HK1160333A - Methods and apparatus of adapting number of advertised transmit antenna ports - Google Patents

Description

Method and apparatus for adapting the number of advertised transmit antenna ports

Claiming priority based on 35U.S.C. § 119

This patent application claims priority to provisional application No.61/092,450 entitled "adaptive number OF ADVERTISED TRANSMIT ANTENNAS," filed on 28.8.2008, which is assigned to the assignee OF the present application and is hereby expressly incorporated by reference.

Technical Field

The present disclosure relates generally to wireless communications, and more particularly to adapting the number of transmit antennas based on user demand in a wireless communication system.

Background

Wireless communication systems are widely deployed to provide various communication contents (e.g., voice, data, etc.). A typical wireless communication system may be a multiple-access system capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, and the like. Further, these systems may conform to specifications such as third generation partnership project (3GPP), 3GPP Long Term Evolution (LTE), Ultra Mobile Broadband (UMB), and/or multicarrier wireless specifications such as evolution-data optimized (EV-DO) and one or more revisions thereof.

Generally, wireless multiple-access communication systems are capable of supporting communication for multiple mobile devices simultaneously. Each mobile device communicates with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Moreover, communications between mobile devices and base stations may be established through single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. Further, in a peer-to-peer wireless network architecture, mobile devices can communicate with other mobile devices (and/or base stations with other base stations).

MIMO systems using multiple (N)_TMultiple) transmitting antenna and multiple (N)_RAnd) receive antennas for data communications. May be composed of N_TA transmitting antenna and N_RDecomposition of MIMO channel formed by multiple receiving antennas into N_SIndividual channels, which may also be referred to as spatial channels, where N_S≤min{N_T，N_R}。N_SEach of the individual channels corresponds to a dimension. MIMO systems can provide improved performance (e.g., higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.

MIMO systems support Time Division Duplex (TDD) systems and Frequency Division Duplex (FDD) systems. In a TDD system, forward link transmissions and reverse link transmissions are on the same frequency domain, so that the forward link channel can be estimated from the reverse link channel by the reciprocity principle. This enables the access point to extract transmit beamforming gain on the forward link when multiple antennas are available at the access point.

Furthermore, some improvements are currently being considered for lte advanced (lte advanced) systems, such as: multi-user MIMO, higher order MIMO (with 8 transmit and receive antennas), network MIMO, restricted association femtocells, range extended picocells, greater bandwidth, and so on. LTE-advanced must support legacy UEs (LTE release 8 UEs) and at the same time provide additional features to new UEs (legacy UEs as well when possible). However, supporting all features in LTE can place inconvenient constraints on LTE-advanced designs and can limit the possible gains. In general, the impact of any such characteristics on new UEs should be carefully considered.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In accordance with one or more embodiments and corresponding disclosure thereof, various aspects are described in connection with adapting a number of antenna ports advertised by a base station in a wireless communication system. This adaptive nature in determining the number of antenna ports enables the base station to intelligently balance the requirements of legacy UEs and new UEs (e.g., LTE-a) for overall efficient operation of the wireless system as a whole (e.g., consider the performance increase of the new user as a compensation for the performance degradation of the legacy user). Such adaptive characteristics include setting the number of antenna ports configured for legacy UE operation and for new UE operation to different values. The number of antenna ports configured for legacy UE usage and new UE usage may then be advertised. In an aspect, resources reserved for Reference Signals (RSs) of legacy users can be released for use by new UEs by first reducing the number of antenna ports advertised to legacy UEs. As a result, performance of the new user can be improved at the expense of the legacy user, which can provide a smooth transition between operation of the legacy UE and the new UE in the wireless communication system.

This innovative concept is in contrast to the market forces that typically require low initial processing overhead and design the system by assuming that only legacy UEs are present (e.g., advertising the number of antenna ports in order to enhance the performance of legacy devices). However, by advertising the number of selected antenna ports that can be adaptively adjusted to system requirements, the unexpected effect of efficient use of the overall system resources can be achieved in a system with legacy UEs and new UEs. When the associated antenna port is not advertised to the UE as part of the operation of the wireless system, the present scheme enables the release of resources normally reserved for Reference Signals (RSs) associated with the antenna. According to a particular aspect, an existing mechanism (e.g., via PBCH in LTE) may be used to advertise a transmit antenna port number to legacy UEs, and another mechanism (e.g., via system information block-SIB in LTE-a) may be used to advertise a larger transmit antenna port number to new UEs.

In a related approach, a base station may determine available users in a wireless system and their related information. This information may be based on collected data regarding: type of user (e.g., legacy, LTE-a); the number of users of each type, relative position to base station, expected performance of each type based on given number of antenna ports, type of exchanged information/data, Qos; the number of rx antennas of the UE, or the capability of the UE, etc. From this collected information, the base station may then determine, such as by calculation or via inference, the number of antenna ports to be advertised (e.g., for legacy users) for the available users. The inference can also be probabilistic-that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. The number of antenna ports advertised may be changed to accommodate system requirements as users enter or leave the wireless network and/or as requirements change. The user may then be notified (e.g., paged, notified by the server) of the number of available antenna ports. According to a particular aspect, the method includes first setting a number of transmit antenna ports for operation of an old User Equipment (UE) in the wireless communication system, then setting another number of antenna ports for operation of a new UE in the wireless communication system, and advertising the transmit antenna ports for operation of the old UE and the antenna ports for operation of the new UE in the wireless communication system. In a related example, this advertising occurs via a common control channel and/or via a Physical Broadcast Channel (PBCH) in Long Term Evolution (LTE). Further, data of each of the legacy UE and the new UE may be transmitted via an antenna port corresponding thereto.

Another aspect relates to a wireless communications apparatus. The wireless communications apparatus includes at least one processor. The at least one processor may be configured to enable the base station to determine an advertised number of antenna ports. Further, the at least one processor may be configured to adapt the number of antenna ports to system requirements, such as advertising one antenna port number to legacy UEs and another antenna port number to new UEs. For example, the system may first advertise 4 antennas, but may then even use all 8 available antennas for legacy UEs. As such, the at least one processor may advertise the determined and/or selected antenna port to the UE based on overall efficient operation of the wireless system as a whole.

Another aspect relates to a communication device. The wireless communications apparatus can include means for determining an advertised antenna port number, which enables a base station to determine an antenna port number to advertise. Further, the wireless communication device may include means for adapting the number of antenna ports to system requirements.

