oscillator) (10) operates in a phase-locked loop at a desired frequency. One input to the VCO is a variable control signal (24) that holds the VCO at the desired frequency. Another input is a bias input (40) that changes the operating point of a transistor (34) in the VCO and also tends to change the VCO's frequency. The value of the variable control signal (24) is sensed while the bias input (40) is changed until a desired, minimum value of the control signal is sensed. The value of the bias input at that point is held constant while operating the VCO at the desired frequency and with minimal side band noise.

Abstract: In a time diversity system (100) including a radio receiving device (110), a temporary address, a group message associated with the temporary address, and an instruction vector for activating the temporary address are transmitted as original information and, subsequently, duplicate information in a radio signal having frames of data. When the original instruction vector is not received by the receiving device (110), a later frame is searched for the duplicate instruction vector, which, when located, activates the temporary address stored by the receiving device (110). The receiving device (110) then determines which frame capable of reception by the receiving device (110) includes the group message, and the receiving device (110) searches for the temporary address and the group message in that frame. The temporary address is then deactivated.

Abstract: An electronic device (100) that has an housing assembly and electrical circuit therein includes a first housing portion (116), a second housing portion (118) coupled to the first housing portion (116), and a cam assembly (102) rotationally coupling the first and second housing portions (116, 118). The cam assembly (102) includes a cam (220), a cam follower (205), and a spring (224). The spring (224) resiliently biases the cam (220) and the cam follower (205) into engagement. At least one of the cam (220) and cam follower (205) is depressible within one of the first and second housing portions (116, 118) for permitting their assembly.

Abstract: A data communication receiver (106) is assigned for receiving message signals within one or more message transmission frames (FIG. 3) transmitted in a predetermined sequence. The message signals include address (1604) and message (1608) information, and information (1710) designating one or more additional message transmission frames to which the data communication receiver (106) is responsive for receiving the message signals. The data communication receiver (106) includes a receiver (804) for receiving the message signals, a decoder (830, 816), coupled to the receiver (804), for decoding the address (1604) and designating (1608) information received during the assigned transmission frames, and a memory (850), for storing the message information received which is intended for the data communication receiver (106) during the assigned transmission frames.

Abstract: A distributed data system utilizing a paging location system includes a plurality of local area networks (LAN) (38) that have a wireless data link associated therewith for accessing one of a plurality of personal data units (PDU) (10). Data transfer can be affected over a wireless link between antennas (18) and (44) by determining from an internal lookup table in each of the LANs (38) which of the LANs (38) is the homebase LAN (38). The data is then transferred to the homebase LAN (38) and the homebase LAN (38) then attempts to transfer the data to the destination PDU (10). If not located at that LAN (38), a paging message is then transferred through a paging system to all of the PDUs (10) and the destination PDU (10) then transmits a Ready-to-Receive message to the one of the LANs (38) that it is closest to. This is the receiving LAN (38) which then requests data to be transferred thereto from the homebase LAN (38) and then affects a transfer to the destination PDU (10).

Abstract: A heat seal connector (100) includes a flexible substrate (105), interconnects (110) disposed thereon, and a parting agent (115) contiguous with the flexible substrate (105) for preventing the heat seal connector (100) from adhering to a heating platen (505) applied thereto, wherein the heating platen (505) does not include a parting agent for preventing the heat seal connector (100) from adhering to the healing platen (505). The heat seal connector (100) is bonded to first and second electronic circuits (415, 420) during application of the heating platen (505) such that the interconnects (110) electrically couple conductive pads (417) formed on the first electronic circuit (415) to corresponding conductive pads (425) formed on the second electronic circuit (420).

Abstract: A display is provided comprising a semi-transparent display element (16, 17, 18, 19), such as double super twisted nematic (DSTN) liquid crystal display (LCD) cell, a sub-assembly having backlight elements (11, 12, 13) mounted thereon, and mounting means (20) mounting the display element over the sub-assembly with the display element adjacent to the back light elements, with no diffuser between the backlight elements and the display element. The backlight elements are an array of light emitting diodes of sufficiently wide angle and spaced sufficiently close together that, when viewed from the front of the display element, the display has substantially evenly dispersed brightness across the array.

Abstract: A data communication receiver (100) for operating in a demonstration mode comprises a receiving circuit (110) for receiving and decoding radio frequency signals, a battery (140) for powering the receiving circuit (110), and a display (150) for displaying information. A switch (142) coupled between the battery (140) and the receiving circuit (110) disconnects the receiving circuit (110) from the battery (140) to disable the receiving circuit (110) when a signal has been received indicating that the data communication receiver (100) is to operate in the demonstration mode. A demonstration element (165, 170) coupled to the display (150) provides at least one demonstration screen to the display (150) in response to the disabling of the receiving circuit (110).

Abstract: A communication receiver (106) receives an address code word (1800) of a transmitted message, the message comprising the address code word (1800) and an associated data portion (1610), the address code word comprising an address portion (1802,1804). The communication receiver (106) corrects (2104) up to a predetermined number of bit errors in the received address code word (1800). The communication receiver (106) can conserve power following a failed correction of the address code word (1800). Alternatively, the communication receiver (106) compares (2108,2111) the address portion (1802,1804) of the corrected address code word (1800) to at least one predetermined subscription address (1704,1706). The communication receiver (106) can conserve power following a determination of no match (2110,2114,2308) between the address portion (1802,1804) of the corrected address code word (1800) and the at least one predetermined subscription address (1704,1706).

Abstract: A radio (100), powered by a battery (170), can be used in remote meter reading applications. In order to conserve battery power, the radio (100) is capable of determining that a signal is an image signal rather than a signal on the desired frequency. This is accomplished by attempting to receive a signal utilizing different local oscillator signals (high side injection and low side injection). If a signal is present, as indicated by the received signal strength with both local oscillator signals, then the radio (100) will attempt to decode data. The radio (100) does not attempt to decode data when the signal is determined to be a spurious signal. The radio (100) can then be operated in a reduced power consumption mode. This results in battery savings for radios operating in the presence of an image frequency signal.

Abstract: A communication system (200) for providing analog signals comprises a terminal (220) for generating tone and voice signals on tone and voice lines (230, 235), respectively, and a signal processor (205) coupled to the terminal (220) for processing the tone and voice signals. The tone signals are coupled to an analog output (215) when the tone signals are determined to be present on the tone lines (230), and the voice signals are coupled to the analog output (215) when the tone signals are determined to not be present on the tone lines (230).