HK1167528A - Antenna virtualization in a wireless communication environment - Google Patents

Description

Antenna virtualization in a wireless communication environment

Cross Reference to Related Applications

The present application claims the benefit of U.S. provisional patent application serial No.61/149,325 entitled "a METHOD and a METHOD FOR MAPPING VIRTUAL patent application' S IN a wide communication SYSTEM," filed on 2.2.2009. The above application is incorporated by reference herein in its entirety.

Technical Field

The following description relates generally to wireless communications, and more specifically to implementing antenna virtualization in a wireless communication system.

Background

Wireless communication systems have been widely deployed to provide various types of communication; for example, voice and/or data may be provided over such wireless communication systems. A typical wireless communication system or network may provide multiple users with access to one or more shared resources (e.g., bandwidth, transmit power, etc.). For example, a system may use multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and so on.

Generally, a wireless multiple-access communication system can simultaneously support communication for multiple User Equipments (UEs). Each UE may be capable of communicating with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the UEs, and the reverse link (or uplink) refers to the communication link from the UEs to the base stations. Such communication links may be established by single-input single-output, multiple-input single-output, or multiple-input multiple-output (MIMO) systems.

MIMO systems typically use multiple (N)_TMultiple) transmitting antenna and multiple (N)_RMultiple) receive antennas for data transmission. From N_TA transmitting antenna and N_RThe MIMO channel formed by the receiving antennas can be decomposed into N_SIndividual channels, which may also be referred to as spatial channels, where N_S≤{N_T，N_R}。N_SEach of the independent channelsOne channel corresponds to one dimension. Furthermore, MIMO systems can provide improved performance (e.g., increased spectral efficiency, higher throughput, and/or higher reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.

MIMO systems may support various duplexing techniques to divide forward and reverse link communications over a common physical medium. For example, a Frequency Division Duplex (FDD) system may use different frequency domains for forward link and reverse link communications. Further, in a Time Division Duplex (TDD) system, forward link communications and reverse link communications may use a common frequency domain, such that the reciprocity principle allows estimation of the forward link channel from the reverse link channel.

Wireless communication systems oftentimes employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast, and/or unicast services, wherein a data stream may be a stream of data that can be of independent reception interest to a UE. A UE within the coverage area of such a base station can be employed to receive one, more than one, or all of the data streams carried by the composite stream. Also, one UE may transmit data to the base station or another UE.

A wireless communication device (e.g., UE, base station, etc.) may be equipped with multiple physical transmit antennas. Oftentimes, the respective signals are provided to use the plurality of physical transmit antennas. Thus, for example, four signals may be provided to use four physical transmit antennas (e.g., each physical transmit antenna transmits a respective one of the four signals, etc.). However, the above-described situation may cause significant overhead. Furthermore, using a subset of the plurality of physical transmit antennas may result in inefficient use of the physical transmit antennas, Power Amplifiers (PAs) associated with the physical transmit antennas, and so on. According to another example, a receiving wireless communication device (e.g., a UE, a base station, etc.) may be unable to receive and/or process the plurality of signals transmitted by the plurality of physical transmit antennas. According to this example, the number of physical transmit antennas equipped by the wireless communication device may exceed the number of physical transmit antennas supported by the receiving wireless communication device.

Disclosure of Invention

The following presents a simplified summary of one or more embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments, and is intended to neither identify key or critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments 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 herein in connection with performance that facilitates antenna virtualization in a wireless communication environment. A set of physical transmit antennas may be divided into a plurality of grouped physical transmit antennas. Further, a precoding vector may be formed for a particular group of physical transmit antennas of the plurality of groups of physical transmit antennas. Furthermore, the particular grouping of physical transmit antennas may form a particular virtual antenna. As another example, different precoding vectors may be formed for different groups of physical transmit antennas of the plurality of groups of physical transmit antennas, and the different groups of physical transmit antennas may form different virtual antennas. The precoding vector may be applied to signals to be transmitted on the particular virtual antenna, and different precoding vectors may be applied to different signals to be transmitted on the different virtual antennas.

According to related aspects, a method that facilitates implementing antenna virtualization in a wireless communication environment is described herein. The method can comprise the following steps: a set of physical transmit antennas is divided into a plurality of grouped physical transmit antennas. Further, the method may comprise: forming a precoding vector for a particular group of physical transmit antennas of the plurality of groups of physical transmit antennas, the particular group of physical transmit antennas forming a particular virtual antenna. Further, the method may comprise: applying the precoding vector to a signal to transmit on the particular virtual antenna.

Another aspect relates to a wireless communications apparatus. The wireless communication apparatus may include: a memory for holding instructions related to: dividing a set of physical transmit antennas into a plurality of grouped physical transmit antennas; generating a precoding vector for a particular group of physical transmit antennas of the plurality of groups of physical transmit antennas, wherein the particular group of physical transmit antennas forms a particular virtual antenna; and applying the precoding vector to a signal to transmit on the particular virtual antenna. Further, the wireless communication apparatus may include: a processor coupled to the memory and configured to execute the instructions retained in the memory.

Yet another aspect relates to a wireless communications apparatus that enables antenna virtualization in a wireless communication environment. The wireless communication apparatus may include: means for dividing a set of physical transmit antennas into a plurality of groups of physical transmit antennas, wherein each of the groups corresponds to a respective virtual antenna. Further, the wireless communication apparatus may include; means for generating respective precoding vectors for the plurality of grouped physical transmit antennas. Further, the wireless communication apparatus includes: means for precoding the transmitted signals using the corresponding precoding vectors.

Yet another aspect relates to a computer program product that may include a computer-readable medium. The computer-readable medium may include: code for dividing a set of physical transmit antennas into a plurality of groups of physical transmit antennas, wherein each of the groups corresponds to a respective virtual antenna. Further, the computer-readable medium may include: code for generating respective precoding vectors for the plurality of grouped physical transmit antennas. Further, the computer-readable medium may include: code for implementing precoding on a signal to transmit using the corresponding precoding vector.

According to another aspect, a wireless communication system may include: a processor, wherein the processor may be configured to divide a set of physical transmit antennas into a plurality of grouped physical transmit antennas. The processor may be further configured to form a precoding vector for a particular group of physical transmit antennas of the plurality of groups of physical transmit antennas, the particular group of physical transmit antennas forming a particular virtual antenna. Further, the processor is further configured to: applying the precoding vector to a signal to transmit on the particular virtual antenna.

To the accomplishment of the foregoing and related ends, the one or more embodiments 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 aspects of the one or more embodiments. These aspects are indicative, however, of but a few of the various ways in which the principles of various embodiments may be employed and the described embodiments are intended to include all such aspects and their equivalents.

Drawings

Fig. 1 depicts a wireless communication system in accordance with various aspects described herein.

Fig. 2 depicts an example system that employs antenna virtualization in a wireless communication environment.

Fig. 3 depicts an example system that facilitates forming precoding vectors corresponding to virtual antennas in a wireless communication environment.

Fig. 4 depicts an example system that performs antenna virtualization at a UE in a wireless communication environment.

Fig. 5 depicts an example system that performs antenna virtualization at a base station in a wireless communication environment.

Fig. 6 depicts an example system that employs virtual antenna ports to transmit signals in a wireless communication environment.

Fig. 7 depicts an example methodology that facilitates implementing antenna virtualization in a wireless communication environment.

Fig. 8 depicts an example methodology that facilitates allowing compatibility with legacy designs by utilizing antenna virtualization in a wireless communication environment.

