Co-channel interference reducing arrangement in a satellite communications systems, and method
Abstract
A method of operating a radio-satellite communications system, in which the method comprises: receiving the first radio signals on a first satellite, wherein the first radio signals received including a desired signal uses a frequency, and an interference signal, using said frequency; the combination of the first radio signals based on a first performance criterion to generate a first output signal; the reception of the second radio signals on a second satellite, wherein the second radio signals received include a measure of the desired signal; the combination of the second radio signals, based on a second performance criterion to produce a second output signal; and the combination of the first and second output signals to generate an estimate of the desired signal.

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20 claims: 3 independent, 17 dependent
- 1ES 2 292 142 T3 REIVINDICACIONES 1. Un método de operación de un sistema de comunicaciones radiotelefónicas por satélite, en el que el método comprende:la recepción de las primera señales de radio en un primer satélite, en donde las primeras señales de radio recibidas incluyendo una señal deseada utiliza una frecuencia, y una señal de interferencia, utilizando dicha frecuencia;la combinación de las primeras señales de radio basándose en un primer criterio de rendimiento para generar una primera señal de salida;la recepción de la segundas señales de radio en un segundo satélite, en donde la segundas señales de radio recibidas incluyen una medida de la señal deseada;la combinación de las segundas señales de radio, basándose en un segundo criterio de rendimiento para producir una segunda señal de salida;y la combinación de la primera y segunda señales de salida para generar una estimación de la señal deseada.
- 2Un método de acuerdo con la reivindicación 1:en el que se combinan las primeras señales de radio, basándose en una primer criterio de rendimiento, para generar una primera señal, que comprende: determinar una primera temporización para la señal deseada según sea recibida por el primer satélite;determinar un error de la primera señal de salida sensible a la temporización primera determinada;y combinar las primeras señales de radio sensibles al error determinado de la primera señal de salida;y en donde la combinación de las segundas señales de radio se basa en un segundo criterio de rendimiento, para generar una segunda señal de salida, que comprende: determinar una segunda temporización para la señal deseada según sea recibida por el segundo satélite;determinar un error de la segunda señal de salida sensible a la segunda temporización determinada;y combinar las segundas señales de radio sensibles al error determinado de la segunda señal de salida.
- 3Un método de acuerdo con la reivindicación 2:en el que la determinación de una primera temporización para la señal deseada según se reciba por el primer satélite, comprende la sincronización con una referencia de una temporización para la señal deseada;en el que la determinación de un error de la primera señal de salida sensible a la primera temporización determinada comprende la determinación de un error para la información conocida en la primera señal de salida sensible a la sincronización;y en el que la combinación de las primeras señales de radio sensibles al error determinado comprende la combinación de las primeras señales de radio sensibles al error para la información conocida en la primera señal de salida.
- 4Un método de acuerdo con la reivindicación 1, en el que la combinación de las primeras señales de radio se basa en un primer criterio de rendimiento para generar una primera señal de salida, que comprende:la aplicación de las primera señales de radio a una pluralidad de filtros;la combinación de la salidas de la pluralidad de filtros para producir la primera señal de salida;y la modificación de al menos un parámetro del filtro sensible a la primera señal de salida.
- 5Un método de acuerdo con la reivindicación 1, en el que la combinación de la primera y segunda señales de salida, para generar una estimación de la señal deseada comprende una relación máxima, combinando la primera y segunda señales de salida.
- 6Un método de acuerdo con la reivindicación 1, en el que el primer satélite atiende a una primer área de cobertura terrena, y en donde el segundo satélite sirve a una segunda área de cobertura terrena adyacente y/o solapándose en la primer área de cobertura. ES 2 292 142 T3
- 7Un método de acuerdo con la reivindicación 6, en el que las señales respectivas de la primera y segunda señales de radio corresponden a las señales de los respectivos haces puntuales del satélite y/o a las alimentaciones de las antenas.
- 8Un sistema de comunicaciones radiotelefónicas por satélite, que comprende:un primer satélite que recibe las primeras señales de radio, incluyendo una señal deseada que utiliza una frecuencia y una señal interferente que utiliza la frecuencia;un segundo satélite que recibe las segundas señales de radio incluyendo una medida de la señal deseada;y un procesador de señales de supresión de interferencias, configurado para combinar las primeras señales de radio, basándose en un primer criterio de rendimiento, para generar una primera señal de salida, para combinar las segundas señales de radio, basándose en un segundo criterio de rendimiento, para producir una segunda señal de salida, y para combinar la primera y segunda señales de salida, para generar una estimación de la señal deseada.
- 9Un sistema de acuerdo con la reivindicación 8:en el que el procesador de señales de supresión de interferencias está configurado para determinar una primera temporización para la señal deseada según sea recibida por el primer satélite, para determinar un error de la primera señal de salida, sensible a la primera temporización determinada, y para combinar las primeras señales de radio sensibles al error determinado de la primera señal de salida;y en el que el proceso de la señal de supresión de interferencias está además configurado para determinar una segunda temporización para la señal deseada, según sea recibida por el segundo satélite, para determinar un error de la segunda señal de salida, sensible a la segunda temporización determinada, y para combinar las segundas señales de radio sensibles al error determinado de la segunda señal de salida.
- 10Un sistema de acuerdo con la reivindicación 9, en el que el procesador de señales de supresión de interferencias está configurado para sincronizarse a una referencia de temporización para la señal deseada, para determinar un error de la señal de salida para la información conocida en la primera señal de salida sensible a la sincronización, y para combinar las primeras señales de radio sensibles al error de la señal de salida.
