Method and apparatus for application of precoder information at the UE in closed loop transmit diversity

Apparatus and methods are described herein for applying precoding information updates at a user equipment (UE). The UE receives precoder information from a network component. The UE can them transmit packet data over a transmit time interval (TTI) of tow or more slots using transmit diversity. The UE updates the precoder for transmit diversity with the precoder information in a slot subsequent to the first slot in the TTI. The precoder information is applied to update the precoder at a slot boundary within the TTI.

BACKGROUND

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, for performing closed loop transmit diversity.

As the demand for mobile broadband access continues to increase, research and development continue to advance the UMTS technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.

SUMMARY

In accordance with some aspects, a method for wireless communication is described. The method includes receiving precoder information and transmitting packet data over a transmit time interval (TTI) of two or more slots from two or more antennas. The method also includes updating a precoder with precoder information in a slot subsequent to a first slot in the TTI. The precoder information is applied at a slot boundary within the TTI.

Other aspects include one or more of: a computer program product having a computer-readable medium including at least one instruction operable to cause a computer to perform the above-described method; an apparatus including one or more means for performing the above-described method; and an apparatus having a memory in communication with a processor that is configured to perform the above-described method.

These and other aspects of the invention will become more fully understood upon a review of the detailed description, which follows.

DETAILED DESCRIPTION

An apparatus and method addresses application of Precoder Information (PCI) at the User Equipment (UE). If the PCI information is applied by the User Equipment (UE) at a Transmit Time Interval (TTI) boundary and the PCI update rate is three slots, then the precoder applied by the UE remains constant for the duration of the TTI. Therefore, if there is a PCI feedback error, the applied erroneous precoder compromises the data transmission in that TTI. The present innovation mitigates this problem by applying the precoder in the second or subsequent slot of a TTI. This allows for the correct precoder to be applied at least in a portion of the TTI. The probability of the erroneous precoding information being applied over the duration of a TTI is reduced.

With reference toFIG. 1, in a cellular communication system100, user apparatus, depicted as user equipment (UE)102, receives feedback104from a base node, or merely node106, which is currently serving the UE102. The node106has a transmitter110and receiver112of a transceiver114for communicating via one or more antennas116with the UE102respectively on a downlink118and an uplink120. The UE102has a transmitter122and receiver124of a transceiver126for communicating via more than one antenna128with the node106respectively on the uplink120and the downlink118. In particular, a diversity controller130uses the feedback data104(e.g., Precoder Information (PCI)) to update a precoder132with delays appropriate for each respective antenna to achieve transmit diversity. In some aspects, transmit diversity may be achieved via beamforming for closed loop transmit diversity (CLTD). In other aspects, transmit diversity may be achieved using uplink (UL) multiple-input-multiple-output (MIMO). Other transmit diversity techniques are equally applicable.

FIG. 2is a timing diagram depicting the application of PCI feedback information. In this example, the PCI feedback update rate is three slots, and the PCI bits are transmitted on the fractional dedicated physical channel (F-DPCH). While the F-DPCH is shown in this example, any other F-DPCH-like channel, such as the fractional transmitted precoding indicator channel (F-TPCH) may also be used for transmitting the PCI bits. The UE updates the precoder only at the TTI boundary. As shown at210, DL signals are transmitted from a network component, such as a UTRAN, via the DL F-DPCH. As shown at220, DL signals are received at the UE via the DL F-DPCH. As shown at230, UL signals are transmitted from the UE via the UL DPCCH, and as shown at240, DL signals are received at the UTRAN via the UL DPCCH.

Each slot comprises 2560 chips. As shown at212, a first PCI bit is transmitted in a first slot, and as shown at214, a second PCI bit is transmitted in a second slot. Due to propagation delay τp, the transmitted signal is received at the UE with a timing offset. The first PCI bit is received at the UE, as shown at222, and the second PCI bit is received at the UE, as shown at224. Upon receipt of the two PCI bits, the UE can update the precoder. As shown at232, the UE may apply the PCI feedback information at the TTI boundary. Because the PCI update is applied at the TTI boundary, the precoder applied by the UE remains constant for the duration of the TTI. As such, if a PCI feedback error occurs, the data transmission transmitted during that TTI may be compromised.

