摘要:
A communication system is described. The system includes: at least one gateway able to provide broadband connectivity, a set of ground terminals, and a set of aerial platforms, where at least one aerial platform is able to communicate with at least one gateway using radio frequencies, each aerial platform is able to communicate with ground terminals using radio frequencies, and each aerial platform is able to communicate with each other aerial platform using radio frequencies. An automated method for determining a beam direction for communication among UAVs includes: dividing a space around the UAV into multiple sub-regions, and, iteratively: selecting a sub-region from among the multiple sub-regions; pointing a signal toward the sub-region; and determining whether a signal is received from another UAV, until all sub-regions from among the multiple sub-regions have been selected.
摘要:
There is provided an apparatus for a satellite communication system comprising: means for determining at least one out of a phase offset for a frequency channel of a plurality of frequency channels demultiplexed from a carrier to compensate for group delay variation within the carrier and a gain offset for the frequency channel to compensate for gain variation within the carrier; and means for applying the determined at least one out of a phase offset and a gain offset to the frequency channel before the carrier is reformed from said plurality of frequency channels. The invention therefore provides a way of digitally compensating for any undesired gain and group delay introduced by, for example, analogue components such as filters in the satellite communication system.
摘要:
A method an apparatus for selecting a forward link and return link data rate for a constant power, variable data rate two-way, mobile satellite communications link. The forward link and return link signal strength (in the form of carrier power to noise power spectral density ratio) is measured, cataloged, and the values are used for the data rate selection. In addition, a ping can be sent by the network operation center to the mobile unit and the response to the ping is used for updating the information of both forward link and return link signal strength, so the chance of wrong data rate selection can be reduced. Multiple re-transmission attempts combined with gradually increased re-transmission margin ensures the proper data rate decision can be eventually achieved even with occasionally inaccurate signal strength information.
摘要:
A network budget for a satellite network is provided, as well as a method of building such a network budget. Estimated power levels for each links of the satellite network are computed through an evaluation of initial power levels of each uplink and downlink beams and an estimation of power variations affecting them. Methods for managing the satellite network and optimizing the installation of a receiver using a network budget are also provided.
摘要:
A method of transmitting information in a wireless communications system can be provided by selectively applying filtering to transmission of a carrier signal of a first band of frequencies of a wireless communications system based on a frequency separation distance between a frequency content of the carrier signal and a second band of frequencies allocated to a communications system other than the wireless communications system.
摘要:
A technique for timing compensation is used in a terrestrial wireless communication system (300) that has a satellite backhaul link (352, 358, 360) to at least one base transceiver station (306, 307, 308). The technique includes establishing a backhaul delay (BHD) of the satellite backhaul link and performing at least one timing compensation function based on the backhaul delay. The technique further includes setting (540, 545) a base controller system time (170). The following timing compensation functions are described: adjustment of packet arrival timing error interval (520), selection of a mobile station power control outer loop path (525), adjustment of at least one protocol timer (530), evaluation of a reverse Markov test call frame based on the BHD and real time (545), adjustment of forward data frame alignment based on the BHD and real time (555), and adjustment of forward Markov test call frame generation based on the BHD and real time (560).
摘要:
Une station de transmission distante (S1 ), pour une installation de transmission (ID) d'un réseau de communication radio comprenant un équipement (MS) de gestion de stations de transmission à protocole d'administration choisi, comprend des équipements gérés (E11, E21) et est située dans une partie du réseau séparée de l'équipement de gestion (MS) par une liaison de transmission (SAT) de l'installation (ID). La station (S1) comprend en outre des moyens de gestion (MG) chargés d'obtenir des états d'informations de gestion relatives aux équipements gérés (E), et des moyens de traitement (MT) chargés i) de stocker l'ensemble des états précédemment obtenus par les moyens de gestion (MG), ii) de comparer les états nouvellement obtenus aux états précédents stockés, de manière à déterminer chaque variation d'état, et iii) de générer des messages comportant chaque variation d'état déterminée afin qu'ils soient transmis à l'équipement de gestion (MS) via la liaison (SAT).
摘要:
A satellite radiotelephone system includes a space-based component that is configured to communicate with multiple radiotelephones over multiple frequency bands and/or multiple air interfaces. An ancillary terrestrial network is configured to communicate terrestrially with the multiple radiotelephones over substantially the multiple frequency bands and/or substantially the multiple air interfaces. An aggregate radiated power controller is configured to limit an aggregate radiated power by the multiple radiotelephones to a maximum aggregate radiated power.
摘要:
Forward link transmission power to a user terminal (124a, 124b, 124c) in a wireless communications system (100) having a plurality of beams (2041-20416) is controlled by identifying the location of a user terminal within one of the plurality of beams (2041-20416), and setting the forward link (404) transmission power in response to the identified user terminal location. Identifying user terminal location (402, 502) may include receiving from the user terminal multiple signal power measurements (602), such as pilot signal measurements. From these measurements, a difference is calculated between a first of the signal power measurements that corresponds to a home beam and each of the other signal power measurements (604). If the largest of the calculated differences is greater than a predetermined threshold (606), it is concluded that the user terminal is within a beam central region (610). However, if the largest of the calculated differences is less than or equal to the predetermined threshold (606), then it is concluded that the user terminal is within a beam crossover region (608).
摘要:
Forward link transmission power to a user terminal (124a, 124b, 124c) in a wireless communications system (100) having a plurality of beams (204) is controlled by determining a baseline power level, Pbaseline, from a received active pilot channel signal-to-noise ratio (SNR) (402); determining a power margin, Pmargin, from an identified interference susceptibility (404); determining a power level correction, Pcorrection, based on an identified packet error rate (PER) (406); and setting Ptransmit based on Pbaseline, Pmargin, and Pcorrection (420). For example, Ptransmit may be set to a power level that is substantially equal to the sum of Pbaseline, Pmargin, and Pcorrection. The determination of each of Pbaseline, Pmargin, and Pcorrection may be performed in independently running control loops or processes.