EP1224748A2 - Augmentation d'une station de base cellulaire - Google Patents

Augmentation d'une station de base cellulaire

Info

Publication number
EP1224748A2
EP1224748A2 EP00973160A EP00973160A EP1224748A2 EP 1224748 A2 EP1224748 A2 EP 1224748A2 EP 00973160 A EP00973160 A EP 00973160A EP 00973160 A EP00973160 A EP 00973160A EP 1224748 A2 EP1224748 A2 EP 1224748A2
Authority
EP
European Patent Office
Prior art keywords
base station
array
diversity
anterma
antenna array
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
EP00973160A
Other languages
German (de)
English (en)
Inventor
Joseph Shapira
Paul Lemson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Celletra Ltd
Original Assignee
Celletra Ltd
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 Celletra Ltd filed Critical Celletra Ltd
Publication of EP1224748A2 publication Critical patent/EP1224748A2/fr
Withdrawn legal-status Critical Current

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
    • H04B7/04—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
    • H04B7/0678—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 different spreading codes between antennas
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
    • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
    • H01Q1/246—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for base stations
    • 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
    • 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
    • H04B7/0667—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 of delayed versions of same signal
    • H04B7/0671—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 of delayed versions of same signal using different delays between antennas
    • 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
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/24—Cell structures

Definitions

  • the present invention in certain respects, relates to wireless communication systems.
  • Other aspects of the invention relate to systems and methods for augmenting existing cellular base station systems and for implementing cellular base station systems.
  • PCS personal communication systems
  • Existing and operational base stations for cellular and personal communication systems (PCS) typically comprise antenna arrangements located at the top of a mast or building. Some of these antenna arrangements utilize diversity antennas arrangements to enhance the performance of the base station by, e.g., combating the deleterious effects of multi-path propagation, such as multi-path fading and dispersion.
  • the types of diversity employed may include, e.g., one or a combination of space diversity, phase diversity, frequency diversity, polarization diversity, and time diversity.
  • Some of those existing/operational antenna arrangements may include a first (main) antenna array of co- located antenna elements and a second (diversity) antenna array (or individual antenna element) located at a distance from the first antenna array.
  • the main antenna array may include antenna elements serving as both transmit and receive antennas.
  • the diversity antenna array may include only receive antenna elements. Either or both the main antenna array and the diversity antenna array may be passive in that the antenna elements are not coupled to proximate amplifiers also provided at the top of the mast/building. Thus, there is a need to augment existing base station antenna setups such as these.
  • LNA low noise amplifiers
  • the transmit elements may be rendered active by installing linearized power amplifiers (LPA) positioned also at the top a building. This will provide certain advantages, including reducing cabling and power consumption costs associated with carrying signals up and down the mast or building.
  • These base station antenna setups may also need augmentation or modification to facilitate a change in cellular technologies, e.g., adding code division multiple access (CDMA) capabilities to a base station using the Advance Mobile Phone Service (AMPS) or Global System for Mobile (GSM) standard or changing the base station altogether for use in a new scheme, e.g., CDMA.
  • CDMA code division multiple access
  • AMPS Advance Mobile Phone Service
  • GSM Global System for Mobile
  • antenna functionality e.g., to accommodate new cellular technologies and/or to enhance performance over the forward and reverse links
  • antenna arrays may take up additional space, or be considered as additional antenna arrangements (which may be a violation of local laws, regulations or ordinances).
  • the present invention is provided to improve upon wireless communications systems.
  • the present invention is provided to facilitate the augmentation of cellular base station systems, e.g., improving the transmit and/or receive performance of a given base station (and its associated cell or sector) and/or providing new cellular technology (e.g.,
  • CDMA Code Division Multiple Access
  • An embodiment is directed to a system and method or one or more components thereof.
  • an existing and operational base station serving a given cell or sector
  • the passive diversity antenna array is replaced with an active radiator unit, including an array of both receive and transmit antenna elements.
  • the transmit and receive antenna elements are connected (at a masthead, or at the top of a building) to amplifiers and bandpass filters.
  • the receive antenna elements of the active radiator unit may comprise sets of receive antenna elements having diverse polarizations, in which case the resulting modified antenna arrangement will have dual diversity for forward link communications - space diversity (due to the spacing between the main antenna array and the new active radiator unit) and polarization diversity (due to the polarization diversity among members of the sets of receive antenna elements within the active radiator unit).
  • space diversity involves physically separating the antennas by a defined physical separation, which can be either horizontal or vertical.
  • Polarization diversity involves utilizing two different antenna elements that are polarized in different (e.g., orthogonal) planes.
  • the existing and operational antenna arrangement may be adaptable for a CDMA cellular system, having no diversity on the forward link (base station to mobile) along with space diversity on the reverse link (mobile to base station).
  • the diversity antenna array which may comprise only receive antenna elements
  • a new active antenna element array comprising transmit as well as receive antenna elements
  • the resulting antenna assembly will have transmit diversity on the forward link due to space diversity.
  • EIRP effective isotropic radiated power
  • augmentation can preserve existing infrastructure while increasing the performance and/or the functionality of the base station.
  • existing and operational base stations may already be configured to operate within the AMPS or GSM standard.