- 11Un sistema de acuerdo con la reivindicación 8, en el que el procesador de la señal de supresión de interferencias comprende:una pluralidad de filtros configurados para recibir las primeras señales de radio;un combinador configurado para combinar las salidas de la pluralidad de filtros, para producir la primera señal de radio;y un controlador operativo para modificar al menos un parámetro de la pluralidad de filtros sensibles a la primera señal de salida.
- 12Un sistema de acuerdo con la reivindicación 8, en el que el procesador de señales de supresión de interferencias comprende un combinador de relación máxima configurado para combinar la primera y segunda señales de salida, para generar la estimación de la señal deseada.
- 13Un sistema de acuerdo con la reivindicación 8, en el que el primer satélite sirve a una primer área de cobertura terrena, y en donde el segundo satélite sirve a una segunda área de cobertura terrena adyacente y/o solapándose en la primer área de cobertura.
- 14Un sistema de acuerdo con la reivindicación 8, en el que las respectivas señales de la primera y segunda señales de radio corresponden a las señales de los respectivos haces puntuales del satélite y/o a las alimentaciones de la antena.
- 15Un aparato que comprende:un procesador de señales de supresión de interferencias, configurado para combinar las primeras señales de radio recibidas en un primer satélite, basándose en un primer criterio de rendimiento, para generar una primera señal de salida, para combinar las segundas señales de radio recibidas en un segundo satélite basándose en un segundo criterio de rendimiento, para producir una segunda señal de salida, y para combinar la primera y segunda señales de salida, para generar una estimación de una señal deseada.
- 16Un aparato de acuerdo con la reivindicación 15:en el que el procesador de señales de supresión de interferencias está configurado para determinar una primera temporización de sincronización para la señal deseada conforme se reciba por el primer satélite, para determinar un ES 2 292 142 T3 error de la primera señal de salida sensible a la primera temporización determinada, y para combinar las primeras señales de radio sensibles al error determinado de la primera señal de salida;y en el que el proceso de la señal de supresión de interferencias está configurado además para determinar una segunda temporización de sincronización para la señal deseada conforme se reciba por el segundo satélite, para determinar un error de la segunda señal de salida sensible a la segunda temporización determinada, y para combinar las segundas señales de radio sensibles al error determinado de la segunda señal de salida.
- 17Un aparato de acuerdo con la reivindicación 16, en el que el procesador de la señal de supresión de interferencias está configurado para sincronizar con una referencia de la temporización par la señal deseada, para determinar un error de la señal de salida para la información conocida en la primera señal de salida sensible a la sincronización, y para combinar las primeras señales de radio sensibles al error de la señal de salida.
- 18Un aparato de acuerdo con la reivindicación 15, en el que el procesador de la señal de supresión de interferencia comprende:una pluralidad de filtros configurados para recibir las primeras señales de radio;un combinador configurado para combinar las salidas de la pluralidad de los filtros, para producir la primera señal de salida;y un controlador configurado para modificar al menos un parámetro de la pluralidad de filtros sensibles a la primera señal de salida.
- 19Un aparato de acuerdo con la reivindicación 15, en el que el procesador de la señal de supresión de interferencia comprende un combinador de relación máxima configurado para combinar la primera y segunda señales de salida, para generar la estimación de la señal deseada.
- 20Un aparato de acuerdo con la reivindicación 15, en el que las señales respectivas de la primera y segunda señales de radio corresponden a las señales de los respectivos haces puntuales del satélite, y/o a las alimentaciones de la antena.
Independent claims20
73 paragraphs in 4 sections, as filed
ES 2 292 142 T3
DESCRIPTION
Arrangement and method of reducing interference in joint channels in satellite communication systems.
Related requests
This application is a continuation in part of US application serial number 10/890758 entitled Systems and Methods for Reducing Intrasystem and / or Intersystem Interference for Satellite Communications Systems, filed July 14 2004, which claims priority of the US provisional application document. number 60/490993, also entitled Systems and Methods to Reduce Intrasystem and / or Intersystem Interference for Satellite Communications Systems, registered on July 30, 2003, these documents having been published as US-2005136836 and uS-2005037749.
Field of the invention
This invention relates to radiotelephone communication systems and methods, and more particularly to terrestrial cellular and satellite cellular radiotelephone communication systems and methods.
Background of the invention
Radiotelephone communication systems and methods by satellite have been widely used for radiotelephony communications. Radiotelephone satellite communication systems and methods generally use at least one component based on space communications, such as one or more satellites that are configured to communicate radioelectrically with a plurality of satellite radiotelephones.
Radiotelephony satellite communication systems or methods may use a single beam (cell) covering an entire area served by the system. Alternatively, in cellular satellite radiotelephone communication systems and methods, multiple beams are provided, each of which can serve different geographic areas in the global service area, to collectively serve a global radio footprint of the satellite. Thus, it is a cellular architecture similar to that used in conventional land-based PCD / cellular radiotelephony systems and methods, which can be implemented in satellite-based cellular systems and methods. The satellite typically communicates with radiotelephones over a two-way communications path, wherein the radiotelephone communications signals are communicated from the satellite to the radiotelephone via a downlink or direct link, and from the radiotelephone to the satellite via of an uplink or return link.
The overall design and operation of cellular satellite radiotelephony systems and methods are well known to those skilled in the art, and need not be described here. Furthermore, as used herein, the term "radiotelephone" includes cellular and / or satellite radiotelephones, with or without a multi-line display; Personal Communications System (PCS) terminals that can combine a radiotelephone with processing, fax, and / or data communications capabilities; Personal Digital Assistants (PDAs) that may include a radio frequency transceiver and a person finder, Internet / Intranet access, WEB page browser, calendar, and a Global Positioning System (GPS) receiver: and conventional handheld and laptop computers or other devices, which may include a radio frequency transceiver. Radiotelephones may also be referred to herein as "radio terminals" or simply "terminals".
