Abstract:
A method includes determining weights corresponding to each of a plurality of antennas used to transmit data signals, each weight suitable to modify a corresponding one of the data signals prior to transmission using a corresponding one of the antennas; and transmitting information corresponding to at least one of the weights, the information allowing at least the at least one weight to be determined. Another method includes receiving information corresponding to at least one of a plurality of weights, the plurality of weights corresponding to a plurality of first antennas used to transmit first data signals, where each weight was used to modify a corresponding one of the first data signals prior to transmission using a corresponding one of the first antennas; using the received information, determining the plurality of weights corresponding to the plurality of first antennas; and using at least the plurality of weights; and decoding second data signals received using a plurality of second antennas to create at least one output signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application claims the benefit under 35 U.S.C. §119(a) of provisional patent application No. 60/696,357, filed on Jun. 30, 2005. 
     
    
     TECHNICAL FIELD  
       [0002]     The examples of this invention relate generally to digital cellular communications systems, methods, terminals and computer programs and, more specifically, relate to techniques for providing antenna-related feedback information between user equipment and a base station.  
       BACKGROUND  
       [0003]     The following abbreviations, at least some of which appear in the description below, are defined as follows: 
        3GPP Third Generation Partnership Project     BS Base Station     BTS Base Transceiver Station     CLM Closed loop transmit diversity mode     CSI Channel state information (the equivalent to CQI in EUTRAN)     CQI Channel quality information     DL Downlink     DPCH Dedicated Physical Channel     EUTRAN Evolved UTRAN     FBI Feedback Information     F-DPCH Fractional Dedicated Physical Channel     HSDPA High Speed Downlink Packet Access     HS DPCCH High Speed Dedicated Physical Control Channel     HS DSCH High Speed Downlink Shared Channel     HS SCCH High Speed Shared Control Channel     MIMO Multiple Input, Multiple Output     Node B Base station     OFDM Orthogonal Frequency Division Duplex     SRB Signaling Radio Bearer     UE User Equipment     UL Uplink     UMTS Universal Mobile Telecommunications System C304     UTRA FDD UMTS Terrestrial Radio Access-Frequency Division Duplex     UTRAN UMTS Terrestrial Radio Access Network     WCDMA Wideband Code Division Multiple Access        
 
         [0029]     The DL packet data transmission in UTRA FDD (WCDMA) is a feature included in Release 5 specifications (HSDPA) and is further enhanced in Release 6 with the support of fractional DPCH (F DPCH), and with the support of SRB mapping on the HS DSCH.  
         [0030]     Currently there is development work proceeding for Release 7. One HSDPA feature that is of most concern to this invention is relates to the transmit and receive sub-systems of the Node-B and the UE.  
       BRIEF SUMMARY  
       [0031]     In an exemplary embodiment, a method is disclosed that determines weights corresponding to each of a plurality of antennas used to transmit data signals. Each weight is suitable to modify a corresponding one of the data signals prior to transmission using a corresponding one of the antennas. The method also includes transmitting information corresponding to at least one of the weights, the information allowing at least the at least one weight to be determined.  
         [0032]     In another exemplary embodiment, an apparatus includes a transceiver configured to be coupled to a plurality of antennas used to transmit data signals. The apparatus also includes one or more memories comprising program code, and one or more data processors coupled to the one or more memories and to the transceiver. The one or more data processors are configured when the program code is executed to perform the following operations: determining weights corresponding to each of the plurality of antennas, each weight suitable to modify a corresponding one of the data signals prior to transmission using a corresponding one of the antennas; and causing the transceiver to transmit information corresponding to at least one of the weights, the information allowing at least the at least one weight to be determined.  
         [0033]     In an additional exemplary embodiment, a signal bearing medium is disclosed that tangibly embodies a program of machine-readable instructions executable by at least one data processor to perform operations. The operations include determining weights corresponding to each of a plurality of antennas used to transmit data signals, where each weight is suitable to modify a corresponding one of the data signals prior to transmission using a corresponding one of the antennas. The operations also include causing information to be transmitted corresponding to at least one of the weights, the information allowing at least the at least one weight to be determined.  
