AU2012203560B2 - Method and apparatus for efficient precoding information validation for MIMO communications - Google Patents

Abstract

A method and apparatus for efficient precoding matrix verification in a multiple input multiple-output MIMO wire-less communication system are disclosed. A wireless transmit/receive unit WTRU sends a precoding matrix index PMI to an eNodeB. The eNodeB sends a verification message including a PMI indicator indicating whether or not the PMI of the WTRU and a PMI of the eNodeB are identical. If the PMI of the WTRU and of the eNodeB are identical, the eNodeB sends just a PMI indicator otherwise the eNodeB sends to the WTRU a PMI indicator and the PMI of the eNodeB. A plurality of PMIs may be sent simultaneously, and the PMIs may be partitioned into a plurality of groups. The PMi indicator may be either attached to or inserted into control signaling. PMI validation messages can be signaled to WTRU by control signaling or use of a dedicated reference signal. + 4/8 CL n) r-- 71, o o ro 0 m~ooo N

Description

Pool Section 29 Reguistlon 3-2(2) AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Method and apparatus for efficient precoding information validation for MIMO communications The following statement is a full description of this invention, including the best method of performing it known to us: P111AHAU/0710 [00011 METHOD AND APPARATUS FOR EFFICIENT PRECODING INFORMATION VALIDATION FOR MIMO GOMMUNICATIQNS* [0002] BACKGROUND [0003] Third generation partaersbip project 3GPP and 3GPP2 are - considering long term- evolution (LTE) for radio interface and network architecture. There is an ever-increasing demand on wireless operators to provide better quality voice and high-speed data services. As a result, wireless communication systems that enable higher data rates and higher capacities areta pressing need. [0004] To achieve this, it is becoming increasingly popular to use multi antenna systems in wireless communications networks to obtain the advantages of increased channel capacity spectrum efficiency, system throughputs, peak data rates, and/or link reliability. Such multi-antenne systems are genericaIly referred to as multiple-input-multiple-output .(MIMO) systems but may also include multiple-input-single-ntput (MISO) and single-input-multiple-output (SIMO) configurations. J0005| Efficient.signalingds essenti-t evle-nvra-ersrardl- - access (E-UTRA), A low overhead control signaling scheme can improve MIMO link performance, system capaaty, system throughputs, information data rates, and increased spectrum efficiency. [0006] MIMO systems promise high spectral efficiency and have been proposed in many wireless communication standards. Research is also currently underway on preceding for spatially- multiplexed or space-time coded MUIM systems. Precoding is a technique used to provide increased array and diversity gains. [0007] Precoding information needs to be communicated from a transmitter - (e.g., a base station) to a receive:(e.g., a wireless transmit/receive unit (WTRU) to avoid a channel mismatch between transmitting and receiving signals. This iS particularly important for MIMO data demodulation when precoding is used. When a receiver uses incorrect channel responses for data detection, significant performance degradation can occur. - 1- ITC-2-1683.Lwo REPLACEMENT SHEET [0008] Generally, precOding information may be communicated using explicit control signaling, pardcujarly when the transmitter and receiver are restricted to using limited sets nf antenna weights and coefficients for preceding. The limited sets of antenna weights and coefficients are sometimes referred to as a precoding codebook. Explicitisignaling to communicate preceding information from a transmitter to a receiver may incur large signaling overhead, particularly for a large size codebook, This signaling overhead is magnified when frequency selective preceding is used. [0009] Precoding matrix or antenna weight validation and verification is used to avoid effective channelmismatch between a transmitter and a receiver, An effective channel between .base station and a mobile handset is a channel that experiences the MIMO preceding affect, and is the multiplication of -a channel matrix H and a preceding matrix V used at an evolved Node-B (eNodefl) or a transmitter. A mismatchof the effective channel between the transmitter and the - receiver causes severe performance degradation for MIMO communication systems. [0010] Figure 1A shvw&acprecoding..matrx-or-antenna-weight-ignaling scheme. -In a scheme as showr in Figure 1A, a wireless transmit/receive unit (WTR) Ill feeds back preceding matrix indices (PMIs) or antenna weights to a base station or an eNodeB 113. Suppose that the WTRU feeds back PMj (having Y bits) 115 to the, eNodeB 113. To inform the WTRU 111 of the eurrert preceding matrix used at the; eNodeB 113 the eNodeB sends a validation message PMILk (Y bits) 117 tk the WTRU 11l In case of feedback error or override, PM-j is not equal to PMIk. In case of no feedback error and no eNodeB override, PMIJ P MI'k The validation message can be sent in several forms, for example via control signaling or via a reference signal. [00111 In some systems, such as Wideband Code Division Multiple Access (WCDMA), only one PMI needs to be signaled to the receiver from the transmitter and vice versa. The signals are transmitted in the time domnix using a spreading code. Signaling the exact single PMt (Y bits) to the receiver does not incur too much overhead as long as the value of Y is reasonable. ....- 2 ~- However, in some systems, such as orthogonal frequency division multiplexing (OPFDM) systems, where the frequency domain is additional to the time domain, - there may be multiple PMIs needed to be fed back from the WTRU and sent from the eNodeB for validation to support frequency selective preceding. Frequency selective precoding performs MIIMO preceding per sub-band within a system's bandwidth. The entire system-bandwidth can be divided into several sub-bands. Each sub-band consists of one or several sub-carriers. One preceding matrix is - used to precede transmitted data per sub-band, In an extreme case, precodi.g can be performed per sub-carrier if a sub-band consists of only a sub-carrier. If multiple PMIs need to be signaled to the receiver, then the signaling overhead could be significant. For example; if there are Z PMs to be signaled and each PMI has Y bits, then the total overhead is Z x Y bits. If Z or Y is large, the . signaling overhead is significant. (00121 The terms "preoding matrix" and "precoding vector" ae interchangeable and depend upon the number of data streams to be preceded. [0013 Each PMI is represented by L bits, wherein the value of L depends upon MIMO c supported. WTRUs are assigned resources for communications. A resource block (RB) consists of M (for example,!12) subcarriers. A resource block group (RBG) or sub-band consists ofN resource blocks (NEB); for example, NRB 2, 4, 5, 6, 10, 25, or entire bandwidth. A system-bandwidth can have one -or more RBGs or sub bands depending on the size of the bandwidth and the valve of NRB per RBG. For example, the number of REGs per system bandwidth, N_RBG, can be one, two, four, ten, twenty, or fifty. In general, the terms "RBG" and "sub-band" ar interchangeable. [0014] The WTRU feeds back one PMI1 for each RBG that is configured for or selected by the WTRU 'for reprting. Among the RBGs for a given bandwidth, N RBGs, where N S NRBG, can be configured for or selected by a WTRU, If N RB3s are configured for or -- elected by a WTRU for reporting precoding information, the WTRU feeds back N PMIs to the eNodeB. The eNodeB sends the preceding validation message comprising N PMIs back to the WTRU.