As is also well known to those skilled in the art, terrestrial networks can improve the availability, efficiency and / or economic viability of the cellular-type radiotelephone satellite system, through the terrestrial reuse of at least some of the frequency bands. which are assigned to cellular radiotelephone satellite systems. In particular, it is known that it can be difficult for cellular radiotelephone satellite systems to reliably serve densely populated areas, because the satellite signal can be blocked by high-rise structures, and / or because they may or may not penetrate buildings. As a result, the satellite spectrum may be underutilized or unused in such areas. The use of ground relay can reduce or eliminate this problem.
Furthermore, the capacity of the global system can be significantly increased by the introduction of terrestrial retransmission, since the reuse of terrestrial frequencies can be more dense than that of the single satellite system. In fact, capacity can be upgraded where it may be most needed, ie in densely populated urban / industrial / commercial areas, as this will allow a much larger subscriber base to be served. Finally, satellite radiotelephones for a satellite radiotelephone system having a ground component within the same frequency band as the satellite, and using substantially the same radioelectric interface for both terrestrial and satellite communications, may be more effective and / or a better aesthetic appearance. Conventional dual band mode alternatives, such as the well-known Thuraya, Iridium and / or Globalstar satellite / dual terrain radiotelephone systems, can duplicate some components, which can lead to increased cost, increasing dimensions and / or weight. of the radiotelephone.
The US patent number 6684057, of the co-inventor Karabinis, and entitled as Systems and Methods for the Terrestrial Reuse of the Frequency Spectrum of the Cellular Satellite, describes that a frequency of the radiote2
ES 2 292 142 T3 satellite phone can be reused on a terrestrial basis by means of a complementary terrestrial network even within the same satellite cell, using interference cancellation techniques. In particular, the satellite radiotelephone system according to some embodiments of the published patent application 2003/0054760 includes a component based on the spatial element that is configured to receive radio communications from a first radiotelephone in a radioelectric footprint of coverage in a band of radiotelephone frequencies from the satellite, and a complementary terrestrial network that is configured to receive radio communications from a second radiotelephone in the radioelectric footprint of satellite coverage through the frequency band of the satellite radiotelephone. The space segment-based component also receives radio communications from a second radiotelephone in the radioelectric footprint of the satellite coverage, in the radiotelephone frequency band of the satellite as interference, together with the radio communications received from the first radiotelephone in the satellite coverage footprint through the satellite's radiotelephone frequency band. The interference reducer is sensitive to the space segment component and the complementary earth network, which is configured to reduce interference from radio communications received by the space segment-based component of the first radiotelephone in the radio coverage footprint through of the satellite radiotelephone frequency band, using radio communications received by the complementary terrestrial network from the second radiotelephone in the satellite coverage footprint through the radiotelephone frequency band of the satellite.
Publication of US patent applications: number 2003/0054761-A1, published on March 20, 2003, by the co-inventor Karabinis, and entitled Space Guardbands for Earth Reuse of Satellite Frequencies, describes some radiotelephone satellite systems, which include a component based on the space segment , which is configured to provide radiotelephone communications in a radioelectric coverage footprint of the satellite through a band of radiotelephone frequencies of the satellite. The radioelectric coverage footprint of the satellite is divided into a plurality of satellite cells, in which the satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused. A complementary terrestrial network is configured to reuse in ground mode at least one of the radiotelephone frequencies of the satellite, which is used in a satellite cell in the satellite coverage footprint, outside the cell and in some separate embodiments of the satellite. same by means of a space guard band. The spatial guardband may be large enough to reduce or prevent interference between at least one of the radiotelephone frequencies of the satellite that is used in the satellite cell in the radio coverage footprint of the satellite, and at least one of the radiotelephone frequencies. of the satellite that is reused on the ground outside the satellite cell and separated from it by the space guard band. The spatial guard band can be about half the radius of a satellite cell wide.
An interference cancellation system for satellite downlink communications received by an earth station is described in US Patent Publication No. 2004/0042569, by Casabona et al. The system is oriented to the interference of the co-channel and adjacent terrestrial satellite. The main and auxiliary signals are derived directly or by coherent conversion to an intermediate frequency, using an auxiliary antenna, interpolarized feed, or an auxiliary angle feed.
Summary of the invention
In some embodiments of the present invention, a first radio signals are received at a first satellite, wherein the first received radio signals include a desired uplink signal transmitted from a first source, using a frequency assigned to the first source. , and an interfering signal transmitted from a second source, using the frequency assigned to the first source. The first radio signals are combined based on a first performance criterion to generate a first out signal. The second radio signals are received at a second satellite, where the second received radio signals include the desired signal. The second radio signals are combined based on a second performance criterion, to produce a second output signal. The first and second signals are combined based on a third performance criterion to generate an estimate of the desired uplink signal from the satellite.
According to some embodiments, a first synchronization signal for the desired signal is received at the first satellite, which is determined for example by synchronizing with a synchronization reference in time, such as a pilot signal or a synchronization sequence. An error of the first output signal responsive to a first determined timing is determined. The first radio signals are combined being sensitive to the determined error of the first output signal. Similarly, a second timing is determined for the desired signal as received by the second satellite, and an error of the second output signal is determined that is responsive to the determined second timing. The second radio signals are combined being sensitive to the second determined error of the second output signal.