Fig. 9 depicts an example UE that employs antenna virtualization in a wireless communication system.

Fig. 10 depicts an example system that establishes and utilizes virtual antennas in a wireless communication environment.

Fig. 11 depicts an example wireless network environment that can be employed in conjunction with the various systems and methods described herein.

Fig. 12 depicts an example system that enables antenna virtualization in a wireless communication environment.

Detailed Description

Various embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. 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 embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

As used in this application, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, either 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 example, 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 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 (e.g., 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).

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), single carrier frequency division multiple access (SC-FDMA), and 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. 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 the like. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is an upcoming release of UMTS that uses E-UTRA, which uses OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE, and GSM are described in documents from an organization entitled "third Generation partnership project" (3 GPP). In addition, CDMA2000 and UMB are described in documents from an organization named "third generation partnership project 2" (3GPP 2). Further, these wireless communication systems may additionally include peer-to-peer (e.g., mobile-to-mobile) ad hoc network systems that typically use unpaired unlicensed spectrum, 802.xx wireless LANs, bluetooth, and any other short-range 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 low peak-to-average power ratio (PAPR) due to its inherent single carrier structure. For example, SC-FDMA may be used in uplink communications where a lower PAPR greatly benefits the UE in terms of transmit power efficiency. Thus, SC-FDMA may be implemented as an uplink multiple access scheme in 3GPP Long Term Evolution (LTE) or evolved UTRA.

Furthermore, various embodiments are described herein in connection with a User Equipment (UE). A UE can also be called a system, subscriber unit, subscriber station, mobile, remote station, remote terminal, mobile device, user terminal, wireless communication device, user agent, user device, or access terminal. A UE may be a cellular 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 embodiments are described herein in connection with a base station. A base station may be utilized for communicating with the UEs and may also be referred to as an access point, a node B, an evolved node B (eNodeB, eNB), or some other terminology.

Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, the phrase "X employs a or B" is intended to mean any normal or permutation, unless stated otherwise or clear from context. That is, the phrase "X employs a or B" is satisfied by any one of the following examples: x is A; b is used as X; or X employs A and 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.

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" can include, but is not limited to: wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

Referring now to fig. 1, a system 100 is depicted in accordance with various embodiments presented herein. The system 100 includes: a base station 102, which can include multiple antenna groups. For example, one antenna group can include antenna 104 and antenna 106, another group can include antenna 108 and antenna 110, and an additional group can include antenna 112 and antenna 114. Two antennas are depicted for each antenna group; however, more or fewer antennas may be used 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 signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, etc.), as will be appreciated by one skilled in the art.

Base station 102 may communicate with one or more User Equipments (UEs) such as UE 116 and UE 122; however, it should be appreciated that base station 102 may communicate with virtually any number of UEs similar to UE 116 and UE 122. For example, UE 116 and UE122 may be cellular phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any other suitable device for communicating over system 100. As depicted, UE 116 is in communication with antennas 112 and 114, where antennas 112 and 114 transmit information to UE 116 over a forward link 118 and receive information from UE 116 over a reverse link 120. In addition, UE122 is in communication with antennas 104 and 106, where antennas 104 and 106 transmit information to UE122 over a forward link 124 and receive information from UE122 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 antenna group 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 UEs in a sector of the areas covered by base station 102. In communication over forward link 118 and forward link 124, the transmitting antennas of base station 102 can use beamforming to improve signal-to-noise ratio of forward link 118 and forward link 124 for UE 116 and UE 122. Moreover, when base station 102 uses beamforming to transmit to UEs 116 and 122 scattered randomly through an associated coverage, UEs in neighboring cells can experience less interference as compared to a base station transmitting through a single antenna to all its UEs.

According to one example, a UE (e.g., UE 116, UE122, etc.) may include multiple physical transmit antennas. Generally, a conventional UE includes one physical transmit antenna; therefore, such a normal UE typically transmits signals through the one physical transmit antenna. In contrast, UE 116 and/or UE122 may include multiple physical transmit antennas (e.g., two, four, any integer greater than 1, etc.). For example, UE 116 and/or UE122 may be a long term evolution-advanced (LTE-a) UE that includes multiple physical transmit antennas.

UE 116 and/or UE122 may create virtual antennas by implementing precoding. Establishing virtual antennas by applying precoding may enable efficient use of Power Amplifiers (PAs) associated with these multiple physical transmit antennas when transmitting over the virtual antennas. For example, a UE (e.g., UE 116, UE122, etc.) may include two physical transmit antennas, each of which may be associated with a respective PA. If the virtual antenna is not established and the UE has a signal to send through one of the two physical transmit antennas, then one of the two PAs is used while the other PA remains unused; therefore, the resources of the UE are not efficiently used. Alternatively, the UE may virtualize the two physical transmit antennas as a single virtual antenna. Further, the UE may transmit a signal through the single virtual antenna, which causes the signal to be transmitted through the two physical transmit antennas using the two PAs associated with the two physical transmit antennas. Therefore, it can more efficiently use resources of the UE compared to the conventional technology that fails to utilize the virtual antenna. Furthermore, from an off-device perspective (e.g., from the perspective of base station 102 or the like, where the base station receives signals from the UE), the two physical transmit antennas that form the virtual antenna may appear as a single antenna. However, it should be understood that claimed subject matter is not limited by the foregoing examples.

As another example, base station 102 may include multiple physical transmit antennas. The number of physical transmit antennas of base station 102 may be greater than the number of antennas that are notified to UE 116 and/or UE122 (e.g., legacy UEs, LTE-AUE, etc.). Thus, the base station 102 may implement antenna virtualization to benefit from full utilization of the power of the PAs associated with the multiple physical transmit antennas and to allow for legacy compatible designs.

As set forth herein, a wireless communication device (e.g., base station 102, UE 116, UE122, etc.) may establish a virtual antenna from multiple physical transmit antennas. Moreover, antenna virtualization may be transparent to the receiving wireless communication device (e.g., UE 116, UE122, base station 102, etc.); in this way, the receiving wireless communication device may not be aware of antenna virtualization being implemented by the wireless communication device, precoding performed by the wireless communication device, and so forth. For example, the formation of virtual antennas by base station 102 may be transparent to UE 116 and/or UE 122. Likewise, the establishment of virtual antennas by UEs (e.g., UE 116, UE122, etc.) may be transparent to base station 102, for example.

As another example, antenna virtualization may be non-transparent. In this way, the wireless communication apparatus forming the virtual antenna can indicate to the receiving wireless communication apparatus that antenna virtualization is used, specify the precoding used, and the like. Additionally or alternatively, the receiving wireless communication device may control (e.g., through signaling, etc.) the virtualization details and thus know the virtualization details implemented by the wireless communication devices forming the virtual antenna.

Turning now to fig. 2, depicted is a system 200 that employs antenna virtualization in a wireless communication environment. System 200 includes a wireless communication device 202 that transmits information, signals, data, instructions, commands, bits, symbols, and the like over a channel (e.g., uplink, downlink, etc.) to a receiving wireless communication device (not shown). For example, wireless communications apparatus 202 can be a base station (e.g., base station 102 of fig. 1, etc.), a UE (e.g., UE 116 of fig. 1, UE122 of fig. 1, etc.), and/or the like. Further, the receiving wireless communication apparatus may be, for example, a UE (e.g., UE 116 of fig. 1, UE122 of fig. 1, etc.), a base station (e.g., base station 102 of fig. 1, etc.), or the like.