  • a space diversity antenna array of such a base station may be replaced to provide an antenna arrangement that can accommodate a new cellular communications scheme (e.g., CDMA) in addition to the existing scheme (e.g., AMPS or GSM) or instead of the existing scheme.
  • CDMA new cellular communications scheme
  • the active diversity array can serve as the transmit and receive elements serving the new scheme, while the main array continues to serve the old scheme.
  • Fig. 1 shows one illustrative augmentation method where an existing space diversity antenna arrangement of a base station having no transmit diversity is converted to a new antenna arrangement having receive (Rx) space diversity antenna elements and transmit (Tx) space diversity antenna elements for use, e.g., in CDMA applications;
  • Fig. 2 shows an illustrative augmentation method where an existing antenna arrangement having Rx polarization diversity but no transmit diversity is converted to a new antenna arrangement having polarization diversity, Rx space diversity elements and Tx and Rx time diversity elements, for use, e.g., in CDMA applications;
  • Fig. 3 shows an illustrative augmentation method where an existing antenna arrangement having Rx polarization diversity configuration and no Tx diversity is converted to a new antenna arrangement having Tx and Rx space diversity, Tx and Rx time diversity, and Rx polarization diversity for use, e.g., in CDMA applications;
  • Fig. 4 shows an illustrative augmentation method where an existing antenna arrangement having Rx polarization diversity configuration, which uses a subset of its elements for both Tx and Rx, without transmit diversity, is converted to a new antenna arrangement having Tx and Rx space diversity, Tx and Rx time diversity, and Rx polarization in two separated antenna arrays;
  • Fig. 5 shows an illustrative augmentation method where an existing antenna arrangement having Rx space diversity configuration is converted to a new antenna arrangement having Tx and Rx space diversity, Tx and Rx time diversity and Rx polarization diversity;
  • Fig. 6 shows an exemplary embodiment of an active radiator unit incorporated into the embodiments of Figs. 4 and 5; and Fig. 7 is a block diagram of an embodiment of the transmit chain according to the present invention.
  • Existing base station antenna arrangements may utilize receive diversity antenna arrays, e.g., to combat the adverse effects of multi-path propagation, and many such antenna arrangements may comprise passive antenna elements that would benefit from being rendered active, e.g., to improve performance and/or to accommodate new standards. Such arrangements would also benefit from enhanced/additional types of diversity, which also can help to improve performance and accommodate new standards.
  • An existing base station antenna arrangement may be augmented by adding a new antenna array and/or replacing an existing antenna array with a new anterma array.
  • Figs. 1-6 illustrate various embodiments of such augmentations of existing base station antenna arrangements lOOa-e with a new antenna array 30a-e.
  • the new antenna array 30a-e may comprise an active antenna array, which includes an active radiator unit 5 a or 5b having both receive and transmit antenna elements.
  • the circled portion 5a shown in Fig. 1 depicts an exemplary structure of the active radiator unit 5 a that may be utilized in the active antenna arrays 30a-c of Figs. 1-3.
  • Fig. 6 depicts an exemplary structure of the active radiator units 5b that may be employed in the active antenna arrays 30d-e of Figs. 4 and 5.
  • Fig. 1 illustrates an augmentation method that modifies an existing base station antenna arrangement 100a, which comprises a main antenna array 10a and a secondary antenna array 12a, by replacing the secondary antenna array 12a with a new antenna array 30a, which may be active or passive.
  • augmentation of the base station in Fig. 1 converts an existing space diversity antenna arrangement of a base station, having no transmit diversity, to an augmented anterma array 200a having receive space diversity antenna elements and transmit time diversity.
  • the existing base station antenna arrangement 100a includes a main antenna array 10a, having a plurality of antenna elements each of which serves as a common single antenna element 36a that permits transmission and reception over the same antenna element.
  • a single cable 20 extends from the main antenna array 10a, which is located at the top of a building 33, and connects to a diplexer 15a, which is located below the top of the mast/building 23.
  • the diplexer 15a serves as a coupler that allows the simultaneous transmission and reception of two signals using the common single antenna elements 36a of the main anterma array 10a.
  • the base station transceiver subsystem (not shown) sends a transmit signal via transmission cable Txl through a power amplifier 85 to an input terminal of the diplexer 15a.
  • the diplexer 15a then sends the transmit signal over a cable 20 to the main anterma array 10a where the transmit signal is radiated to the mobile unit (not shown).
  • the receive signal arrives at the common single anterma elements 36a, which then sends the receive signal to the diplexer 15a via cable 20.
  • the diplexer 15a transmits the receive signal to the base station transceiver subsystem (not shown) by directing the signal over the receive line Rxl and through a LNA.
  • the secondary anterma array 12a includes a space diversity anterma array, having only receive elements 37a.
  • the scope of the embodiment of Fig. 1 is not limited to this exemplary arrangement.
  • Other types of secondary antenna array arrangements may be employed alone or in combination, such as a Tx only diversity antenna array, a Rx only diversity antenna array or a Tx-Rx diversity antenna array.
  • a single cable 22 extends from the secondary antenna array 12a, which is located at the top of a building 33, to a LNA 17, which is located below the top of the mast/building 23.