FIG. 3depicts an example timing diagram wherein PCI updates are performed at slot boundaries, and not restricted to the TTI boundary. Similar toFIG. 2, the PCI feedback update rate is three slots, and the PCI bits are transmitted on the F-DPCH (or other similar channel such as the F-TPICH). As shown at310, DL signals are transmitted from a network component, such as a UTRAN, via the DL F-DPCH. As shown at320, DL signals are received at the UE via the DL F-DPCH. As shown at330, UL signals are transmitted from the UE via the UL DPCCH, and as shown at340, DL signals are received at the UTRAN via the UL DPCCH.

As shown at312, a first PCI bit is transmitted in a first slot, and as shown at314, a second PCI bit is transmitted in a second slot. Due to propagation delay τp, the transmitted signal is received at the UE with a timing offset. The first PCI bit is received at the UE, as shown at322, and the second PCI bit is received at the UE, as shown at324. Upon receipt of the two PCI bits, the UE can update the precoder. As shown at332, the UE may apply the PCI feedback information at the next available slot boundary upon receipt of the second PCI bit. This allows the correct precoder to be applied during at least a portion of the TTI, even if a PCI feedback error occurs.

FIG. 4depicts a method400for applying precoder update information, in accordance with some aspects. As shown at402, precoder information may be received via a downlink transmission channel. For example, the precoder information may be received from a network component, such as a UTRAN, providing information that can be used for uplink data transmission by a UE. In some aspects, the precoder information may be received by the UE on the F-DCPH, F-TPICH, and/or another similar channel

The UE may transmit packet data over a transmit time interval (TTI), as shown at404. The TTI may be, for example, two or more slots. In some aspects, the packet data may be transmitted using closed loop transmit diversity (CLTD), and may be transmitted from two or more antennas. In other aspects, the UE may transmit packet data via UL MIMO. As shown at406, a precoder may be updated with the received precoder information in a slot subsequent to a first slot in the TTI. The precoder information may be applied at a slot boundary within the TTI, and not at the TTI boundary, in order to increase accuracy of the transmitted data.

The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. By way of example and without limitation, the aspects of the present disclosure illustrated inFIG. 5are presented with reference to a UMTS system500employing a W-CDMA air interface. A UMTS network includes three interacting domains: a Core Network (CN)504, a UMTS Terrestrial Radio Access Network (UTRAN)504, and User Equipment (UE)510. In this example, the UTRAN502provides various wireless services including telephony, video, data, messaging, broadcasts, and/or other services. The UTRAN502may include a plurality of Radio Network Subsystems (RNSs) such as an RNS505, each controlled by a respective Radio Network Controller (RNC) such as an RNC506. Here, the UTRAN502may include any number of RNCs506and RNSs505in addition to the RNCs506and RNSs3005illustrated herein. The RNC506is an apparatus responsible for, among other things, assigning, reconfiguring and releasing radio resources within the RNS505. The RNC506may be interconnected to other RNCs (not shown) in the UTRAN502through various types of interfaces such as a direct physical connection, a virtual network, or the like, using any suitable transport network.

Communication between a UE510and a NodeB508may be considered as including a physical (PHY) layer and a medium access control (MAC) layer. Further, communication between a UE510and an RNC506by way of a respective NodeB508may be considered as including a radio resource control (RRC) layer. In the instant specification, the PHY layer may be considered layer1; the MAC layer may be considered layer2; and the RRC layer may be considered layer3. Information herein below utilizes terminology introduced in Radio Resource Control (RRC) Protocol Specification, 3GPP TS 25.331 v9.1.0, incorporated herein by reference.