100151 To inform the WTRU of the current PMIs used at the eNodeB, the eNodeB sends N PMIs back tc the WTRU. The total number of bits that the eNodeB sends to the WTHU per PMI validation message is NJPh4 x N bits. [0016] Table 1 shows the number of bits for the PAI validation message assuming NPMI = 5 bits. Th~anumbers are summarized for 5, 10, and 20 AIEi system bandwidth. The second row is NJPB, the number of RBs per RBG. Fr example, N_RB ranges from 2.t 100 for 20Miz. The third row is N_RBG par system bandwidth, i.e., the number of RBGs per system bandwidth for 5, 10, or 20 MIfz, and the value of N_RB& ranges from 1 to 50. The fourth row is the total number of bits for PI validation signaling per validation message or grart channel. 5 MHz 10 MHz 20MHz 300 600.(subcarriers) 1200 (subcarriers) - . Jnbcarr~ers) NREperRBG 2 .5 025 2,15 10 2550 2 5 102550100 NBG 'S - 5 TT126i T 5 0 T Per band Total # of bits for PMI 5 5 125 50 25 10 5 250Q100 50 20 10 5 _ ignaling p__r va'lidation . message ssume 12 subearriers per RB. NRB: Number of resource blocks. NWBG: Number of frequency blocks for pre-coding control unit to wbich assigned RBs belong. N.-2MI: Number of bits to represent a PML Masium total number of bits per PI validation message N __ G x NPML. Table 1 [00171 This precoding matrix or antenna weight validation, hereinaftelr called "precoding information validation" or "PAI validationi", may require up to 250 bits or more per validation:message. Hence, this scheme is inefficient. 10018] Therefore, it would be desirable to provide a method and apparatus to reduce the signaling overhead for PMI validation. -4- [0019] SUMMARY [0020] A method and apparatus for efficient preceding information validation in a MTMO wireless communications is provided. [0021] A wireless transmait/receive unit (WTRJ) transmits one or multiple preceding information or preceding matrix indices (PMIs) to an eNodeB. in response, the WTRU receives a validation message (a PM[f indicator) from the eNodeB including a preceding vonfirnation message indicating whether or not there is a match to the precoding information reported by the WTRU. If there i.s a match between the preceding information, i.e., the preceding information is identical, a preceding validatilsn message including a preceding confirmation message is received by the WThU from the eNodeB to confirm that the preceding information used at the eNodeB is the same as the preceding information fed back from the WTRU. However, if there is a mismatch or if the precoding information fed back from the VTRU is overridden by the eNodeB, the VWT receives a validation message: including a preceding confinnation/indication message from the eNodeB to indicate that the eNodeB does not use the preceding informal on fed b ackfrptheWTRU. The WTRU-may-also-reeeive -a-validationmessage including a preceding indication message from the eNodeB to indicat-e the preceding information that is being used at the eNodeB. Precodingvalidatiou using a preceding confirmationnessage is used to reduce signaling overhead. [0022] The eNodeB sends a precoding-contrmation message to a WTR-U. The preceding confirmation message can be carried by a PMI indicator which indicates the state of the downlinak.(DL) preceding validation. The PMIindicator could be one bit or a bit sequence representing the preceding confirmation state or one or several preceding information states for the preceding validation corresponding to the WTRU preoding feedback [0023] The validation message or PMI indicator using preceding confirmation may consist of oneor more bits. The PI indicator helps indicate - the preceding information and slate used and therefore helps to reduce overhead and increase efficiency.