  • the single cable 22a further extends from the LNA 17 in the direction of reception cable Rx2 to the receive input terminal of the base station transceiver subsystem (not shown).
  • the secondary antenna array 12a may be passive in that the antenna elements are not coupled to proximate amplifiers provided at the top of the mast/building.
  • both the main antenna array 10a and the secondary anterma array 12a are passive.
  • either or both the main anterma array 10a and the secondary anterma array 12a may be passive.
  • Fig. 1 in order to convert the existing base station antenna arrangement 100a to an augmented anterma array 200a, several modifications are made to the secondary antenna array 12a and to the section of the main anterma array 10a located below the top of the mast/building 23. Modifications to the secondary active anterma array 12a include replacing the secondary antenna array 12a with a new antenna array 30a, which may be either active or passive.
  • the newly added antenna array 30a comprises an active anterma array, which includes an active radiator unit 5a having both receive 55 and transmit 50 antenna elements, (as disclosed in U.S. application No. 09/357,845).
  • the transmit 50 and receive 55 antenna elements connect at the masthead or at the top of the building to amplifiers 60, 70 by way of bandpass filters 65.
  • the transmit anterma elements 50 connects to a LPA and a bandpass filter 65
  • the receive antenna element 55 connects to a LNA 70 and a bandpass filter 65.
  • Fig. 1 illustrates the new antenna array as having four active radiator units 5, this embodiment is not the limited to the exemplary configuration as shown.
  • the augmentation method also modifies the lower portion of the main antenna array 10a.
  • a modification which occurs at the lower portion of the main anterma array 10a, relocates the diplexer 15a from its original position, below the top of the mast/building 23 to a relocated position at the top of the building 33.
  • the directional coupler 40 serves as a directive feed that couples the main anterma 10a and new antenna array 30a.
  • the base station transceiver subsystem (not shown) transmits a signal via the transmission cable Txl to the transmit elements of the common single anterma element 36a of the main antenna array 10a
  • the directional coupler 40 obtains a sample of the transmit signal before the main anterma array 10a radiates the signal along the forward link to a mobile unit (not shown).
  • the directional coupler 40 then sends the sample of the transit signal to a delay unit 35 by way of cable Tx2.
  • the delay unit 35 facilitates transmit time diversity within the augmented antenna array 200a by sending, at least one or more time-delayed copies of the sample of the signal to the transmit elements 50 of the new antenna array 30a, at connection point Tx in, for broadcasting the copy signal to mobile units.
  • any passive element of the main antenna array 10a may also be rendered active by connecting the output terminal of the relocated diplexer 15b to a new antenna array 30a, which is active.
  • the connection between the output terminal of the diplexer 15a and the base station also changes during the augmentation process.
  • the receive signal now travels from the relocated diplexer 15b to the receive elements 55 of the new antenna array 30 via reception cable Rxl and enters the new anterma array 30a at connection point Rx in.
  • all signals received at the new antenna array 30 exit the new anterma array 30 and travel to the base station transceiver subsystem (not shown) via reception cables Rxl and Rx2.
  • Augmentation of the existing base station antenna arrangement 100a provides several benefits to the augmented anterma array 200a of Fig. 1.
  • the augmentation may be implemented within the same dimensions as the existing base station antenna arrangement 100a.
  • the space required to implement the augmentations encompasses approximately the same amount of space as the existing base station anterma arrangement 100a.
  • implementation of the augmented antenna array does not require any additional space. This is an important benefit because it adds anterma functionality within an existing base station without adding antenna arrays that may take up additional space or be considered as additional antenna arrangements, which may be a violation of local laws, regulations or ordinances.
  • the configuration includes at least two types of diversity — space diversity and transmit time diversity.
  • the spacing between the main antenna 10a and the new anterma array 30a creates space diversity.
  • the directional coupler 40 and delay unit 35 helps to facilitate time transmit diversity, as discussed above.
  • a further benefit derived from the augmentation of the base station includes cost reductions, which inherently flow from rendering the passive receive diversity antenna array 12a and any passive elements of the main antenna array 10a of the existing base station antenna arrangement 100a to be active anterma arrays This is achieved by installing amplifiers 60, 70 and bandpass filters 65 at the top of the mast of the building, rather than only at the bottom of the mast or the building. By rendering the passive antenna array to be active, this augmentation decreases the power consumption cost and cabling cost.
  • Fig. 2 illustrates an augmentation method that converts an existing antenna arrangement 100b, having receive polarization diversity but no transmit diversity, to an augmented antenna array 200b, having polarization diversity, Rx space diversity elements and Tx and Rx time diversity elements in two separate anterma arrays.
  • the augmentation of Fig. 2 involves adding a new antenna array 30b, which may be active or passive, to the existing base station antenna arrangement 100b, having receive polarization diversity.
  • the existing base station antenna arrangement 100b of Fig. 2 comprises a transmission cable Txl, a power amplifier 85, diplexer 15a, LNA 14, and reception cable Rxl. These components are generally connected in the same fashion as the components of Fig. 1, and, they may be implemented in the same fashion as the components of Fig. 1. Thus, a specific discussion of these components will not be provided herein.
  • the main anterma array 10b of Fig. 2 comprises a dual diversity antenna array including a receive space diversity antenna array and a polarization diversity antenna array.
