WO2010093293A1 - Appareil destiné à économiser l'énergie dans une chaîne d'émission - Google Patents

Appareil destiné à économiser l'énergie dans une chaîne d'émission Download PDF

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Publication number
WO2010093293A1
WO2010093293A1 PCT/SE2009/050145 SE2009050145W WO2010093293A1 WO 2010093293 A1 WO2010093293 A1 WO 2010093293A1 SE 2009050145 W SE2009050145 W SE 2009050145W WO 2010093293 A1 WO2010093293 A1 WO 2010093293A1
Authority
WO
WIPO (PCT)
Prior art keywords
controlling node
power
transmitter chain
polarizations
cell
Prior art date
Application number
PCT/SE2009/050145
Other languages
English (en)
Inventor
Bo Göransson
Sven Oscar Petersson
Original Assignee
Telefonaktiebolaget L M Ericsson (Publ)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget L M Ericsson (Publ) filed Critical Telefonaktiebolaget L M Ericsson (Publ)
Priority to PCT/SE2009/050145 priority Critical patent/WO2010093293A1/fr
Publication of WO2010093293A1 publication Critical patent/WO2010093293A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/10—Polarisation diversity; Directional diversity
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0686—Hybrid systems, i.e. switching and simultaneous transmission
    • H04B7/0691—Hybrid systems, i.e. switching and simultaneous transmission using subgroups of transmit antennas
    • H04B7/0693—Hybrid systems, i.e. switching and simultaneous transmission using subgroups of transmit antennas switching off a diversity branch, e.g. to save power
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0261—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level
    • H04W52/0274—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level by switching on or off the equipment or parts thereof
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0682—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission using phase diversity (e.g. phase sweeping)
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0686—Hybrid systems, i.e. switching and simultaneous transmission
    • H04B7/0689—Hybrid systems, i.e. switching and simultaneous transmission using different transmission schemes, at least one of them being a diversity transmission scheme
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present invention discloses a transmitter chain for a controlling node of a cell in a cellular communications system.
  • the controlling node of a cell has differing roles in different kinds of cellular systems, but a basic role is to control the traffic to and from users in the cell.
  • NodeB the controlling node of a cell
  • RBS Radio Base Station
  • eNodeB the controlling node of a cell
  • PA power amplifier
  • the solution should be applicable to controlling nodes of a number of different cellular systems, such as the RBS of GSM systems, the NodeB of WCDMA systems and the eNodeB of LTE systems.
  • the solution could reduce the power consumed by the power amplifiers in the controlling node.
  • Such a solution is offered by the present invention in that it discloses a transmitter chain for a controlling node of a cell in a cellular communications system.
  • the transmitter chain of the invention comprises an antenna with at least a first and a second radiation element of a first and a second polarization, respectively.
  • the transmitter chain of the invention also comprises at least a first and a second power amplifier, and additionally comprises a splitter for splitting an incoming signal to the first and the second power amplifier.
  • the first power amplifier is connected to the antenna's radiation element of the first polarization
  • the second power amplifier is connected to the antenna's radiation element of the second polarization
  • the power amplifiers are connected to radiation elements of different polarizations, the combined transmitted signal from the antenna will be perceived by users in the cell as one signal, albeit with a composite polarization, as compared to the polarizations of the individual radiation elements of the antenna.
  • the first and second polarizations are orthogonal to each other.
  • the first and second polarizations are vertical and horizontal polarizations.
  • the first and second polarizations are right and left circular polarizations.
  • the invention also discloses a controlling node for a cell in a cellular communications system, which comprises a transmitter chain of the invention.
  • Fig 1 shows an overview of a system in which the invention is applied
  • Figs 2a and 2b show block diagrams of embodiments of the transmitter chains of the invention
  • Figs 3 and 4 show controlling nodes of the invention
  • Fig 5 shows a closer view of a part of a transmitter chain of the invention
  • Fig 6 shows a further embodiment of a transmitter chain of the invention.
  • Fig 1 shows an example of a cellular communications system 100 in which the invention may be applied.
  • the system 100 will be described using terminology borrowed from a system of the WCDMA kind, Wideband Code Division Multiple Access, but it should be pointed out that this is in order to clarify the invention and should not be used to restrict the scope of protection sought for or granted to the present invention, which is suitably for use in a variety of cellular systems besides WCDMA systems, such as, for example, GSM systems, LTE systems and TD SCDMA systems.
  • WCDMA Wideband Code Division Multiple Access
  • the system 100 comprises a number of cells, one of which, 105, is shown in fig 1 by way of example. Each cell can accommodate a number of user terminals, one of which, UE 115, is shown by way of example. (UE, User Equipment) The number of UEs in a cell can of course vary, as can the number of cells in a system.
  • NodeB For each cell in the system 100, there is a controlling node, in a WCDMA system referred to as the NodeB, shown in fig 1 as 110.
  • One of the roles of the NodeB 110 is to control the traffic to and from the UEs in the cell 105.