The geographic region covered by the SRNS505may be divided into a number of cells, with a radio transceiver apparatus serving each cell. A radio transceiver apparatus is commonly referred to as a NodeB in UMTS applications, but may also be referred to by those skilled in the art as a base station (BS), a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), or some other suitable terminology. For clarity, three NodeBs508are shown in each SRNS505; however, the SRNSs505may include any number of wireless NodeBs. The NodeBs508provide wireless access points to a core network (CN)504for any number of mobile apparatuses. Examples of a mobile apparatus include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a notebook, a netbook, a smartbook, a personal digital assistant (PDA), a satellite radio, a global positioning system (GPS) device, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, or any other similar functioning device. The mobile apparatus is commonly referred to as user equipment (UE) in UMTS applications, but may also be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. In a UMTS system, the UE510may further include a universal subscriber identity module (USIM)511, which contains a user's subscription information to a network. For illustrative purposes, one UE510is shown in communication with a number of the NodeBs508. The downlink (DL), also called the forward link, refers to the communication link from a NodeB508to a UE510, and the uplink (UL), also called the reverse link, refers to the communication link from a UE510to a NodeB508.

The core network504interfaces with one or more access networks, such as the UTRAN502. As shown, the core network504is a GSM core network. However, as those skilled in the art will recognize, the various concepts presented throughout this disclosure may be implemented in a RAN, or other suitable access network, to provide UEs with access to types of core networks other than GSM networks.

The core network504includes a circuit-switched (CS) domain and a packet-switched (PS) domain. Some of the circuit-switched elements are a Mobile services Switching Centre (MSC), a Visitor location register (VLR) and a Gateway MSC. Packet-switched elements include a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN). Some network elements, like EIR, HLR, VLR and AuC may be shared by both of the circuit-switched and packet-switched domains. In the illustrated example, the core network504supports circuit-switched services with a MSC512and a GMSC514. In some applications, the GMSC514may be referred to as a media gateway (MGW). One or more RNCs, such as the RNC506, may be connected to the MSC512. The MSC512is an apparatus that controls call setup, call routing, and UE mobility functions. The MSC512also includes a visitor location register (VLR) that contains subscriber-related information for the duration that a UE is in the coverage area of the MSC512. The GMSC514provides a gateway through the MSC512for the UE to access a circuit-switched network516. The GMSC514includes a home location register (HLR)515containing subscriber data, such as the data reflecting the details of the services to which a particular user has subscribed. The HLR is also associated with an authentication center (AuC) that contains subscriber-specific authentication data. When a call is received for a particular UE, the GMSC514—queries the HLR515to determine the UE's location and forwards the call to the particular MSC serving that location.

The core network504also supports packet-data services with a serving GPRS support node (SGSN)518and a gateway GPRS support node (GGSN)520. GPRS, which stands for General Packet Radio Service, is designed to provide packet-data services at speeds higher than those available with standard circuit-switched data services. The GGSN520provides a connection for the UTRAN502to a packet-based network522. The packet-based network522may be the Internet, a private data network, or some other suitable packet-based network. The primary function of the GGSN520is to provide the UEs510with packet-based network connectivity. Data packets may be transferred between the GGSN520and the UEs510through the SGSN518, which performs primarily the same functions in the packet-based domain as the MSC512performs in the circuit-switched domain.

The UMTS air interface is a spread spectrum Direct-Sequence Code Division Multiple Access (DS-CDMA) system. The spread spectrum DS-CDMA spreads user data through multiplication by a sequence of pseudorandom bits called chips. The W-CDMA air interface for UMTS is based on such direct sequence spread spectrum technology and additionally calls for a frequency division duplexing (FDD). FDD uses a different carrier frequency for the uplink (UL) and downlink (DL) between a NodeB508and a UE510. Another air interface for UMTS that utilizes DS-CDMA, and uses time division duplexing, is the TD-SCDMA air interface. Those skilled in the art will recognize that although various examples described herein may refer to a WCDMA air interface, the underlying principles are equally applicable to a TD-SCDMA air interface.

