Abstract: Systems and methods to enable different types of radio communication devices to communicate using a common language in order to enable the devices to regulate their use of the spectrum. Each device participating in the ad hoc control channel (ACC) protocol transmits information using a common signal format that each of the other participant devices is capable of recognizing, in order to share information about how it uses the radio frequency band. Each device receives the information transmitted by other participant devices and based on that information, controls one or more of its operational parameters that impact usage of the radio frequency band. The ACC protocol enables devices of the same or different type to harmonize (instead of alienate) themselves with each other by allowing them to communicate about their usage of the radio frequency band using a common signaling framework.

Abstract: A VCO having an automatic amplitude control circuit In the form of a sensing amplifier provided in the feedback loop to sense the oscillator amplitude and draw current away only when the positive peak voltage Is above a certain value. In general, any amplifier may be used in the feedback loop that outputs current proportional to a peak positive input (in a non-linear and asymmetric fashion with respect to the changing voltage). In one example, the amplifier in the feedback loop comprises first and second transistors that are set nominally in cut off and behave as class C amplifiers. The advantage of this amplifier transistor configuration is that the amplifier they form has a low load on the LC tank circuit and a high input impedance.

Abstract: A wideband radio transceiver system that features a wideband RF section and a flexible and scalable baseband signal processing section. The transceiver system architecture has configurable baseband processing to process signals for multiple communication protocol standards, or multiple instances of the same communication protocol standard, that operate over the same frequency band. Optional additional features include a transmit carrier suppressor and transmit interference canceller to suppress the effects of a transmit signal on receive signal processing when signals are being transmitted and received simultaneously.

Abstract: A receiver circuit (10), and method for automatic frequency control of a receiver circuit (10) suitable for receiving a radio frequency (RF) signal, featuring determination of at least one parameter other than a frequency error of a signal which is mixed with the RF signal received by the receiver circuit; and adjusting the frequency of the signal which is mixed with the RF signal based on the frequency error if the at least one parameter satisfies a predetermined criterion.

Abstract: A modulation scheme (600) useful in a voice paging system in which both of two orthogonal modulation components (500 and 510) are used to carry two halves of a single voice message destined for a receiver, or two separate voice messages for a receiver. The single voice message is transmitted in half the time.

Abstract: A two-way messaging system (100) having a plurality of message subscriber units (500) and a base station (220) in each of a plurality of cells (210). The base station has a transmitter (224) for transmitting messages in an associated cell (210) and a receiver (228) associated therewith for receiving response signals from message subscriber units in a cell. A system controller (300) is coupled to each base station (220) and has a memory (320) for storing the customer paging area data for each message subscriber unit. The system controller (300) receives message requests and automatically updates the customer paging area data for each message subscriber unit (500) by tracking the mobility pattern of each message subscriber unit (500) in the messaging system coverage area (200).

Abstract: Error detection and correction of a received message, such as a digitized voice message is achieved by generating (318) interpolated vectors for each error vector corresponding to a codebook index in a sequence of codebook indexes representing parameters of portions of the message. A plurality of error corrected candidate vectors for the vector corresponding to the codebook index in error, are generated (322,324,326) by flipping one bit in a sequence of bits representing the codebook index in error. The error corrected candidate vector which has a minimal difference from its corresponding interpolated vector is used (338) to replace the error vector. In the case of digital voice, the vectors are spectral vectors which represent spectral information for a time sample of a voice message. An ordering property of vector components is exploited to detect errors in a received codebook index without parity bits.

Abstract: A method for determining whether a baud rate of a frequency modulated (FM) signal received by a receiver matches a predetermined baud rate. A parameter other than the baud rate is detected and used to confirm whether baud rate detection should be made, or whether if made, is reliable. The parameter is frequency deviation of the received FM signal, or other suitable parameters of the received FM signal.

Abstract: A messaging system capable of transmitting messages to receivers which roam between coverage areas. In one configuration, a coverage area (100) is divided into a plurality of zones (110). A single simulcast system identification (SSID) number is assigned which consists of a local identification number which identifies the coverage area (100), a zone identifier which identifies a zone (110) within the coverage area, traffic splitting flags and a frequency. For larger roaming areas, a network (200) is defined as consisting of a plurality of service areas (210) and is identified by network roaming identification information (NRI). NRI information and/or SSID information is stored in a receiver according to desired coverage and like information is transmitted in the corresponding zone or service area.

Abstract: An integrated circuit chip carrier (100) provides an improved mounting pad density. The chip carrier (100) includes a flexible substrate (102) with pads (104) on the top surface for interconnection with an attached integrated circuit chip (302). The chip carrier (100) further includes a mounting pad array (502) on the bottom surface having an interconnection with the pads (104), and a rigid substrate (202) having an array of holes (204) extending through it. The top surface of the rigid substrate (202) is fixedly attached to the bottom surface of the flexible substrate (102). Individual holes of the array of holes (204) correspond to and align with individual pads of the mounting pad array (502). The chip carrier (100) further includes solder (206) disposed on the mounting pad array (502) and extending through the array of holes (204) beyond the bottom surface of the rigid substrate (202) for mounting the integrated circuit chip carrier (100) to a circuit bearing substrate (700).