         [0034]     In yet another exemplary embodiment, a method is disclosed that includes receiving information corresponding to at least one of a plurality of weights, the plurality of weights corresponding to a plurality of first antennas used to transmit first data signals. Each weight was used to modify a corresponding one of the first data signals prior to transmission using a corresponding one of the first antennas. The method also includes, using the received information, determining the plurality of weights corresponding to the plurality of first antennas; and using at least the plurality of weights, decoding second data signals received using a plurality of second antennas to create at least one output signal.  
         [0035]     In a further exemplary embodiment, an apparatus is disclosed that includes a transceiver configured to be coupled to a plurality of first antennas used to receive first data signals. The transceiver is configured to receive information corresponding to at least one of a plurality of weights, the plurality of weights corresponding to a plurality of second antennas used to transmit second data signals. Each weight was used to modify a corresponding one of the second data signals prior to transmission using a corresponding one of the second antennas. The apparatus also includes one or more memories comprising program code, and one or more data processors coupled to the one or more memories and to the transceiver. The one or more data processors are configured when the program code is executed to perform the operation of determining, using the received information, the plurality of weights corresponding to the plurality of second antennas. The operations further include, using at least the plurality of weights, decoding the first data signals to create at least one output signal.  
         [0036]     In an additional exemplary embodiment, a signal bearing medium tangibly embodies a program of machine-readable instructions executable by at least one data processor to perform operations including causing information to be received. The information corresponds to at least one of a plurality of weights, and the plurality of weights correspond to a plurality of first antennas used to transmit first data signals, where each weight was used to modify a corresponding one of the first data signals prior to transmission using a corresponding one of the first antennas. The operations also include, using the received information, determining the plurality of weights corresponding to the plurality of first antennas, and additionally include, using at least the plurality of weights, decoding second data signals received using a plurality of second antennas to create at least one output signal. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0037]     The foregoing and other aspects of embodiments of this invention are made more evident in the following Detailed Description of Exemplary Embodiments, when read in conjunction with the attached Drawing Figures, wherein:  
         [0038]      FIG. 1  is a simplified block diagram showing exemplary major elements used to implement an exemplary embodiment of this invention.  
         [0039]      FIG. 2  is another simplified block diagram showing exemplary elements used to implement an exemplary embodiment of this invention using diversity transmission and reception.  
         [0040]      FIG. 3  is another simplified block diagram showing exemplary elements used to implement an exemplary embodiment of this invention using multiple input, multiple output (MIMO) transmission and reception.  
         [0041]      FIG. 4  is a flowchart of an exemplary method performed by a network node for providing closed loop transmit antenna operation.  
         [0042]      FIG. 5  is a flowchart of an exemplary method performed by a user equipment for providing closed loop transmit antenna operation.  
         [0043]      FIG. 6  is a table used to map antenna weight information to phase for a given antenna weight.  
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0044]     By way of introduction, it can be shown that a desirable HSDPA transmission scheme would be based on a closed loop antenna transmit technique with two transmit (Tx) and two receive (Rx) antennas (e.g., if used for HSDPA under realistic operating conditions in combination with fast packet scheduling). However, there are currently problems associated with closed loop modes 1 and 2 schemes defined for HSDPA in 3GPP Release 5. A 3GPP specification of particular interest in this regard is 3GPP TS 25.214, Physical layer procedures (FDD) (Release 5). The problems are related to the resolution and update rate of the feedback from the UE, and antenna verification. The problem with antenna verification occurs because the UE does not have knowledge of the antenna weights that the Node B is using for transmission. The problem with antenna verification is compounded with the introduction of F-DPCH in HSDPA, where it has been decided that it is no longer mandatory for the UE to support neither CLM1 nor CLM2 in the case of F-DPCH. Hence, closed loop transmit diversity is generally not usable for HSDPA in 3GPP Rel&#39;6.  