Another aspect relates to a computer program product that may include a computer-readable medium. The computer-readable medium can include code for causing a computer to determine an advertised antenna port number. The computer-readable medium may also include code for adapting the antenna port to system requirements as the requirements change over time. The code implements adaptive characteristics in determining the number of advertised antenna ports and enables the base station to intelligently balance the requirements of legacy and new UEs (e.g., LTE-a) for overall efficient operation of the wireless system as a whole (e.g., treating the performance gain of the new user as an offset of the performance degradation of the legacy user).

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed and the following description is intended to include all such aspects and their equivalents.

Drawings

Fig. 1 illustrates a wireless communication system consistent with various aspects of the present disclosure.

Fig. 2 illustrates an exemplary system for supporting determining antenna port counts and adaptation thereof, consistent with an aspect of the invention.

Fig. 3 illustrates a related methodology for implementing adaptive advertised transmit antenna port numbers, consistent with another aspect of the subject innovation.

Fig. 4 illustrates an exemplary communication system for implementing the adaptive feature in determining the number of antenna ports.

Fig. 5 illustrates an exemplary wireless communication system capable of incorporating adaptive features for antenna port selection consistent with an aspect of the subject innovation.

Fig. 6 illustrates a system for enabling flexibility in allocating resources by adjusting the number of antenna ports, consistent with an aspect of the subject innovation.

Fig. 7 illustrates a system that facilitates adapting a number of antenna ports in a wireless communication environment.

Fig. 8 illustrates a particular methodology for adapting a number of antenna ports in a communication environment, consistent with aspects related to the subject innovation.

FIG. 9 illustrates a mobile device consistent with another aspect of the invention.

Fig. 10 illustrates an exemplary wireless communication system configured to support multiple users in which aspects of antenna adaptation may be implemented.

Fig. 11 is a block diagram of a system for adapting a number of antenna ports in a communication system, consistent with various aspects of the present application.

Fig. 12 illustrates another method for adapting the number of antenna ports, consistent with related aspects of the invention.

Detailed Description

Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details.

As used in this application, the terms "component," "module," and "system" and the like are intended to encompass a computer-related entity and/or electronic device, such as, but not limited to, hardware, firmware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being: a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component may be localized on at least one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets, such as data from one component interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal.

Furthermore, aspects are described herein in connection with a terminal, which may be a wired terminal or a wireless terminal. A terminal can also be called a system, device, subscriber unit, subscriber station, mobile device, remote station, remote terminal, access terminal, user terminal, communication device, user agent, user device (user equipment), or User Equipment (UE). A wireless terminal may be a cellular telephone, a satellite telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having wireless connection capability, a computing device, or other processing device connected to a wireless modem. Various aspects are described herein in connection with a base station. A base station may be used for communicating with wireless terminal(s) and may also be referred to as an access point, node B, evolved node B (node B, eNB), femto cell, pico cell, micro cell, macro cell, home evolved node B (henb), home node B (hnb), or some other terminology.

Furthermore, the term "or" means an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X employs A or B" means any of the natural inclusive permutations. That is, X employs A, X employs B, or X employs either of A and B, which satisfies "X employs A or B". In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form.

The techniques described herein may be used for various wireless communication systems such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), and single carrier-frequency division multiplexing (SC-FDMA), among others. The terms "system" and "network" are often used interchangeably. A CDMA system may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, and so on. UTRA includes wideband-CDMA (W-CDMA) and other variants of CDMA. In addition, CDMA2000 covers IS-2000, IS-95 and IS-856 standards. TDMA systems may implement wireless technologies such as global system for mobile communications (GSM). The OFDMA system may implement wireless technologies such as evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM, and so on. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is a release version of UMTS that employs E-UTRA, which uses OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE, and GSM are described in a document of the organization entitled "third Generation partnership project" (3 GPP). In addition, CDMA2000 and Ultra Mobile Broadband (UMB) are described in a document entitled "third generation partnership project 2" (3GPP 2). In addition, such wireless communication systems also include peer-to-peer (e.g., mobile-to-mobile) ad hoc network (ad hoc network) systems (such peer-to-peer ad hoc network systems typically use unpaired unlicensed frequencies), 802.xx wireless LANs, bluetooth, and any other short or long range wireless communication technologies.

Single carrier frequency division multiple access (SC-FDMA) uses single carrier modulation and frequency domain equalization. SC-FDMA has similar performance and substantially the same overall complexity as OFDMA systems. The SC-FDMA signal has a lower peak-to-average power ratio (PAPR) due to its essentially single carrier structure. For example, SC-FDMA can be used in uplink transmissions, where a lower PAPR greatly facilitates access terminals in terms of transmit power efficiency. Thus, SC-FDMA is implemented as an uplink multiple access scheme in 3GPP Long Term Evolution (LTE) or evolved UTRA.

Various aspects or features described herein may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD), etc.), smart cards, and flash memory devices (e.g., EPROM, card, stick, key drive, etc.). In addition, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" includes, but is not limited to: wireless channels and various other media capable of storing, and/or carrying instruction(s) and/or data.

Fig. 1 illustrates a wireless communication system 100 consistent with various embodiments of the present application. System 100 comprises a base station 102, where base station 102 comprises multiple antenna groups. For example, one antenna group includes antennas 104 and 106, another group includes antennas 108 and 110, and an additional group includes antennas 112 and 114. Although two antennas are shown for each antenna group, more or fewer antennas may be utilized for each group. Base station 102 can additionally include a transmitter chain and a receiver chain, each of which can in turn comprise a plurality of components associated with transmission and reception of signals (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antenna ports, etc.), as will be appreciated by one skilled in the art.

Base station 102 can communicate with one or more mobile devices, such as mobile device 116 and mobile device 122; however, it should be appreciated that base station 102 can communicate with substantially any number of mobile devices similar to mobile devices 116 and 122. For example, mobile devices 116 and 122 can be: cellular phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any device suitable for communicating over wireless communication system 100. As depicted, mobile device 116 is in communication with antennas 112 and 114, where antennas 112 and 114 transmit information to mobile device 116 over a forward link 118 and receive information from mobile device 116 over a reverse link 120. In addition, mobile device 122 is in communication with antennas 104 and 106, where antennas 104 and 106 transmit information to mobile device 122 over a forward link 124 and receive information from mobile device 122 over a reverse link 126. In a Frequency Division Duplex (FDD) system, forward link 118 can utilize a different frequency band than that used by reverse link 120, and forward link 124 can employ a different frequency band than that employed by reverse link 126, for example. Further, in a Time Division Duplex (TDD) system, forward link 118 and reverse link 120 can utilize a common frequency band and forward link 124 and reverse link 126 can utilize a common frequency band.

Each group of antennas and/or the area in which they are designated to communicate can be referred to as a sector of base station 102. For example, antenna groups can be designed to communicate to mobile devices in a sector of the areas covered by base station 102. In communication over forward links 118 and 124, the transmitting antennas of base station 102 employ beamforming to improve signal-to-noise ratio of forward links 118 and 124 for mobile devices 116 and 122. In addition, when base station 102 uses beamforming to transmit to mobile devices 116 and 122 scattered randomly through an associated coverage, mobile devices in neighboring cells can be subject to less interference as compared to a base station transmitting through a single antenna to all its mobile devices.

It is to be appreciated that base station 102 can be any type of base station (e.g., a macrocell base station, a microcell base station, a picocell base station, a femtocell base station). Each mobile device 116, 122 can generate preferences for selecting respective target base stations (e.g., base station 102, other types of base stations (not shown)). According to one example, the mobile devices 116, 122 can employ various access control approaches (e.g., operator-controlled approaches, user-and operator-controlled approaches). One or more aspects of the present invention enable the number of antennas advertised by the base station 102 to be determined in a wireless communication system. This adaptive nature in determining the number of antennas enables the base station 102 to intelligently balance the needs of legacy UEs and new UEs (e.g., LTE-a) for overall efficient operation of the wireless system 100 as a whole. For example, the performance increase of a new user may be considered as a compensation for the performance decrease of an old user. In an aspect, by first reducing the number of antennas advertised to legacy UEs, the corresponding resources reserved for Reference Signals (RSs) of legacy users may be released for use by new UEs. This can improve performance for the new user at the expense of the legacy user (e.g., increase the peak rate of the new UE at the expense of the peak rate of the legacy UE), which can provide a smooth transition between operation of the legacy UE and the new UE of the wireless communication system 100. As used in this application, the term "antenna" may refer to an actual physical antenna. Furthermore, the term "antenna port" refers to a virtual antenna (a beam formed by using a physical antenna advertised to the UE), wherein a beam refers to transmitting the same signal through different antennas using different gains and phase rotations. It is to be understood that for legacy UEs, each antenna port may correspond to one Common Reference Signal (CRS) port. It is also to be understood that the advertised number of antenna ports configured for operation by the legacy UE may be used for transmission of all control channels (common and dedicated) for the legacy UE and the new UE, for example, while data transmission for the legacy UE and the new UE use the corresponding number of antenna ports configured for them.

Fig. 2 illustrates a wireless communication system 200 consistent with various aspects described herein. System 200 includes one or more base stations 202 in one or more sectors, base stations 202 that receive, transmit, repeat, etc., wireless communication signals to each other and/or to one or more mobile devices 204. Each base station 202 can comprise a plurality of transmitter chains and a plurality of receiver chains (e.g., one for each transmit antenna and one for each receive antenna), each of which can in turn comprise a plurality of components associated with transmission and reception of signals (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.). Each mobile device 204 can include one or more transmitter chains and receiver chains, which can be employed in a multiple-input multiple-output (MIMO) system. Each transmitter and receiver chain can include a plurality of components associated with the transmission and reception of signals (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.), as will be appreciated by one skilled in the art.

When base station 202 transmits a signal in a signal format over another signal format, such as OFDM, the timing of the samples of the signal received at mobile device 204 can be scrambled and/or erroneous. Thus, the mobile device 204 may be configured to rearrange the sampled data and discard erroneous sampled data in order to improve detection of the signal. Because there are different types of signal formats used, system 200 may provide a platform for allowing these multiple formats to be employed. Thus, the system 200 does not use these formats independently, but rather selectively superimposes them.

The base station 202 further comprises an antenna adaptation component 214, the antenna adaptation component 214 comprising an antenna selection component 210 and an adjustment component 211, the components 210 and 211 operating together to intelligently tailor antenna ports according to system requirements.

The antenna selection component 210 is used to select the number of antenna ports and the adjustment component 211 is used to increase/decrease the number of selected antenna ports. For example, the adjusting component adjusts the number of antenna ports to the requirements of the wireless communication system.

This adaptive nature in adjusting the number of antenna ports enables the base station 202 to intelligently balance the requirements of legacy UEs and new UEs (e.g., LTE-a) for overall efficient operation of the wireless system as a whole (e.g., considering the performance increase of the new user as compensation for the performance degradation of the legacy user). For efficient operation of the wireless communication system as a whole, the antenna adaptation component adaptively sets different antenna port numbers in order to intelligently balance the requirements between the legacy UE and the new UE. In addition, the antenna advertisement component 220 notifies the user of available antenna ports.

In an aspect, by first reducing the number of advertised antenna ports, the corresponding resources reserved for Reference Signals (RSs) of legacy users may be released for use by new UEs. Thus, performance of the new user can be improved at the expense of the legacy user, which can provide a smooth transition between operation of the legacy UE and the new UE in the wireless communication system. This innovative concept is contrary to market forces that typically require low initial processing overhead. It has been found that by increasing the processing overhead associated with advertising the number of antenna ports selected, which can be adaptively adjusted according to system requirements, unexpected advantages associated with efficient use of overall system resources can be achieved. Thus, resources normally reserved for Reference Signals (RSs) associated with an antenna may be released when the UE is not informed about the antenna port in question as part of the operation of the wireless system. Thus, the antenna advertisement component 220 is used to advertise antenna ports in order to accommodate changing requirements of the communication system.

According to related aspects, antenna adaptation component 214 sets a number of transmit antenna ports for legacy User Equipment (UE) operation in a wireless communication system via adjustment component 211. Such an adjusting component 211 can also set another transmit antenna port number for the new UE operation in the wireless communication system, and the antenna advertising component 220 can then advertise the antenna ports for the legacy UE operation and the new UE operation in the wireless communication system.

Specifically, in LTE release 8, the number of transmit antenna ports is advertised by a Physical Broadcast Channel (PBCH). Furthermore, in conventional systems, the transmit antenna port number is determined by attempting to blindly decode PBCHs for different advertised transmit antenna port numbers while checking which likelihood works. Furthermore, release 8 supports advertising 1, 2 or 4 transmit antenna ports. In this standard, Reference Signals (RSs) corresponding to each advertised transmit antenna are required to be forcibly transmitted. This operation is required because the UE needs to inform the base station of the channel quality observed on different antenna ports. For example, an enodeb (enodeb) may use channel quality information to make a decision on a MIMO scheme suitable for a UE. The number of resources occupied by the RS increases as the number of advertised antenna ports increases. Advertising more antenna ports will likely provide additional MIMO gain. However, the efficiency of the system may decrease significantly as more RS symbols are transmitted. The following describes an exemplary scenario in which a smaller number of antenna ports is advertised for legacy users, which improves the performance of non-legacy and legacy UEs.