An HSPA air interface includes a series of enhancements to the 3G/W-CDMA air interface, facilitating greater throughput and reduced latency. Among other modifications over prior releases, HSPA utilizes hybrid automatic repeat request (HARQ), shared channel transmission, and adaptive modulation and coding. The standards that define HSPA include HSDPA (high speed downlink packet access) and HSUPA (high speed uplink packet access, also referred to as enhanced uplink, or EUL).

HSDPA utilizes as its transport channel the high-speed downlink shared channel (HS-DSCH). The HS-DSCH is implemented by three physical channels: the high-speed physical downlink shared channel (HS-PDSCH), the high-speed shared control channel (HS-SCCH), and the high-speed dedicated physical control channel (HS-DPCCH).

Among these physical channels, the HS-DPCCH carries the HARQ ACK/NACK signaling on the uplink to indicate whether a corresponding packet transmission was decoded successfully. That is, with respect to the downlink, the UE510provides feedback to the NodeB508over the HS-DPCCH to indicate whether it correctly decoded a packet on the downlink.

HS-DPCCH further includes feedback signaling from the UE510to assist the NodeB508in taking the right decision in terms of modulation and coding scheme and precoding weight selection, this feedback signaling including the CQI and PCI.

HSUPA utilizes as its transport channel, the enhanced dedicated channel (E-DCH). The E-DCH is implemented by three physical channels: the enhanced dedicated physical data channel (E-DPDCH), the enhanced dedicated physical control channel (E-DPCCH), and the enhanced hybrid ARQ indicator channel (E-HICH)

“HSPA Evolved” or HSPA+ is an evolution of the HSPA standard that includes MIMO and 64-QAM, enabling increased throughput and higher performance. That is, in an aspect of the disclosure, the NodeB508and/or the UE510may have multiple antennas supporting MIMO technology. The use of MIMO technology enables the NodeB3008to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity.

Multiple Input Multiple Output (MIMO) is a term generally used to refer to multi-antenna technology, that is, multiple transmit antennas (multiple inputs to the channel) and multiple receive antennas (multiple outputs from the channel). MIMO systems generally enhance data transmission performance, enabling diversity gains to reduce multipath fading and increase transmission quality, and spatial multiplexing gains to increase data throughput. On the other hand, Single Input Multiple Output (SIMO) generally refers to a system utilizing a single transmit antenna (a single input to the channel) and multiple receive antennas (multiple outputs from the channel). Thus, in a SIMO system, a single transport block is sent over the respective carrier.

UE510can incorporate the diversity controller130(FIG. 1) to perform the methodology400and other aspects as described herein. The UTRAN502can similarly incorporate the diversity controller130(FIG. 1) to perform the methodology400and other aspects as described herein.

Referring toFIG. 6, an access network600in a UTRAN architecture is illustrated. The multiple access wireless communication system includes multiple cellular regions (cells), including cells602,604, and606each of which may include one or more sectors. The multiple sectors can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell. For example, in cell602, antenna groups612,614, and616may each correspond to a different sector. In cell604, antenna groups618,620, and622each correspond to a different sector. In cell606, antenna groups624,626, and628each correspond to a different sector. The cells602,604and606may include several wireless communication devices, e.g., User Equipment or UEs, which may be in communication with one or more sectors of each cell602,604or606. For example, UEs630and632may be in communication with NodeB642, UEs634and636may be in communication with NodeB644, and UEs638and640can be in communication with NodeB646. Here, each NodeB642,644,646is configured to provide an access point to a core network for all the UEs630,632,634,636,638,640in the respective cells602,604, and606.

As the UE634moves from the illustrated location in cell604into cell606, a serving cell change (SCC) or handover may occur in which communication with the UE634transitions from the cell604, which may be referred to as the source cell, to cell606, which may be referred to as the target cell. Management of the handover procedure may take place at the UE634, at the NodeBs corresponding to the respective cells, at a radio network controller606, or at another suitable node in the wireless network. For example, during a call with the source cell604, or at any other time, the UE634may monitor various parameters of the source cell604as well as various parameters of neighboring cells such as cells606and602. Further, depending on the quality of these parameters, the UE634may maintain communication with one or more of the neighboring cells. During this time, the UE634may maintain an Active Set, that is, a list of cells that the UE634is simultaneously connected to (i.e., the UTRA cells that are currently assigning a downlink dedicated physical channel DPCH or fractional downlink dedicated physical channel F-DPCH to the UE634may constitute the Active Set).