  • the polarization diversity anterma array contains a plurality of antenna elements each of which includes a common single anterma element 36b and a receive element 37b.
  • the scope of Fig. 2 is not limited only to the types of diversity shown in the exemplary embodiment. Other combinations of multiple diversity schemes may be utilized, for example, time diversity, frequency diversity and/or phase diversity.
  • the third difference of the existing base station anterma arrangement is the addition of a reception cable Rx2 extending from the main antenna array 10b and traveling through a LNA 85 to the base station transceiver subsystem (not shown).
  • Augmentation of the existing base station antenna arrangement 100b of Fig. 2 which includes a Rx polarization diversity anterma array but no transmit diversity, provides an augmented anterma array 200b, having Rx polarization diversity, Rx space diversity elements and Tx and Rx time diversity elements.
  • Rx polarization diversity anterma array but no transmit diversity
  • Augmentation of the existing base station antenna arrangement 100b of Fig. 2 which includes a Rx polarization diversity anterma array but no transmit diversity, provides an augmented anterma array 200b, having Rx polarization diversity, Rx space diversity elements and Tx and Rx time diversity elements.
  • modifications e.g., relocating the diplexer 15b at the top of the mast/building within the anterma arrangement and adding a directional coupler 40 and a delay unit 35 to the antenna arrangement, connect in the same fashion as shown in the circled portion 300 of Fig. 1.
  • the operation of these components may be implemented in the same fashion as the components of Fig. 1.
  • the passive elements of Fig. 2, like Fig. 1, may also be rendered active.
  • the existing base station anterma arrangement 100b does not include a secondary anterma array 12a
  • one notable difference between the modifications of Figs. 1 and 2 is that instead of replacing an existing antenna array with a new anterma array, the modification of Fig. 2 involves the addition of a new anterma array 30b.
  • the configuration of the new antenna array 30b which may comprise a passive antenna array or an active antenna array 5 a, remains substantially the same as the embodiment of Fig. 1.
  • Another modification of the augmented antenna array 200b of Fig. 2 includes changing the path that the receive signals travel to arrive at the base station transceiver subsystem (not shown).
  • This augmentation to the travel path facilitates the addition of various diversity schemes within the augmented anterma array 200b.
  • the augmentation method provides within the travel path of received signals a combiner 44 and a delay unit 42 downstream of the main antenna array 10b and the new antenna array 30b.
  • the receive elements of the main antenna array 10b and the receive elements of the new anterma array 30b intercept the receive signals and send the receive signals to the base along the respective reception path of the main antenna array 10b and the new anterma array 30b.
  • the travel path of the cable extending from the main anterma array 10b feeds directly into the new anterma array 30b by way of reception cable Rx In(l).
  • Receive signals may also travel through the relocated diplexer 15(b) along the reception path Rx In(2) to the new antenna array 30d.
  • the signals may exit through several different routes, e.g., Rx Out (1), (2) and (3).
  • the delay unit 42 within the travel path of Rx Out(l) and (2), collects the received signals to perform a diversity analysis on the characteristics of the receive signals.
  • the combiner 44 located within the reception cable Rxl, combines the receive signals transmitted over the reception cables Rx Out (1) and (2) to the base station transceiver subsystem (not shown).
  • the receive signals may travel from the new antenna array 30b to the base station transceiver subsystem (not shown) via reception cable Rx2.
  • the addition of the directional coupler 40 and the delay unit 35 provides Tx time diversity, as discussed with respect to Fig. 1.
  • the augmented antenna array 200b is capable of providing Tx and Rx time diversity on the main antenna array 10b.
  • the spacing between the main antenna 10b and the new antenna array 30b creates space diversity, and the polarization diversity among the members of the set of elements within the main anterma array 10b facilitates polarization diversity.
  • augmenting Fig. 2 also enhances the antenna arrangement by providing multiple types of diversity to an existing base station anterma arrangement 100b. Augmentation of Fig. 2 further reduces the cost of operation by rendering a passive antenna array to be an active anterma array.
  • the main anterma array 10c of Fig. 3 provides separate transmit and receive elements 71, 72, and 73 for the respective transmit and receive signals. Furthermore, since Fig. 3 does not contain a diplexer, as shown in Fig. 1, a transmit signal flowing from the base station transceiver subsystem (not shown) to the transmit element of the main anterma array 10c passes through power amplifier 85 as the signal travels along transmission cable Txl .
  • the receive signals travel from the receive elements of the main anterma array 10c pass through a LNA 14, and flow to the base station transceiver subsystem (not shown), by way of reception cable Rxl.
  • a second reception cable Rx2 extend from the main antenna array 10c so that the receive signals travel through a LNA 17 and continue to the base station.
  • the existing base station anterma arrangement 100c of Fig. 3, like Fig. 2, does not include a secondary antenna array, as shown in Fig.1.
  • the augmentation method of Fig. 3 modifies an existing antenna arrangement having Rx polarization diversity configuration and no Tx diversity by adding a new anterma array 30c, having Tx and Rx space diversity, Tx and Rx time diversity, and Rx polarization diversity.
  • the augmentation of Fig. 3 is implemented in a manner similar to the modifications of Fig. 2.