5a [0023a] In one aspect the present invention provides a method for signaling control information for a Wireless Transmit/Receive Unit, WTRU, the method including: sending, by the WTRU, a plurality of precoding matrix indexes, PMIs, or 5 codebook values, as feedback; receiving, by the WTRU, a message including (1) a single bit PMI indicator in a first field, and (2) only a single PMI in a second field or only a single codebook value representing only the single PMI in the second field, the second field being separate from the first field; and 10 processing, by the WTRU, at least the single bit PMI indicator, the single bit PMI indicator indicating whether to use the PMIs or codebook values sent as the feedback. [0023b] In another aspect the present invention provides a method implemented by an evolved Node B (eNB), the method including: 15 receiving, by the eNB from a wireless transmit/receive unit (WTRU), a precoding report including a plurality of precoding matrix indexes (PMIs) or codebook values, as feedback; generating a single bit PMI indicator indicating whether precoding according to the PMIs or codebook values sent as the feedback; and 20 sending a message including (1) the generated single bit PMI indicator in a first field, and (2) only a single PMI in a second field or only a single codebook value representing only the single PMI in the second field, wherein the second field is separate from the first field. [0023c] In a further aspect the present invention provides a Wireless 25 Transmit/Receive Unit, WTRU, configured to signal control information, including: a processor and transmitter/receiver unit configured to: send a plurality of precoding matrix indexes, PMIs, or codebook values, as feedback; receive a message including (1) a single bit PMI indicator in a first field, 30 and (2) only a single PMI in a second field or only a single codebook value representing only the single PMI in the second field, the second field being separate from the first field; and 5b process at least the single bit PMI indicator, the single bit PMI indicator indicating whether to use the PMIs or codebook values sent as the feedback. [0023d] In yet another aspect the present invention provides an evolved Node B (eNB), including: 5 a processor and a transmit/receive unit configured to: receive, from a wireless transmit/receive unit (WTRU), a precoding report including a plurality of precoding matrix indexes (PMIs) or codebook values, as feedback; generate a single bit PMI indicator indicating whether precoding according 10 to the PMIs or codebook values sent as the feedback; and send a message including (1) the generated single bit PMI indicator in a first field, and (2) only a single PMI in a second field or only a single codebook value representing only the single PMI in the second field, wherein the second field is separate from the first field. 15 [0024] BRIEF DESCRIPTION OF TI0 DRAWINGS [0025] A more detailed t derstanding ofthe invention may be had from the ibllowing description of a preferred embodiment, given by way ofexanple and to be understood in conjunction with the accompanying drawings, wherein: [0026] Figure 1A illustrates a preceding matrix or antenna weight signaling schema; [0027] Figure 1B shows an example block diagram of a transmitter and - receiver configured to implement a precoding matrix transmission; [0028] . Figure 2 illustrates a first embodiment of a signaling scheme (single PMI validation for single PVI .eedback); [00293 Figure 8A illustrates a second embodiment of a signaling scheme for preceding matrix or antenna weight verification (multiple PIU validation for multiple PMI feedback); [0030] Figure 3B illustrates another embodiment of a signaling scheme for single PI validation for multiple PMI feedback; [0031] Figures 4-8 illustrate various PMI validation message schemes; .003]_ _ . g.....llustraes...a- control-signaling.-scheme--with-a-PMI~ - - validation signaling attached; [0038] Figure 10 illustrates a control signaling scheme with a PME validation signaling inserted; and 100341 Figure 11 shows a wireless -communication system with multiple Node Bs in communication with various WTRUs.. [0035] DETAILED DESCRIPTION 10036] When referred to hereafter, the term "WTRU" includes, but is not limited to, a Wireless.TransmitAReceive Unit (WTRU), a mobile station, a fixed or - -mobile subscriber unit, a pager, a cellular telephone, a personal digital assistan (PDA), a computer; or any other type of user device capable of operating in a wireless environment. When referred to hereafter, the term "eNodeB' includes, - but is not limited to, a Node-B, a base station, a site controller, an access point (AP), or any other type of interfacing device capable of operating in a wireless environment. [0037] The term "PMI indicator" is used to refer to an indicator responding to the feedback signal of or crirresponding to the validation state of antena weights, PM, beamforming weights, etc. The PM indicator may carry a preceding confirmation message, a preceOding indication message, other preceding-related messages, ora combination of them, The preceding indicati-n message could be a preceding information indication message, a rank override message, a feedback error message, etc., depending on the state of precodineg validation and may indicate -rank information or other preceding related information. [0038] The methods as described hereafter provide an EJUTRA scheme for antenna weight, beamforming information, preceding information, or precoding matrix indication PMI signaling and validation. [0039] Figure 1B is a block diagram ofa transmitter 110 and a receiver 120 configured to perform a method of preceding matrix indication as described hereafter. In addtionagqmponanta-icluderin-a-typicaltransmitterle-ei-ve,transmitter 110 comprises a preceding information determiner 114, a precoding processor 116, an antenna amay 118, and a preceding validation message generator 136 comprising a pmecoding confirmation message block 132 and a precoding indication message Wbiock 134. -The preceding information determiner 114 is used to determine preceding information based on the received precoding feedback from the precoding information generator 124 of the receiver 120. The output of the preceding information determiner 114 is used by the precoding processor 116 and the transmitter 110 when transmitting a data transmission, for example, orthogonal froquenoy division multiplexing (OFDM) symbols, to the receiver 120. The preceding validation message generator 136 is used to generate the validation messagebased on the output ofthe preceding information determiner 114. The preceding validation message generator 136 uses the received preceding feedback signal from the precoding information generator 124 and the preceding information generated from the preceding information -7determiner 114 to determine the state of the preceding validation and to generate the corresponding validation message. For example, if there is a match between the preceding information generated by the preceding information determier -114 and the preceding information generator 124, a validation message including a precoding confirmation message is sent; otherwise, a validation message including a preceding indication message is sent. [0040] The receiver 120 comprises a receiver 128, a precoding information generator 124, a channel estinator 130, a demodulator/processor 126, and a precoding validation message to preceding information converter 138. Tlte receiver 120 receives an OFDM block from the transmitter 110, performs channel estimation by the channel esthuator 130, and generates preceding information using the precodtg information generator 124 that is then sent via antennas 127. The receiver 120 also receives the preceding validation message from the preceding validation message generator 136, detects and decodes the preceding validationxmessage, and translates the preceding validation message to precoding information using the preceding validation message to preceding information converter 138. The precodin ingmation theoutputoprecoding-validation

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message to preceding information converter 138 is fed to the demodulator/processor 126 for MIMO data detection, decoding, and. processing. [0041] It is noted that theitransmitter 110 maybe located at a WTRU, at a - base station, or both, and the receiver 120 may be located at -the WTRU, at the - base station, or both, [00421 A validation message or a PAI indicator using the preceding confirmation may consist of a single bit. For example, the precoding confirmation or the PI indicator can carry two possible validation mess ages using a single - bit. (1) The precoding confirmation message informs the WTRU that the preceding information used at the eNodeR is exactly the same as the preceding information fed back from the WTRU. (2) The preceding indication message informs the WTRU that the preceding information used at the eNodeB is not the same as the preceding information fed back from the WTRU.