The modulation and multiple access scheme employed by the access network600may vary depending on the particular telecommunications standard being deployed. By way of example, the standard may include Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interface standards promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and employs CDMA to provide broadband Internet access to mobile stations. The standard may alternately be Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM) employing TDMA; and Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM employing OFDMA. UTRA, E-UTRA, UMTS, LTE, LTE Advanced, and GSM are described in documents from the 3GPP organization. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communication standard and the multiple access technology employed will depend on the specific application and the overall design constraints imposed on the system.

UE632can incorporate the CLTD controller130(FIG. 1) to perform the methodology400and other aspects as described herein. The NodeB642can similarly incorporate the CLTD controller130(FIG. 1) to perform the methodology400and other aspects as described herein.

FIG. 7is a block diagram of a NodeB710in communication with a UE750, where the NodeB710may be the node106(FIG. 1), and the UE750may be the UE102(FIG. 1). In the downlink communication, a transmit processor720may receive data from a data source712and control signals from a controller/processor740. The transmit processor720provides various signal processing functions for the data and control signals, as well as reference signals (e.g., pilot signals). For example, the transmit processor720may provide cyclic redundancy check (CRC) codes for error detection, coding and interleaving to facilitate forward error correction (FEC), mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), and the like), spreading with orthogonal variable spreading factors (OVSF), and multiplying with scrambling codes to produce a series of symbols. Channel estimates from a channel processor744may be used by a controller/processor740to determine the coding, modulation, spreading, and/or scrambling schemes for the transmit processor720. These channel estimates may be derived from a reference signal transmitted by the UE750or from feedback from the UE750. The symbols generated by the transmit processor720are provided to a transmit frame processor730to create a frame structure. The transmit frame processor730creates this frame structure by multiplexing the symbols with information from the controller/processor740, resulting in a series of frames. The frames are then provided to a transmitter732, which provides various signal conditioning functions including amplifying, filtering, and modulating the frames onto a carrier for downlink transmission over the wireless medium through antenna734. The antenna734may include one or more antennas, for example, including beam steering bidirectional adaptive antenna arrays or other similar beam technologies.

At the UE750, a receiver754receives the downlink transmission through an antenna752and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver754is provided to a receive frame processor760, which parses each frame, and provides information from the frames to a channel processor794and the data, control, and reference signals to a receive processor770. The receive processor770then performs the inverse of the processing performed by the transmit processor720in the NodeB710. More specifically, the receive processor770descrambles and despreads the symbols, and then determines the most likely signal constellation points transmitted by the NodeB710based on the modulation scheme. These soft decisions may be based on channel estimates computed by the channel processor794. The soft decisions are then decoded and deinterleaved to recover the data, control, and reference signals. The CRC codes are then checked to determine whether the frames were successfully decoded. The data carried by the successfully decoded frames will then be provided to a data sink772, which represents applications running in the UE750and/or various user interfaces (e.g., display). Control signals carried by successfully decoded frames will be provided to a controller/processor790. When frames are unsuccessfully decoded by the receiver processor770, the controller/processor790may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames.