In further embodiments, combining the first radio signals based on a first performance criteria to generate a first output signal includes applying the first radio signals to a plurality of filters, combining the outputs of the plurality of filters to generate a first output signal, and modifying the plurality of filters in response to the first output signal. Combining the first and second output signals to generate an estimate of the desired satellite uplink signal may include combining with a maximum ratio of the first and second output signals.
ES 2 292 142 T3
In accordance with further embodiments of the present invention, the satellite radiotelephone communication system includes a first satellite that receives the first radio signals including a desired satellite uplink signal transmitted from a first source, using a frequency assigned to the first source and an interfering signal transmitted from a second source, using the frequency assigned to the first source. The system also includes a second satellite that receives the second radio signals, including the desired signal. The system further includes an interference suppression signal processor, configured to combine the first radio signals based on a first performance criterion, to generate a first output signal, to combine the second radio signals based on a second performance criterion. performance, to produce a second exit signal, and to combine the first and second output signals to generate an estimate of the desired satellite uplink signal.
In even further embodiments, a receiving apparatus includes an interference suppression signal processor, configured to combine the first radio signals, to combine the first radio signals from a first satellite, based on a first performance criterion to generate a first output signal, to combine the second radio signals from a second satellite, based on a second performance criterion, to generate a second output signal, and to combine the first and second output signals, to generate an estimate of the desired satellite uplink signal.
Brief description of the drawings
Figure 1 is a schematic diagram showing a satellite communication system and operations thereof, in accordance with some embodiments of the present invention.
Figure 2 is a cellular schematic diagram showing exemplary operations of a satellite communication system, in accordance with further embodiments of the present invention.
Figure 3 is a schematic diagram of an interference suppression signal processor, in accordance with some embodiments of the present invention.
Figures 4-6 are schematic diagrams showing satellite communication systems and operations thereof, in accordance with further embodiments of the present invention.
Figure 7 is a schematic diagram of an interference suppression signal processor in accordance with further embodiments of the present invention.
Detailed description
Specific exemplary embodiments of the invention will now be described with reference to the accompanying drawings. This invention, however, can be made in many different ways, and will not be considered limited to the embodiments set forth herein; instead these embodiments are supplied so that their exposition will be complete and complete, fully covering the scope of the invention for all technicians specialized in the art. In the drawings, like numbers refer to like items. It will be understood that when an element is referred to as "connected" or "coupled" to another element, it can be connected or coupled to the other element or else by involving elements that may be present. In addition, the terms "connected" or "coupled" as used herein may include radio linkage or coupling. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed elements.
The terminology used herein is for the purpose of describing the particular embodiment only, and is not intended to limit the invention. As used herein, the singular forms of "a" and "the" are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms "includes", "comprises", "including" and / or "comprising", when used in this specification, specify the presence of the expressed characteristics, integers, steps, operations, elements, and / or components, but not excluding the presence or addition of one or more of the other characteristics, stages, operations, elements, components, and / or groups thereof.
Unless otherwise stated, all terms (including technical and scientific terms) used herein have the same meaning as understood by the person skilled in the art to which this invention may pertain. It will also be understood that terms such as those defined in the common dictionaries used, should be interpreted as having a meaning compatible with their meaning in the context of the corresponding art, not being interpreted in the idealized sense unless it is expressed and defined in this way. shape.
Some embodiments of the present invention described herein include the use of various satellite reception paths to receive the desired uplink signals, and one or more interference signals. As used herein, a "satellite reception path" refers to one or more elements that are configured to receive and transport the signals received from the satellite, that is, signals incident on a satellite from, for example, the sources. positioned on the earth's surface, such as radiotelephones. Consequently, a satellite reception path may include, but is not limited to, a satellite antenna, a spot beam supported by a satellite antenna, electronic circuits that receive and transport the signals received by a satellite antenna,
ES 2 292 142 T3 and antennas and hardware based on the earth's surface, which can receive a signal received by satellite, through, for example, a “bent conduit”, “regenerative”, “non-regenerative”, and / or others satellite relay mechanisms. As used herein, the "radio signal" received by said satellite reception path may include a modulated radio frequency carrier signal transmitted by a source and / or data, voice, or other signals combined or embedded in said signal. radio frequency.
Some embodiments of the present invention will be described herein with respect to first and second radiotelephone satellite communication systems. For convenience, the first radiotelephone satellite communication system, and the components thereof, may be referred to as "MSV", and may correspond in some embodiments to a radiotelephone satellite system supplied by Mobile Satellite Ventures, LP, the licensee hereof. invention. The second satellite radiotelephone system and / or its components thereof may be referred to as "non-MSV". However, it will be understood that the invention is not limited to applications that include combinations of the MSV and non-MSV systems, and that any of the first and second radiotelephone satellite communication systems may be encompassed by the MSV designations and not -MSV.
Figure 1 shows a satellite 100 that is configured with two antennas 110, 120, in accordance with some embodiments of the present invention. The antennas 110, 120 of the satellite 100 can be of different sizes (in the shown embodiments, 26 meters and 9 meters, respectively), and they can be directed towards different radio coverage footprints 130, 140. The service radio coverage footprints may be disjointed (as shown in Figure 1), but may have some overlap, or may have total overlap. Specifically, Figure 1 shows the larger antenna 110 of the two satellite antennas 110, 120 directed towards an area 130 labeled "MSV service coverage footprint", while the smaller antenna 120, also referred to here as an auxiliary antenna , is directed toward an area 140 labeled "non-MSV service coverage footprint." The smaller antenna 120 may be configured to receive only. The larger antenna 110 may be configured to receive and transmit. Each antenna 110, 120, can be configured to form a plurality of spot beams (cells) over its respective footprint or radio coverage area.