  • a corresponding function is performed in GSM systems by a controlling node referred to as RBS, Radio Base Station, and in LTE systems the corresponding node is referred to as the eNodeB.
  • the present invention is applicable to all of these systems, as well as to the controlling nodes of cells in the TD SCDMA system.
  • the NodeB consumes a great deal of energy, which leads to the energy consumption of the NodeB being a major OPEX (Operational Expenditure) for an operator of a cellular system such as the one 100 of fig 1.
  • OPEX Operaational Expenditure
  • a particularly energy-consuming component of the NodeB is the so called PA, the Power Amplifier, of which a NodeB may have one or more.
  • a first embodiment 200 of the invention is shown in fig 2a: the embodiment 200 comprises a splitter 210, two PA:s 215, 220, and an antenna 225 with at least a first 230 and a second 235 radiation element, 235, 230.
  • the splitter 210 an incoming signal to an input 215 to the transmitter chain 200 is split between the two PAs 215, 220.
  • the two signals which are output from the splitter, one to each of the PAs 215, 220, may have the same phase, or the splitter may comprise a component which introduces a phase difference between the two output signals. This will be described in more detail below, in connection with the description of fig 2b.
  • the radiation elements 230 and 235 are of differing polarizations, and can as shown in fig 2a, in one embodiment be of horizontal, 230, and vertical, 235, polarization respectively.
  • the polarizations of the first 230 and second 235 radiation elements are suitably, although not necessarily, orthogonal with respect to each other, as shown in fig 2a.
  • the radiation elements with horizontal and vertical polarizations can be rotated together whilst maintaining the orthogonality between the radiation elements.
  • the transmitter chain 200 also comprises connectors, e.g. wave guides and cables, between the components enumerated above, although such connectors are not explicitly described here.
  • each of the PAs 215, 220 is connected to one of the radiation elements 230, 235, so that each polarization in the antenna 225 has "its" PA.
  • the antenna 200 will suitably comprise a feeder network in order to connect, for example, the
  • PA 215 to the radiation elements of vertical polarization
  • PA 220 to the radiation elements of the horizontal polarization
  • the antenna 200 can comprise virtually any number of pairs of radiation elements such as the pair 230, 235.
  • the pairs of radiation elements with different polarizations do not need to be co-located as shown in fig 2a, the radiation elements can also be placed so that they do not intersect each other.
  • each polarization has "its" PA, it is perfectly within the scope of the present invention to equip the antenna 200 with an odd number of radiation elements, so that, for example, the PA 215 is connected to two radiation elements of one and the same polarization, and the PA 220 is connected to three radiation elements of the other polarization. In such a case, if the radiation elements are arranged in pairs, there would also be a "lone" radiation element of one of the polarizations.
  • a user 115 in the cell 105 will perceive the combined signals from the antenna 200 as having one composite polarization.
  • the power which is used for the transmissions via one of the PAs is reduced or entirely shut off, users in the cell will merely perceive a signal with a new polarization, although the received signal will be weaker.
  • a NodeB which is equipped with one or more transmitter chain 200 will be arranged to vary, or entirely shut off, the power through one or both of the PAs depending on various predetermined parameters, which will be exemplified below.
  • the power through a PA is shut off or reduced when such a predetermined parameter reaches a predetermined threshold.
  • the controlling node is also suitably arranged to increase or turn on the power of the signal or signals which is/are transmitted by means of such a PA, which is suitably done as a function of one or more predetermined parameters in the cell reaching a predetermined threshold.
  • these parameters are the same as those used to decrease or turn off the power through the PA.
  • the exact mechanism for varying (reducing or increasing) or shutting off/turning on the power through a PA may vary between different kinds of PAs, but is suitably done by means of varying a control voltage to the PA in question.
  • Examples of predetermined parameters which are used by a NodeB which is equipped with the present invention to vary (increase/decrease) or shut off or turn back on the power through a PA include the load in the cell, the time of day or the load in the surrounding cells, since a high load in the surrounding cells may imply that the own cell needs to have a high degree of readiness for hand-over from those cells.
  • the coverage of the NodeB 110 in the cell 105 may, in one embodiment of the NodeB, be maintained by increasing the output power of one or more of the following: the so called pilot signal or a reference symbol signal, or one or more broadcast channels which carry, for example, system information, so that the UEs in the cell 105 will still be able to detect those signals at a more or less constant level.
  • Fig 2b shows a variation 200' of a transmitter chain of the invention: as mentioned previously, the splitter 210 may output signals with a phase difference ⁇ between them, caused by, for example, a phase shifter 211 which is internal or external to the splitter 210.
  • the phase difference ⁇ may be more or less any phase difference, although examples of suitable phase differences are 90 degrees and 180 degrees.
  • the splitter may perform its function on RF level.
  • the splitter may perform its function on baseband (BB) level, in which case a phase shifter is not necessary; instead, the BB signal is multiplied by a complex number.
  • BB baseband