In the uplink, data from a data source778and control signals from the controller/processor790are provided to a transmit processor780. The data source778may represent applications running in the UE750and various user interfaces (e.g., keyboard). Similar to the functionality described in connection with the downlink transmission by the NodeB710, the transmit processor780provides various signal processing functions including CRC codes, coding and interleaving to facilitate FEC, mapping to signal constellations, spreading with OVSFs, and scrambling to produce a series of symbols. Channel estimates, derived by the channel processor794from a reference signal transmitted by the NodeB710or from feedback contained in the midamble transmitted by the NodeB710, may be used to select the appropriate coding, modulation, spreading, and/or scrambling schemes. The symbols produced by the transmit processor780will be provided to a transmit frame processor782to create a frame structure. The transmit frame processor782creates this frame structure by multiplexing the symbols with information from the controller/processor790, resulting in a series of frames. The frames are then provided to a transmitter756, which provides various signal conditioning functions including amplification, filtering, and modulating the frames onto a carrier for uplink transmission over the wireless medium through the antenna752.

The uplink transmission is processed at the NodeB710in a manner similar to that described in connection with the receiver function at the UE750. A receiver735receives the uplink transmission through the antenna734and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver735is provided to a receive frame processor736, which parses each frame, and provides information from the frames to the channel processor744and the data, control, and reference signals to a receive processor738. The receive processor738performs the inverse of the processing performed by the transmit processor780in the UE750. The data and control signals carried by the successfully decoded frames may then be provided to a data sink735and the controller/processor, respectively. If some of the frames were unsuccessfully decoded by the receive processor, the controller/processor740may also use an acknowledgement (ACK) and/or negative acknowledgement (NAK) protocol to support retransmission requests for those frames.

The controller/processors740and790may be used to direct the operation at the NodeB710and the UE750, respectively. For example, the controller/processors740and790may provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The computer readable media of memories742and792may store data and software for the NodeB710and the UE750, respectively. A scheduler/processor746at the NodeB710may be used to allocate resources to the UEs and schedule downlink and/or uplink transmissions for the UEs.

UE750can incorporate the CLTD controller130(FIG. 1) in memory792to perform the methodology400and other aspects as described herein. The NodeB710can similarly incorporate the CLTD controller130(FIG. 1) resident in memory742to perform the methodology400and other aspects as described herein.

FIG. 8is a conceptual diagram illustrating an example of a hardware implementation for an apparatus800employing a processing system802, such as for node106(FIG. 1) or UE102(FIG. 1). In this example, the processing system8004may be implemented with a bus architecture, represented generally by the bus804. The bus804may include any number of interconnecting buses and bridges depending on the specific application of the processing system802and the overall design constraints. The bus804links together various circuits including one or more processors, represented generally by the processor806, and computer-readable media, represented generally by the computer-readable medium808. The bus804may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface810provides an interface between the bus804and a transceiver812. The transceiver812provides a means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface814(e.g., keypad, display, speaker, microphone, joystick) may also be provided.

The processor806is responsible for managing the bus804and general processing, including the execution of software stored on the computer-readable medium808. The software, when executed by the processor806, causes the processing system802to perform the various functions described infra for any particular apparatus. The computer-readable medium808may also be used for storing data that is manipulated by the processor806when executing software.

The computer-readable medium808can store the CLTD controller130for the node106or the UE102(FIG. 1).

With reference toFIG. 9, illustrated is a system900for wireless communication. For example, system900can reside at least partially within user equipment that is capable of Over-The-Air (OTA) communication. Alternatively, the system900can be a network apparatus. It is to be appreciated that system900is represented as including functional blocks, which can be functional blocks that represent functions implemented by a computing platform, processor, software, or combination thereof (e.g., firmware). System900includes a logical grouping902of electrical components that can act in conjunction. For instance, logical grouping902can include an electrical component904for receiving precoder information on a downlink communication channel. Moreover, logical grouping902can include an electrical component906for transmitting packet data over a transmit time interval of two or more slots from two or more antennas. For instance, logical grouping902can include an electrical component908for updating a precoder with the precoder information in a slot subsequent to a first slot in the transmit time interval. The precoder information may be applied at a slot boundary within the TTI. Additionally, system900can include a memory920that retains instructions for executing functions associated with electrical components904-908. While shown as being external to memory920, it is to be understood that one or more of electrical components904-908can exist within memory920.

Several aspects of a telecommunications system have been presented with reference to a W-CDMA system. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards.