Abstract: A sigma delta interpolator for use in a fractional N synthesizer having a multi-modulus divider for controlling the output frequency of the synthesizer. The sigma delta interpolator includes an accumulator operative for receiving an input signal representing the desired frequency output of the fractional N synthesizer and for generating a digital output signal having M bits, which include N most significant bits and n least significant bits. The N most significant bits output by the accumulator are coupled to the multi-modulus divider and are operative for controlling the operation of the multi-modulus divider. The sigma delta interpolator further includes a delay circuit coupled to the accumulator, which functions to receive the n least significant bits and implement a delay function defined by equation: 1?(1?Z?1)N, where N corresponds to the order of the sigma delta interpolator.

Abstract: A method and an apparatus are provided for performing parameter negotiation in a data compression link. When data is sent along the communication link in a compressed form, the escape character is not modified. When sending data in an uncompressed form, the escape character is followed by a command and the escape character is modified. A parameter mode can be entered when data is being sent uncompressed. During parameter mode, parameter negotiation between the modem peers can be accomplished without interrupting the communication link.

Abstract: An approach for allocating system capacity of a communication switching system for exchange of traffic is disclosed. The system includes multiple terminals that request allocations of system capacity. The capacity is partitioned into a provisioned portion and an unprovisioned portion, in which a portion of the terminals constitutes a pool having a plurality of sub-pools. According to one embodiment, a control computer communicates with the plurality of terminals and allocates the provisioned portion of the capacity to the plurality of sub-pools of the terminals. The provisioned portion of the capacity is arranged into sub-partitions, wherein one of the sub-partitions is not associated with the sub-pools of terminals. Remaining sub-partitions are associated with the sub-pools of terminals.

Abstract: A system and method is provided that employs a frequency domain interpolative CODEC system for low bit rate coding of speech which comprises a linear prediction (LP) front end adapted to process an input signal that provides LP parameters which are quantized and encoded over predetermined intervals and used to compute a LP residual signal. An open loop pitch estimator adapted to process the LP residual signal, a pitch quantizer, and a pitch interpolator and provide a pitch contour within the predetermined intervals is also provided.

Abstract: A requesting terminal includes an interface that allows a user to select whether data downloaded from a network (such as the Internet) is transmitted to the requesting terminal via a high-speed link, such as a satellite link, or a lower speed link, such as a terrestrial link. Preferably, the terrestrial link (which may comprise a conventional dial-up Internet connection) is a two-way link, wherein the requesting terminal transmits data requests to the network via the terrestrial link. The data requests generated by the requesting terminal are modified to designate whether the requested data should be downloaded from the network via the terrestrial link or the satellite link. The terrestrial link may also be automatically selected for certain applications.

Abstract: A method of interleaving blocks of indexed data of varying length is disclosed. The method includes the steps of: providing a set of basic Interleavers comprising a family of one or more permutations of the indexed data and having a variable length; selecting one of the basic Interleavers based upon a desired Interleaver length L; and adapting the selected basic Interleaver to produce an Interleaver having the desired Interleaver length L.

Abstract: A method and apparatus for transmitting, receiving and displaying electronic program guide data having a number of segments, wherein each segment is associated with a program and wherein some of the segments have a keyword therein includes a receiver having a memory that stores a keyword list containing the keyword or keywords. The receiver receives the program guide data and compares the segments of the program guide data to the keyword list to determine if any keywords are contained in the segments. The receiver displays the keyword on a display screen so that the keyword may be selected by the user.

Abstract: A method for making a thin film device on integrated circuits including the steps of applying a first photoresist layer to a first surface, and patterning the first photoresist layer to have at least a first opening that exposes the first surface. A film is deposited onto the first photoresist layer, wherein a portion of the deposited film is deposited onto the exposed first surface. A second photoresist layer is applied onto the deposited layer, wherein the second photoresist layer is applied to the portion of the deposited film within the first opening and covers a second portion of the deposited layer, wherein the first photoresist layer and the second photoresist layer assist in the defining of the deposited layer. The deposited layer, first photoresist layer, and second photoresist layer are selectively removed, therein exposing the first surface and the second portion of the deposited layer.

Abstract: An apparatus for providing automatic gain control for use in a satellite terminal of a satellite communication system capable of transmitting a plurality of different modes of data. The apparatus includes a demodulator circuit having an analog to digital converter; a first variable attenuator having an attenuation value set on the basis of a measured power level of a predetermined data signal; and a second variable attenuator having an attenuation value set on the basis of the mode of data being received by the satellite terminal, where each of the data modes have a corresponding predetermined attenuation value associated therewith which is utilized as the attenuation value of the second variable attenuator when the satellite terminal receives the data mode.

Abstract: An approach for managing system capacity of a satellite communications system is disclosed. A satellite communications system provides communication services to a region. A terminal (101, 103) is located within the region and is configured to transmit and receive signals over a satellite (105) having a payload that processes the signals. The terminal (101, 103) has a predetermined profile that includes service class information and rate information. A hub (107) is configured to receive system capacity resource configuration data that reflect capacity requirements of a service provider and to determine partitioning of system capacity over the region based upon the system capacity resource configuration data. The hub (107) transmits configuration information to the payload of the satellite (105) according to the determined partitions. The terminal (101, 103) is configured to transmit a bandwidth request message to the payload.