         [0045]     As such, it can be appreciated that in order to have robust and attractive usage of a 2 Tx closed loop antenna scheme for HSDPA evolution a new approach is required.  
         [0046]     The exemplary embodiments of this invention provide an enhancement to the closed loop transmit diversity scheme that is currently specified for HSDPA in 3GPP Releases 5 and 6. However, and while the exemplary embodiments of this invention are described in the context of HSDPA, it should be kept in mind that these teachings are applicable to other types of wireless communications systems including, but not limited to EUTRAN.  
         [0047]      FIG. 1  is a simplified block diagram showing the major elements used to implement this invention, specifically a HSDPA terminal  10 , also referred to as User Equipment (UE)  10 , and a BS, also referred to as a Node-B  20 . As used herein, but not as a limitation on the practice of this invention, the Node-B may be assumed to be functionally equivalent to a 3GPP 25-series specification term Node-B.  
         [0048]      FIG. 1  shows that the HSDPA terminal  10  includes a suitable wireless transceiver  12  having first and second receive antennas  13 A,  13 B. The transceiver  12  is coupled to at least one data processor (DP)  14  that in turn includes or is coupled to a volatile and/or non-volatile memory  16 . The memory  16  stores program code  18  that is executable by the DP  14  to operate with a Node-B  20 , including program code that is provided to implement the UE  10  aspects of this invention. The Node-B  20  is constructed to include a transceiver  22  having first and second transmit antennas  23 A,  23 B. Associated with antennas  23 A,  23 B are assumed to be corresponding antenna weights (W 1 , W 2 ). The Node-B  20  is also assumed to include at least one DP  24  that in turn includes or is coupled to a volatile and/or non-volatile memory  26 . The memory  26  stores program code  28  that is executable by the DP  24  to operate with the UE  10 , including program code that is provided to implement the Node-B  20  aspects of this invention.  
         [0049]     Note that while  FIG. 1  shows the use of separate transmit and receive antennas at the UE  10  and at the Node-B  20 , in practice the same antenna(s) may used for both transmission and reception.  
         [0050]     The memories  16  and  26  may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors  14  and  24  may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi core processor architecture, as non limiting examples.  
         [0051]     In general, the various embodiments of the UE  10  can include, but are not limited to, cellular telephones, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.  
         [0052]     In accordance with the teachings of this invention there is an enhancement to the HSDPA to allow the UE  10  to send closed loop antenna transmit feedback information to the Node B  20 , where the UE  10  sends the closed loop antenna transmit feedback information on the UL HS DPCCH, rather than sending FBI information on the DPCCH. This approach beneficially enables the use of more bits for sending feedback information to the Node B  20 . Further, the feedback rate may be made dynamic (e.g., corresponding to the CQI feed back rate).  
         [0053]     The feedback information may comprise information for specifying UE-recommended antenna weights to be used by the Node B  20  (e.g., BS or BTS), where an antenna weight may be expressed in terms of amplitude and phase. For instance, antenna weights are typically complex numbers of the type W i =a i +jb i  and the amplitude and phase can be determined using the weight.  
         [0054]     Further in accordance with exemplary embodiments of this invention, the transmission format for the DL HS SCCH is modified such that the HS SCCH also contains information on the applied transmit antenna scheme used at the Node B  20 , including antenna weight (W 1 , W 2 ) information. Sending this information on the HS SCCH to the UE  10  reduces or eliminates the problems referred to above regarding antenna verification (e.g., 3GPP Release &#39;5).  
         [0055]     The closed loop transmit antenna feedback scheme in accordance with the exemplary embodiments of this invention supports antenna transmit diversity weights, and also MIMO multi stream closed loop feedback information. This is described in more detail in reference to  FIGS. 2 and 3 .  