[00431 The preceding vaidation message or the PMI indicator may also consist of more than one bit.' Precoding validation messages may carry one preceding confirmation message and several preceding indication messages. For example, the preceding validation message or PMI indicator can carry several - possible messages using more than one bit, (1) The preceding confirmation message informs the WTRU tkat the preceding information used at the eNodeB is exactly the same as the preceding information fed back from the WTRU. (2) One of several possible precodiag indicatiQn messages informs the WTIRU thAt the preceding information used at the eNodeB is not the same as the preceding information fed back from the WTRU and indicates which preceding information is being used at the eNodeB. [0044] The precOding ilication message may indicate the kind of preceding information used if the WTRU preceding feedback has an error, is not reliable, or is overridden by the eNodeB. Furthermore, the preceding indication message may indicate which subset of the preceding information is used if the WTRU's rank information in its preceding feedback is overridden by the eNodeB. [0045] The precodiLng infarmationor.P__MUjnaycontain-allthe informationrelated to MIMO preceding, including rank information. The method as described reduces the overhead for PMI validation by using an efficient validation message that consists of confirmation messages pertaining to the WrRU's preceding. feedback. A validation message may also include an indication message. As an example, a Q-bit validation message or PMI indicator is used. Q can be greater than or equal to one for every PMI indicator. For example, if a validation message is either one confirmation message or one indication message, then Q=1 bit is sufficient. Ifthe validation message is either one confirmation message or one of the several indication messages, then Q> bits may be used. [0046] The confirmation message and indication message can be separately coded or encoded or jointly coded or encoded. In a separate coding or encoding scheme, the validation messagemay consist of two parts - a confirmation part and an indication part. The confirmation pert usually uses one bit to carry a positive confirmation message or a negative confirmation message. The indication part usually uses ane or more bits to carry two or more indication messages. In the confirmations message, a positive confumation message is used to inform the WTRU that the precoding information used at the eNodeB is exactly the same as the precoding information fed back from the WTRU, On the otherhand, a negative confirnaation message is used to inform the WTRU that the precoding information used at the eNodeB is not the same as the precoding information fed back from the WTRU, This indicates to the WTRU that different precoding information is being used at the eNodeB. The kind of preceding information being used at the eNodeB is indicated in the indication part of validation message. [00471 A separate coding message format having confirmation and indication parts or fields is depicted as follows: Confirmation Message hIdication Message Validation Message. [00481 in a joint coding er encoding scheme, the validation message may -. -- consist-o-oly-onepatthat- mbineseonfnmation--and-indication- messages; .

Each validation message can carry either one confirmation message (a positive confirmation message) or one off the possible indication messages. The indication message in joint coding serves wo purposes - to provide negative confirmation and preceding indication at the same time. That is, the indication message is used to inform the WTRU that Ie precoding information used at the eNodeB is not the same as the preceding information fed back from the WTRU and it also - indicates the precoding information being used at the eNodeB. A joint coding message format having a single combined confunmation/indication part or field for the validation message is depicted as follows: Confirmationfndication Messages Validation Message, [0049] Separate coding or encoding of confirmation and indication messages is simple. In addition, most of the time only the confirmation message or one bit needs to be sent, therefore the efficiency is high. However, the receiver - 10has to distinguish between aieonfirmation message and a confirmation and indication message because they are of different lengths. This may increase the detection complexity of the receiver. To avoid the issue of different lengths between a confirmation message and a confirmation and indication message, the same format may be used regardless ofwhether the preceding information of the eNodeB and the WTRU are identical or not. For example, the same format fora confirmation and indication message may be used by a confirmation message, [0050] Furthermore, only one confirmation message and one indication message may be sent, instead of sending one conftimation message and multiple indication messages in the case of multiple sub-band preceding. The schenve using only one confirmation message and one indication message is a wide-band precoding-or-non-frequency selective preceding, since only one indication message is sent corresponding to a single precoding information or matrix that is used at the eNodeB for all the sub-bands. The scheme using one confirmation message and multiple- indication messages is a multi-band preceding or frequenciY selective precoding, since nultiile preceding information is used for multiple sub _bands,_whbexgeevah-predignomios-sdfrneubad,--- - - [0051] By using the same format for both the confirmation only message and the confirmation and indication messages, and using the non-frequency selective precoding when the preouding information used at the eNodeB and the preceding information fed back from the WTEU are not identical; detection complexity at receiver is reduced or avoided. When the precoding information used at the eNodeB and the preceding information fed back from the WTRU are identical, multi-band precodingor frequency selective precoding is used. [0052] Joint coding combine confirmation and