Wireless communication device 202 may further include an antenna virtualization component 204 and a plurality of physical transmit antennas. Wireless communication device 202 may include T physical transmit antennas (e.g., physical transmit antenna 1206. -, and physical transmit antenna T208), where T may be almost any integer greater than 1. The T physical transmit antennas, including physical transmit antenna 1206. -, and physical transmit antenna T208, are referred to hereinafter as physical transmit antennas 206-. Further, antenna virtualization component 204 can support multiple virtual antennas. For example, the number of virtual antennas provided by antenna virtualization component 204 may be less than or equal to the number of physical transmit antennas 206 and 208 (e.g., the number of virtual antennas is an integer less than or equal to T).

Antenna virtualization component 204 can implement precoding to efficiently utilize physical transmit antennas 206 and 208 and the PAs associated with physical transmit antennas 206 and 208, respectively. For example, antenna virtualization component 204 can use respective precoding vectors for the virtual antennas that it supports. Thus, if two virtual antennas are formed, antenna virtualization component 204 can use two precoding vectors, wherein each of the virtual antennas is associated with a respective one of the precoding vectors; however, it should be understood that claimed subject matter is not so limited. The precoding vectors can be used to form virtual antennas from multiple physical transmit antennas 206-208 (e.g., the set of physical transmit antennas 206-208, a subset from the set of physical transmit antennas 206-208, etc.).

For example, wireless communication device 202 may include two physical transmit antennas (e.g., physical transmit antenna 1206 and physical transmit antenna T208, etc.). Furthermore, antenna virtualization component 204 can support one virtual antenna formed from the two physical transmit antennas, and thus, can use one precoding vector. For example, the precoding vector for the virtual antenna may be a 2-by-1 dimensional vector such as [ α β ]. According to this example, antenna virtualization component 204 can receive signal X to be transmitted over the virtual antenna. Antenna virtualization component 204 can apply the precoding vector to signal X. Thus, antenna virtualization component 204 can multiply signal X by α to produce a first output signal to be transmitted on a first physical transmit antenna (e.g., physical transmit antenna 1206, etc.). Further, antenna virtualization component 204 can multiply signal X by β to generate a second output signal to be transmitted on a second transmit antenna (e.g., physical transmit antenna T208, etc.). At the receiver side, after channel combining, the receiving wireless communication device (not shown) may effectively observe one transmit antenna (e.g., if the receiving wireless communication device has one receive antenna, etc.). However, it is contemplated that claimed subject matter is not limited by the foregoing examples.

Referring to fig. 3, depicted is a system 300 that forms precoding vectors corresponding to virtual antennas in a wireless communication environment. System 300 includes a wireless communication device 202 that can transmit signals over a channel (e.g., uplink, downlink, etc.). Wireless communication device 202 may include an antenna virtualization component 204 and a plurality of physical transmit antennas (e.g., physical transmit antenna 1206.

The wireless communication apparatus 202 may further include: a precoding vector generation component 302 that can form precoding vectors for the virtual antennas. For example, precoding vector generation component 302 can select a number of virtual antennas to be formed from the T physical transmit antennas 206 and 208. Further, precoding vector generation component 302 can generate a respective precoding vector for each virtual antenna to be formed.

According to the example in which the wireless communication apparatus 202 is a UE, the virtualization details including the number of virtual antennas to be formed and the precoding vector for each virtual antenna may be generated by the UE itself through the precoding vector generation component 302. Additionally or alternatively, such virtualization details may be semi-statically signaled by a base station and received by a UE (e.g., wireless communication device 202, etc.). Accordingly, precoding vector generation component 302 (and/or antenna virtualization component 204, etc.) can collect received information specifying the number of virtual antennas to be formed and/or a precoding vector for each virtual antenna.

According to another example, wireless communication apparatus 202 can be a base station. Accordingly, the base station can employ the precoding vector generation component 302 to produce virtualization details including the number of virtual antennas to be formed and the precoding vector for each virtual antenna.

Although not shown, the precoding vectors generated, collected, etc., by precoding vector generation component 302 can be stored in a memory of wireless communication device 202. Further, when performing precoding as described herein, the precoding vector can be fetched by antenna virtualization component 204. The memory may store data to be transmitted, received data, and any other suitable information related to performing the various actions and functions set forth herein. It will be appreciated that the data stores (e.g., memories, etc.) described herein can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. By way of example, and not 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 can include Random Access Memory (RAM), which acts as external cache memory. By way of example, 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 memories of the present systems and methods are intended to include, but not be limited to: these and any other suitable types of memory.

Turning now to fig. 4, depicted is a system 400 that performs antenna virtualization at a UE in a wireless communication environment. System 400 includes a UE 402 (e.g., wireless communication device 202 of fig. 2, etc.) and a base station 404 (e.g., a receiving wireless communication device, etc.). UE 402 may send and/or receive information, signals, data, instructions, commands, bits, symbols, and the like. UE 402 may communicate with base station 404 via the forward link and/or reverse link. Base station 404 can transmit and/or receive information, signals, data, instructions, commands, bits, symbols, and the like. Further, although not shown, it is contemplated that any number of UEs similar to UE 402 can be included in system 400 and/or any number of base stations similar to base station 404 can be included in system 400.

UE 402 includes multiple physical transmit antennas (e.g., physical transmit antenna 1206. -, and physical transmit antenna T208). Further, UE 402 can include precoding vector generation component 302 and antenna virtualization component 204. According to one example, the virtual antennas can be generated by precoding vector generation component 302 by producing a precoding vector. For example, precoding vector generation component 302 can establish L precoding vectors (e.g., precoding vector 1.,. and precoding vector L), where L can be an almost arbitrary integer less than or equal to T (e.g., where T is the number of physical transmit antennas 206. -. 208.). Although not shown, it is contemplated that one precoding vector can be created by precoding vector generation component 302. The precoding vectors provided by precoding vector generation component 302 can enable efficient use of the PA while transmitting signals over the virtual antennas.

According to one example, virtualization details including the number of virtual antennas to be formed and the precoding vector for each virtual antenna may be generated by the UE 402 itself through the use of the precoding vector generation component 302. Additionally or alternatively, the virtualization details may be signaled semi-statically by the base station 404 to the UE 402. Accordingly, precoding vector generation component 302 (and/or antenna virtualization component 204, etc.) can collect received information specifying the number of virtual antennas to be formed and/or a precoding vector for each virtual antenna.

As another example, details regarding precoding to form the virtual antennas may be transparent to the base station 404. Thus, the UE 402 may use the virtual antennas by performing precoding without indicating to the base station 404 that such virtualization is being implemented. However, it is also contemplated that the antenna virtualization performed by the UE 402 may be opaque to the base station 404, and thus, the base station 404 may be aware of the antenna virtualization performed by the UE 402.

The UE 402 may transmit information, signals, data, instructions, commands, bits, symbols, and the like through the uplink to the base station 404. The uplink waveform may be a Discrete Fourier Transform (DFT) precoded OFDM waveform (e.g., a single carrier FDM (SC-FDM) waveform, etc.). A single carrier waveform may have a lower peak-to-average power ratio than a multi-carrier waveform, which may result in a PA with higher efficiency. Thus, when forming virtual antennas, precoding vector generation component 302 can attempt to reduce as much as possible the chances of generating multicarrier waveforms at physical transmit antennas 206 and 208. Accordingly, precoding vector generation component 302 can employ various rules as described herein to produce a precoding vector based on antenna selection.