  • the modifications of adding the new anterma array 30c and the travel path over the reception cables Rx Out (1), (2) and (3) connect in the same manner and operate in the same manner as the components of Fig. 2. Therefore, these modifications will not be specifically discussed, in the interest of brevity.
  • the augmentation method of Fig. 3 provides a transmission cable Tx2 and reception cables Rx In (1) and (2), respectively, extending from the main antenna array 10c to the base station transceiver subsystem (not shown), to accommodate the separate Tx and Rx elements of the main antenna array 10c.
  • the transmission cable Tx2 extends from the main anterma array 10c through the directional coupler 40 and the delay unit 35 to the new antenna array 30c.
  • the reception transmission cables Rx In (1) and (2) extend directly, from the main antenna array 10c, to the new antenna array 30c.
  • a directional coupler 40 serves as a directive feed that couples the main anterma 10c and new antenna array 30c.
  • the base station transceiver subsystem (not shown) transmits a signal via the transmission cable Txl to the transmit elements of the main anterma array 10c
  • the directional coupler obtains a sample of the transmit signal before the main antenna array 10c radiates the signal along the forward link to a mobile unit (not shown).
  • the directional coupler 40 then sends the sample of the signal to a delay unit 35.
  • the delay unit 35 facilitates transmit time diversity within the augmented antenna array 200c by sending, by way of cable Tx2, at least one or more time-delayed copies of the sample of the signal to the transmit elements of the new anterma array 30c, at connection point Tx In, for broadcasting the copy signal to mobile units.
  • the augmentation method provides within the travel path of received signals a combiner 44 and a delay unit 42 downstream of the main antenna array 10c and the new antenna array 30c.
  • a mobile unit transmits a signal to the base station transceiver subsystem (not shown)
  • the receive elements of the main anterma array 10c and the new antenna array 30c intercept the receive signals and sends the receive signals to the base along the respective reception path of the main antenna array 10c and the new anterma array 30c.
  • the travel path of the cables Rx In(l) and (2) extends from the main antenna array 10c of the existing base station antenna arrangement 100c and feeds directly into the new anterma array 30c.
  • the signals may exit through several different routes, e.g., Rx Out (1), (2) and (3).
  • the delay unit 42 within the travel path delays the received signal to provide time diversity in the receive signals.
  • the combiner 44 located within the reception cable Rxl, combines the receive signals transmitted over the reception cables Rx Out (1) and (2) and transmit the combined signal to the base station transceiver subsystem (not shown).
  • the spacing between the main antenna 10c and the new antenna array 30b creates space diversity, and the polarization diversity among the members of the set of elements within the main anterma array 10c facilitates polarization diversity.
  • Fig. 3 the augmentation of Fig. 3 provides the ability to enhance an existing antenna arrangement by incorporating multiple types of diversity schemes and provides cost reduction benefits by rendering any passive antenna element active.
  • Fig. 4 all of the components of the existing base station antenna arrangement lOOd connect in the same manner and operate in the same manner as the components shown in Fig. 2. Thus, the existing base station antenna arrangement lOOd of Fig. 4 will not be specifically discussed.
  • Fig. 4 illustrates an augmentation method that modifies an existing base station antenna arrangement lOOd by adding a new anterma array 30d. Augmentation of the base station of Fig. 4 converts an existing base station anterma arrangement lOOd, having Rx polarization diversity configuration and no Tx diversity, to an augmented anterma array 200d, having Tx and Rx space diversity, Tx and Rx time diversity and Rx polarization in two separate antenna arrays.
  • the augmentation method of Fig. 4 provides an even wider variety of diversity schemes by adding a different type of new antenna array 30d.
  • the newly added antenna array 30d may contain either an active or passive anterma array.
  • Fig. 6 illustrates an exemplary embodiment of an active radiator unit 5b, (as disclosed in U.S. application No. 09/357,845) which may be employed in an active antenna array according to the embodiment of Fig. 4.
  • the active anterma array 5b of Fig. 6 includes both transmit and polarization diversity elements.
  • the spacing between the Tx elements of the main anterma array lOd and the Tx elements of the new antenna array 30d provides Tx space diversity.
  • the spacing between the Rx elements of the main antenna array lOd and the Rx elements of the new anterma array 30d provides Rx space diversity.
  • a directional coupler 40 serves as a directive feed that couples the main anterma lOd and new anterma array 30d.
  • the directional coupler obtains a sample of the transmit signal before the main antenna array lOd radiates the signal along the forward link to a mobile unit (not shown).
  • the directional coupler 40 then sends the sample of the signal to a delay unit 35.
  • the delay unit 35 facilitates transmit time diversity within the augmented antenna array 200d by sending, by way of cable Tx2, at least one or more time-delayed copies of the sample of the signal to the transmit elements of the new anterma array 30d, at connection point Tx In, for broadcasting the copy signal to mobile units.
  • the augmentation method provides within the travel path of received signals a pair of combiners 44, 54 and a pair of delay units 42, 52 downstream of the main antenna array lOd and the new antenna array 30d.
  • a mobile unit transmits a signal to the base station transceiver subsystem (not shown)
  • the receive elements of the main antenna array lOd and the new antenna array 30d intercept the receive signals and send the receive signals to the base along the respective reception path of the main antenna array lOd and the new anterma array 30d.