indication messages and can save greater bits per validationomessage. But, every validation message that is sent contains both confumation and indication messages, and therefore, there are a constant number of bits that are sent consistently in a validation message. The overall efficiency may be lower for joint coding as compared to separate coding, but joint coding may not increase the detection complexity of the receiver. The use of confirmation and indication messages for responding to precodingfeedback - ~- 11 using either the separate or joint coding or encoding schemes for preceding information provides greater efficiency than the straightforward method, as-it uses a very high number of bits. [0053] As another example, for Q=2 bits, using separate coding for the confirmation and indication messages, the confirmation part of the validation message may use one bit and the indication part of the validation message may use the other bit. The conrfimation part of the validation message with bit 0 may represent the positive confirmation message, and bit 1 may represent the negative confirmation message. The indication part of the validation message with bit 0 and 1 may representiindication message 1 and indication message 2, respectively, which may correspondingly indicate a precoding information 1 and preceding information 2. [0054] For Q=2 bits, using joint coding for the confirmation and indication messages, a validation message with a bit sequence 00 may represent a confirmation message (a positive confirmation message). A validation message with a bit sequence 01, 10, or 1I may represent indication message 1, indication _ . __message 2, or indication message, rse3ctively,_whichnmay-correspondingly- indicate a precoding information 1, preceding information 2, and preceding information 3. A validation message with the bit sequence 01, 10, or 11 automatically represents the negative confirmation message, due to the joint coding or encoding of the confirmation and indication messages. 10055] Similarly for Q43 bits, when using separate coding for the confirmation and indication messages, the confirmation part of the validation message may use one bit and the indication part of the validation message may use two hits. The confirmationm part of the validation message with bit 0 may represent the positive confirmation message and bit I may represent the negative confirmation message. The indication part of the validation message with bits 00-11 may represent indication message number 1 to message number 4, respectively, that indicates the corresponding preceding information numbers 1 to 4. -12 - [0056] Similarly for Q- bits, when using joint coding or encoding of the confirmation and indication messages, a validation message with a bit sequence 000 may represent the positiveconfirmatiuon message. A validation message with. - a bit sequence 001 to 111 may Mpresent the negative confirmation message and at the same time represent the indication message number 1 to indication message number 7, respectivey, which indicates the corresponding precodig information number 1 to precoding information number 7, [00571 . The indication message may indicate additional information. For example, the indication zoess;ge may indicate one or more of the following: which preceding information ear matrix is used (this may also include ranlk information), how the eNodeBoverrides (e.g., which preceding information cr matrix subset should be used; when WTRU's 'rank in -precoding feedback is - overridden), or how the eNodeB handles the case when the WTRU feedback is erroneous (e.g., use the previouly used valid preceding information). According to what information is indicated, the indication message may have different types, e.g., a preceding information indication type message, a precoding or rank _--_--override message, a feedback error messaggtc..AccringLyth alidaton message may have two types:- a confirmation message and an indication mesage as sunmarized in Table 2A. Type of Validation Usage Message Confirmation message Cotfirm the same preceding information fed back from the WTRU is used at the eNodeB. Indication message Indicate the preceding information used at the eNodeB. Table 2A - [0058] A validation message may have four types of messages - a confirmation message, an indication message, an override message, and a - feedback error message as sonmarized in Table 2B. - 13- Type of Validation Usage Message Confirmation Confin the same preceding infrmation fed back message from the WTRU is used at the eNodeB, Indication message Indicate the precoding information. used at the - eNodeB. Override message Indicae the eNodeB overrides the WTRU's FeedhacL If it isa rank override, indicate which preceding information subset should be used. Feedback error Indicate the WTRUs feedback is in error. message Table 2B (0059] The method as described above is applicable to any MIMO wirele s communication system and is 'applicable to the uplink (UL) and the downlink (DL). {0060] In general there can be one confirmation message, M1 indication - -- msge(iratig-diffemti-pWe-dinig inf kd YMWfloe sag (indicating different override ,rules for preceding), and MS feedback error messages (indicating different preceding rules to handle feedback error), The total number of bits to represoat the validation message is log2 (1 +M1 + M2 + MS). [0061] Joint coding maybe performed for the precoding confirmatioM message, preceding information, or indication messages which may or may not include rank-information. In addition, joint coding may also be performed for ran override messages, feedback error messages, or other IMIMO related . information and messages if used. [0062] An implementation ofthe above scheme using either a single bit or more bits is described as fOllows. When there is a match between the PMs, i.e.. the PMIs are identical, only -a PI indicator is received by the WTRU. Alternatively, a PMI indicator with the PMI of the eNodeB can also be received -14by the WTRU. However, if there is a mismatch between the PMIs or if the PMIls ofthe WTRU are overridden, the WTRU receives a PMhindieator with the