Precoding vector generation component 302 can form packets from physical transmit antennas 206 and 208 as described below, where a packet corresponds to a particular virtual antenna. Assume that precoding vector generation component 302 is to form L virtual antennas from T physical transmit antennas 206-208. Thus, precoding vector generation component 302 can divide the T physical transmit antennas 206-208 into L groups. Packet i identifies the physical transmit antennas of the T physical transmit antennas 206-208 (e.g., a subset of the T physical transmit antennas 206-208, etc.) that are used to form virtual antenna i, where i is an index, i 0, 1.

Further, precoding vector generation component 302 can form precoding vectors for the packets. Precoding vector generation component 302 can generate a precoding vector from a particular packet, where the precoding vector is a unit norm (unit norm) T-by-1 dimensional vector, where non-zero entries correspond to physical transmit antennas in the particular packet that participate in forming a particular virtual antenna.

According to one example, assume that two virtual antennas (e.g., L2..) are to be formed from four physical transmit antennas 206 and 208 (e.g., T4.). The two virtual antennas may include virtual antenna 1 and virtual antenna 2, four of whichThe physical transmit antennas may include physical transmit antenna 1, physical transmit antenna 2, physical transmit antenna 3, and physical transmit antenna 4. According to this example, an example packet that may be formed by precoding vector generation component 302 may be { {3, 4} {1, 2} }, where a first packet corresponding to virtual antenna 1 includes physical transmit antenna 3 and physical transmit antenna 4 and a second packet corresponding to virtual antenna 2 includes physical transmit antenna 1 and physical transmit antenna 2. Further, precoding vector generation component 302 can form a vector such as [ 00 e ] for virtual antenna 1^jD1 e^jD2]A first precoding vector (e.g., precoding vector 1, etc.) such as/sqrt (2), and a reference signal such as [ e ] for virtual antenna 2^jD3 e^jD4 0 0]A second precoding vector (e.g., precoding vector 2, etc.) such as/sqrt (2), wherein the phase value may be different for different frequency tones (e.g., resources, etc.), and/or the phase value may change over time. However, it should be understood that claimed subject matter is not limited by the foregoing examples.

As another example, two virtual antennas (e.g., L2..) may be formed from four physical transmit antennas 206 and 208 (e.g., T4.). Again, the two virtual antennas may include virtual antenna 1 and virtual antenna 2, and the four physical transmit antennas may include physical transmit antenna 1, physical transmit antenna 2, physical transmit antenna 3, and physical transmit antenna 4. For example, precoding vector generation component 302 may generate two precoding vectors, each having a size of T by 1 dimension (e.g., 4 by 1 dimension). The precoding vector 1 for virtual antenna 1 formed by the precoding vector generation component 302 may be [ α β γ δ ] and the precoding vector 2 for virtual antenna 2 formed by the precoding vector generation component 302 may be [ a b c d ]. Further, the first signal X may be transmitted by using the virtual antenna 1 of the precoding vector 1, [ α β γ δ ], and the second signal Y may be simultaneously transmitted by using the virtual antenna 1 of the precoding vector 2, [ a b c d ]. As such, antenna virtualization component 204 can precode first signal X and second signal Y using precoding vector 1 and precoding vector 2. Thus, X times α plus Y times a, X times β plus Y times b, X times γ plus Y times c, and X times δ plus Y times d may be transmitted on physical transmit antenna 1, physical transmit antenna 2, physical transmit antenna 3, and physical transmit antenna 4. To preserve the single carrier nature of the DFT-precoded OFDM waveform transmitted by the UE 402 to the base station 404 on the uplink, α or a is zero, β or b is zero, γ or c is zero, and δ or d is zero. Thus, each physical transmit antenna 206-208 may be used for one virtual antenna (e.g., virtual antenna 1 or virtual antenna 2 in the foregoing example, etc.) so that multiple signals may be avoided from being transmitted on one physical transmit antenna; thus, each physical transmit antenna 206-208 can transmit a single carrier waveform regardless of whether different signals are transmitted simultaneously on different virtual antennas. However, it should be understood that claimed subject matter is not limited by the foregoing examples.

Precoding vector generation component 302 can cause the formed virtual antennas to occupy a subset of physical transmit antennas 206 and 208. For all physical transmit antennas, non-zero values may be included at respective positions corresponding to a subset of the physical transmit antennas in the precoding vector formed for the virtual antenna. Further, for physical transmit antennas not included in the subset, zeros may be included at corresponding positions in the precoding vector formed for the virtual antennas.

Further, after the virtual antenna has been formed, the virtual antenna may be considered as a physical transmission antenna from the viewpoint of data, reference signal, and control. For example, if the UE 402 has four physical transmit antennas 206-208, the precoding vector generation component 302 may virtualize the four physical transmit antennas 206-208 into two virtual antennas. After virtualization is achieved, the UE 402 may be considered to have two transmit antennas (e.g., two virtual antennas), even though it actually has four physical transmit antennas 206-. Further, the base station 404 may view the UE 402 as having two transmit antennas (e.g., two virtual antennas), and may receive different reference signals, control, data, etc. from the two transmit antennas of the UE 402.

Referring to fig. 5, depicted is a system 500 that performs antenna virtualization at a base station in a wireless communication environment. System 500 includes a base station 502 (e.g., wireless communication device 202 of fig. 2, base station 404 of fig. 4, etc.) and a UE504 (e.g., receiving wireless communication device, UE 402 of fig. 4, etc.). Base station 502 can transmit and/or receive information, signals, data, instructions, commands, bits, symbols, and the like. The base station 502 may communicate with the UE504 via the forward link and/or the reverse link. The UE504 may send and/or receive information, signals, data, instructions, commands, bits, symbols, and the like. Moreover, although not shown, it is contemplated that any number of base stations similar to base station 502 can be included in system 500 and/or any number of UEs similar to UE504 can be included in system 500.

Base station 502 includes multiple physical transmit antennas (e.g., physical transmit antenna 1206. -, and physical transmit antenna T208). Further, base station 502 can include precoding vector generation component 302 and antenna virtualization component 204. According to one example, virtual antennas can be created by precoding vector generation component 302 by generating a precoding vector. For example, L precoding vectors (e.g., precoding vector 1.,. and precoding vector L) can be established by precoding vector generation component 302, where L can be an almost arbitrary integer less than or equal to T (e.g., where T is the number of physical transmit antennas 206. -. 208). Although not shown, it is contemplated that one precoding vector can be created by precoding vector generation component 302. The precoding vectors provided by precoding vector generation component 302 can enable efficient use of the PA while transmitting signals over virtual antennas, such that base station 502 can benefit from full utilization of the PA's power.

In addition, base station 502 can include a notification (advertisement) component 506 that indicates the number of antennas to UE 504. For example, the indicated number of antennas may be the number of virtual antennas formed by precoding vector generation component 302 and/or used by antenna virtualization component 204. The number of physical transmit antennas 206 and 208 included in the base station 502 may be greater than the number of antennas notified to the UE504 (e.g., legacy UE, LTE-a UE, etc.) by the notification component 506. For example, in LTE release 8, the maximum number of downlink physical transmit antennas may be four, while in LTE-a, the maximum number of downlink physical transmit antennas may be eight. Thus, if the UE504 is a legacy UE (e.g., an LTE release 8UE, etc.) operating in an LTE-a network in which the base station 502 includes eight physical transmit antennas 206-. Thus, antenna virtualization may support legacy UEs by providing a design that is compatible with legacy. However, it should be understood that claimed subject matter is not limited by the foregoing examples.