         [0056]     Turning to  FIG. 2 , a simplified block diagram is shown illustrating exemplary elements used to implement an exemplary embodiment of this invention using diversity transmission and reception. Wireless communication system  200  comprises a Node B  220  and a UE  210  communicating using the communication channels HS DSCH  240 , the HS SSCH  245  and HS DPCCH  250 . The Node B  220  comprises a DP  224 , a memory  226 , multipliers  296 - 1  and  296 - 2 , and a transceiver  222 . The memory  226  comprises program code  228 , received weights  235 , input data  260 , and pilot symbols  265 . The Node B  220  is coupled to or comprises antennas  230 - 1 ,  230 - 2 , and  230 - 3 . The UE  210  comprises a DP  234 , a memory  236 , and a transceiver  232 . The UE  210  is coupled to or comprises antennas  290 - 1 ,  290 - 2 , and  290 - 3 . The memory  236  includes program code  238 , received weight information  280 , determined weight information  282 , feedback weight information  284 , and output data DS 1 ′  286  corresponding to the data in data signal DS 1   225 .  
         [0057]     Node B  220  communicates input data  260  by performing such functions as modulation, spreading, scrambling (e.g., encryption), and frequency shiffing (e.g., from baseband to transmission band) to create data signal DS 1   225 . In this example, the data signal DS 1   225  is coupled to both multipliers  296 - 1  and  296 - 2  and modified (e.g., multiplied) by a corresponding antenna weight W 1 , W 2 , respectively, to create modified data signals  297 - 1 ,  297 - 2  and communicated using antennas  230 - 1 ,  230 - 2 , respectively. Periodically, the DP  224  also causes the pilot symbols  265  to be transmitted as data signal DS 1   225 , although one or both antennas  230 - 1  and  230 - 2  may be used to transmit the data signal DS 1   225  having the pilot symbols  265 .  
         [0058]     The data signal DS 1   225  is transmitted using HS DSCH  240  to the UE  210 . Additionally, the Node B  220  transmits (e.g., under control of the program code  228  and DP  224 ) weight information  270  on the HS SCCH  245  to the UE  210 . The weight information  270  is “feed forward” indications of the weights W 1 , W 2 , and the weight information  270  can include information  271  corresponding to both antenna weights (i.e., W 1 , W 2 ) or information  272  corresponding to one of the weights (e.g., W 1  or W 2 ). It is noted that the weight information  270  could include, e.g., a phase difference between the antenna weights W 1  and W 2 , values of W 1 , W 2 , or information that is mapped to give the W 1  and/or W 2 . When information  272  (e.g., corresponding to antenna weight W 2 ) is transmitted, the UE would then be able to determine information corresponding to the other antenna weight (e.g., W 1 ) using the transmitted information  272 . The UE  210  (e.g., under control of the program code  238  and the DP  234 ) places the weight information  270  in received weight information  280 , and if necessary determines determined weight information  282  from the received weight information  280 . In one embodiment, the received weight information  280  corresponds to both W 1  and W 2  and determined weight information  282  corresponds to both W 1  and W 2 . In another embodiment, the received weight information  280  corresponds to W 2  (e.g., or W 1 ) and the UE  210  determines determined weight information  282  (e.g., corresponding to both W 1  and W 2 ) using the received weight information  280  of W 2  (e.g., or W 1 ).  
         [0059]     The UE  210  uses the determined weight information  282  during decoding of the received data signals  291 - 1  and  291 - 2  and determines output data (DS 1 ′)  286  corresponding to the data in data signal DS 1   225 . The UE  210  also uses this determined weight information  282  for channel estimation, including for estimating new antenna weights (i.e., feedback weight information  284 ) which are afterwards signaled back to the Node-B. The UE  210  (e.g., again under control of the program code  238  and the DP  234 ) therefore determines feedback weight information  284  using, e.g., the pilot symbols  265  that are transmitted on the HS DSCH  240  and corresponding channel estimation determined using the determined weight information  282 . The UE  210  communicates the feedback weight information  276  (corresponding to feedback weight information  284 ) to the Node B as part of closed loop transmit feedback information  275  on the HS DPCCH  250 . The feedback weight information  276  includes one or more of feedback weight information W 1 ′  241  corresponding to a calculated W 1  and feedback weight information W 2 ′  242  corresponding to a calculated W 2 . Note also that the feedback weight information  276  could include differences, such as a phase difference, between the antenna weights W 1  and W 2 . The closed loop transmit feedback information  275  may also include CQI/CSI  278  and may also include Acknowledge (Ack)/No Acknowledge (Nack) from the current or previous transmissions.  