PM1 of the eNodeB. In this example, the PMI indicator is a preceding confirmation field and the PMI is a precodinginiication field. [00631 A plurality ofPMXs may be sent simultaneously, and the PMIs may be partitioned into a pluralitynf groups, {0064] Figure 2 depicts.a signaling scheme in accordance with another embodiment. A WTRU or a receiver 211 transmits a PMI or antenna weightsto an eNodeB or transmitter 213pdenoted as PMJj (having Y bits) 215. To inform the WTRU 211 of the currentlyused precoding matrix or antenna weights at the eNodeB 213, the eNodeB 213 sends a validation message back to the WTRU 21.1, denoted as PMIk (Y bits) 2172 When the eNodeB 213-and the WTRU 211 use the same preceding matrix or antenna weights, the eNodeB 213 sends only a PIVLI indicator, PMUIND (one bit) 217, indicating that the preceding matrix or the antenna weights are identical instead of sending the entire PMI or antenna weights bits, The feedback error is usually small, typically 1%. Most ofthe time, the eNodeB 213 andjte WTRU 211tuse thesameprecodingmatz-or-antennia weights. Therefore, most of the time, the one bit PMI indicator (positive confirmation or negative confination messages) is sent. 10065] This signaling scbeme significantly reduces the signaling overhead and is summarized as follows. When the PMI indicator, the PMI, or the antenna weight indicator is set at 1, it imicates a negative confirmation message and that the PMI or antenna weights used at the eNodeB and the WTRTJ are not identical. This usually occurs in the event of a feedback error or if the eNodeB overrides the WTRUs feedback. [0066] When the PMI indicator, the PMI, or the antenna weight indicator is set at -0, it indicates a positive confirmation message and that the PI or antenna weights used at the eNbdeB and the WTRU are identical. Thffis usually occurs in the event of no feedback error and if the eNodeB does not override the WTRU's feedback. This scheme is sammarized in Tables 3A and 33. The PMI. indicator is denoted by PMJINiD. - 15 -- PM-IN D State Usage 0 Confirmation Confirm the eNodeB to use the (or positive confirm) preceding information fed back from. the WTRU. 1 Not confirm The eNodeB uses different preceding (or negative confirm) information than those fed back from the WTRU, This is usually due to a feedback error or an eNodeB override. This coud also be due to other factors. Table 3A; PI indicator using i bit, PMUJND Message Usage 0 Positive conAmnation Confirm to use PMIn fed back from the message WTRU. ... ..... ..- _... 1..-.._................... .Negative confimat -- o- Send-singe -lV-Sen-PI---wic-is message a preceding matrix used at the eNodeB for all the sub-bands or RBGs, e., the same single preceding matrix is used for - --. entire system bandwidth. Table 3M: Non-Frequency Selective Precoding (for non-frequency selective feedback or single PMI feedback) - [0067] The PI indicatori may also be used to indicate the beamforming matrix/matrices or vectors, antinna weights, and any other matrix, vector, or weights when applicable. Other notations for the PMI indicator other than PMi_IlD may also be used. The hit assignment for the PMIIND is arbitrary and any other values than '1' aiid '0' may be used for the PMI indicator. [0068] Figure 3A shows. a signaling scheme for preceding matrix or -antenna weight validation insaccordance with another embodiment, This embodiment is for an efficient signaling for multiple PMI validation or -16verification. This embodiment is for the case of a frequency selective channel. - For example, the entire system bandwidth may be divided into multiple sub bands (or RBGs) and one PIn ay be reported for each sub-band when there are multiple PMIs to be reported for the entire bandwidth, Ia this embodiment, there can be N PMIs for reporting. [0069] A 'WTRU or receiver 311 transmits preceding matrix indices or antenna weight information 315 to an eNodeB or transmijtter 313, denoted .ss PMIJ1, PMIj2, ..., PMIjN. To inform the WTIU 3 11 of the currently used preceding matrices or antenna weights at the eNodeB 313, the eNodeB 313 sends a validation message 817 backto the WTRU 311, denoted as PMlki, PM[_k2, ., PMI_kN which corresponds to preceding feedback PMjl, PMIJ2, ..., PMILJN respectively. [0070] When the oNodeW'313 and the WTIU 311 use the same precoding matrices or same sets of antenaa weights for all the sub-bands, (it, PMI...j=. PMLkl, PMIj2= PMtk2..., PMjN- PMIN), the eNodeB 313 sends only a PMI indicator (1 bit) indicatingthat the PMILs are identical, instead of sending all the PMI~p 4L a~t ~f~nte__taweights. bitsback~to thelTRU.L31L--The- - ledback error is usually small, typically 1%. Most of the time, the eNodeB 313 and the WTRU 311 use the same preceding matrices or antenna weights. [0071] In case of no feedback error and no override, the eNodeB 313 send's only the PMIIJND to the WTRU 311. In case of a feedback error-or preceding or rank override, the eNodeB 113 sends the PMJIND and the precoding information to the WTRU 311. Depending on whether frequency selective preceding is used or not, the eNodeB. 313 sends a different amount of preceding information to the WTRU 311. For example, if frequency selective preceding is used at the eNodeB 313, the'eNedeB sends the PMIIND and PMIki, PMI_k2, - ..., PMIkN to the WTRU 811, where PMIikl, PMLk2, .., PMJkN represent N preceding matrices for N sub-bands or RBGs. If non-frequency selective precoding is used at the eNodeB 313, the eNodeB sends the PMIND and a single preceding information PMI-m, where PMIm is a preceding matrix used -17for all the sub-bands or RBGs. That is, the same preceding matrix is used for all sub-bands or RBGs. This scheme is snmmarized in Tables 4 and 5, respectively. PMUND Message Usage 0 Positive Confirm to use PMU-1, PMj2, PMIjq{ confirmation fed back from the WTRU. message 1 Negative Send N PMs. (Send PM2Lk1, confirmation PMI~k2,...,PML,.NN) message N preceding matrices are used for N sub bands. Table 4: Frequency Selective Precoding when positive and negative confirmation (for frequency selective feedback or multiple PMIs feedback) PAILIND Message Usage O Positive confirmation Confirm to use PMIJl PMI11j2, -..,PMIjNi message fed back from the WTRU. 1 Negative Send a single PAI. Send PAIm which is -.