Further, legacy UEs and non-legacy UEs (e.g., LTE-a UEs, etc.) may coexist and operate in a common network. Antenna virtualization may be used for legacy UEs (e.g., four or fewer virtual antennas formed from the eight physical transmit antennas 206 and 208 of the base station 502 for legacy UEs, etc.). According to one example, antenna virtualization can be used for non-legacy UEs (e.g., four or fewer virtual antennas formed from the eight physical transmit antennas 206 and 208 of the base station 502, etc. for non-legacy UEs). As another example, when antenna virtualization is used for legacy UEs, antenna virtualization need not be used for non-legacy UEs. As such, notification component 506 can indicate to non-legacy UEs (e.g., UE504, etc.) the number of physical transmit antennas 206 and 208 of base station 502 or the number of virtual antennas formed by precoding vector generation component 302 and implemented by antenna virtualization component 204. According to the above example where notification component 506 signals to a legacy UE that base station 502 includes four (or fewer) transmit antennas (e.g., four or fewer virtual antennas, etc.) instead of eight physical transmit antennas 206 and 208, notification component 506 may further signal to a non-legacy UE that base station 502 includes four (or fewer) transmit antennas (e.g., four or fewer virtual antennas, etc.) or eight transmit antennas (e.g., eight physical transmit antennas 206 and 208, etc.).

Further, for a downlink scenario, virtualization may be transparent to the UE 504. Thus, the UE504 may lack knowledge of the virtualization details used by the base station 502, e.g., the virtualization implemented, the precoding vectors used, how to generate the precoding vectors, and so on.

The waveform for the downlink may be an OFDM waveform. Thus, in system 500, the constraints employed in connection with uplink antenna virtualization (as described in connection with fig. 4) need not be employed. For example, multiple signals may be transmitted simultaneously on a particular physical transmit antenna (e.g., from physical transmit antennas 206, 208, etc.), and thus, the waveform need not be a single carrier waveform. However, it should be understood that claimed subject matter is not so limited.

The precoding vector generation component 302 can virtualize the physical transmit antennas 206 and 208 as described below. For example, the mapping from physical transmit antennas 206 and 208 to virtual antennas may be any unit modulus precoding vector. The precoding vector may be designed such that the dimensions of the virtual channel are not reduced beyond the number of virtual antennas desired. For example, precoding vector generation component 302 can divide physical transmit antennas 206 and 208 into groups, where each group corresponds to a virtual antenna. Precoding vector generation component 302 can generate one precoding vector for each packet. For example, the precoding vector for a particular packet may be a unit norm vector, where the non-zero entries correspond to the physical transmit antennas in the particular packet that participate in the virtual antenna. As another example, precoding vector generation component 302 can utilize a fixed precoding vector (e.g., different columns of a DFT matrix as precoding vectors for virtual antennas, etc.).

Further, after the virtual antenna has been formed, the virtual antenna may be considered as a physical transmission antenna from the viewpoint of data, reference signal, and control. For example, if the base station 502 has four physical transmit antennas 206-208, the precoding vector generation component 302 can virtualize the four physical transmit antennas 206-208 into two virtual antennas. After virtualization is achieved, the base station 502 may be considered to have two transmit antennas (e.g., two virtual antennas), even though it actually has four physical transmit antennas 206-. Further, the UE504 may view the base station 502 as having two transmit antennas (e.g., two virtual antennas), and may receive different reference signals, control, data, etc. from the two transmit antennas of the base station 502.

Referring now to fig. 6, depicted is a system 600 that employs virtual antenna ports for transmitting signals in a wireless communication environment. The system 600 includes a wireless communication device 202 (e.g., the UE 402 of fig. 4, the base station 502 of fig. 5, etc.). Wireless communication device 202 may further include an antenna virtualization component 204 and a plurality of physical transmit antennas (e.g., physical transmit antenna 1206. Furthermore, L virtual antennas may be formed from the plurality of physical transmit antennas 206-208 described above (e.g., utilizing precoding vector generation component 302 of fig. 3, etc.). As such, wireless communication device 202 may include L virtual antenna ports (e.g., virtual antenna port 1602.,. and virtual antenna port L604) that may be used to transmit respective signals.

According to one example, the wireless communication device 202 may include four physical transmit antennas 206 and 208 (e.g., T4). Furthermore, two virtual antennas (e.g., L2..) may be formed from the four physical transmit antennas 206 and 208. Thus, the wireless communication device 202 may include two virtual antenna ports 602 and 604. Further, a first signal to be transmitted through a first virtual antenna may be provided to a first virtual antenna port (e.g., virtual antenna port 1602, etc.), and a second signal to be transmitted through a second virtual antenna may be provided to a second virtual antenna port (e.g., virtual antenna port L604, etc.). Antenna virtualization component 204 can apply a first precoding vector (e.g., precoding vector 1, etc.) to a first signal obtained by a first virtual antenna port and a second precoding vector (e.g., precoding vector L, etc.) to a second signal obtained by a second virtual antenna port. Thus, according to the above example, two signals may be transmitted over the four physical transmit antennas 206 and 208 (e.g., which results in reduced overhead, since the wireless communication device 202 needs to generate fewer reference signals to transmit).

Furthermore, the precoding vectors described in the present application need not be frequency invariant. Virtualization may be a frequency dependent mapping to provide additional frequency diversity for frequency flat scenes. Schemes similar to Cyclic Delay Diversity (CDD) or frequency-based phase shifting in each packet are examples of frequency-dependent mapping. Furthermore, if wireless communication apparatus 202 is a base station (e.g., base station 502 of fig. 5, etc.), the frequency-dependent mapping may be smooth and not vary rapidly with frequency in order to provide a reasonable channel estimate of the virtual antennas to legacy UEs (not shown) (e.g., UE 502 of fig. 5, etc.). Thus, in order for the virtual antennas to appear similar to physical transmit antennas, the precoding vector may vary smoothly with tone, rather than arbitrarily with tone.

Referring to fig. 7-8, methodologies relating to employing antenna virtualization in a wireless communication environment are depicted. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more embodiments.

With reference to fig. 7, illustrated is a methodology 700 that facilitates implementing antenna virtualization in a wireless communication environment. At 702, a set of physical transmit antennas may be divided into a plurality of grouped physical transmit antennas. For example, the set of physical transmit antennas may include T physical transmit antennas, where T may be almost any integer. Further, the set of T physical transmit antennas may be divided into L groups, where L may be almost any integer less than or equal to T.

At 704, a precoding vector can be formed for a particular group of physical transmit antennas of the plurality of groups of physical transmit antennas. The particular grouping of physical transmit antennas may form a particular virtual antenna. Furthermore, if the set of T physical transmit antennas is divided into L groups, L precoding vectors may be formed. Further, the L precoding vectors may correspond to L virtual antennas. According to one example, different precoding vectors may be formed for different groups of physical transmit antennas of the plurality of groups of physical transmit antennas, wherein the different groups of physical transmit antennas may form different virtual antennas. At 706, the precoding vector can be applied to a signal to transmit on the particular virtual antenna. Further, different precoding vectors corresponding to different virtual antennas may be applied to different signals to be transmitted on the different virtual antennas.

