Abstract: Information encoded in a spread spectrum signal transmitted in a communications medium is recovered. A composite signal including a spread spectrum signal is received from the communications medium, and correlated with a spreading sequence to generate time-offset correlations. Respective first and second groups of the correlations are combined, e.g., according to estimated channel coefficients, to produce respective first and second combined values. The first and second combined values are then combined in a manner that compensates for correlated impairment in the composite signal to generate an estimate information in the transmitted spread spectrum signal, e.g., using weighting factors generated from an estimated composite channel response and an estimated impairment correlation, or adaptively generated weighting factors. Related apparatus are also described.

Abstract: Methods and devices for extracting a joint probability from a MAP decision device are provided. Probability information associated with a first symbol and a second symbol is obtained from the MAP decision device. A joint probability of the first symbol and the second symbol is determined from the probability information associated with the first symbol and the second symbol. Methods and devices for processing a signal containing information associated with a plurality of transmitted bits using the generated joint probability information are also provided. The MAP decision device in various embodiments is a demodulator or a decoder.

Abstract: A paging attribute descriptor (PAD) the indicates content of a page message is transmitted in a first time slot and/or a succeeding second time slot of a physical channel, and the page message is transmitted in the second time slot. The second slot may be, for example, a Digital Control Channel (DCCH) slot mapped on a physical channel (DTCH) of an IS-136 system. The transmitted PAD is recovered at wireless station, which then determines whether to recover the page message based on the recovered PAD, e.g., if the PAD indicates that the page message is an empty page message, a page message addressed to another wireless station or a page message that includes control information that has changed. For example, in an IS-136 compliant system, the PAD may be transmitted in the coded superframe phase (CSFP) field of a Paging Channel (PCH) message transmitted in a Digital Control Channel (DCCH) slot, or in reserved bits of a slot preceding a PCH message.

Abstract: A Fast Notification Access Channel is used in a system for multiplexing users on a shared cellular packet data traffic channel in a cellular packet data network system. The system includes a mobile station having a mobile station control system. The mobile station control system transmits packet data on the shared packet data traffic channel to a base station until it reaches an inactive period and upon having additional data to transmit transmits a notification signal to the base station, the notification signal uniquely identifying the mobile station on the shared cellular packet data traffic channel. A network control system is operatively associated with the base station. The network control system allocates uplink on the shared packet data channel to the mobile station after receiving the notification signal until the mobile station reaches the inactive period.

Abstract: The present invention provides a method, apparatus and system of completing a call when a called party has not answered the call from a calling party. A signal indicating that the called party has not answered the call is detected (300) and the call is terminated (302). A message is presented to the calling party that indicates the called party has not answered the call and prompts the calling party to compose a multimedia message to be delivered to the called party (304). The multimedia message is then sent to a multimedia messaging service server (402) for subsequent delivery to the called party whenever the calling party completes composition of the multimedia message (308). This functionality can be implemented using a computer program embodied on a computer readable medium wherein each function is executed using a code segment.

Abstract: A constant gain, constant phase RF power block, e.g., for use in a RF amplifier apparatus. In a preferred embodiment, the power block includes a DC to DC power supply circuit co-located with an RF power transistor device on a common heat sink. The power supply circuit has as an input a varying DC voltage and as outputs a constant supply voltage and a constant bias voltage. The power device has as inputs the constant supply voltage and the constant bias voltage, and further configured to receive and amplify an RF signal. The power supply circuit preferably includes a first laser trimmable resistor for setting the constant supply voltage and a second laser trimmable resistor for setting the bias voltage. In this manner, the constant supply and bias voltages may be easily tuned to a desired level during assembly of the power block device. The input and amplified RF signals are each matched to a relatively high impedance, e.g., approximately fifty ohms.

Abstract: Cellular radiotelephone communication systems and methods downlink digital coded speech from a cellular radio exchange to a cellular radiotelephone base station and uplink downsampled (i.e. undersampled relative to the Nyquist rate of two samples per symbol) radiotelephone signals from the cellular radiotelephone base station to the cellular radio exchange. The downsampled radiotelephone signals are demodulated at the cellular radio exchange and the digital coded speech is modulated at the cellular radiotelephone base station. Diversity demodulation may be used at the cellular radio exchange, to diversity demodulate the downsampled radiotelephone signals at the cellular radio exchange.

Abstract: Downlink signal bursts are transmitted from a plurality of visible satellites to a plurality of user terminals in a downlink region that is serviced by the plurality of visible satellites. A first downlink signal burst is sent from a first one of the visible satellites to a first user terminal in the downlink region. A second downlink signal burst is sent from a second one of the visible satellites to the first user terminal to be received at a time that is a function of a separation distance of the first user terminal in the downlink region from the Time Alignment Center (TAC) of the downlink region. First downlink signal bursts and second downlink signal bursts also are sent to other user terminals in the downlink region. The first and second downlink signal bursts preferably are sent over respective first and second carrier frequencies.

Abstract: The selection of the primary control signal bus to use for a given radio head is based on propagation delay to the relevant radio head. A plurality of radio heads are cascaded in a chain with buffered error correction therebetween. At least first and second control interfaces connect to the chain and supply control information thereto via respective control signal busses, which may be virtual busses. The propagation delay from a first control interface to a first radio head over a first bus is determined. Likewise, the propagation delay from a second control interface to the first radio head over a second bus is determined. Thereafter, the radio head determines which control signal bus to select as its primary control signal bus based on the respective propagation delays between the first radio head and the first and second control interfaces.