  • the travel path of the Rx In(l) cable extends from the main antenna array lOd and feeds directly into the new anterma array 30c.
  • Receive signals may also travel through the relocated diplexer 15b along reception path Rx In(2) to the new antenna array 30d. Once the receive signals enter the new antenna array 30d, the signals may exit through several different routes, e.g., Rxl Out (1) and (2) and Rx2 Out (3) and (4).
  • the delay units 42, 52 within the travel path of the respective reception lines delay the receive signals to provide time diversity.
  • the combiners 44, 54 located within the reception cables Rxl and Rx2, respectively, combine the receive signals and transmit the receive signals to the base station transceiver subsystem (not shown).
  • the polarization diversity configurations of the elements of both the main anterma array lOd and new anterma array 30d provide Rx polarization diversity schemes.
  • augmentation of Fig. 4 also provides additional benefits to the base station, such as the incorporation of multiple types of diversity schemes within an existing and operating base station.
  • the augmented antenna array 200d of Fig. 4 is capable of providing, at least, Tx and Rx space diversity, Tx and Rx time diversity and Rx polarization diversity in two separate anterma arrays.
  • the embodiment of Fig. 4 is not limited to the exemplary embodiment, various other diversity schemes may be employed, such as phase diversity and frequency diversity.
  • the cost of operating the base station also decreases when the augmentation renders a passive antenna array to be an active antenna array.
  • Installation of an active anterma array helps to alleviate the cost associated with the power consumptions of the base station and reduces the amount of cabling required within the base station since the length of capable needed to connect the component is shorter due to the fact that the amplifiers and bandpass filters associated with each active antenna array are also located at the top of the mast/building.
  • Fig. 5 illustrates an exemplary embodiment of an active radiator unit 5b, which may be employed in the active antenna array according to the embodiment of Fig. 5.
  • the spacing between the Rx elements of the main anterma array lOe and the Rx elements of the new anterma array 30e provides Rx space diversity.
  • a directional coupler 40 serves as a directive feed that couples the main anterma lOe and new antenna array 30e.
  • the base station transceiver subsystem (not shown) transmits a signal via the transmission cable Txl to the transmit elements of the main anterma array lOe
  • the directional coupler obtains a sample of the transmit signal before the main antenna array lOe radiates the signal along the forward link to a mobile unit (not shown).
  • the directional coupler 40 then sends the sample of the signal to a delay unit 35.
  • the delay unit 35 facilitates transmit time diversity within the augmented antenna array 200e by sending, by way of cable Tx2, at least one or more time-delayed copies of the sample of the signal to the transmit elements of the new anterma array 30e, at connection point Tx In, for broadcasting the copy signal to mobile units.
  • the augmentation method provides within the travel path of received signals a combiner 64 and a delay unit 62 downstream of the main anterma array lOe and the new anterma array 30e.
  • the receive elements of the main antenna array lOe and the new anterma array 30e intercept the receive signals and send the receive signals to the base along the respective reception path of the main antenna array lOe and the new anterma array 30e.
  • the travel path of the cable Rxl extends from the main antenna array lOe, travels through relocated diplexer 15b and feeds into the new antenna array 30e at connection point Rx In.
  • the signals may exit through several different routes, e.g., Rx Out (lp) and (2p) and Rx Out.
  • the delay unit 62 within the travel path of the reception lines, collects the receive signals of Rx(lp) and (2p) to perform a diversity analysis on the characteristics of the receive signals. Then, the combiner 64, located within the reception cable Rx2, combines the receive signals and transmits the receive signals to the base station transceiver subsystem (not shown). Alternatively or in conjunction with the reception cables lines of reception cable Rx2, the receive signals may travel from the new anterma array 30e to the base station transceiver subsystem (not shown) via reception cable Rxl.
  • the polarization diversity configurations of the elements of both the main antenna array lOd and new anterma array 30d provide Rx polarization diversity schemes.
  • Augmentation of Fig. 5 renders several benefits to the augmented antenna arrangement base station, which are similar to the benefits obtained by Fig. 1. For example, augmentation of the base station adds functionality without requiring any additional amount of space. Another benefit is the incorporation of multiple diversity schemes. For instance, in the exemplary embodiments of the augmented antenna array 200e of Fig. 5, Tx and Rx space diversity, Tx and Rx time diversity and Rx polarization diversity may be achieved. A further benefit is a cost reduction in power consumption and cabling associated with rendering a passive anterma array active.
  • Augmentation of an existing base station anterma arrangement lOOa-e, as shown in Figs. 1-5 provides several benefits as discussed above, however, the addition of a new antenna array, which is active, to a main anterma array 1 Oa-e may produce nearby, co-located antennas.
  • the co-located anterma may comprise, for example, a main antenna lOa-e and a new active anterma array 30a-e.
  • co-location-induced spurious emissions may be generated when each anterma transmits or receives a signal.
  • the level of interference which may be injected back toward the BTS transmitter, may cause a high level of interference power to be amplified by the transmitter section of the new active antenna array 3 Oa-e and radiated by the active antenna array 3 Oa-e.