  • Introducing a phase shifting between the signals to the radiation elements of different polarization may be done for a number of reasons. For example, if it is desired to create a certain combined or resulting polarization of the signal which is received by the user terminals in the cell.
  • the radiation elements 230', 235', of different polarizations need not be co-located as in the example shown in fig 2a; instead, they can,.
  • the radiation elements of different polarizations shown as 230', 235', in fig 2b, can be located apart from each other.
  • the controlling node itself following measurements of the relevant parameters by functions for this in the controlling node, or, as an alternative or a complement, the controlling node may be equipped with an interface towards a "higher node" in the system, i.e. a RNC, Radio Network Controller, a BSC, Base Station Controller, a centre for O&M, Operations and Maintenance, etc, depending on the exact nature and kind of system, i.e. GSM, WCDMA, LTE, TD SCDMA etc.
  • a "higher node” in the system i.e. a RNC, Radio Network Controller, a BSC, Base Station Controller, a centre for O&M, Operations and Maintenance, etc, depending on the exact nature and kind of system, i.e. GSM, WCDMA, LTE, TD SCDMA etc.
  • the controlling node could, for example, receive instructions regarding how much total output power that should be transmitted by the controlling node.
  • the controlling node would then be equipped with a function for determining how this power level could be achieved best, i.e. by one or more PAs at suitable power levels,
  • a controlling node comprises first 200 and a second 200' transmitting chain of any of the embodiments described above, and the controlling node 300 is arranged to use the two transmitter chains for the transmission of one data stream each.
  • the transmitter chain 200 is used to transmit a first data stream shown as "Data 1”
  • the transmitter chain 200' is used to transmit a second data stream shown as "Data 2”.
  • the embodiment 300 i.e. two or more transmitter chains in one and the same controlling node is useful in, for example, a system which uses MIMO technology, Multiple Input, Multiple Output, since one MIMO data stream can be transmitted via each transmitter chain.
  • An embodiment with two or more transmitter chains is also suitable for use in a system in which there is transmit diversity, Tx diversity. In both of these cases, i.e. MIMO and Tx diversity, if separate antennas are used for each of the transmitter chains, the antennas should be separated from each other by a distance of a few wavelengths, in the range of at least 2-10 wavelengths.
  • phase shifters to introduce phase differences between the signals to the radiation elements of different polarizations, since the signals which are transmitted from the different transmitter chains in a MIMO system should be orthogonally polarized with respect to each other.
  • the signals which are fed to the radiation elements of different polarizations in one of the transmitter chains can be of the same phase. If this phase is referred to as "zero phase shift", the signals to the radiation elements in the other transmitter chains can have a phase difference of 180 degrees between them, with one of the signals having the same phase as the "zero phase shift”. This will result in two orthogonally polarized signals, one from each transmitter chain.
  • FIG. 4 symbolically shows a controlling node 400 which comprises one transmitter chain 200 of the invention.
  • a controlling node as well as the controlling node 300 of fig 3, can be an RBS of a GSM system, a NodeB of a WCDMA system, or an eNodeB of an LTE system or of a TD SCDMA system.
  • Fig 5 shows the antenna 225 and the PAs of figs 2a and 2b in more detail.
  • each PA 215, 220 is connected to the radiation elements (only one of each has been numbered) 230, 235, of "its" polarization by means of one distribution network each, which comprises branches 515, 520, 525 and 515', 520', 525', respectively.
  • An alternative embodiment 600 of the invention is shown in fig 6: in the embodiment 600, only one antenna 625 is used, with a number of radiation elements of a first and a second polarization.
  • There are two streams of data, Data 1 and Data 2 which should be transmitted by the transmitter chain 600.
  • there are two splitters, 611 , 613 comprised in the transmitter chain 600, with one splitter being used for each of the data streams Data 1 and Data 2, and there are also two power amplifiers, 615, 620.
  • One of the power amplifiers 615 is connected to the radiation elements of the first polarization, "Pol. 1 ", and the other power amplifier 620 is connected to the radiation elements of the second polarization, "Pol. 2".
  • the splitter 610 also comprises a phase shifter 611 which introduces a phase shift ⁇ into the data stream of Data 1 which is to be transmitted from one of the polarizations, in this case "Pol. 1", while the data stream of "data 1" to “Pol. 2” is not subjected to a phase shifter.
  • the splitter 613 i.e. the one used for the other data stream, "Data 2”. does not comprise a phase shifter, but splits "Data 2" into two streams, one to each polarization, i.e. one to each PA 615, 620. In this manner, from one of the polarizations, "Pol. 1 ", there will be transmitted Data 1 phase shifted and Data 2 with no phase shift, while from the other polarization, "Pol. 2", there will be transmitted Data 1 and Data 2 with no phase shift in either data stream.
  • phase shift ⁇ is 180degrees
  • the resulting polarizations perceived by a receiver will be +45 degrees for Data 1 and -45 degrees for Data 2, so that the two data streams are orthogonally polarized with respect to each other, which is a prerequisite for MIMO applications.
  • phase shifts may also be introduced which will produce the same result, i.e. that a receiver will perceive two resulting polarizations which are orthogonal with respect to each other.
  • the embodiment 600 may be comprised in any of the controlling nodes for a cell shown and described in this text.

