Abstract: A high efficiency, multiple power output power amplifier uses a pair of amplifiers having similar characteristics coupled to a pair of radio frequency RF couplers. When both amplifiers are operating, the power output is the sum of the outputs of the two amplifiers. When lower power operation is desired, one of the amplifiers is turned off and a high impedance is presented to the isolated port of the output RF coupler, thereby ensuring that all of the power output of the remaining power amplifier is available for output.

Abstract: A packet-based or cell-based data communication system is capable of determining whether a new call is a modem call or a voice call before a modem connection is established between the two end devices. The network switches are configured to monitor for distinctive facsimile modem and data modem calling and answer signals. In response to the detection of such calling or answer signals, the data communication system selects a speech coding scheme and/or a data transmission technique for use in connection with the current call, while a conventional 64 kbps PCM transmission scheme is maintained for communications between the network and the end devices. A speech coding protocol, such as ADPCM, may be enabled for voice calls, thus conserving network bandwidth. The 64 kbps PCM scheme may be employed to facilitate high speed modem transmissions.

Abstract: A multi-rate speech coded supports a plurality of encoding bit rate modes by adaptively selecting encoding bit rate modes to match communication channel restrictions. In higher bit rate encoding modes, an accurate representation of speech through CELP (code excited linear prediction) and other associated modeling parameters are generated for higher quality decoding and reproduction. To support lower bit rate encoding modes, a variety of techniques are applied many of which involve the classification of the input signal. For each bit rate mode selected, pluralities of fixed or innovation subcodebooks are selected for use in generating innovation vectors. The fixed codebook contains pulse subcodebooks and noise-like subcodebooks. To assist in selection of one of the subcodebooks, an adaptive weighting approach is applied in a searching procedure wherein residual classification and various parameters are used to generate a weighting function that is used to favor one subcodebook over another.

Abstract: A digital image printer that performs bit rotation and row alignment in preparation for final image reproduction. The present invention combines the two digital image data processing functions of bit rotation and row alignment into a single functional step. The two functions are performed simultaneously, in that, while row alignment is being performed during the deposition of a portion of the digital image data into a certain portion of a group of memory buffers, bit rotation is performed by extracting another portion of the digital image data from another portion of a group of memory buffers. The present invention reduces the number of required digital image data memory buffers required to perform the two functions of bit rotation and row alignment from conventional systems that perform the two functions sequentially and utilize a direct memory access channel to perform the data transfer between integrated circuitry that performs the two functions.

Abstract: According to a disclosed embodiment, the surface of a semiconductor wafer is covered by an etch stop layer. For example, the etch stop layer can be composed of silicon dioxide. A cap layer is then fabricated over the etch stop layer. For example, the cap layer can be a polycrystalline silicon layer fabricated over the etch stop layer. The cap layer is then selectively etched down to the etch stop layer creating an opening in the cap layer according to a pattern. The pattern can be formed, for example, by covering the cap layer with photoresist and selective etching. Selective etching can be accomplished by using a dry etch process which etches the cap layer without substantially etching the etch stop layer. The etch stop layer is then removed using, for example, a hydrogen-fluoride cleaning process. A semiconductor crystal is then grown by epitaxial deposition in the opening. For example, the semiconductor crystal can be silicon-germanium. Moreover, a single crystal semiconductor structure of high quality, i.

Abstract: An integrated multimedia encoding system is disclosed. Multimedia encoders which are capable of adjusting bit rates receive multimedia data to compress the data. After compressing the data, the multimedia encoders adjust the bit rates of the elementary streams responsive to a control input. Bit rates are increased or decreased using delays or, for video data, by allocating more or less bits to each macroblock, frame or group of frames. A unified memory module is coupled to the multimedia encoders to store the multimedia elementary stream data, the Program or Transport stream data, and data from other sources as needed. The unified memory is capable of adjusting storage allocations responsive to the realtime requirements of the incoming multimedia streams and the outgoing Program or Transport stream data.

Abstract: A method and system for assigning during configuration of a computer device a unique serial number is disclosed. The method uses firmware embedded within the device which when first initialized executes code for assigning and storing a unique serial number by use of a random number generator. In one embodiment, the unique serial number is generated based on the device's internal clock. Based on the amount of bit space typically reserved for a device's serial number, the number of combinations are great enough to make the serial number unique by use of a random number. Once the serial number is stored in the devices embedded firmware a random number is never generated again.

Abstract: An image data addressing system for a digital image printer operates on a plurality of image data having a horizontal format. Ink jet type digital printers require the alignment of the image data in a horizontal fashion to accommodate the vertical, mechanical arrangement of the ink jet nozzles. A program adapted to the specific components, circuitry and other characteristics of the digital image printer performs data addressing on the image data for preparation for ink jet firing by the ink jet nozzles. A common, integrated memory is used to perform the image data processing of the plurality of image data. The digital image printer adaptable program governs the storing of the image data so that it is adaptable to the specific components, circuitry and other characteristics of the digital image printer. An unused, consecutive portion of the integrated memory is provided at certain times during the image data processing.

Abstract: A traffic manager coupled to a communication system for scheduling transmission of information associated with a plurality of connections in the communication system. The traffic manager includes a priority queue, a connection data structure, and a scheduler. The connection data structure includes a guaranteed bit frame rate field for each connection. The scheduler is coupled to the connection data structure and the priority queue. The scheduler loads information from the data structure to the queue, wherein the scheduler shapes the connection for a minimum cell rate and allows use by the connection of excess bandwidth if the guaranteed bit rate field is set.