- ---- ---- confirmation -apeoigmti-mda-heodBfr message all the sub-bands or RBGs, i.e., the same single preceding matrix is used for the entire system bandwidth. Table 5: Frequency Selective Precoding when Positive Confirmation and Non Frequency Selective Precoding-When Negative Confirmation (for frequency selective feedback or multiple PAIs feedback) [0072] Figure 3B shows a signaling scheme for precoding matrix or antenna weight validation in. accordance with another embodiment. This embodiment is for an efflcient signaling for multiple PMI feedback and a validation message including a ingle preceding indication message. A WTRU or receiver 311 transmits precoding matrix indices or antenna weight information 316 to an eNodeB or transmitter 313, denoted as PMI-jl, PMLj2, ..., PMjN. To inform the WTRU 311 of the currently used precoding matrices or antenna weights at the eNodeB 313, the eNodeB sends a validation message 318 back to - 18 the WTRU 811, denoted as PIIND + PMVLk, which responds to precoding feedback PMIjl, PMIfj2,.-.,PM_jN. This is used when there is multiple PMI feedback and a validation message with a single PMI indication message is used. [0073] When the eNodeBf 318 and the WTRU 811 use the same preceding matrices or same sets of antenna weights, the eNodeB 318 sends a confirmation message indicating that the PMLs are identical, instead of sending all the PMTs or all sets of antenna weight bits back to the WTRU 31-L Otherwise, the eNodefB 818 sends an indication message to the WTRU 311 indicating that the PMIs are not identical, If separate coding is used, PMLIND and PMI are sent, in which the PMUND serves as a positive or negative confirmation message and the PMI serves as the indication message, In this case, PMVLIND is one bit and PMI is at least one bit. If joint coding is used, the P IJND- contains the P,1, and the PMIND serves as both a positive or negative confirmation message and an indication message. In thisrcase, PMIJND is at least one bit. [00741 The validation message format with two fields can be depicted sa follows: Validation Message Format 1 [00751 For a validation message using joint coding of confrmation and indication messages, the validation message format with a single field can be, depicted as follows: FMIIND Validation Message Format 2 [00761 In validation message format 2, the single PIIND field contains - the combined information of th PMIJND and the PMI as in validation message' format 1. [0077] Another implementation is to use a default precoding message instead of sending an indication message or PMIs. The signaling can be done in another way, wherein there is no fbedback error and no override. The eNode sends only the P INWD (positive confirmation message) to the WTRU, in which the PMI_IND confirms that the eNodeB uses the same preceoding information fed back from the WPRU. L the case of feedback error or PMT override, the eNodeB sends the PMUND (negative confirmation message) to the WTRU, in which the PMUND informs the WTRUto use the default- or pro-determined precoding indication message or information. Therefore, only the PMIUND) containing the confirmation message is sent, while the indication message or PMI(s) are not seht in any case. This scheme is summarized in Table 6. - PMUND Message- Usage 0 Positive Use preceding information fed back from the confirmation WTRU. I Negative Use the default or predetermined precoding confirmation indication message or information. Table T& Negative confirmation using default preceding indication message. [0078] The confirmation state for the PMIJND as positive and negative is arbitraryr and any other valuesuthan positive and negative may be used for the PMI indicator. [0079] As described earlier, the signaling overhead for the PMI validation or verification may require up tt 250 bits or more per validation signaling in the case of multiple RBGs and multiple PM s each time.PMI validation messages are sent. Therefore, the signaling scheme using the preceding confirmation message as described saves a significant amount of signaling overhead. [00801 The downlink PMI indicator signaling scheme in accordance with another embodiment is summarized as follows. When the PMUND (the PMI or antenna weight indicator) is set at 1, it indicates a negative confirmation message and that at least one of a plurality of PMIs used at the eNodeB 313 and . the WTRU 311 are not identicl. This usually occurs in the event of feedback . errors or when the eNodeB 313 overrides the WTRU's 311 feedback. All PMs are sent following the PMIIN-(1 bit) as shown in Figare 4. In Figure 4, the first element is PiIND 411 allowed by individual PMIs 413(a) to 413(n). {0081] When the PIIN]) (the PMI or antenna weight indicator) is set at 0, it indicates a positive confirmation message and that all of the PMs used at -20 the eNodeB 313 and the WTRU 311 are identical. This usually occurs in the event of no feedback error and! the eNodeB 313 does not override the WTRU's feedback: PMs are not sent, but only the PMU1ND (one bit) 411 is sent. [0082] In accordance with another embodiment, PMIs are partitioned into groups, for example, G groups, As shown in Figure 5, each group has one bit to indicate whether the precodingsmatrices or antenna weights are the same for the eNodeB 313 and the WTRU 311. Such signaling can be implemented to have either Q hits in one indicator oriQ PMI indicators each of which has one bit. PVI[ indicators, PMIUND(1) 511, PMIIND(2) 513, -, and PMIIND(G) 5g, may be spread over the validation messages as shown in Figure 5. [0083] An alternate mode of grouping can be seen in Figure 6, wherein thie PMI indicators (611, 613, and 61g), - PMUND(1), PMUND ), x, and PMIND(G), may be grouped in the front portion of the validation message as shown in Figure 6. [0084] The signaling mechanism in accordance with PI indicators (PMII(g), g=1,2,...,G) for gvoup PMIs, is summarized as follows. When the PMIIND (the PM or antennaiweightindicAtP) for group ofWTRUs-is-set-at--.