According to an example, the set of physical transmit antennas can be associated with a User Equipment (UE) and the signal can be for transmission over an uplink to a base station. For example, a number of virtual antennas to be formed may be selected (e.g., by a UE or the like), where the number of virtual antennas may be the number of packets into which the set of physical transmit antennas is divided. Further, a precoding vector for the particular packet (and/or a different precoding vector for a different packet) may be selected (e.g., selected by the UE, etc.). As yet another example, an indication can be received from a base station specifying at least one of: the number of virtual antennas to be formed (e.g., the number of virtual antennas may be the number of packets into which the set of physical transmit antennas is divided..) or the precoding vector for a particular packet (and/or different precoding vectors for different packets). Further, information related to antenna virtualization may be transparent to the base station. Further, the waveform transmitted on the uplink may be a single carrier waveform (e.g., a Discrete Fourier Transform (DFT) precoded Orthogonal Frequency Division Multiplexing (OFDM) waveform, etc.). As another example, the precoding vector may be a unit norm vector of size T by 1, where the non-zero entries correspond to physical transmit antennas in a particular group forming the particular virtual antenna, where T is the number of physical transmit antennas in the group. Further, the remaining entries in the T-by-1 dimensional unit norm vector (e.g., corresponding to physical transmit antennas not included in the particular packet, corresponding to physical transmit antennas associated with a different virtual antenna, etc.) may be zero. Furthermore, the non-zero entries in the precoding vector may be constant. Furthermore, the non-zero entries in the precoding vector may be frequency dependent and/or time dependent.

As another example, the set of physical transmit antennas can be associated with a base station and the signal can be for transmission on a downlink to a User Equipment (UE). For example, information related to antenna virtualization may be transparent to the UE. According to one example, the precoding vector may be a unit norm vector. According to another example, the precoding vector can be a unit norm vector whose non-zero entries correspond to physical transmit antennas in a particular group participating in the particular virtual antenna. Yet another example involves: the precoding vector is a particular column of a Discrete Fourier Transform (DFT) matrix, where different columns of the DFT matrix are used for different virtual antennas. Furthermore, the non-zero entries in the precoding vector may be constant. Further, the non-zero entries in the precoding vector may be frequency dependent and/or time dependent.

Turning to fig. 8, depicted is a methodology 800 that facilitates allowing legacy-compatible designs through use of antenna virtualization in a wireless communication environment. At 802, a set of virtual antennas can be established from a set of physical transmit antennas. For example, the set of virtual antennas may be established by a base station. Further, the set of physical transmit antennas associated with the base station may include a greater number of physical transmit antennas than the maximum number of physical transmit antennas that may be used by a legacy base station. For example, the set of physical transmit antennas associated with a base station may include eight physical transmit antennas, while the maximum number of physical transmit antennas that may be used by a legacy base station may be four physical transmit antennas; however, it should be understood that the invention is not so limited. At 804, a legacy User Equipment (UE) may be notified of a number of virtual antennas in the set of virtual antennas. At 806, a non-legacy UE (e.g., a long term evolution-advanced (LTE-a) UE, etc.) may be notified of the number of physical transmit antennas in the set of physical transmit antennas. Thus, virtualization may be used for legacy UEs (e.g., when informing the number of virtual antennas in the set of virtual antennas). However, it is further contemplated that the non-legacy UEs may be informed of the number of virtual antennas in the set of virtual antennas and/or that virtualization may be used for the non-legacy UEs.

It is to be appreciated that, in accordance with one or more aspects described herein, inferences can be made regarding implementing antenna virtualization in a wireless communication environment. As used herein, the term to "infer" or "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 inference can 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-layer events from a set of events and/or data. Such inference results in the construction of new events or actions from a set of observed events and/or stored event data, whether or not the events are correlated in close temporal proximity, and whether the events and stored event data come from one or several event and data sources.

Fig. 9 depicts a UE 900 using antenna virtualization in a wireless communication system. UE 900 includes a receiver 902 that receives a signal from, for instance, 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 symbols and provide them to a processor 906 for channel estimation. Processor 906 can 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 UE 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 UE 900.

The UE 900 may additionally include: a memory 908 operatively coupled to the processor 906 and may store data to be transmitted, received data, and any other suitable information related to performing the various actions and functions described herein. Memory 908, for example, can store protocols and/or algorithms associated with dividing a plurality of physical transmit antennas into a plurality of packets, forming respective precoding vectors for the plurality of packets, and/or the like. Memory 908 may also maintain precoding vectors.

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. By way of example, and not 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 can include Random Access Memory (RAM), which acts as external cache memory. By way of example, and not limitation, RAM may be available in a variety of forms such as Static 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 present systems and methods is intended to comprise, without being limited to: these and any other suitable types of memory.

Processor 906 may be operatively coupled to an antenna virtualization component 910 and/or a precoding vector generation component 912. Antenna virtualization component 910 can be substantially similar to antenna virtualization component 204 of fig. 2 and/or precoding vector generation component 912 can be substantially similar to precoding vector generation component 302 of fig. 3. Precoding vector generation component 912 may generate precoding vectors associated with virtual antennas formed from multiple physical transmit antennas (not shown) of UE 900. Further, antenna virtualization component 910 can implement precoding (e.g., using precoding vectors generated by precoding vector generation component 912, etc.) to transmit signals for transmission over virtual antennas. UE 900 also includes a modulator 914 and a transmitter 916 that transmits data, signals, etc. to the base stations. Although antenna virtualization component 910, precoding vector generation component 912, and/or modulator 914 are depicted as being separate from processor 906, it is to be appreciated that such components can be part of processor 906 or multiple processors (not shown).

Fig. 10 depicts a system 1000 that establishes and utilizes virtual antennas in a wireless communication environment. System 1000 includes a base station 1002 (e.g., an access point, etc.) having a receiver 1010 that receives signals from one or more UEs 1004 via a plurality of receive antennas 1006 and a transmitter 1024 that transmits to the one or more UEs 1004 via a plurality of transmit antennas 1008. Receiver 1010 can receive information from receive antennas 1006 and is operatively associated with a demodulator 1012 that demodulates received information. The demodulated symbols are analyzed by a processor 1014, which is similar to the processor described above with respect to fig. 9, the processor 1014 being coupled to a memory 1016, the memory 1016 holding data to be sent to or received from the UE 1004 and/or any other suitable information related to performing the various actions and functions described herein. Processor 1014 is further coupled to an antenna virtualization component 1018 and/or a precoding vector generation component 1020. Antenna virtualization component 1018 can be substantially similar to antenna virtualization component 204 of fig. 2 and/or precoding vector generation component 1020 can be substantially similar to precoding vector generation component 302 of fig. 3. Precoding vector generation component 1020 can generate precoding vectors associated with virtual antennas formed from multiple physical transmit antennas 1008 of base station 1002. Further, antenna virtualization component 1018 can implement precoding (e.g., using precoding vectors generated by precoding vector generation component 1020, etc.) to transmit signals for transmission over the virtual antennas. Although not shown, it is contemplated that base station 1002 can further include a notification component substantially similar to notification component 506 of fig. 5. Base station 1002 can further comprise a modulator 1022. A modulator 1022 can multiplex the frame for transmission by a transmitter 1024 via antenna 1008 to UE 1004 as described supra. Although depicted as being separate from processor 1014, it is to be appreciated that antenna virtualization component 1018, precoding vector generation component 1020, and/or modulator 1022 can be part of processor 1014 or multiple processors (not shown).

Fig. 11 illustrates an exemplary wireless communication system 1100. The wireless communication system 1100 depicts one base station 1110 and one UE 1150 for sake of brevity. However, it is to be appreciated that system 1100 can include more than one base station and/or more than one UE, wherein additional base stations and/or UEs can be substantially similar or different from example base station 1110 and UE 1150 described below. Moreover, it is to be appreciated that base station 1110 and/or UE 1150 can employ the systems (e.g., fig. 1-6, 9-10, and 12) and/or methods (fig. 7-8) described herein to facilitate wireless communication there between.