  • One scenario that may produce interference, generated from co-location-induced spurious emissions may occur when the patterns of the signals transmitted from the co-located antennas are relatively too close to each other so that their signals are correlated. In such a case, the transmitter filter, because of its bandwidth, may not be able to provide a sufficient amount of suppression of the undesired spurious emission. This issue becomes a more significant problem especially when the co-located antennas are located on the same rooftop or anterma mast.
  • Fig. 7 shows an embodiment of the invention, which provides a solution to mitigate such spurious emissions and to decorrolate the signals of the co-located antennas.
  • This embodiment augments the architecture of the transmit chain of the embodiments of Figs. 1-5.
  • such augmentation involves (a) adding an isolator 75 on the mainline output port of the directional coupler 40 and (b) selecting a coupling factor of the directional coupler 40 to maintain the proper relationship between the power of the fundamental signal (F) to be amplified with respect to out-of-band interference "injected" into the augmented antenna array 200a-e.
  • F fundamental signal
  • These modifications may help to ensure that the level of spurious emissions amplified and radiated by the transmitter section 50 of the active anterma array 3 Oa-e is not excessive, and in full compliance with FCC, TLA, and other industry and regulatory requirements.
  • FIG. 7 The exemplary block diagram, as shown in Fig. 7, reflects examples of final values of fundamental (F) and adjacent-band (AB) signal levels for the scenario described as follows.
  • the analysis begins with the assumption that the augmented antenna array 200a-e includes one (or more) PCS operator's transmitter antennas located nearby the transmit-receive (Tx-Rx) as shown in Figs. 1-5. If at least one of the PCS operator's transmitter frequency operates, e.g., in the band adjacent to the band in which the Tx-Rx antenna operates, significant radio frequency (RF) power at the transmitter frequency employed by the other PCS operator may be injected into the Tx-Rx antenna of the augmented anterma array 200a-e.
  • RF radio frequency
  • the actual value of the conducted (measured) power for the adjacent-band of the other PCS operator's signals present at the Tx-Rx antenna terminals may depend on such factors as the Tx-Rx antenna gain, its antenna pattern, and the location and antenna pattern of the transmitter anterma belonging to the other PCS operator.
  • the analysis assumes that the two transmitter antennas belonging to the two PCS operators include an effective coupling factor of 60 dB (Fig. 7), from one transmitter antenna port to the other transmitter anterma port.
  • a poor coupling assumption for a co-location scenario may fall, for example, in the range of 35 to
  • the 60 dB coupling value may result, e.g., from a vertical separation of the two respective transmitter antennas, installed on the same mast at approximately 3.5 feet apart.
  • the 60 dB coupling factor may result from two respective transmitter antennas mounted on a rooftop with a horizontal spacing of about 40 feet or less, depending on the respective anterma patterns.
  • the injected adjacent band per-carrier power present at the anterma port of the Tx-Rx antenna of the augmentation system 200a-e is -20 dBm (Fig. 7).
  • the adjacent-band per-carrier power present at the mainline output port of the directional coupler 40 of -20 dBm should not, according to FCC rules and TIA requirements, cause an excessive level of spurious emissions at the output of the new active antenna array 30a-e.
  • the FCC and TIA requirement is -13 dBm per 1 MHz (conducted) for all spurious emissions, expressed as a composite power level associated with all the active radiator units 5a or 5b in an active anterma array 3 Oa-e. For example, if there are 4 active radiator units 5 a or 5b in the active antenna array 3 Oa-e, the total composite power at the adjacent band (per 1 MHz) is -19 dBm per active antenna array. Furthermore, even if the "injected" signal is not created within the augmented configuration 200a-e, it is still possible that significant power may be generated at the adjacent-band frequency of interest due to the nonlinearity of the LPA 60 in the active radiator unit 5a or 5b.
  • the analysis adjusts the "injected" signal accordingly to be 10 dB below the FCC/TIA limit, or -29 dBm per active radiator unit 5a or 5b, measured at each active radiator unit output 50.
  • the next supposition of the analysis assumes that the 1 MHz value of measurement bandwidth represents approximately the same bandwidth as the assumed CDMA signal (1 MHz vs. 1.25 MHz) transmitted by the adjacent-band of the other PCS operator.
  • the analysis calculates how much additional suppression of the adjacent-band signal may be needed to define a solution for mitigating the co-location-induced spurious emissions.
  • the analysis presumes that there are 4 active radiator units in the active antenna array and that each active radiator unit gain is at 40 dB (appropriate for the muiticarrier active radiator unit). Since the adjacent-band signal is -29 dBm at each active radiator unit output 50, as discussed above, the input 55 of the active radiator unit equals -69 dBm.
  • a transmitter splitter 80 Fig.
  • the delay unit 35 consists of a time delay element (e.g., a SAW device) with, e.g., 16 dB loss followed by an RF amplifier 82, e.g., a WJ AH1 with 13 dB gain and +41 dBm Output IP3, the system needs a fundamental delay unit input signal level of +3 dBm per carrier.
  • the corresponding maximum allowable level of adjacent-band power at the delay unit 35 input becomes -59 dBm.
  • the relative level of adjacent-band power with respect to one desired transmitter carrier equals -62 dBc.