Abstract: A threaded space-time (TST) architecture in a multiple antenna wireless communication system uses the coded transmission in each layer of a transmission resource array as a space-time code. Each layer of a layer set is active during all available symbol transmission intervals, and each of the transmit antennas are used equally often, such that layers each transmit a symbol using a different antenna during each symbol transmission interval. A receiver is provided for multi-user reception using an iterative, soft-input/soft-output (SISO) multi-user detection algorithm based on minimum mean square error (MMSE) criterion, among other methods.

Abstract: A method and apparatus for Turbo encoding uses a set of rate-compatible Turbo Codes optimized at high code rates and derived from a universal constituent code. The Turbo Codes have rate-compatible puncturing patterns. The method comprises: encoding a signal at a first and second encoder using a best rate ½ constituent code universal with higher code rates, the first encoder and the second encoder each producing a respective plurality of parity bits for each information bit; puncturing the respective plurality of parity bits at each encoder with a higher rate best puncturing patterns; and puncturing the respective plurality of parity bits at each encoder with a lower rate best puncturing pattern. In a variation, the best rate ½ constituent code represents a concatenation of polynomials 1+D2+D3 (octal 13) and 1+D+D3 (octal 15), D a data bit. A Turbo Encoder is provided which has hardware to implement the method.

Abstract: A light weight fuel tank for a hydrogen powered airplane used as a platform for communication repeaters for communication services. An outer spherical shell member of a sandwich configuration surrounds an inner thin walled spherical shell member in which the liquid hydrogen is contained. A radial gap between the shell members is evacuated to a high vacuum. The facing surfaces of the shell members are coated with a low emissivity material. Electrical heaters are provided to control the evaporation rate of the hydrogen to match the fuel usage and to prevent icing during ascent and descent of the airplane.

Abstract: A system in which a personal computer sends messages into a TCP/IP network using a conventional dial-up link and downloads data from the TCP/IP network using a high-speed one-way satellite link. A preferred embodiment uses a conventional SLIP provider to connect to the TCP/IP network and uses a commercial software TCP/IP package that has a standard driver interface. A spoofing protocol compensates for the long propagation delays inherent to satellite communication.

Abstract: An approach for managing queues of a terminal operating in satellite communications system is disclosed. A hub controls bandwidth allocations in conjunction with a satellite. A plurality of terminals is configured to issue bandwidth allocation requests to the satellite. Each of the terminals has queues that are configured to store the packets, and a queue control logic that is configured to dynamically change depths of the queues according to a prescribed scheme. The prescribed scheme specifies new depths of the plurality of queues based upon past bandwidth allocations associated with the respective queues.

Abstract: An approach for is provided for adapting to a variety of link propagation conditions is disclosed. A source terminal generates a packet data burst that includes a header and an optional payload. The header is modulated using a default modulation scheme and is coded using a default coding scheme. A switch is configured to receive and to forward the packet data burst. A destination terminal is configured to demodulate the header using the default modulation scheme and the default coding scheme, and to examine the header to determine a particular coding scheme and a particular modulation scheme associated with the payload. The protocol can be applied to any radio communication system, particularly, to a satellite communication system with multiple satellite terminals.

Abstract: A system and method for decoding encoded data is provided. A parser receives and parses the encoded data into data streams, with each of the data streams including a portion of said encoded data. A decoder decodes the data streams to provide decoded data which includes soft decision data. The decoder performs an decoding iteration on each of the data streams to provide the decoded data, and performs such decoding iterations based on additional information. The system and method alternatively can be configured without a parser, and can employ at least one soft decoder module and another decoder module. The soft decoder module performs multiple decoding iterations on the encoded data to provide soft decision data and the other decoded module decodes the encoded data based on the soft decision data to provide hard decoded data representative of a decoded condition of said encoded data and/or soft decision data.

Abstract: A method of providing forward error correction for data services uses a parallel concatenated convolutional code which is a Turbo Code comprising a plurality of eight-state constituent encoders wherein a plurality of data block sizes are used in conjunction with said Turbo Code. A variation uses the method in a cellular radio system. Another variation uses the method in both forward and reverse likes of a cellular radio system.

Abstract: A method, system, device and computer program product for moving pictures experts group (MPEG) variable bit rate (VBR) video traffic classification using a nearest neighbor classifier, including determining I, P and B frame sizes for an input MPEG VBR video sequence; computing mean values of the I, P and B frame sizes; and classifying the input video sequence into one of a plurality of categories based on the computed mean values using a nearest neighbor classifier.

Abstract: A method of transmitting time division multiplexed data from a satellite terminal to a satellite wherein the satellite terminal receives a command indicating to transmit data during a frame comprising a plurality of timeslots in accordance with a timeslot reordering scheme. The timeslot reordering scheme is selected to spread data from respective satellite terminals to different timeslots throughout the frames. A processor monitors the use of channels by the satellite terminals, stores bandwidth requests using queues, allocates channels in accordance with bandwidth requests and a bandwidth allocation algorithm, and transmits the channel allocations in a frame. Timeslots not allocated to any of the satellite terminals are contention channels. The number of contention channels changes dynamically, depending on demand for the plurality of channels by the satellite terminals. Queues are provided for each channel for storing high and low priority rate requests and high and low priority volume requests.