At base station 1110, traffic data for a number of data streams can be provided from a data source 1112 to a Transmit (TX) data processor 1114. According to an example, each data stream can be transmitted over a respective antenna. TX data processor 1114 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 for each data stream can be multiplexed with pilot data using Orthogonal Frequency Division Multiplexing (OFDM) techniques. Additionally or alternatively, the pilot symbols may be Frequency Division Multiplexed (FDM), Time Division Multiplexed (TDM), or Code Division Multiplexed (CDM). In general, the pilot data is a known data pattern that is processed in a known manner and may be used by the UE 1150 to estimate the channel response. The multiplexed pilot and coded data for each data stream can be 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 1130.

The modulation symbols for the data streams can be provided to a TX MIMO processor 1120, and the modulation symbols can be further processed by TX MIMO processor 1120 (e.g., for OFDM). TX MIMO processor 1120 then forwards to N_TN are provided by transmitters (TMTR)1122a through 1122t_TA stream of modulation symbols. In various embodiments, TX MIMO processor 1120 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

Each transmitter 1122 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. In addition, from N respectively_TN transmitted by antennas 1124a through 1124t from transmitters 1122a through 1122t_TA modulated signal.

At UE 1150, N_RThe transmitted modulated signals are received by antennas 1152a through 1152r and the received signal from each antenna 1152 is provided to a respective receiver (RCVR)1154a through 1154 r. Each receiver 1154 conditions (e.g., filters)Waves, 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 1160 may be selected from N_RN is received by a receiver 1154_RA received symbol stream is processed based on a particular receiver processing technique to provide N_TA "detected" symbol stream. RX data processor 1160 can demodulate, deinterleave, and decode each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 1160 is complementary to that performed by TX MIMO processor 1120 and TX data processor 1114 at base station 1110.

As described above, processor 1170 may periodically determine which available technology to use. Further, processor 1170 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 can be processed by a TX data processor 1138, modulated by a modulator 1180, conditioned by transmitters 1154a through 1154r, and transmitted back to base station 1110, wherein TX data processor 1138 also receives traffic data for a number of data streams from a data source 1136.

At base station 1110, the modulated signals from UE 1150 are received by antennas 1124, conditioned by receivers 1122, demodulated by a demodulator 1140, and processed by a RX data processor 1142 to extract the reverse link message transmitted by UE 1150. Further, processor 1130 can process the extracted message to determine which precoding matrix to use for determining the beamforming weights.

Processor 1130 and processor 1170 can direct (e.g., control, coordinate, manage, etc.) operation at base station 1110 and UE 1150, respectively. Respective processors 1130 and 1170 can be associated with memory 1132 and 1172 that store program codes and data. Processor 1130 and processor 1170 can also perform computations to derive frequency and impulse response estimates for the uplink and downlink, respectively.

In one aspect, logical channels are divided into control channels and traffic channels. The logical control channels may include: broadcast Control Channel (BCCH), which is DL channel for broadcasting system control information. Further, the logical control channels may include: paging Control Channel (PCCH), which is DL channel that transmits paging information. Further, the logical control channels may include: multicast Control Channel (MCCH), which is a point-to-multipoint DL channel used for transmitting Multimedia Broadcast and Multicast Service (MBMS) scheduling and control information for one or several MTCHs. Generally, after establishing a Radio Resource Control (RRC) connection, this channel is only used by UEs receiving MBMS (note: old MCCH + MSCH). Additionally, the logical control channels may include: dedicated Control Channel (DCCH), which is a point-to-point bi-directional channel that transmits dedicated control information, which may be used by UEs having an RRC connection. In one aspect, a logical traffic channel may include: dedicated Traffic Channel (DTCH), which is a point-to-point bi-directional channel dedicated to one UE for user information transfer. In addition, the logical traffic channels may include a Multicast Traffic Channel (MTCH) of a point-to-multipoint DL channel for transmitting traffic data.

In one aspect, the transport channels are divided into DL and UL. DL transport channels include a Broadcast Channel (BCH), a downlink shared data channel (DL-SDCH) and a Paging Channel (PCH). The PCH may support UE power saving by being broadcast over the entire cell and mapped to physical layer (PHY) resources that may be used for other control/traffic channels (e.g., Discontinuous Reception (DRX) cycles may be indicated to the UE by the network, etc.). The UL transport channels may include a Random Access Channel (RACH), a request channel (REQCH), an uplink shared data channel (UL-SDCH), and a plurality of PHY channels.

The PHY channels may include a set of DL channels and UL channels. For example, DL PHY channels may include: common pilot channel (CPICH); a Synchronization Channel (SCH); common Control Channel (CCCH); shared DL Control Channel (SDCCH); multicast Control Channel (MCCH); shared UL Allocation Channel (SUACH); acknowledgement channel (ACKCH); DL physical shared data channel (DL-PSDCH); UL Power Control Channel (UPCCH); a Paging Indicator Channel (PICH); and/or a Load Indicator Channel (LICH). As another example, the UL PHY channels may include: physical Random Access Channel (PRACH); a Channel Quality Indicator Channel (CQICH); acknowledgement channel (ACKCH); an Antenna Subset Indicator Channel (ASICH); shared request channel (SREQCH); UL physical shared data channel (UL-PSDCH); and/or a wideband pilot channel (BPICH).

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the processing units may be implemented within one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

When the embodiments are implemented in software, firmware, middleware or microcode, program code or code segments, they may be stored in a machine-readable medium, such as a storage component. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted using any suitable means including memory sharing, message passing, token passing, network transmission, etc.

For a software implementation, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory units and executed by processors. The memory unit may be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art.

Referring to fig. 12, depicted is a system 1200 that enables antenna virtualization in a wireless communication environment. System 1200 can reside in a UE, for instance. As another example, system 1200 can reside at least partially within a base station. It is to be appreciated that system 1200 is represented as including functional blocks, which can represent functions implemented by a processor, software, or combination thereof (e.g., firmware). System 1200 includes a logical grouping 1202 of electrical components that can act in conjunction. For example, logical grouping 1202 may include: an electrical component 1204 for dividing a set of physical transmit antennas into a plurality of grouped physical transmit antennas. Further, each of these packets corresponds to a respective virtual antenna. Further, logical grouping 1202 may include: an electrical component 1206 for generating respective precoding vectors for the plurality of grouped physical transmit antennas. Further, logical grouping 1202 may include: an electrical component for implementing precoding on the transmitted signals using the respective precoding vectors 1208. Additionally, system 1200 may include: memory 1210 retains instructions for executing functions associated with electrical components 1204, 1206, and 1208. While electrical components 1204, 1206, and 1208 are illustrated as being located outside of memory 1210, it is to be understood that one or more of electrical components 1204, 1206, and 1208 may be located within memory 1210.

What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim.

Claims (41)

1. A method that facilitates implementing antenna virtualization in a wireless communication environment, comprising:

dividing a set of physical transmit antennas into a plurality of grouped physical transmit antennas;

forming a precoding vector for a particular group of physical transmit antennas of the plurality of groups of physical transmit antennas, the particular group of physical transmit antennas forming a particular virtual antenna; and

applying the precoding vector to a signal to transmit on the particular virtual antenna.