Supporting higher order MIMO with 8 transmit antenna ports

In one aspect, consider a design that advertises 2 transmit antenna ports (associated with antennas 1 and 2) to legacy users. The new user is then informed of the 8 transmit antenna ports by a new mechanism (e.g. by a new system information block SIB in LTE-a). This mechanism is necessary to support 8 transmit antenna ports because it is not currently supported in LTE release 8.

Thus, the resources that would have been used for antenna ports 3 and 4 (assuming 4 antenna ports have been advertised) can now be used for transmitting the low duty cycle RS for antenna ports 3 through 8. For example, instead of sending RSs for antenna ports 3 and 4 on all subframes, the present invention implements: transmitting RSs of antennas 3 and 4 on one subframe; transmitting the RSs of antenna ports 5 and 6 on the next subframe; and transmits the RSs of antennas 7 and 8 on the following sub-frames; after that, the RSs for antenna ports 3 and 4 are sent again, and so on. As such, legacy UEs do not perceive the new RS transmission and only operate on 2Tx transmissions. In addition, the new UE observes RSs for at least 4Tx antennas on each subframe and is thus able to support 4Tx MIMO transmission. Furthermore, since the RS can circulate over all 8Tx transmit antennas, this can support even MIMO schemes involving up to 8Tx antennas. Accordingly, support for 8 transmit antennas can be obtained for a new UE by sacrificing the 4Tx mode of a legacy UE without increasing overhead. Other alternatives to support 8Tx transmission are to introduce more RSs for the other antennas (5 to 8) that are transmitted together with the RSs for antennas 1 to 4. This adds overhead and makes the design inefficient and difficult to implement.

Support of network MIMO

Network MIMO refers to a synchronized network in which a UE is simultaneously assisted by two or more enbs. To support network MIMO, the UE needs to estimate the channels from multiple enbs. Depending on the eNB's physical cell ID, the RSs of multiple enbs may collide and thus not be sufficient to estimate the channel for network MIMO purposes. Thus, in case of significant network MIMO gain, only one or two transmit antennas may be advertised and the corresponding RS sequence transmitted. As such, a new common RS structure more suitable for network MIMO purposes than the current RS design scheme can be designed using the resources saved by not transmitting other RSs.

Situation of significant interference

In networks using range extension/limited association, situations are typically encountered where a UE is required to connect to a weaker eNB in the presence of significant interference. As such, communications are typically established through a division of resources between the dominant and weaker base stations (e.g., by splitting subframes between the two). However, these base stations all transmit RS on all subframes as required by the standard. A UE may not hear its serving eNB on the resources on which the stronger base station transmits its RS, and may not hear its serving eNB even on the resources allocated to the weaker eNB. Therefore, in this case, it is advantageous to adapt the number of antennas advertised.

For example, if a macro cell decreases the number of advertised antenna ports, it increases the number of resources available to the pico cell within its coverage area. The resources used by the macro cell to transmit its RS become available to each pico cell. This can significantly increase the overall capacity of the system if there are several active pico cells (pico cells with UEs connected to them) within the coverage area of the macro cell (since resources can be used by different pico cells at the same time and thus the losses that a legacy UE would normally experience due to reduced MIMO functionality when connected to the macro cell can be compensated for). By sending the new RS only on the resources reserved for the macro cell, more transmit antennas for the new UE can still be supported. However, if there are few active pico cells, it is feasible that the macro cell supports 4Tx transmission of legacy UEs.

Thus, the decision on the number of transmit antennas for legacy UEs advertised by the PBCH is based on MIMO gain for legacy users and the performance of new and legacy UEs exploiting other advanced features of LTE-a. Further, another number of transmit antennas may be advertised to the new UE in order to obtain MIMO gain for the new UE. Furthermore, such decisions may be adaptive based on current system requirements, since the optimal choice (for the number of antennas advertising legacy UEs) depends on the current architecture of the network. For example, when only a legacy UE is present in the coverage area of the base station, the legacy UE may be notified of 4 antennas and RSs of all 4 antennas may be transmitted.

When there are sufficiently few legacy UEs present, only 1 transmit antenna may be advertised for legacy UEs. For example, one method of adapting the number of transmit antennas in LTE is to make a change at the eNB and then page all UEs to notify them of such a system information change. The present invention also optimizes the design of LTE-advanced (e.g., 8 x 8 MIMO) by reducing the number of transmit antennas advertised for legacy users.

Fig. 3 illustrates a related methodology 300 for adjusting the number of antenna ports to accommodate system requirements. While the exemplary method is described and illustrated as a series of blocks representative of various events and/or acts, the present invention is not limited by the illustrated ordering of such blocks. For example, some acts or events may occur in different orders and/or concurrently with other acts or events, apart from the ordering illustrated herein, in accordance with the invention. Moreover, not all illustrated blocks, events or acts, may be required to implement a methodology in accordance with the subject invention. Further, it will be appreciated that the exemplary method and other methods according to the invention may be implemented in association with the method illustrated and described herein, as well as in association with other systems and apparatus not illustrated or described. First, at 310, the base station can determine available users in the wireless system and their related information. This information may relate to: type of user (e.g., legacy, LTE-a); the number of legacy users, the number of new users (e.g., the number of each user type), the relative location to the base station, the expected performance of each type based on the given number of antennas, the type of information exchanged, and the Qos; rx antenna number of the UE, and so on. From this collected information, the base station then determines, at 320, the number of antenna ports (e.g., for legacy users) to advertise, such as by calculation or by inference. The inference can also be probabilistic-that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. The number of antenna ports advertised may be changed to accommodate system requirements as users enter or leave the wireless network and/or as demand changes. The system may then notify (e.g., page, notify through a server, etc.) the user of the number of available antenna ports. As used herein, the term "inference" refers generally to the process of reasoning about or inferring states of the system, environment, and/or user from a set of observations as captured via events and/or data. Inference can be employed to identify a specific context or action, or can generate a probability distribution over states, for example. The antenna ports are advertised at 330 and the number can be adjusted as system requirements change at 340.

Fig. 4 illustrates an exemplary communication system 400 for implementing the adaptive feature in determining the number of antenna ports. This adaptive nature in determining the number of antennas enables the base station to intelligently balance the requirements of legacy and new UEs (e.g., LTE-a) (e.g., treating the performance increase of the new user as a compensation for the performance degradation of the legacy user) for overall efficient operation of the wireless system 400 as a whole. In an aspect, by first reducing the number of advertised antenna ports, corresponding resources reserved for Reference Signals (RSs) of legacy users can be released for use by an access point base station (e.g., femtocell base station.) in a network environment to deploy new UEs. As shown in fig. 4, the system 400 includes a plurality of femtocell base stations, which are also referred to as access point base stations, home evolved node B units (henbs), home node B units (HNBs), femtocells, and so on. For example, each femtocell base station (HeNB 410) may be installed in a corresponding small-scale network environment, such as in the residence 430 of one or more users, and may be configured to serve associated and alien mobile devices 420. Each HeNB 410 is also coupled to the internet 440 and mobile operator core network 450 through a DSL router (not shown), or alternatively, through a cable modem (not shown).