         [0060]     The Node B  220  uses the received weight information  235 , which correspond to the feedback weight information  276 , to revise antenna weights W 1 , W 2 . Exemplary techniques for determinations of antenna weights by the UE  210  and the revision of the antenna weights by the Node B  220  are described in, e.g., 3GPP TS 25.214, V5.0.0 (2002-03) and later documents. It is noted that the system  200  of  FIG. 2  uses diversity transmission because the same signal (data signal DS 1   225 ) is transmitted using different antennas  230 - 1 ,  230 - 2 .  
         [0061]     By contrast,  FIG. 3  shows another simplified block diagram showing exemplary elements used to implement multiple input, multiple output (MIMO) transmission and reception. System  300  in  FIG. 3  includes many of the same elements as in  FIG. 2 , and therefore only differences will be described herein. The communication system  300  includes a Node B  320  including DP  224  that is coupled to multipliers  336 - 1  through  336 - 4  and through transceiver  322  to the antennas  330 - 1  through  330 - 4 . The DP  224  splits the input data  260  into the data signals DS 1   325 - 1  to DS 4   325 - 4 , each of which is modified (e.g., multiplied) using the multipliers  336  by a corresponding weight W 1  through W 4  to create a modified data signal  337 - 1  through  3374  that is then transmitted using the transceiver  322  and the antennas  330 . The Node B  320  also communicates weight information  370 , including one or more of the weight information  371  corresponding to W 1 , weight information  372  corresponding to W 2 , weight information  373  corresponding to W 3 , and weight information  374  corresponding to W 4    374 , to the UE  210 .  
         [0062]     The UE  210  receives the HS DSCH  240  using the antennas  390 - 1  through  390 - 4  and the transceiver  332  creates the received data signals  391 - 1  through  391 - 4 . The DP  234  then creates output data DS 1 ′  386 - 1 , DS 2 ′  386 - 2 , DS 3 ′  386 - 3 , and DS 4 ′  386 - 4 , corresponding to data signals DS 1   325 - 1 , DS 2   325 - 2 , DS 3   325 - 3 , and DS 4   325 - 4 , respectively. In MIMO, N receive antennas  390  receive information from M transmit antennas  330 , and there can be min(M,N) independent subchannels. In an exemplary embodiment, M is not equal to N. In the example of  FIG. 3 , there are four independent subchannels, although fewer subchannels could be used for this amount of transmit antennas  330 . The UE  310  communicates feedback weight information  376 , including one or more of feedback weight information W 1 ′  341  corresponding to a calculated W 1 , including feedback weight information W 2 ′  342  corresponding to a calculated W 2 , including feedback weight information W 3 ′  343  corresponding to a calculated W 3 , including feedback weight information W 4 ′  344  corresponding to a calculated W 4 , using the HS DPCCH  250  to the Node B  320 . The feedback weight information  376  (and also “feed forward” information  270 ,  370 ) can also include phase difference  345  (φ 1,2 ) between W 1  and W 2 , phase difference  346  (φ 3,4 ) between W 3  and W 4 , amplitude difference  347  (A 1,2 ) between W 1  and W 2 , and amplitude difference  348  (φ 3,4 ) between W 3  and W 4 . Furthermore, each feedback weight information  341 ,  342 ,  343 ,  344  can include weight information  349  (A 1 ,φ 1 ) having an amplitude and a phase, in this example for W 1 . It is also noted that such feedback weight information  376  will typically be mapped from a set of bits to an appropriate amplitude and/or phase, as described below in reference to  FIG. 6 .  
