摘要:
One or more computer processors receive one or more tasks and, for each task, one or more opportunities are identified. Each opportunity corresponds to a satellite from a network of satellites potentially performing the task. For each opportunity, a scheduling score is generated. The scheduling score is based on one or more task constraints including one or more of the following constraints on the task associated with the opportunity corresponding to the scheduling score: a priority assigned to the task; a duration of time before the satellite corresponding to the opportunity is able to perform the task; and an availability of a future downlink. Based on each scheduling score, at least one of the one or more tasks is assigned to the satellite corresponding to an opportunity identified for the at least one task.
摘要:
Multibeam coverage for a high altitude platform is disclosed. An example apparatus includes a plurality of antennas configured to provide communication coverage among a plurality of terminals within a specified area on the ground, each antenna being configured to communicate with a specified cell within the specified area. The antennas of the example apparatus have differently sized apertures to maintain a similar surface spectral density among the cells within the specified area.
摘要:
A methods and apparatus useful for correlating measurements of communications signals taken at base stations and gateways and user terminals in a communication system. Gateway measurements are taken at regular intervals and stored. Then, when a user terminal measurement is reported to the gateway, the gateway selects one or more stored gateway measurements that were taken nearest the time at which the user terminal measurement was taken. The gateway then applies an interpolation process using the gateway measurements to obtain a gateway measurement that roughly corresponds to the user terminal measurement. Several techniques such as extrapolation, averaging, and so forth using two or more data values can be employed as part of this process.
摘要:
A method for determining (36) whether a location associated with a wireless station, such as a cellular telephone (28), is located within an area of interest. The area of interest is defined using a quadtree representation of an area that includes the area of interest and identifying nodes within the quadtree that represent the area of interest. By iterative comparison of the location (60A-60N) associated with the wireless station (28) to the locations associated with a node at each level of the quadtree, a determination can be made as to whether or not the location associated with the wireless station is within the area of interest.
摘要:
Multibeam coverage for a high altitude platform is disclosed. An example apparatus includes a plurality of antennas configured to provide communication coverage among a plurality of terminals within a specified area on the ground, each antenna being configured to communicate with a specified cell within the specified area. The antennas of the example apparatus have differently sized apertures to maintain a similar surface spectral density among the cells within the specified area.
摘要:
A spread spectrum code division multiple access (CDMA) receiver for receiving data from a spread spectrum CDMA transmitter in a same geographic region as covered by a cellular system, the cellular system communicating using a plurality of predetermined frequency bandwidths, is disclosed. The receiver is characterized by means (149, 140, 147, 141, 169, 161, 163, 330, 331, 332) for receiving a spread spectrum CDMA data signal from said CDMA transmitter, the CDMA data signal having a wide bandwidth overlaying said plurality of predetermined frequency bandwidths, means (143, 333) for notch filtering the received CDMA data signal at said plurality of predetermined frequency bandwidths, and means (145, 165, 334, 335) for recovering data from said notch filtered CDMA data signal. A method of receiving data is also disclosed.
摘要:
A system and method for passively determining the position of a user terminal (for example, a mobile wireless telephone) in a low-Earth orbit satellite communications system. The system includes a user terminal, at least two satellites with known positions and known velocities, and a gateway (that is, a terrestrial base station) for communicating with the user terminal through the satellites. The method includes the steps of determining a range difference parameter and a range-rate difference parameter. A range difference parameter represents the difference between (1) the distance between a first one of the satellites and the user terminal and (2) the distance between a second one of the satellites and the user terminal. A range-rate difference parameter represents the difference between (a) a relative radial velocity between a first one of the satellites and the user terminal and (b) a relative radial velocity between a second one of the satellites and the user terminal. The position of the user terminal on the Earth's surface is then determined based on the known positions and known velocities of the satellites, the range difference parameter, and the range-rate difference parameter.
摘要:
A selective call receiver (24) that receives signals transmitted by orbiting satellites (A, B) uses certain information transmitted by the satellites to calculate an estimate of its position. Using that estimate and other information, the selective call receiver (24) is able to save power by disregarding certain information contained in transmitted signals that are not intended for it.