Abstract: An amplifier circuit includes a power amplifier biased for saturated mode operation, and a controllable current source to provide supply current to the power amplifier. The controllable current source effects desired amplitude modulation of the output signal from the power amplifier by modulating the supply current it provides responsive to an amplitude information signal.

Abstract: An ATM connection (45) and call connection equipment 22 can be dynamically allocated between exchanges (20, 30). The connection is setup and released by a master switch (20) on one side of the connection. The slave 30 is controlled using standard signaling protocols and the physical connections (45) between the interworking units (40, 50) use circuit-emulation according to AAL1. The master (20) controls the ATM connection (45) with standard signaling and the slave (30) with normal trunk signaling. The ATM connection 45 and connection 26 can be setup between the nodes (40, 50) when needed based on the traffic needs of the network (10).

Abstract: A method for optimizing call service in a VLAN including at least one Voice over Internet Protocol device involves determining the current traffic levels of the VLAN, then adjusting the priority handling of data packets in the VLAN in relationship to current traffic levels so that voice packets receive an optimum number of network resources. Default priorities are used when level of traffic is in a normal range. During times when network traffic is below the normal range, signaling data packets may be increased in priority and when network level of traffic is above the normal range, the priority of all data packets except for voice data packets will be decreased.

Abstract: A method of mitigating phase nulls in a local wireless telephone system comprises inserting one or more random bits into a frame of a simulcast signal. The introduction of the random bits into the frame causes subsequent bits in the frame to be modulated differently, thereby reducing phase cancellation nulls. While particularly suited to localized wireless telephone systems, the methodology may be equally adapted to any mobile network wherein geographically proximate antennas broadcast the same signals.

Abstract: Methods and systems are provided for a wireless terminal to select a control channel from a plurality of channels provided on a plurality of respective operating frequencies in which a first group of the operating frequencies are first scanned to locate a control channel that satisfies a first set of selection criteria. During this scan, channels are identified that fail to satisfy the first set of selection criteria but that have an increased probability of satisfying a second set of selection criteria. If a channel that satisfies the first set of selection criteria is not located during the first scan, the wireless terminal determines an order in which a second group of operating frequencies are to be scanned based on the identified channels, and then scans the second group of operating frequencies in the determined order to locate a control channel that satisfies the second set of selection criteria.

Abstract: A method for receiving transmissions includes receiving a first symbol-spaced baseband signal corresponding to first portions of first and second encoded data sequences transmitted over first and second baseband channels, and receiving a second symbol-spaced baseband signal corresponding to second portions of the first and second encoded data sequences transmitted over the first and second baseband channels. The first and second symbol-spaced baseband signals are combined to provide a combined baseband signal, and the combined baseband signal is prefiltered to provide minimum phase channel characteristics. The prefiltered combined baseband signal is equalized to provide an estimate of a data sequence. Related receivers are also discussed.

Abstract: An open network gateway system for use with networks that do not have dedicated Signaling System No. 7 signaling is provided by associating channel-associated signaling received over a first communication line with individual media channels on a second communication line and embedding channel-associated signaling in a media stream in the form of line supervision signaling and register signaling and using a public switched telephone network line supervision driver to monitor and manipulate line supervision signals and interface to the public switched telephone network dial manager. The associated signaling is then backhauled into a media gateway controller for processing and manipulating the data connection.

Abstract: A computationally efficient method for computing the filter coefficients for a prefilter in a decision feedback equalizer solves linear equations using a fast Toeplitz algorithm. Computations performed to compute the filter coefficients for the right half burst may be used to compute the prefilter for the left hand burst, thereby reducing the number of computations. Also, a square root-free algorithm may be used to solve the system of linear equations, further reducing computational complexity.

Abstract: An improvement in manual bar code readers to improve the reliability and eliminate read errors. The improvement comprises a plurality of sensors in a single unit arranged such that a single manual scan results in multiple reads of the bar code. The results of the reads are then compared bit-wise and any read error in any bit is corrected via a bitwise majority voting scheme.

Abstract: A mobile communications system receiver has improved synchronization and channel estimation for receiving a transmitted signal passing through a radio channel. A processor receives and samples the transmitted signal for a plurality of timing hypotheses. A channel estimator hypothesizes unknown symbols at a pilot cluster of the sampled signal and estimates the radio channel of the pilot cluster for each hypothesized symbol sequence. The estimator determines an error corresponding to each hypothesized symbol sequence using the sampled signal, the estimated radio channel and the hypothesized symbols and determines actual timing estimates and actual radio channel estimates by selecting the radio channel estimates associated with the hypothesized symbols and the timing and hypothesis that minimizes the error.

Abstract: Quadrature modulators include a quadrature splitter and a pair of Gilbert Multiplier Cells coupled to the quadrature splitter, each of which is biased in Class-B. The quiescent current bias in the Gilbert Multiplier Cells may be substantially zero. Each of the Gilbert Multiplier Cells may include a pair of cross-coupled, emitter-coupled transistor pairs transistor pairs and a driver circuit that is coupled to at least one of the emitter-coupled transistor pairs and that is biased in Class-B. The driver circuit may include at least one current mirror circuit that is coupled to at least one of the emitter-coupled transistor pairs. The driver circuit also may include at least one current source that selectively applies current to at least one of the emitter-coupled transistor pairs, more specifically by selectively applying current to the at least one current mirror circuit.