Abstract

L'invention porte sur une chaîne d'émission (200, 200') pour un nœud de commande (110) d'une cellule (105) dans un système de communications cellulaires (100), qui comprend une antenne (225) comprenant un premier (230) et un second (235) éléments rayonnants d'une première et d'une seconde polarisation, respectivement. La chaîne d'émission (200, 200') comprend également un premier (215) et un second (220) amplificateur de puissance, et comprend de plus un séparateur (210) pour séparer un signal entrant vers les premier (215) et second (220) amplificateurs de puissance. Le premier amplificateur de puissance (215) est connecté à l'élément rayonnant (230) de la première polarisation, et le second amplificateur de puissance (220) est connecté à l'élément rayonnant (235) de la seconde polarisation. De façon appropriée, les première et seconde polarisations sont perpendiculaires l'une à l'autre, et sont des polarisations verticale et horizontale, ou des polarisations circulaires, droite et gauche.
PCT/SE2009/050145 2009-02-11 2009-02-11 Appareil destiné à économiser l'énergie dans une chaîne d'émission WO2010093293A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/SE2009/050145 WO2010093293A1 (fr) 2009-02-11 2009-02-11 Appareil destiné à économiser l'énergie dans une chaîne d'émission

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/SE2009/050145 WO2010093293A1 (fr) 2009-02-11 2009-02-11 Appareil destiné à économiser l'énergie dans une chaîne d'émission

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018210425A1 (fr) * 2017-05-18 2018-11-22 Telefonaktiebolaget Lm Ericsson (Publ) Transmission de signal de référence de sondage écoénergétique

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002007464A1 (fr) * 2000-07-18 2002-01-24 Telefonaktiebolaget Lm Ericsson (Publ) Gestion de puissance adaptative d'un noeud d'un reseau cellulaire de telecommunications
WO2003090378A1 (fr) * 2002-04-18 2003-10-30 Motorola, Inc. Systeme amplificateur de puissance lineaire redondant

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002007464A1 (fr) * 2000-07-18 2002-01-24 Telefonaktiebolaget Lm Ericsson (Publ) Gestion de puissance adaptative d'un noeud d'un reseau cellulaire de telecommunications
WO2003090378A1 (fr) * 2002-04-18 2003-10-30 Motorola, Inc. Systeme amplificateur de puissance lineaire redondant

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018210425A1 (fr) * 2017-05-18 2018-11-22 Telefonaktiebolaget Lm Ericsson (Publ) Transmission de signal de référence de sondage écoénergétique
US10375647B2 (en) 2017-05-18 2019-08-06 Telefonaktiebolaget Lm Ericsson (Publ) Energy-efficient sounding reference signal transmission

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