         [0063]     The slot formats for the HS SCCH and HS DPCCH messaging that carries the aforementioned additional information may be arranged in any suitable manner.  
         [0064]     Referring to  FIG. 4  with appropriate reference to preceding figures, a flowchart is shown of an exemplary method  400  performed by a network node such as the Node B  20 ,  220 ,  320  (although other network nodes are also possible) for providing closed loop transmit antenna operation. The Node B  20 ,  220 ,  320  would operate under control of the program code  28 ,  228  for performing method  400 . Method  400  starts in block  405  when the closed loop transmit feedback information  275 ,  375  is determined from data on the UL HS DPCCH  250 . In block  410 , the antenna weights are determined using the closed loop transmit feedback information  275 ,  375  (e.g., feedback antenna weight information  276 ,  376 ). For instance, there might be a situation where the W 1  is fixed at (1/√{square root over (2)}) and the magnitude of the amplitude of W 2  is fixed but the phase is allowed to vary in the range {0, −π/2, π/2, π}. The feedback antenna weight information  276  would therefore include only information  242  corresponding to W 2 , and the information  242  includes two bits, e.g., 00 (corresponding to a phase of zero), 01 (corresponding to a phase of π/2), 10 (corresponding to a phase of π), or 11 (corresponding to a phase of −π/2). This is shown in  FIG. 6 , wherein weight information  610 - 1  through  610 - 4  corresponds to antenna weight information  242 . Each weight information  610 - 1  through  610 - 4  is mapped using the table  600  to a corresponding phase  620 - 1  through  620 - 2 . The network node, Node B  220  for instance, could then set the antenna weight W 2  equivalent to the phase indicated by the information  242  as the amplitude is already known.  
         [0065]     In block  415 , the antenna weights are communicated to the UE  210 ,  310  on the DL HS SCCH  245 . In this example, the network node uses two bits in the weight information  270  (including only weight information  272  corresponding to W 2 ) to indicate the phase of W 2 . In the example of  FIG. 6 , one of the two-bit sequences in weight information  610 - 1  through  6104  is transmitted by the network node to the UE. It is noted that the table  600  could also map bits to amplitudes or amplitudes and phase, if desired. In block  420 , the antenna weights are applied to the data signals  225 ,  235  being transmitted.  
         [0066]     Turning to  FIG. 5  with appropriate reference to other figures, a flowchart is shown of an exemplary method  500  performed by a user equipment (UE  10 ,  210 ,  310 ) for providing closed loop transmit antenna operation. Method  500  is performed by a UE under direction, e.g., of the program code  18 ,  238 . Method  500  begins in block  505  when the UE receives information corresponding to antenna weights (e.g., weight information  270 ,  370 ) in data from the DL HS SCCH  245 . In block  510 , antenna weights are determined using the weight information. Block  510  is also performed when less the weight information corresponds to less than all antenna weights. For instance, if weight information corresponding to only antenna weight W 2  is received, then antenna weight W 1  (and possibly antenna weights W 3 , W 4 ) can be determined based on information corresponding to the received antenna weight of W 2 . In the previously cited example, the antenna weight W 1  is fixed and the information  270  corresponding to the antenna weight W 2  includes two bits, as shown in  FIG. 6  as weight information  610 - 1  through  610 - 4 . The two bits from weight information  610 - 1  through  610 - 4  select a phase  620 - 1  through  620 - 4  in the range the range {0, −π/2, π/2, π} for the weight W 2  and the magnitude of the amplitude of W 2  is fixed. In block  510 , the bits are used to determine what the phase for W 2  should be. The antenna weights used by the Node-B  220  (e.g., weights W 1 , W 2  in  FIG. 2 , information about which is transmitted using the weight information  270 ) are used by the UE  210  when the UE  210  performs channel estimation (block  515 , described below), and the channel estimation allows the UE  210  to estimate new antenna weights (e.g., corresponding to feedback weight information  276 ) to be signaled back to the Node-B  220 . In case of two antennas, only the relative phase and/or amplitude difference between the antenna weights used for the two antennas needs to be estimated. It should be noted that this example assumes both the network node (e.g., Node B  220 ) and UE (e.g., UE  210 ) use the same number of bits to communicate antenna weight information. However, this is merely for example and the network node and UE can use different numbers of bits for antenna weight information and can differ in the amount (e.g., bits per unit time) of antenna weight information transmitted.  