Abstract: Systems for controlling the amplitude of the output signal of a controllable oscillator in a frequency synthesizer are provided. One such system provides a circuit having a controllable oscillator and an amplitude control circuit. The controllable oscillator is configured to generate an output signal having a predefined frequency and a predefined amplitude. The controllable oscillator is also configured with a plurality of operational states that are controlled by the amplitude control circuit. Each operational state of the controllable oscillator defines a particular current bias associated with a distinct amplitude of the output signal of the controllable oscillator. The amplitude control circuit receives the output signal of the controllable oscillator and determines the amplitude. When the amplitude of the output signal of the controllable oscillator is less than the predefined amplitude, the amplitude control circuit provides a control signal to the controllable oscillator.

Abstract: A method and apparatus are provided for exchanging information between a cordless telephone application and physical hardware of a cordless telephone system. The method includes the steps of intercepting information exchanged between the application and the physical hardware, processing the intercepted information in order to ascertain whether the exchange requires at least one API macro and translating between the at least one API macro and a telephone command to be executed by the physical hardware of the cordless telephone system.

Abstract: A GmC filter that suppresses unwanted signals generated by a GmC compression stage. The GmC filter utilizes the same compression stage for the decompression stages. By using the same compression stage for the decompression stages unwanted in-band signals generated by the compression stage are suppressed. Further, over all circuitry is decreased, power is saved, and GmC filter design is simplified.

Abstract: A system for detecting a burst in a wireless communications system. A signal strength indicator indicates the strength of an incoming signal representative of incoming packets. A signal strength change detector detects changes in the signal strength of the incoming signal. Signal strength detection logic determines if a change in signal strength of a predetermined magnitude has occurred. A pattern detector detects patterns of symbols, or symbol estimates, in the incoming signal to determine if a predetermined pattern of symbols is present. Burst detection logic signals detection of a burst if the signal strength detection logic determines that a change in signal strength of predetermined magnitude has occurred, and the pattern detector determines that a predetermined pattern of symbols is present.

Abstract: A modem system having two modem devices digitally connected to a digital telephone network includes an inband control signal channel. The inband control signal channel is formed by using the most significant bit position of every sixth transmitted codeword for the transmission of control data. The control signal includes a predetermined header section that is monitored by the receiving modem to maintain frame synchronization and to correct for digital frame slippage. The control signal also includes a number of control data packets that contain information related to the initiation of control procedures such as rate renegotiations and retraining requests. The disclosed inband transmission techniques may additionally (or alternatively) be utilized to define a secondary data channel.

Abstract: A data communications system and method are provided, for example, in a facsimile machine to establish a data link with a gateway over a local loop. The data link is established employing pulse code modulation with prioritization in the upstream direction. Alternatively, a modulation type may be employed that is equivalent to pulse code modulation that provides similar or higher speed data communication. By using pulse code modulation in the upstream direction, the resulting facsimile transmission in accomplished with much greater speed.

Abstract: A resolution enhancement phase shift mask is disclosed. In one embodiment, a first clear region and second and third clear regions on each side of the first clear region and contiguous to the first clear region are used. All of the clear regions can be made of quartz. The second and third clear regions have an equal thickness. However, both the second and third clear regions are thinner than the first clear region. The difference in thickness between the first clear region and the second and third clear regions is calculated to cause a 180 degree phase shift in light passing through the second and third clear regions relative to light passing through the first clear region. The destructive interference caused at the phase boundaries of the first clear region and the second and third clear regions results in a dark unexposed area on the surface of an underlying photoresist layer; the dark unexposed area having geometry and dimensions corresponding to the geometry and dimensions of the first clear region.

Abstract: A multi-rate speech codec supports a plurality of encoding bit rate modes by adaptively selecting encoding bit rate modes to match communication channel restrictions. In higher bit rate encoding modes, an accurate representation of speech through CELP (code excited linear prediction) and other associated modeling parameters are generated for higher quality decoding and reproduction. To achieve high quality in lower bit rate encoding modes, the speech encoder departs from the strict waveform matching criteria of regular CELP coders and strives to identify significant perceptual features of the input signal. The encoder generates pluralities of codevectors from a single, normalized codevector by shifting or other rearrangement. As a result, searching speeds are enhanced, and the physical size of a codebook built from such codevectors is greatly reduced.

Abstract: A dynamically varying linearity system “DVLS” capable of varying the linearity of a radio frequency (RF) front-end of a communication device responsive to receiving a condition signal indicating a desired mode of operation of a transmitter. The DVLS may include a condition signal indicative of the desired mode of operation and a controller that adjusts the linearity of the transmitter responsive to the condition signal. The condition signal may be responsive to a user interface. The controller, responsive to the condition signal, may dynamically adjust the operating current of the transmitter.

Abstract: The invention includes an amplifier and a biasing circuit. The amplifier may have one or more driver stages and a final stage. Each stage may be connected in series to pass along and amplify an input signal from one stage to the next. The input signal level may increase over time. The biasing circuit may include a voltage follower having an output and a reference transistor. Each stage may include a transistor having a base that is connected to the output of the voltage follower. A resistor may be placed between each transistor stage base and the output of the voltage follower. The base of the final stage transistor may be DC connected to the reference transistor base. In operation, the reference transistor collector current and thus the final stage base bias voltage may be maintained at fixed level by feedback through the voltage follower.

Abstract: Methods and apparatus for establishing secure wireless links between a handset and a base station in cordless telephone systems are described. A method of generating a secure wireless link between a handset and a base station includes initiating a linking procedure, generating a security code, displaying the security code at the base station, entering the security code into the handset and then establishing a radio frequency link between the handset and the base station utilizing the security code. A cordless telephone system capable of generating a secure wireless link includes both a handset and a base station. The handset includes a control circuit, a transmitter and a receiver coupled to the control circuit along with a keypad also coupled to the control circuit.