Although the embodiments described herein use 3GPP technology, it will be appreciated that these embodiments may be applicable to 3GPP (Rel99, Rel5, Rel6, Rel7) technology, as well as 3GPP2(1xRTT, 1xEV-DO Rel0, RevA, RevB) technology, and other known and related technologies. In the embodiments described herein, the owner of HeNB 410 may subscribe to mobile services such as 3G mobile services provided through mobile operator core network 450, for example, and mobile device 420 may be capable of operating in a macro cellular environment through macro cell base station 460 as well as a residential small scale network environment. Thus, HeNB 410 may be backward compatible with any existing mobile device 420.

It is to be understood that HeNB 410 includes CSG henbs, hybrid henbs, and/or open henbs. Each HeNB 410 is able to advertise a respective set of antenna ports and to determine the available users in the wireless system and their related information. This information may relate to: type of user (e.g., legacy, LTE-a); the number of users of each type, the relative position to the base station, the performance of each type expected based on the given number of antenna ports, the type of information exchanged, and the Qos; rx antenna number of the UE, and so on. From this collected information, the base station then determines, such as by calculation or by inference, the number of antenna ports (e.g., for legacy users) to be advertised. The inference can also be probabilistic-that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. The number of antenna ports advertised may be changed to accommodate the needs of the system as users enter or leave the wireless network and/or as needs change. The user may then be notified (e.g., paged, notified through a server) of the number of available antenna ports.

Fig. 5 illustrates an exemplary wireless communication system 500 capable of incorporating the adaptive features of the present invention. The wireless communication system 500 depicts one base station 510 and one mobile device 550 for sake of brevity. However, it is to be appreciated that system 500 can include more than one base station and/or more than one mobile device, wherein additional base stations and/or mobile devices can be substantially the same as or different from example base station 510 and mobile device 550 described below. Moreover, it is to be appreciated that base station 510 and/or mobile device 550 can employ the systems and/or methods described herein to facilitate wireless communication there between.

At base station 510, traffic data for a number of data streams is provided from a data source 512 to a Transmit (TX) data processor 514. According to an example, each data stream can be transmitted over a respective antenna. TX data processor 514 formats, codes, and interleaves the traffic data stream based on a particular coding scheme selected for that data stream to provide coded data.

The coded data and pilot data for each data stream may be multiplexed using Orthogonal Frequency Division Multiplexing (OFDM) techniques. In addition, or alternatively, the pilot symbols may be Frequency Division Multiplexed (FDM), Time Division Multiplexed (TDM), or Code Division Multiplexed (CDM). The pilot data is typically a known data pattern that is processed in a known manner and can be used at the mobile device 550 to estimate channel response. The multiplexed pilot and coded data for each data stream is modulated (e.g., symbol mapped) based on a particular modulation scheme (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), etc.) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by instructions performed or provided by processor 530.

The modulation symbols for the data streams are provided to a TX MIMO processor 520, which TX MIMO processor 520 may further process the modulation symbols (e.g., for OFDM). TX MIMO processor 520 then forwards N_TA plurality of transmitters (TMTR)522a through 522t provide N_TA stream of modulation symbols. In various embodiments, TX MIMO processor 520 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

Each transmitter 522 is connected toThe various symbol streams are received and processed to provide one or more analog signals, and the analog signals are further conditioned (e.g., amplified, filtered, and upconverted) to provide a modulated signal suitable for transmission over the MIMO channel. In addition, from N respectively_TN transmitted from transmitters 522a through 522t are transmitted by antenna ports 524a through 524t_TA modulated signal.

At the mobile device 550, the transmitted modulated signal is represented by N_RThe individual antenna ports 552a through 552r receive and provide a received signal from each antenna 552 to a respective receiver (RCVR)554a through 554 r. Each receiver 554 conditions (e.g., filters, amplifies, and downconverts) a respective signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.

RX data processor 560 from N_RA receiver 554 receives N_RA stream of symbols and N according to a particular receiver processing technique_RA stream of received symbols is processed to provide N_TA "detected" symbol stream. RX data processor 560 can demodulate, deinterleave, and decode each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 560 is complementary to that performed by TX MIMO processor 520 and TX data processor 514 at base station 510. Processor 570 periodically determines which pre-coding matrix to use as described above. Further, processor 570 can formulate a reverse link message comprising a matrix index portion and a rank value portion.

The reverse link message may comprise various types of information regarding the communication link and/or the received data stream. The reverse link message is processed by a TX data processor 538, which also receives traffic data for a number of data streams from a data source 536, modulated by a modulator 580, conditioned by transmitters 554a through 554r, and transmitted back to base station 510.

At base station 510, the modulated signals from mobile device 550 are received by antenna port 524, conditioned by receiver 522, demodulated by a demodulator 540, and processed by a RX data processor 542 to extract the reverse link message transmitted by mobile device 550. Further, processor 530 processes the extracted message to determine which precoding matrix to use for determining the beamforming weights.

Processors 530 and 570 can direct operations (e.g., control, coordinate, manage, etc.) at base station 510 and mobile device 550, respectively. Respective processors 530 and 570 are associated with memory 532 and 572 for storing program codes and data. Processors 530 and 570 can also perform computations to derive frequency response estimates and impulse response estimates for the uplink and downlink, respectively.

Fig. 6 illustrates a system 600 for flexibly allocating resources by adjusting antenna port numbers, in accordance with an aspect of the subject innovation. System 600 can reside at least partially within a base station, for instance. As depicted, system 600 includes functional blocks that can represent functions implemented by a processor, software, or combination of both (e.g., firmware). System 600 includes a logical grouping 602 of cooperating electrical components. Logical grouping 604 includes an electrical component (e.g., an adaptation module) for adapting the number of antenna ports to user requirements. Logical grouping 604 also includes logical grouping 608 and logical grouping 609, where logical grouping 608 includes an electrical component (e.g., a selection module) for selecting a number of antenna ports and logical grouping 609 (e.g., an adjustment module) for adjusting the number of antenna ports to system requirements as described in detail above. For example, logical grouping 609 can set a transmit antenna port number for legacy User Equipment (UE) operation and set another transmit antenna port number for new UE operation, wherein logical grouping 606 (e.g., advertising module) can subsequently advertise and/or transmit corresponding antenna ports for both legacy UE operation and new UE operation in the wireless communication system.