Abstract: In each receiver (40) at least one datecode is stored which defines a subscription period during which the receiver is entitled to display received messages. For each message (200) to be transmitted, a datecode which defines a particular subscription date to be associated with the message is generated, the datecode defined by a predetermined number of bits. The datecode is compressed into a compressed datecode (220) based on the datecode, the compressed datecode being less in number of bits than the predetermined number of bits of the corresponding datecode. A modified checksum word (230) for the message is generated based on the plurality of bits which represent the message (200) and the predetermined number of bits which represent the datecode that corresponds to the compressed datecode (220). The modified checksum word (230) is associated with the message and the compressed datecode (220) for transmission.

Abstract: Network roaming information (NRI), which comprises identifies a network (200) and a service area (210) within the network (200), a receiver address, is transmitted in a network (200) during a predetermined number of time slots of a signal, whereby the signal is transmitted in consecutive cycles, each cycle comprising a plurality of consecutive time slots. The placement of the NRI in the transmitted signal is made to be predicted by a receiver so that the receiver can compute an expected time slot location of a NRI to be compared with a stored NRI. The placement of the NRI is made according to an algebraic relationship between moduloN of the transmission frequency of the signal, moduloN of the order of the cycle, and moduloN of a portion of the NRI, wherein N is an integer.

Abstract: An oscillator circuit (143) comprises a master phase-locked loop (PLL) circuit (202) that receives as input a first reference frequency signal (136) and generates a first clock signal (210) in response to an oscillator control signal (212). The oscillator circuit (143) includes a frequency sensitive slave circuit (206) having at least one frequency sensitive element (322) that is responsive to a tracking control signal (214) to generate a second clock signal (216). A tracking control circuit (204) is responsive to the oscillator control signal (212) for generating the tracking control signal (214). The tracking control signal (214) serves as a bias signal, and is connected to the frequency sensitive slave circuit (206) for achieving a fast power up sequence of the oscillator circuit (143).

Abstract: A zero-intermediate frequency receiver circuit (11) for receiving a radio frequency signal detected by an antenna (14). The receiver circuit (10) comprises a second local oscillator circuit (25) and an oscillator circuit (60) of a phase locked loop demodulator (36) which are identical and track each other so as to provide a more accurate reference for processing a demodulated signal. A current reference (39) providing a current reference signal utilized by the second local oscillator circuit (25) and the oscillator circuit (60) of the phase locked loop demodulator (36).

Abstract: A phase locked loop (PLL) circuit for use as a demodulator and other applications. The PLL circuit (200) comprises a phase detector (210), a transconductance amplifier (212) and a current controlled oscillator (ICO) (214). The phase detector has two signal inputs and two outputs, and detects a phase difference between signals at its inputs. A capacitor C1 is connected to the output of phase detector (210) and develops an output voltage signal vo(t). A transconductance amplifier (212) is coupled to the capacitor C1 and converts the output voltage signal vo(t) to an output current signal. The ICO (214) is coupled to the transconductance amplifier (212) and the second output of the phase detector (210) and generates an output signal having a frequency which is proportional to an input current signal. The output signal of the ICO (214) is coupled to the second signal input of the phase detector (212).

Abstract: A messaging system and method capable of transmitting group messages throughout a Network (200) such that receivers which are outside of a "local" or "home" area of coverage receive such group messages, whereas receivers which are in a "local" area of coverage over ride and do not receive the group message as a result of decoding system identifiers and ignoring those messages having network roaming identification.

Abstract: A method of interconnecting circuit modules (30) to mother boards (50) each having a plurality of mating solder pads (32, 52) is available. The solder pads (32, 52) have respective pairs of arms (40, 42) and (54, 56) with a venting channel (36, 58) formed between each pair of arms to vent solder medium when the solder pads are reflowed to interconnect the circuit modules and mother boards.

Abstract: A fax selective call receiver system (10) featuring compression of a fax message with an optimal one of a plurality of compression code-books (50). At least a portion (44) of a source document (26) is compressed with each of a plurality of code-books (50) and the smallest resulting data file is selected as the optimal compressed file. The compressed data file is transmitted to a selective call receiver (40) together with an index identifying the optimal code-book. The selective call receiver (40) stores each of the plurality of code-books and accesses the particular code-book for decompressing the data file on the basis of the received index. In an alternative embodiment, the fax message is divided into composing segments (SI1, SI2 and SI3) and each segment is compressed with each code-book to determine the optimal code-book for each segment.