Abstract: A satellite communication system (10) includes a satellite (20) which receives first and second data from sources. Each satellite receives control data from a satellite control center (100). An earth processing center (PC) is arranged to process the data received from the satellites, and a wide band network (30) is arranged to transmit the data to the processing center. A receptor terminal (A) is arranged to receive the first data and to place the first data on the network (30) for transmission to the processing center (PC). A second receptor terminal (B) is arranged to receive the second data and to place the second data on the network (30) for transmission to the processing center (PC).

Abstract: The present method for reducing latency in satellite communication includes the steps of applying, at a first earth terminal, a discriminator to user data. The discriminator delineates action data and forward data, thereby forming delineated user data. The action data represents data to be processed on board a satellite, while the forward data represents data to be forwarded through the satellite without processing. At the satellite, the delineated user data is partitioned into the action data and the forward data. The satellite then processes the action data to form processed action data and transmits, if necessary, the processed action data from the satellite. During processing of the user data, the satellite may generate result data in response to the action data and may transmit the result data alone or appended to the processed action data. Furthermore, the satellite may store a world model in a memory onboard the satellite.

Abstract: A method for configuring a satellite antenna (20) to receive a downlink signal from a geosychronous orbiting satellite (12) in a satellite communication system (10), comprising the steps of: (a) providing a satellite antenna (20) with a feed positioner mechanism (40) for adjusting the position of a feed device (42), such that the feed device (42) is selectively movably between a focus position (46) and a defocus position (44); (b) defocusing a beam of the satellite antenna (20) by using the feed positioner mechanism (40) to adjust the feed device (42) in relation to a dish component of the satellite antenna (20); (c) pointing the satellite antenna (20) towards the satellite (12), such that the downlink signal from the satellite (12) is received by the satellite antenna (20); (d) optimizing the beam of the satellite antenna (20) in relation to a near center of the downlink signal from the satellite (12); and (e) focusing the beam of the satellite antenna (20) using the feed positioner mechanism (40), thereby c

Abstract: A digital audio radio system where multiple digital data versions of a single source signal are transmitted to one or more satellites to be rebroadcast to a defined reception area where the multiple versions are delayed with respect to each other. One of the signals is intended to be used by a mobile receiver if the transmission from the satellite is not blocked, and the other one or more versions are intended to be used if the broadcast signal from the satellites is blocked. Because the multiple versions represent the same source signal that is received at different times, if the signal from satellites is blocked, the signal being received at a different time can be used. The signals that are to be used when the broadcast signal is blocked can be of a lesser data quality to conserve system resources.

Abstract: A communication system 10 for providing uninterrupted radio operation, including: a pre-transmitter system 12 comprising: (i) a first buffer 14 for storing a sequence of digital audio samples from an audio source 16, the first buffer 30 having a beginning 18, an end 20 and a length 22; (ii) storing means 24 for storing the audio samples in the first buffer 14 in shift register configuration format; and (iii) frame construction means 26 for constructing a data frame including a first audio sample from the end 20 of the first buffer 14 and a second audio sample from the beginning 18 of the first buffer 14; wherein the data frame can be transmitted and received.

Abstract: A digital audio radio system that employs transmitting multiple time-separated versions or legs of the same or substantially the same source signal to accommodate signal blockage problems while using no or little additional bit data rate. In one embodiment, a first leg transmits only right channel data and a second leg transmits only left channel data when no blockage occurs, the two legs can be combined to provide a complete signal and perfect reception. If one of the legs is blocked, then a cloning technique is used to clone the existing channel as the non-existing channel to provide either a combination of two right channels or two left channels. In another embodiment, a first leg transmits a sequence of the even frames including both right and left channel data and leaves the odd frames blank, and a second leg transmits a sequence of the odd frames including both the right and left channel data and leaves the even frames blank.

Abstract: A communication system 10 for providing uninterrupted radio operation, including: a pre-transmitter system 12 comprising: (i) a first buffer 14 for storing a sequence of digital audio samples from an audio source 16, the first buffer 14 having a beginning 18, an end 20 and a length 22; (ii) storing means 24 for storing the audio samples in the first buffer 14 in shift register configuration format; and (iii) frame construction means 26 for constructing a data frame including a first audio sample from the end 20 of the first buffer 14 and a second audio sample from the beginning 18 of the first buffer 14; wherein the data frame can be transmitted and received.

Abstract: A computer speech system for digitally storing and reproducing representations of human speech. An analog waveform representative of a segment of speech is compressed for storage by storing companded differences between adjacent local maxima and minima of the waveform together with the lengths of time between the occurrences of the maxima and minima. The compressed speech is reproduced by looking up precomputed values in a lookup table according to the companded differences and times and furnishing the values from the lookup table to a digital-to-analog converter and thence to a conventional audio output device. The values are furnished to the converter by putting them on lower bits of the address bus and performing an operation at an address to which the converter responds.

Abstract: Apparatus, which first de-interleaves a signal, that comprises a plurality of interleaved pulse trains, into its constituent pulse trains and then identifies the emitter which transmitted each pulse train, is described herein. Specifically, this apparatus comprises a folded shift register which performs the de-interleaving. The folded shift register comprises a plurality of serially connected identical "active" cells, each of which detects a pulse occurring at a particular group pulse repetition interval (PRI) and, in an embodiment described herein, ascertains the inter-pulse PRI for each detected pulse for use in identifying an emitter. One or more processors analyze the group and inter-pulse PRI data, provided by the folded shift register, in order to identify each emitter.

Abstract: Disclosed is a method and apparatus for reproducing remotely sensed images in which the effect of attitude perturbation in the sensing device is removed from the image.The image is acquired by means of an electromagnetic radiation sensor mounted on a non-stationary body, such as an earth satellite, a helicopter, or the shoulder of a cameraman. An electronic signal representative of the three-axis attitude perturbation of the sensor is generated simultaneously with the data signal from sensor and a signal representative of the instantaneous nominal attitude thereof. These signals are transmitted (in some cases with the intermediate step of tape recording) to an image reproduction device such as a cathode ray tube or a portion of photographic film exposed by a narrow-beam light source. The data signal activates the image generator (i.e., the electron beam or the exposing light source); the signal corresponding to the nominal sensor attitude scans the image generator (e.g.