2. The method of claim 1, wherein the set of physical transmit antennas comprises T physical transmit antennas, and the set of T physical transmit antennas is divided into L groups of physical transmit antennas, where T is an integer and L is an integer less than or equal to T.

3. The method of claim 2, wherein L precoding vectors corresponding to L virtual antennas are formed.

4. The method of claim 1, further comprising:

forming different precoding vectors for different groups of physical transmit antennas of the plurality of groups of physical transmit antennas, the different groups of physical transmit antennas forming different virtual antennas; and

applying the different precoding vectors to different signals to transmit on the different virtual antennas.

5. The method of claim 1, wherein the set of physical transmit antennas is associated with a User Equipment (UE) and the signal is for transmission on an uplink to a base station.

6. The method of claim 5, further comprising:

selecting a number of virtual antennas to form, wherein the number of virtual antennas is the number of packets into which the set of physical transmit antennas is divided.

7. The method of claim 5, further comprising:

for the particular packet, a precoding vector is selected.

8. The method of claim 5, further comprising:

receiving an indication from the base station, the indication specifying at least one of:

the number of virtual antennas to be formed or the precoding vector for the particular packet.

9. The method of claim 5, wherein the information related to antenna virtualization is transparent to the base station.

10. The method of claim 5, wherein the precoding vector is a unit norm vector of size T by 1, where non-zero entries correspond to physical transmit antennas in a particular group forming the particular virtual antenna, where T is a number of physical transmit antennas in the set of physical transmit antennas.

11. The method of claim 10, wherein remaining entries in the precoding vector corresponding to physical transmit antennas associated with different virtual antennas are zeros.

12. The method of claim 10, wherein the non-zero entries in the precoding vector are constant.

13. The method of claim 10, wherein the non-zero entries in the precoding vector are at least one of frequency dependent or time dependent.

14. The method of claim 1, wherein the set of physical transmit antennas is associated with a base station and the signal is for transmission on a downlink to a User Equipment (UE).

15. The method of claim 14, wherein the information related to antenna virtualization is transparent to the UE.

16. The method of claim 14, wherein the precoding vector is a unit norm vector.

17. The method of claim 14, wherein the precoding vector is a unit norm vector with non-zero entries corresponding to physical transmit antennas in a particular group participating in the particular virtual antenna.

18. The method of claim 14, wherein the precoding vector is a particular column of a Discrete Fourier Transform (DFT) matrix, wherein different columns of the DFT matrix are used for different virtual antennas.

19. The method of claim 14, further comprising:

establishing a set of virtual antennas from the set of physical transmit antennas;

notifying the legacy UE of the number of virtual antennas in the set of virtual antennas; and

notifying a non-legacy UE of the number of physical transmit antennas in the set of physical transmit antennas.

20. A wireless communications apparatus, comprising:

a memory for holding instructions related to the following operations:

dividing a set of physical transmit antennas into a plurality of grouped physical transmit antennas;

forming a precoding vector for a particular group of physical transmit antennas of the plurality of groups of physical transmit antennas, wherein the particular group of physical transmit antennas forms a particular virtual antenna; and

applying the precoding vector to a signal to transmit on the particular virtual antenna; and

a processor, coupled to the memory, configured to execute the instructions retained in the memory.

21. The wireless communications apparatus of claim 20, wherein the information related to antenna virtualization is transparent to a receiving wireless communications apparatus.

22. The wireless communications apparatus of claim 20, wherein the set of physical transmit antennas is associated with a User Equipment (UE) and the signal is for transmission on an uplink to a base station.

23. The wireless communications apparatus of claim 22, wherein the memory further retains instructions related to:

selecting a number of virtual antennas to form, wherein the number of virtual antennas is the number of packets into which the set of physical transmit antennas is divided; and

for the particular packet, a precoding vector is selected.

24. The wireless communications apparatus of claim 22, wherein the memory further retains instructions related to:

receiving an indication from the base station, the indication specifying at least one of:

a number of virtual antennas to be formed, wherein the number of virtual antennas is a number of packets into which the set of physical transmit antennas is divided;

or a precoding vector for the particular packet.

25. The wireless communications apparatus of claim 22, wherein the precoding vector is a unit norm vector of size T by 1, where non-zero entries correspond to physical transmit antennas in a particular group forming the particular virtual antenna, where T is a number of physical transmit antennas in the group, and remaining entries in the precoding vector are zero.

26. The wireless communications apparatus of claim 20, wherein the set of physical transmit antennas is associated with a base station and the signal is for transmission on a downlink to a User Equipment (UE).

27. The wireless communications apparatus of claim 26, wherein the precoding vector is a unit norm vector with non-zero entries corresponding to physical transmit antennas in a particular group participating in the particular virtual antenna.

28. The wireless communications apparatus of claim 27, wherein non-zero entries in the precoding vector are constant.

29. The wireless communications apparatus of claim 27, wherein the non-zero entries in the precoding vector are at least one of frequency dependent or time dependent.

30. The wireless communications apparatus of claim 26, wherein the precoding vector is a particular column of a Discrete Fourier Transform (DFT) matrix, wherein different columns of the DFT matrix are utilized for different virtual antennas.

31. The wireless communications apparatus of claim 26, wherein the memory further retains instructions related to:

notifying a legacy UE of a number of virtual antennas corresponding to the number of packets; and

notifying a non-legacy UE of the number of physical transmit antennas in the set of physical transmit antennas.

32. A wireless communications apparatus that enables antenna virtualization in a wireless communication environment, comprising:

means for dividing a set of physical transmit antennas into a plurality of groups of physical transmit antennas, wherein each of the groups corresponds to a respective virtual antenna;

means for generating respective precoding vectors for the plurality of grouped physical transmit antennas; and

means for precoding the transmitted signals using the corresponding precoding vectors.

33. The wireless communications apparatus of claim 32, wherein the respective precoding vectors are respective unit norm vectors of size T by 1, where non-zero entries correspond to physical transmit antennas that respectively form respective virtual antennas, where T is a number of physical transmit antennas in the group.

34. The wireless communications apparatus of claim 32, wherein the respective precoding vectors are respective unit norm vectors.

35. The wireless communications apparatus of claim 32, wherein the respective precoding vectors are respective columns of a Discrete Fourier Transform (DFT) matrix.

36. The wireless communications apparatus of claim 32, wherein information related to antenna virtualization is transparent to a receiving wireless communications apparatus.

37. A computer program product, comprising:

a computer-readable medium comprising:

code for dividing a set of physical transmit antennas into a plurality of groups of physical transmit antennas, wherein each of the groups corresponds to a respective virtual antenna;

code for generating respective precoding vectors for the plurality of grouped physical transmit antennas; and

code for precoding the transmitted signal using the corresponding precoding vector.

38. The computer program product of claim 37, wherein the respective precoding vectors are respective unit norm vectors of size T by 1, where non-zero entries correspond to physical transmit antennas that respectively form each respective virtual antenna, where T is a number of physical transmit antennas in the group.

39. The computer program product of claim 37, wherein the respective precoding vectors are respective columns of a Discrete Fourier Transform (DFT) matrix.

40. The computer program product of claim 37, wherein the information related to antenna virtualization is transparent to a receiving wireless communication device.

41. A wireless communications apparatus, comprising:

a processor configured to:

dividing a set of physical transmit antennas into a plurality of grouped physical transmit antennas;

forming a precoding vector for a particular group of physical transmit antennas of the plurality of groups of physical transmit antennas, the particular group of physical transmit antennas forming a particular virtual antenna; and

applying the precoding vector to a signal to transmit on the particular virtual antenna.