  • the maximum allowable adjacent-band signal at the coupled port of the directional coupler 40 may be -60 dBm.
  • the directivity of the directional coupler 40 is such that the level of adjacent-band power appearing at the coupled port is 40 dB lower.
  • the 40-dB value is quite attainable, because 40 dB is not a worst-case scenario, the directivity of the directional coupler 40 may be, for example, 25 dB more stringent for some co-location scenarios. Therefore, it is necessary to select an alternative approach for more demanding applications.
  • the solution is to include an isolator 75 with enough isolation to easily meet the requirement for the application of interest.
  • the isolator 75 is a ferrite isolator, which passes energy traveling in one direction while absorbing energy from the opposite direction. This solution is also effective where the co-location- induced spurious emissions are due to nearby PCS transmitters which are not adjacent-band.
  • the invention includes a ferrite isolator that possesses low internal intermodulation distortion, at the RF power levels of interest.
  • the 30 dB coupler may be employed with a delay unit 35 which offers higher RF gain than previously discussed.
  • an RF bandpass filter with a notch response could potentially be used to provide attenuation of the adjacent-band and other PCS signals, a ferrite isolator is most likely to cost less, and it has less associated loss to reduce the transmitter power reaching the Tx-Rx antenna. Since the previously discussed higher incremental EIRP, which results from the addition of the active anterma array 30a-e, will more than compensate for the isolator loss, the loss due to the ferrite isolator 75 should not be problematic.
  • some augmentation applications may employ a delay element 35 comprising an optical fiber cable, for example, an optical delay unit.
  • an E/O interface transducer such as a laser diode may drive a section of the optical fiber cable, which in turn will drive an O/E interface transducer or optical receiver.
  • a value for the total RF gain of this cascade of devices is typically 0 dB.
  • the assumed signal power value of +3 dBm per carrier for the test scenario discussed above may be excessive.
  • a more likely signal power value is, for example, in the range of -20 dBm per carrier.
  • a ferrite isolator in general, helps to ensure that FCC and/or TIA spurious emissions limits will not be exceeded. If, in the future, additional PCS operators co-locate their antennas nearby, in accordance with the embodiment disclosed herein, a ferrite isolator (and optionally appropriate RF filters) may be included at the time of installation of the augmentation system.
  • this solution (along with possible use of additional bandpass and bandpass/notch filters) should deliver improved system performance, while ensuring compliance with FCC and TIA requirements.
  • Figs. 1-5 the following additional benefits may be achieved by some or all of the embodiments disclosed in Figs. 1-5.
  • the cost of installing an active anterma array using active radiator units 5 a or 5b is comparable to merely installing a pair of amplifiers into an existing base station.
  • adding an active anterma array using active radiator units 5a or 5b can achieve several additional advantages, which are as follows. Cost/ Assets trade-off:
  • the replacement of the conventional diversity anterma in Figs. 1 and 5 with the new active antenna array provides several benefits to the sector when the active antenna array 5 a, 5b achieves the same gain and EIRP as the main anterma. For instance, the following benefits may be achieved:

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Abstract

L'invention concerne un système et un procédé permettant d'augmenter des stations de base opérationnelles de manière à y intégrer de multiples programmes de diversité et à activer des éléments rayonnants passifs. Le réseau d'antennes passif de la station de base existante est remplacé par un réseau d'antennes actif constitué d'un bloc rayonnant comprenant un réseau d'éléments rayonnants de réception et d'émission. Les éléments rayonnants de réception et d'émission du bloc rayonnant actif sont connectés respectivement pour transmettre des amplificateurs et des filtres passe-bande installés sur un mât ou au sommet d'un édifice.
EP00973160A 1999-10-28 2000-10-27 Augmentation d'une station de base cellulaire Withdrawn EP1224748A2 (fr)

Applications Claiming Priority (5)

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US16191899P 1999-10-28 1999-10-28
US161918P 1999-10-28
US17765300P 2000-01-27 2000-01-27
US177653P 2000-01-27
PCT/IB2000/001686 WO2001031807A2 (fr) 1999-10-28 2000-10-27 Augmentation d'une station de base cellulaire

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JP (1) JP2003513506A (fr)
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GB0616449D0 (en) 2006-08-18 2006-09-27 Quintel Technology Ltd Diversity antenna system with electrical tilt
GB2460112A (en) * 2008-05-19 2009-11-25 Nokia Corp Controlling transmission diversity by delaying a signal on a second transmit path relative to a first transmit path
CN103329355B (zh) * 2012-03-20 2016-01-20 华为技术有限公司 天线系统、基站系统和通信系统
EP2822100B1 (fr) * 2012-04-01 2016-12-21 Huawei Technologies Co., Ltd. Module émetteur-récepteur, antenne, station de base et procédé de réception de signal
US11770809B2 (en) * 2020-07-22 2023-09-26 Samsung Electronics Co., Ltd. MIMO antenna array for cross division duplex

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GB2281010B (en) * 1993-08-12 1998-04-15 Northern Telecom Ltd Base station antenna arrangement
GB2290006A (en) * 1994-05-28 1995-12-06 Northern Telecom Ltd Base station transmitter control
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AU1170201A (en) 2001-05-08
JP2003513506A (ja) 2003-04-08

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