Transmissions from satellite terminal 142 that can be attempted for a non-MSV satellite (such as an Inmarsat satellite) can also be intercepted (intentionally or unintentionally) by at least one MSV satellite. At least some transmissions from the satellite terminal by non-MSV satellite terminals may be of the co-channel type with at least some of the transmissions from satellite MSV terminals. Thus, at least some satellite terminal transmissions by non-MSV satellite terminals targeting a non-MSV satellite, and which are co-channels with at least some satellite terminal transmissions 132 by MSV satellite terminals (for MSV satellites), they can cause co-channel interference in at least some of the MSV satellite receivers. In accordance with some embodiments of the present invention, the systems and methods provided are capable of adaptively mitigating the effects of intersystem and co-channel interference, in order to allow improved communications performance, and also to potentially facilitate a more efficient reuse of radio frequency resources between the different systems.
At least one complementary antenna on an MSV satellite (the smaller antenna 120 on the MSV satellite of Figure 1) can be configured and / or positioned to maximize its reception of broadcasts by non-MSV satellite terminals targeting a non-MSV satellite. This antenna, so configured and / or positioned, can receive substantially strong interference signals that can be used in an element of an MSV infrastructure (such as a satellite gateway), to mitigate (reduce, suppress or substantially eliminate) the signals of interference that may be received by an MSV satellite antenna, whose mission will be to provide the communications service to MSV user terminals through the MSV service area.
Still referring to Figure 1, the Complementary Ground Network (ATN) comprising a plurality of Complementary Ground Components (ATC) may be deployed across certain areas of the radio coverage footprint 130 of the MSV service. An ATC comprises one or more radiating infrastructure elements, such as a base station with associated rear end infrastructure. At least one radioterminal will be able to communicate with at least one element of the radiation infrastructure. Signals 134 that are radiated by an ATC and / or a radio terminal that may be in communication with an ATC and / or a satellite may inadvertently be intercepted by the satellite (s) MSV 100, causing additional interference.
According to some embodiments of the present invention, the Space Based Network (SBN), including the Space Based Component (SBC) (for example, at least one satellite) and the terrestrial infrastructure (for example, at least one gateway), includes the systems and / or methods to adaptively mitigate the interference received from at least some elements of the ATN and / or radioterminals. According to some embodiments of the present invention, the SBN also includes systems and / or methods that are capable of adaptively mitigating the interference caused by the reuse of the intrasystem and / or intersystem frequencies.
Figure 2 shows an example of intra-system frequency reuse. As shown in figure 2, a given frequency set, frequency set 1 for example, can be used and reused for satellite communications through at least a part of a system coverage footprint according to for example with a seven-cell frequency reuse pattern. A given satellite cell, such as the S cell of the satellite, is configured to receive at least some frequencies of the set 1 of frequencies, from the radio terminals that are operating through its coverage footprint, being able to also receive interference from
ES 2 292 142 T3 other emissions from the intra-system terminals, for example, for T to Y cells that may be radiating at least some of the same frequencies as the radio terminals are being operational through the S cell of the satellite. Figure 2 also shows the location of two ATCs, labeled A and B, which may be reusing all or some of the frequencies from set 1 of frequencies. Thus, ATC emissions from ATC A and / or B can also cause interference to one or more receivers associated with the satellite S cell and / or other satellite cells. Spatial guard bands, as described in US Patent Application Publication No. 2003/0054761 A1, are shown by the unshaded rings in Figure 2.
With reference to Figures 1 and 2 and regarding the satellite antenna 110 that is serving the MSV service coverage footprint 130 (see Figure 1), at least some signals from at least some of the neighboring satellite cells of a given satellite cell, such as the satellite S cell, may contain signals that are correlated with at least some components of an aggregate interference from the given satellite cell (such as the satellite S cell). Such signals can be carried, for example, to a satellite gateway via the satellite feeder link, such as the satellite feeder link 101 shown on the left side of Figure 1, to serve as the inputs to an interference suppressor. . With respect to the satellite antenna 120 that is directed toward the non-MSV service coverage footprint 140, at least some signals that may be relevant to the suppression of interference that can be received by the satellite antenna 110 serving the coverage footprint 130 MSV, can be transported to, for example, an MSV satellite gateway via a satellite feed link, such as the satellite feed link 102 shown on the right hand side of FIG. 1.
The two satellite feed links 101,102, shown in Figure 1, can use different frequencies and / or different frequency bands to transmit the information to the ground segment to two or more spatially different or close receiving antennas. In some embodiments, information carried to the ground (eg, a satellite gateway) via feeder links 101, 102 shown in Figure 1, can be accommodated by a single feeder link using the frequencies of a single frequency band. In other embodiments, a satellite may be configured with two or more feeder links, using the frequencies of one or more frequency bands, to transport the information from the satellite to at least one terrestrial facility (eg, a satellite gateway). through terrestrial reception antennas spatially separated and / or close to the power link.
Figure 3 shows an architecture of an adaptive receiver 300, also known as adaptive interference reducer, which can be configured in a satellite gateway (and / or another position), to suppress the interference that may be generated by the reuse of frequencies from the intra-system or intersystem type. Specifically, the receiver architecture of Figure 3 is shown operative to suppress interference that may be superimposed on a "wanted signal" received by the satellite S cell. As such, the receiver 300 described in Figure 3 combines (in a combiner 320), according to a control law or a performance index (of a controller 340), such as the least mean square error control law ( LMSE) or performance index, through a plurality of cross-sectional filters 310 (fractionally and / or synchronously separated, feedforward, and / or decision feedback), a plurality of signal inputs from a plurality of satellite cells that may be formed by one or more antennas of the satellite or satellites, to form a variable decision for retrieval of a desired signal at a detector 330.