         [0067]     In block  515 , the determined antenna weights are used for decoding and channel estimation. In block  520 , feedback antenna weights (e.g., feedback antenna weights  276 ,  376 ) are calculated based on the channel estimation. The amount of feedback information (e.g., closed loop antenna transmit feedback information  275 ,  375 ) is determined in block  540 . The amount of closed loop antenna transmit feedback information  275 ,  375  can be made dynamic and can correspond, e.g., to the CQI/CSI feedback rate. For instance, in 3GPP Release 5, the CQI reporting is periodic, with a maximum reporting every 2 milliseconds (MS). Each CQI word is five bits. This is described in 3GPP TSs 25.214 and 25.215. The amount of closed loop antenna transmit feedback information  275 ,  375  can therefore also vary over time. The calculated antenna weights from step  520  are then encoded (e.g., as feedback weight information  276 ,  376 ) in block  545  and communicated from the UE to the network node on the UL HS DPCCH  250 .  
         [0068]     It should be realized that the exemplary embodiments of this invention may be extended as well to the EUTRAN concept where OFDM will likely be used in the DL. This implies that when the Node B  20  sends a so called allocation table to the UE  10 , information is also sent to specify which transmit diversity weights (or closed loop MIMO scheme) is being used (for those UEs  10  that are operable with such transmit diversity or MIMO schemes). Similarly, those UEs  10  that support transmit diversity or closed loop MIMO are enabled to send transmit antenna feedback information in conjunction with sending UL Ack/Nack and CSI/CQI to the Node-B  20 .  
         [0069]     Based on the foregoing description of non-limiting embodiments of this invention it can be appreciated that an aspect of this invention relates to apparatus, methods and a computer program to operate a Node-B with a UE so as to transmit on the DL HS SCCH information descriptive of a transmit antenna scheme used by the Node B, the information comprising Node-B transmit antenna weight information.  
         [0070]     Based on the foregoing description of non-limiting embodiments of this invention it can be appreciated that a further aspect of this invention relates to apparatus, methods and a computer program to operate a UE with a Node-B so as to transmit closed loop antenna transmit feedback information on the UL HS DPCCH.  
         [0071]     It is noted that the functionality in the network node (e.g., Node B) and the UE can be performed as shown above, i.e., through software instructions that cause a corresponding DP to perform the functions described above. As such the embodiments may comprise a signal bearing medium tangibly embodying a program of machine-readable instructions executable by at least one data processor for carrying out functions described above. Furthermore, in general, the various embodiments may be implemented in hardware such as special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in software (e.g., firmware) which may be executed by a data processor such as a controller, digital signal processor, general purpose microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, flowcharts, or other pictorial representation described herein may be implemented in, as non-limiting examples, hardware, software, some combination thereof.  
         [0072]     Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.  
         [0073]     Programs, such as those provided by Synopsys, Inc. of Mountain View, Calif. and Cadence Design, of San Jose, Calif. automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or “fab” for fabrication.  
         [0074]     Various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawing. As but some examples, the use of other similar or equivalent messages and/or signaling techniques may be attempted by those skilled in the art, and more that two transmit and/or receive antennas may be employed. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.  
         [0075]     Furthermore, some of the features of the examples of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings, examples and embodiments of this invention, and not in limitation thereof.