In addition, logical grouping 606 includes an electrical component for advertising an antenna port to the UE. As such, the base station can intelligently balance the needs of the legacy UEs and the new UEs (e.g., LTE-a) for overall efficient operation of the wireless system as a whole (e.g., consider the performance increase of the new users as compensation for the performance degradation of the legacy users).

For example, by first reducing the number of advertised antenna ports, the corresponding resources reserved for Reference Signals (RSs) of legacy users can be released for use by new UEs. Thus, performance of the new user can be improved at the expense of the legacy user, which can provide a smooth transition between legacy UE and new UE operation in the wireless communication system.

Further, logical grouping 602 includes a memory 610, memory 610 storing instructions for performing the functions associated with electrical components 604 and 606. While shown as being external to memory 610, it is to be understood that electrical components 604 and 606 can exist within memory 610.

Fig. 7 illustrates a system 700 that facilitates adapting a number of antenna ports in a wireless communication environment. System 700 includes a base station 702 (e.g., an access point) having a receiver 710 that receives signals from one or more mobile devices 704 via a plurality of receive antennas 706 and a transmitter 724 that transmits to the one or more mobile devices 704 via a transmit antenna 708. Receiver 710 receives information from receive antennas 706 and is operatively associated with a demodulator 712 that demodulates received information. Demodulated symbols can be analyzed by a processor 714 that is similar to the processors described above, processor 714 can be coupled to a memory 716, and memory 716 can store data to be transmitted to or received from mobile device 704, and/or any other suitable information related to performing the various operations and functions described herein. The processor 714 is further coupled to an antenna adaptation component 718 and an advertisement component 720. As described above, the antenna adaptation component 718 enables the base station to intelligently balance the requirements of legacy UEs and new UEs (e.g., LTE-a) for overall efficient operation of the wireless system as a whole (e.g., consider the performance increase of the new user as a compensation for the performance degradation of the legacy user). The advertising component 720 can advertise the determined antenna port to the system.

Base station 702 also includes a modulator 722. Modulator 722 can multiplex frames for transmission by a transmitter 724 through antenna 708 to mobile device 704 in accordance with the description supra. Although shown as being separate from the processor 714, it is to be understood that the identity notification component 718, the mode publication component 720 and/or the modulator 722 can be part of the processor 714 or multiple processors (not shown).

Fig. 8 illustrates a particular methodology 800 that corresponds to a related aspect of the subject innovation for adapting antenna port count in a communication environment. According to methodology 800, by first reducing the number of advertised antenna ports at 810, corresponding resources reserved for Reference Signals (RSs) of legacy users can then be released at 820 for use by new UEs. Thus, performance of the new user can be improved at the expense of the legacy user, which can provide a smooth transition between operation of the legacy UE and the new UE in the wireless communication system.

As such, resources normally reserved for Reference Signals (RSs) associated with the antenna may be released when the antenna port is not advertised to the UE as part of the operation of the wireless system. According to one particular aspect, the legacy UEs may be advertised a number of transmit antenna ports using an existing mechanism (e.g., by PBCH in LTE), and the new UEs may be advertised a greater number of transmit antenna ports by another mechanism.

Fig. 9 illustrates a mobile device in accordance with another aspect of the present invention. Mobile device 900 includes a receiver 902, for instance, receiver 902 receives a signal from a receive antenna (not shown), performs typical operations on (e.g., filters, amplifies, downconverts, etc.) the received signal, and digitizes the conditioned signal to obtain samples. Receiver 902 can be, for example, an MMSE receiver, and can comprise a demodulator 904 that can demodulate received signals and provide them to a processor 906 for channel estimation. According to an example, receiver 902 can obtain an advertised signal, where the signal is obtained after identification of a base station. The processor 906 may be: a processor dedicated to analyzing information received by receiver 902 and/or generating information for transmission by a transmitter 916, a processor that controls one or more components of mobile device 900, and/or a processor that both analyzes information received by receiver 902, generates information for transmission by transmitter 916, and controls one or more components of mobile device 900.

The mobile device 900 may also include a memory 908 operatively coupled to the processor 906, the memory 908 may store data to be transmitted, received data, and any other suitable information related to performing the various operations and functions described herein. For example, the memory 908 can store protocols and/or algorithms associated with analyzing an obtained signal related to adapting a number of antenna ports advertised by a base station in a wireless communication system. This adaptive nature in determining the number of antenna ports enables the base station to intelligently balance the needs of legacy and new UEs (e.g., LTE-a) for overall efficient operation of the wireless system as a whole. Further, memory 908 may store protocols and/or algorithms associated with balancing the performance gains of new users as a compensation for the performance degradation of older users.

It will be appreciated that the data store (e.g., memory 908) described herein can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. For purposes of illustration, and not by way of limitation, nonvolatile memory can include: read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable PROM (EEPROM), or flash memory. Volatile memory includes Random Access Memory (RAM), which acts as external cache memory. For purposes of illustration and not limitation, RAM may be available in a variety of forms, such as: synchronous RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 908 of the subject systems and methods is intended to comprise, without being limited to, these and any other suitable types of memory. Although depicted as being separate from the processor 906, it is to be understood that the modulator 914 can be part of the processor 906 or multiple processors (not shown).

Fig. 10 illustrates an exemplary wireless communication system 1000 configured to support multiple users in which various aspects of adaptive operation may be implemented. By way of example, the system 1000 provides communication for a plurality of cells 1002, such as macrocells 1002a-1002 g. Each macrocell 1002a-1002g is served by a respective access point 1004, such as access points 1004a-1004 g. Each cell 1002a-1002g may also be divided into one or more sectors. Various devices 1006 (including devices 1006a-1006k) are distributed throughout system 1000. For example, at a given moment, each device 1006 can communicate with one or more access points 1004 on a Forward Link (FL) and/or a Reverse Link (RL), depending on whether the device 1006 is active and whether the device 1006 is in soft handoff. The wireless communication system 1000 may provide service over a large geographic area, for example, the macro cells 1002a-1002g may cover several neighborhoods, while the macro cells may adapt the number of antenna ports advertised by the base stations in the wireless communication system. In this manner, system 1000 can adapt the number of antenna ports advertised by an access point and intelligently balance the needs of legacy UEs and new UEs (e.g., LTE-a) for overall efficient operation of the wireless system as a whole. For example, if a macro cell decides to reduce the number of advertised antenna ports, it can increase the number of resources available to the pico cell within its coverage area. The resources used by the macro cell to transmit its RS become available to each pico cell.