Those skilled in the art will recognize that different control laws (other than LMSE), such as zero forcing, can be used to form and / or update the coefficients of the cross-sectional filters. Those skilled in the art will also recognize that different control law input signals may be required by different control laws to derive the update information for the plurality of cross filter coefficients.
For example, according to a zero forcing control law, the amount of error (see Figure 3) and the output of the decision stage of Figure 3 can serve as inputs to the control law. It will also be recognized by those skilled in the art that the number of cross filter coefficients per cross filter need not be the same across the set of cross filters shown in Figure 3. Some cross-section filters, for example, may have seven (7) coefficients or taps, while others may have five (5) or only three (3), and some cross-section filters may be limited to a single coefficient. In some embodiments, all cross-sectional filters have an identical number of coefficients or taps (greater than or equal to one). Furthermore, in some embodiments, the architecture of each cross filter of the set of cross filters of Figure 3 may not be the same as for all of the cross filters in the set. For example, some crossover filters may be synchronously separated, others fractionally separated, and others with decision feedback with synchronous or fractionally separated feed-forward sections.
Referring back to Figure 3, it is noted that the upper (first) cross filter input, labeled "satellite S cell signal" denotes the desired signal plus interference, as received by the satellite S cell. (see figure 2). The cross filter inputs T to Y represent signals that may be correlated to the desired signal from the satellite S cell, and / or to the satellite S cell interference signal (s), which may be due to reuse. of the frequencies of the intra-satellite and / or intersatellite system. These T to Y signals represent signals from adjacent cells in the satellite system, using the same frequency or frequencies as the S cell. It will be understood that non-adjacent satellite cells using the same frequency or frequen6
ES 2 292 142 T3 cies that the satellite S cell, shown by some or all of the shaded cells, and / or some or all of the unshaded cells, other than SY cells, can also provide signals to other cross-sectional filters of the set of transverse filters (not shown), and also contribute elements to the combination junction 320 of Figure 3.
The transverse filter inputs A2 to A7 and B6 to B4 represent signals that can be correlated with, among other signals, the interference components of the satellite S cell signal, generated by ATC A and B, respectively. In some embodiments, fewer or more signals A and / or B and fewer or more cross filters may be provided than shown in Figure 3. In particular, in Figure 3, the signals of the three adjacent cells are provided to an ATC that is reusing the same frequency or frequencies as the satellite S cell on earth. Thus, for ATC A, the signals from satellite cells 3, 5, and 7 are provided as inputs, and for ATC B, signals from satellite cells 4, 6, and 7 are provided. In other embodiments, signals from non-adjacent satellite cells can be provided.
The transverse filter inputs Ii to I<sub>N</sub> they provide signals for the smaller antenna of Figure 1, which may be correlated, among other signals, with the interference components of S, which are due to inter-system and / or intra-system frequency reuse. It will be understood that, in general, all signals from the cross filter inputs shown in Figure 3 can provide both components of the interference and of the wanted signal.
In some embodiments, the number of antennas on a satellite that may be directed toward another coverage footprint of a satellite's radiotelephone system can be reduced or eliminated. Thus, in some embodiments, the small antenna of the satellite of Figure 1 can be eliminated. In such embodiments, the filter inputs Ii to IN of Figure 3 can be replaced with signals derived from the co-system (intra-system) satellite antenna cell patterns.
Thus, some embodiments of the present invention may utilize an adaptive interference reducer, to reduce, minimize, eliminate intra-system and / or intersystem interference, and improve the desired signal measurement, by supplying a plurality of input signals. of transversal filters, the signals from a given satellite cell (such as the satellite S cell) and the signals from one or more satellite cells (such as the satellite TY cells) that can be reused and / or received one or more frequencies of the desired satellite signal of the given satellite cell (such as the satellite S cell). Thus, in some embodiments, the signals from the satellite SY cells can be used as an adaptive interference reducer, to enhance a measure of the desired signal (such as signal strength) of a desired signal, such as a wanted signal from the satellite S-cell, and to reduce interference from intra-system and / or intersystem co-frequency reuse. Other embodiments of the present invention may add one or more of the following groups of signals as inputs to an adaptive interference reducer, to further reduce interference and improve the measurement of the desired signal:
1) The signals from adjacent and / or non-adjacent cells being reused and / or the reception of one or more frequencies of a wanted satellite signal such as the wanted satellite signal from the satellite S cell;
2) The signals from satellite cells whose geographic service area contains an ATC and / or whose antenna pattern receives signals from an ATC (such as, but not limited to, satellite cells 6, 4, 7 that contain and / or receive signals from ATC B, and / or satellite cells 3, 7, and 5, which contain and / or receive signals from ATC A), which are reusing on earth at least one of the frequencies of the satellite of a desired satellite signal, such as the desired satellite signal from the S-cell of the satellite;
3) The signals from satellite cells that are immediately adjacent to a satellite cell described in 2) above;
4) The satellite cell signals that are remote from the satellite cells described in 2) above;
5) Signals from a complementary antenna on the satellite that are pointing to the satellite coverage footprint of another satellite system that reuses at least one of the frequencies of a wanted satellite signal as the wanted satellite signal from the S cell from the satellite, for example, the input signals Ii IN of Figure 3;
6) Signals from a second satellite in the given satellite radiotelephone system, receiving at least one of the frequencies of the given satellite cell, if the space segment-based network includes multiple satellites, as shown in the figure 3, by means of the dotted box labeled "second satellite input signals"; me
7) The signals of another satellite radiotelephone system that reuses at least one of the frequencies of the satellite S cell that can be provided, for example, by a gateway and / or another component of the other satellite radiotelephone system.
ES 2 292 142 T3
Subcombinations and combinations of these input signals can also be fed to an adaptive interference reducer.
Additional embodiments of the present invention are shown in Figure 4. As indicated in Figure 4, the system 400 includes first and second satellite reception paths 410, 420. The first satellite reception path 410 over a a satellite cell 442 of a coverage area 440 of a satellite radiotelephone communication system (eg, the MSV system of FIG. 1). It will be appreciated that the first pro-satellite reception path 410 may include, for example, a spot beam from a satellite (eg, satellite 100 of FIG. 1), along with other components for carrying the received satellite signals. The first satellite reception path 410 receives a first signal that includes a wanted signal 455 transmitted by a source 450 (eg, a subscriber terminal) and an interference signal transmitted by a second source, which may include, for example , an interference signal 465a transmitted by a source 460a within coverage area 440 (for example, another terminal and / or an ATC), and / or an interference signal 465b transmitted by a source 460b positioned outside the coverage area (eg, in a coverage area 470 of a second satellite communication system).
The signals received by the first and second satellite reception paths 410, 420 are provided to an interference suppression signal processor 430, which processes the received signals to recover the desired signal 455. The signal processor 430 may include, for example, an adaptive interference reducer in the lines described above with reference to Figure 3.
In further embodiments of the present invention, intersystem interference can be suppressed by using a satellite receive path, which is sensitive to elements of an interfering satellite communication system. For example, as shown in Figure 5, interference in a first radiotelephony satellite communication system 510 introduced by an adjacent or overlapping second satellite communication system 520 can be reduced by capturing downlink signals 524 from power supply, which includes a measurement of the interfering signals generated by the users and / or the components of the jamming system 520. In particular, the first satellite radiotelephone communication system 510 includes at least one satellite 511 that supports a satellite reception path that includes a spot beam 514 that serves the satellite cell 513. Spot beam 514 receives a signal that includes a wanted signal 515 transmitted by a terminal in cell 513 and an interfering signal 523 transmitted by a source that is in communication with a satellite 521, an ATC and / or a radio terminal of the second system 520 The satellite 521 of the second system 520 receives a signal 523 that includes a measurement of the jamming signal 523.
As shown in Figure 5, the first system 510 includes a gateway 518 served by a terrestrial gateway antenna 517, which receives a feed downlink signal 516 from the satellite 511. It will be noted that the downlink signal 516 Power includes the signal received by the spot beam 514. Second system 520 similarly includes a gateway 526 that is served by a terrestrial gateway antenna 525, which receives a feed downlink signal 524 from satellite 520. It will be noted that feed downlink signal 524 includes the signal 523 generated in terrestrial form, received by satellite 521, and therefore, a measure of the interference signal 523 '.
Signal 523 received by satellite 521 of the second system 520 is carried from the gateway 526 of the second system 520 to the gateway 518 of the first system 510. The gateway 518 of the first system 510 may include an interference reducer (IR) 519, which it is configured to process the signals received by the first and second satellites 511, 521, to recover the desired signal 515. The recovered signal 515 can be transported to other network components 530, such as telephone network components (exchanges, routers, etc.) and / or ATN components. It will be noted that the IR 519 may receive other signal inputs (not shown in Figure 5), which provide one or more measurements thereof, and / or other interfering signals, for example, the inputs of the signals other than other point beams, satellites, satellite gateways, complementary antennas, and / or other components of the system of the same satellite system or another, and / or ATC / ATN), for example, set out along the lines described above with reference to Figures 1-4.
With reference to Figure 6, in other embodiments of the present invention, for example, in applications where signals generated in conjunction with an interfering system are not directly available from the interfering system, an interfering signal can be obtained by the direct capture of a downlink feed signal transmitted by the jamming system. For example, in addition to the ground antenna 517a that is configured to receive signals 516 from the downlink feed by the satellite 511 of a first system, a ground antenna 517b may be coupled to the gateway 518 of the first system 510, and configured to receiving a measurement of the downlink feed signal 524 from the second jammer system 520. It will be appreciated that the first and second antennas 517a, 517b can be physically independent antennas, and / or spatially diverse antenna beams, supported by a single antenna structure, eg, a beamforming network. It will be appreciated that the ground antenna 517a can be coupled to the first system 510 in any one of several ways. It will further be noted that the IR 519 may be positioned in a component other than the first system 510, and that it may be distributed among the various components of the first system 510.
In embodiments where the adaptive jammer uses signal information received from different satellites, the differences in signal propagation delays between the two satellites can
ES 2 292 142 T3 cause sub-optimal reception along the lines shown in Figure 3. In the exemplary embodiments of the present invention shown in Figure 7, an adaptive interference suppression signal processor (interference reducer) 700 separately includes the stages of combining the signals received by independent satellites to accommodate such sync timing differences. In particular, the signals received at a first satellite, including a wanted signal and one or more interference signals, are filtered by a first set of cross-section filters 710 (or other types), and the resulting filtered signals are combined into a first union 714 of sum. It will be understood that the signals supplied to the cross filters 710 can take many forms. For example, the signals may correspond respectively to the respective satellite spot beam signals, and / or may include signals received by one or more feed elements of the satellite antenna.
As shown in Figure 7, a controller 712 adjusts the cross filter coefficients of the cross filters 710 responsive to an error signal generated by comparing the output of summation junction 714 and the known information present and / or associated with the desired signal (eg, a pilot signal and / or a sync sequence), in a second summation junction 716. It will be appreciated that the known information may be used to provide a time synchronization reference for this branch of the interference suppression signal processor 700, for example by supplying interference suppression signal processor 700, such as time position. of the particular symbols in the desired signal as they are received from the satellite.