In another example, the performance increase of the new user is considered to be a compensation for the performance decrease of the old user. In addition, access point 1004 can determine available users 1006 on wireless system 1000 and information related thereto. This information may relate to: type of user (e.g., legacy, LTE-a); the number of users of each type, the relative position with the base station, and the expected performance of each type according to the given number of antenna ports, the type of information exchanged and the Qos; number of receive antennas for the UE, etc. From this collected information, the access point 1004 then determines, such as by calculation or via inference, the number of antenna ports (e.g., for legacy users) to advertise. The inference can also be probabilistic-that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. The number of antenna ports advertised may be changed to accommodate system requirements as users enter or leave the wireless network and/or as requirements change. The user may then be notified (e.g., paged, notified through a server) of the associated number of available antenna ports.

Fig. 11 is a block diagram of a system 1100 for adapting a number of antenna ports in a communication system, in accordance with various aspects of the present disclosure. In one example, system 1100 includes one or more base stations 1110 and one or more terminals 1140, which can communicate with each other via respective antennas 1118 and 1148. The number of antenna ports associated with the antenna 1148 may be adapted via the antenna adaptation component 1166 according to the type of user or terminal (e.g., legacy, LTE-a). The number of antenna ports advertised may be changed to accommodate system requirements as users enter or leave the wireless network and/or as requirements change. The user may then be notified (e.g., paged, notified through a server) of the number of associated available antennas. For example, an existing mechanism (e.g., by PBCH in LTE) may be used to advertise the number of transmit antenna ports to legacy UEs, and a larger number of transmit antennas to new UEs by another mechanism. Although only one base station 1110 and one terminal 1140 are illustrated in system 1100, it is to be appreciated that system 1100 can include any suitable number of base stations 1110 and/or terminals 1140, wherein each base station and terminal can employ any suitable number of antenna ports 1118 and/or 1148.

In accordance with one aspect, base station 1110 can transmit data, control signaling, and/or other information in the following manner. First, a data source 1112 at base station 1110 generates information to transmit and/or provides the information to one or more terminals 1140. In one example, data source 1112 can be associated with one or more upper layer applications that provide application data, with a network controller that provides power control and/or scheduling information, and/or with any other suitable entity that provides any other information for communication to terminal 1140. In another example, the information is provided by the data source 1112 in the form of a series of packets, such as Packet Data Convergence Protocol (PDCP) Service Data Units (SDUs).

Information provided by the data source 1112 is then received by a transmit (Tx) buffer 1114, where the Tx buffer 1114 stores transmissions that have not yet been completed by the transmitter 1116. In one example, information transmitted by transmitter 1116 is transmitted as a signal through antenna 1118 to terminal 1140, which is received by receiver 1150 via antenna 1148. The data received at terminal 1140 is then provided to a data sink 1152, which data sink 1152 can be associated with an upper layer application at terminal 1140, a device controller of terminal 1140, and the like.

Additionally, and/or alternatively, terminal 1140 transmits information to base station 1110 using a data source 1142, Tx buffer 1144, transmitter 1146, and antenna 1148 in a manner similar to that described above. Information transmitted by terminal 1140 is then received by base station 1110, receiver 1120, and data sink 1122 in a manner similar to that described above for antenna 1148, receiver 1150, and data sink 1152 at terminal 1140. In one example, base station 1110 can additionally employ processor 1130 and/or memory 1132 to assume and/or implement the functionality of one or more components of the base station described above. As further illustrated by system 1100, terminal 1140 can employ processor 1160 and/or memory 1162 in a similar manner.

Fig. 12 shows a methodology 1200 that begins at 1210 with setting a number of transmit antenna ports for legacy User Equipment (UE) operation in a wireless communication system. The method 1200 then proceeds to 1220 where another number of antenna ports for the new UE to operate in the wireless communication system is set 1220. Next, the method 1200 proceeds to 1230, where transmit antenna ports for legacy UE operation and antenna ports for new UE operation in the wireless communication system are advertised 1230. At 1240, method 1200 transmits data for each of the legacy UE and the new UE via antenna ports corresponding to the legacy UE and the new UE.

The various illustrative logics, logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Further, at least one processor may comprise one or more modules operable to perform one or more of the steps and/or operations described herein.

Further, the steps and/or operations of a method or algorithm described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium may be coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. In addition, in some aspects, the processor and the storage medium may reside in an ASIC. Additionally, the ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. Further, in some aspects, the steps and/or operations of an invention or algorithm may reside as one or any combination or set of codes and/or instructions on a machine readable medium and/or computer readable medium, which may be incorporated into a computer program product.

In one or more exemplary embodiments, the functions described may be implemented as hardware, software, firmware, or any combination of the preceding. When implemented in software, the functions may be one or more instructions or code stored or transmitted on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Magnetic and optical disks, as used in this application, include: compact Discs (CDs), laser discs, optical discs, Digital Versatile Discs (DVDs), floppy discs, and blu-ray discs where discs usually reproduce data magnetically, while optical discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

While exemplary aspects and/or embodiments have been discussed above, it should be noted that various changes and modifications could be made herein without departing from the scope of the described aspects and/or embodiments as defined by the appended claims. Furthermore, although elements of the described methods and/or embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Moreover, all or a portion of any aspect and/or embodiment may be utilized with all or a portion of any other aspect and/or embodiment, unless stated otherwise.

Claims (46)

1. A method for use in a wireless communication system, the method comprising:

setting a number of transmit antenna ports for legacy User Equipment (UE) operation in the wireless communication system;

setting the number of ports of another transmitting antenna used for the operation of the new UE in the wireless communication system;

advertising in the wireless communication system a transmit antenna port for operation of an old UE and a transmit antenna port for operation of a new UE.

2. The method of claim 1, the advertising occurs via a common control channel.

3. The method of claim 1, the advertising occurs via a Physical Broadcast Channel (PBCH) in Long Term Evolution (LTE).

4. The method of claim 1, further comprising the steps of: transmitting all control channels via the transmit antenna ports for legacy UE operation.

5. The method of claim 1, further comprising the steps of: data for each of the legacy UE and the new UE is transmitted via respective transmit antenna ports corresponding to the legacy UE and the new UE.

6. The method of claim 1, the number of additional transmit antenna ports for new UE operation is greater than the number of transmit antenna ports for legacy UE operation.

7. The method of claim 5, further comprising the steps of: increasing the peak rate of the new UE at the expense of the peak rate of the legacy UE.

8. The method of claim 1, further comprising the steps of: the number of advertised antenna ports for legacy UEs is reduced in order to free up resources reserved for Reference Signals (RSs) for use by new UEs.

9. The method of claim 6, further comprising the steps of: the antenna ports are determined based on collecting information related to the number of legacy users, or the number of new users, or the location of the users relative to the base station, or the type of users or exchanged data or expected performance of QoS, or the capabilities of the Rx antennas or UEs, or a combination of the above.

10. An electronic device configured to perform the method of claim 1.

11. A wireless communications apparatus, comprising:

at least one processor configured to:

setting a number of transmit antenna ports for legacy User Equipment (UE) operation in a wireless communication system;

setting the number of ports of another transmitting antenna used for the operation of the new UE in the wireless communication system;

advertising in the wireless communication system a transmit antenna port for operation of an old UE and a transmit antenna port for operation of a new UE.

12. A computer program product, comprising:

a computer-readable medium comprising:

code for causing at least one computer to set a number of transmit antenna ports in a wireless communication system for an old User Equipment (UE) operation and another number of transmit antenna ports for a new UE operation;

code for causing at least one computer to advertise an antenna port in the wireless communication system.

13. An apparatus, comprising:

an antenna adaptation component that sets a number of transmit antenna ports for an old User Equipment (UE) operation and another number of transmit antenna ports for a new UE operation in a wireless communication system;

an antenna advertising component that advertises antenna ports in the wireless communication system.

14. A method for use in a wireless communication system, the method comprising:

adapting the number of antenna ports to intelligently balance the requirements of old and new UEs for overall efficient operation of the wireless communication system;

advertising antenna ports in the wireless communication system.

15. A wireless communications apparatus, comprising:

at least one processor configured to:

the number of antenna ports is adapted so that, for efficient operation of the wireless communication system as a whole,

intelligently balancing the requirements of old User Equipment (UE) and new UE;

advertising antenna ports in the wireless communication system.

16. The wireless communications apparatus of claim 15, the at least one processor further configured to: the antenna ports are advertised to legacy UEs over a Physical Broadcast Channel (PBCH) in Long Term Evolution (LTE).

17. The wireless communications apparatus of claim 15, the at least one processor further configured to: the number of antenna ports is reduced in order to release resources reserved for Reference Signals (RSs) of legacy UEs.

18. The wireless communications apparatus of claim 17, the at least one processor further configured to: improving performance of the new UE at the expense of the legacy UE.

19. The wireless communications apparatus of claim 15, the at least one processor further configured to: the number of available users is determined according to a probabilistic inference.

20. The wireless communications apparatus of claim 19, the at least one processor further configured to: the number of antenna ports is changed according to whether a user enters or leaves the wireless communication system.

21. The wireless communications apparatus of claim 20, the at least one processor further configured to: informing the user of the number of available antenna ports.

22. The wireless communications apparatus of claim 20, the at least one processor further configured to: information is collected about the number of legacy users, or the number of new users, or the location of the users relative to the base station, or the type of users or exchanged data or the expected performance of quality of service (QoS), or the capabilities of the Rx antennas or UEs, or a combination of the above.

23. The wireless communications apparatus of claim 20, the at least one processor further configured to: advertising an antenna port to the new UE through a System Information Block (SIB).

24. An apparatus, comprising:

an adaptation module for adapting the number of antenna ports to intelligently balance the requirements of legacy User Equipment (UE) and new UE for overall efficient operation of the wireless communication system;

an advertising module for advertising antenna ports in the wireless communication system.

25. The apparatus of claim 24, the adaptation module further comprising: means for selecting a number of antenna ports.

26. The apparatus of claim 25, the adaptation module further comprising: means for adjusting the number of antenna ports to requirements of the wireless communication system.

27. The apparatus of claim 25, wherein the adaptation module reduces the number of antenna ports in order to free resources reserved for Reference Signals (RSs) of legacy users.

28. The apparatus of claim 25, wherein the adaptation module improves performance of the new UE at the expense of the legacy UE.

29. The apparatus of claim 25, wherein the adaptation module determines an available number of users based on a probabilistic inference.

30. The apparatus of claim 25, wherein the adaptation module changes the advertised antenna port number based on a user entering or leaving the wireless communication system.

31. The apparatus of claim 26, wherein the advertising module notifies a user of a number of available antenna ports.

32. A computer program product, comprising:

a computer-readable medium comprising:

code for causing at least one computer to adapt a number of antenna ports to intelligently balance requirements of legacy User Equipment (UE) and new UE for overall efficient operation of a wireless communication system;

code for causing at least one computer to advertise an antenna port in the wireless communication system.

33. The computer program product of claim 32, wherein the computer-readable medium further comprises: code for causing at least one computer to reduce the number of antenna ports to release resources reserved for Reference Signals (RSs) of legacy users.

34. The computer program product of claim 32, wherein the computer-readable medium further comprises: code for causing at least one computer to improve performance of the new UE at the expense of the legacy UE.

35. The computer program product of claim 32, wherein the computer-readable medium further comprises: code for causing at least one computer to determine a number of available users based on a probabilistic inference.

36. The computer program product of claim 32, wherein the computer-readable medium further comprises: code for causing at least one computer to change a number of antenna ports in accordance with a user entering or leaving the wireless communication system.

37. The computer program product of claim 32, wherein the computer-readable medium further comprises: code for causing at least one computer to notify a user of a number of available antenna ports.

38. The computer program product of claim 32, wherein the computer-readable medium further comprises: code for causing at least one computer to determine antenna ports based on collecting information related to a number of legacy users, or a number of new users, or a location of a user relative to a base station, or a type of user or exchanged data or expected performance of quality of service (QoS), or capabilities of Rx antennas or UEs, or a combination thereof.

39. The computer program product of claim 32, wherein the computer-readable medium further comprises: code for causing at least one computer to advertise an antenna port to the new UE via a System Information Block (SIB).

40. An apparatus, comprising:

an antenna adaptation component that adapts the number of antenna ports to intelligently balance the needs of legacy User Equipment (UE) and new UE for overall efficient operation of the wireless communication system;

an antenna advertising component that advertises antenna ports in the wireless communication system.

41. The apparatus of claim 40, further comprising: an antenna selection component that selects the antenna port.

42. The apparatus of claim 41, further comprising: an adjustment component that adjusts the number of antenna ports to requirements of the wireless communication system.

43. The apparatus of claim 40, wherein the antenna advertising component advertises antenna ports to the legacy UEs via a PBCH in LTE.

44. The apparatus of claim 42, wherein the adjusting component reduces a number of antenna ports to free resources reserved for Reference Signals (RSs) of legacy users.

45. The apparatus of claim 40, wherein the antenna adaptation component improves performance of the new UE at the expense of the legacy UE.

46. The apparatus of claim 43, wherein the antenna adaptation component determines antenna ports based on collecting information related to a number of legacy users, or a number of new users, or a location of users relative to a base station, or a type of user or exchanged data or expected performance of quality of service (QoS), or capabilities of Rx antennas or UEs, or a combination thereof.