Similarly, signals received at a second satellite, including the wanted signal and one or more interfering signals, are filtered by a second set of cross filters 720, and the resulting filtered signals combined at a second summation junction 724. Controller 722 adjusts cross-sectional filters 720 responsive to an error signal generated by comparing the output of summation junction 724 and the information present and / or associated with the desired signal (e.g., a pilot signal and / or a sync sequence) at summation junction 726.
It will be appreciated that the adaptive interference suppression signal processor 700 can be implemented in a number of ways. For example, the interference suppression signal processor 700 portions may be positioned on a satellite and / or on gateways or on satellite-coupled network equipment. It will also be understood that the controllers 712, 722 may use a performance index control law, such as the Least Mean Square Error (LMSE) control law or performance index. Cross-section filters 710, 720 may include, for example, fractional and / or synchronously spaced, feed-through filters, and / or decision feedback filters. Those skilled in the art will recognize that different control laws (other than LMSE), such as for example zero forcing or based on the Kalman type, can be used to form and / or update the cross filter coefficients of the filters. 710 and / or 720, and that the control laws 712 and 722 may be the same or different. Those skilled in the art will also recognize that different control law input signals may be required by different control laws to derive update information for the plurality of cross-sectional filter coefficients. It will also be recognized by those skilled in the art that the number of cross filter coefficients for each cross filter need to be the same across sets of cross filters 710, 720. Some cross filters, for example, may have seven (7) coefficients or taps, while others may have five (5) or only three (3), and some cross-sectional filters may be limited to a single coefficient. In some embodiments, all cross-sectional filters have an identical number of coefficients or taps (greater than or equal to one). Furthermore, in some embodiments, the architecture of each cross filter of the set of cross filters of Figure 7 may not be the same for all of the cross filters in the set. For example, some cross-section filters may be of the independent synchronous type, others of the separate fractional type, and others of the decision feedback type, with synchronized or fractionally separate feed-forward sections.
The signals produced by summation junctions 714, 724 are combined in a maximum ratio combiner (MRC) 730 (or other). The MRC 730 combines the estimated signals sensitive to the comparison of the signal estimates generated by the MRC 730 with the known information from the signal. The MRC 730 can combine the signals to optimize a ratio of the desired signal to noise and / or interference. The general operations of maximum ratio combiners are known to those skilled in the art, and will not be discussed in further detail here.
Exemplary embodiments of the invention have been set forth in the drawings and specifications. Although specific terms have been used, they have been used in a generic and descriptive sense, and not for the purpose of limitation, the scope of the invention being defined by the following claims.
Contents4
7 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7
36 members in 14 offices
Priority claims5
| Document | Office | Kind | Date |
|---|---|---|---|
| 20040890758 | United States of America | – | |
| 89075804 | United States of America | A | |
| 89075804 | United States of America | A | |
| 89075805771252 | – | – | – |
| US20040890758 | – | – | – |
Members36
| Document | Office | Kind | |
|---|---|---|---|
| US2005037749A1 | United States of America | A1 | |
| AU2004306356A1 | Australia | A1 | |
| CA2534079A1 | Canada | A1 | |
| WO2005034361A2 | World Intellectual Property Organization (WIPO) | A2 | |
| US2005136836A1 | United States of America | A1 | |
| WO2005034361A3 | World Intellectual Property Organization (WIPO) | A3 | |
| WO2006019667A1 | World Intellectual Property Organization (WIPO) | A1 | |
| EP1649707A2 | European Patent Office (EPO) | A2 | |
| IL173311D0 | Israel | D0 | |
| BRPI0413040A | Brazil | A | |
| CN1860804A | China | A | |
| KR20060129154A | Republic of Korea | A | |
| JP2007501546A | Japan | A | |
| EP1766810A1 | European Patent Office (EPO) | A1 | |
| CN1989707A | China | A | |
| EP1766810B1 | European Patent Office (EPO) | B1 | |
| AT377299T | Austria | T | |
| ATE377299T1 | Austria | T1 | |
| DK1766810T3 | Denmark | T3 | |
| DE602005003136D1 | Germany | D1 | |
| BRPI0511619A | Brazil | A | |
| ES2292142T3This record | Spain | T3 | |
| US7340213B2 | United States of America | B2 | |
| AU2004306356B2 | Australia | B2 | |
| DE602005003136T2 | Germany | T2 | |
| EP1649707A4 | European Patent Office (EPO) | A4 | |
| CN1860804B | China | B | |
| IL173311A | Israel | A | |
| JP4695593B2 | Japan | B2 | |
| KR101098007B1 | Republic of Korea | B1 | |
| EP1649707B1 | European Patent Office (EPO) | B1 | |
| AT542311T | Austria | T | |
| ATE542311T1 | Austria | T1 | |
| CN1989707B | China | B | |
| CA2534079C | Canada | C | |
| US8670705B2 | United States of America | B2 |
Numbers
- Publication
- 2292142
- Publication, DOCDB
- 2292142
- Publication, EPODOC
- ES2292142T
- Application
- 5771252
- Application, DOCDB
- 05771252
- Application, EPODOC
- ES20050771252T
Titles2
- Spanish
- DISPOSICION Y METODO DE REDUCCION DE INTERFERENCIAS EN CANALES CONJUNTOS EN SISTEMAS DE COMUNICACION POR SATELITE.
- English
- PROVISION AND METHOD OF REDUCTION OF INTERFERENCES IN JOINT CHANNELS IN SATELLITE COMMUNICATION SYSTEMS.
Classification
- CPC, 1
- H04B7/1851
- IPC, 1
- H04B7 185