1, it indicates a negative confirmation message and that at least one of the PMIls belonging to that group that are used at the eNodeB 18 and the WTRU 311 are not identical. This usually occurs in the event of feedback errors or if the eNodeB overrides the WTRU's feedback for that PMI group. If PMIIND (g). = 1, indicating a negative confirmation message for the gtb group, then all the PMlIs belonging to the gtb group are -sent following the PITUND (g) that is set to . For example, in Figure 5, if any of PI_1, PM2, and PMIS are not the same for the eNodeB and the WTRU, then PMIJND(1), PML1, PMI_2, and PMLS are sent by the eNodeB. [0085] When the PMLIND, the PMI, or the antenna weight indicator for a group of WTRUs is set at 0, it iMicates a positive confirmation message and that all of the PMIs belonging to that group that are used at the eNodeB and the WTRT are identical. This usually occurs in the event of no feedback error or if the eNodeB does not override, the WTRU's feedback. If PMUND(g) - 0, -21indicating a positive confirmation message for theg group, then PMls belonging to the g 1 group are not sent. bdt only the PMI indicator for the gt group is sent The sent PMLJND(g) is set to 0, For example, in Figure 5, if all of PMJ_4 VPML5, and PML6 are the samne for the eNode3 and the WTRU, only the 1-hit PMLIND(2) is sent by the eNfodeB, Alternatively, the fields reserved for the unsent PfIs ean be used for sending other information or data. This increases the information or data throughput and spectrum efficiency. For example, the fields reserved for PMIL4, PMLS5, and PML6 can be used for sending other information or data. [00861 A special case for group PMI indicator signaling is when each group has only one PMI, i.e., G=N. Inithis implementation, each group has exactly one PML This schemsisillustrated in Figure 7. An increase in the groups (G) may increase the signaling efficiency because only a few PMIs which are not identical need to be signaled. [00871 In general, the PMLIND can represent the messages or states that consist of a bit sequence. For example, the PMILIND can represent the precodig confirmation message or statz_ r inginformationmessag__state-,- - - - - preceding information message 2 or state 2, and so on. This scheme is summarized in Table 7A. A tymilar scheme in case of an override scheme is shown in Table 7B. PMI ND Message state4 Usage 000 Precoding Confirm that the eNodeB uses the confirmation message precoding information fed back from the

WTRU.

001 Precoding Inform the WTRU to use preceding information iatris 1. message#1 010 -Precoding Inform the WTRU to use precoding information matrix 2 message#2 -22 - 110 Precoding Inform the WTRU to use preceding information matrix 6 message#6 - 111 Precoding Inform the WTRU to use preceding information message matrix 7 Table 7A PMUIND Message Usage 000 Precoding Confirm that the eNode3 uses the confirmation message preceding information fed back from the WTRU. 001 Precoding Inform the WTRU to use preceding information matrix 1. mtessage#1 ------ ,--Rnk-information---- Informhe-W-PU to-use-precoding-subr - override message#1 matrix 1 111 Rank information Inform the 'WTRU to use precoding sub (override message#2 matrix 2 Table 1B. With rank OverTde [0088] As an example, codebook (1) using the above scheme has four preceding vectors for rank 1 and two precoding matrices for rank 2. There are sik preceoding matrices/vectors in tttal in codebook (1.) as shown in Table 8. Rtnk 1 Rank 2 ci C5 ono C4 Tale 8: Codebook (1) -23- - 10089] A corresponding PMI confirmation and indication scheme to - codebook 1, when the rank is jointly indicaLted, can be seen in Table 9A. PMUNDJ' Message Usage 000 Precoding confiraxation Confirm that the eNodeB uses the message preceding information fed back from the WTRU. 001 Precoding information or inform the WTRU to nse preceding indication message#1 matrix CL - 101 Precoding information or Infom the WTRU to use precoding indication-messags#5 matrix C5. 110 Precoding information or Inform the WTRU to use preceding indication message#6 matrix C6. 111 Reserved Reserved or used for other purposes. Table 9A: PMI confirmation and indication scheme [0090] Another scheme far codebook (1) using the above scheme, when the rank is jointly indicated and a.rtak override is indicated, uses the corresponding PMI confrmation and indication scheme table for rank 1, as shown in Table 9E PM-I_IND. . Message - . - Usage 000 Precoding confirmation Confirm that the eNodeBi uses the message precoding information fed back from the WTRU. 001 Precoding informadon Inform the WTRU to use precoding or indication message#1 matrix C1. 010 Precoding informadon Inform the W

T

RU to use preceding or indication message#2 matrix 02. -24 - 110 Precoding information Inform the WTRUI to use preceding or indication message#6 matrix C6. 111 Rank information Inform the WTRU to use the preceding ovenide message. uatrix subset of a higher rank precoding matrix. Table 9]B: Joint Coding for -Precoding Confirmation, Indication and Rarnk Override Messages [00911 A PMUND- 111 as used in Table 9B indicates that the eNodeB informs the WTRU to use the precoding matrix subset of a higher rank preceding matrix. For example, a rank 2hprecoding matrix consists of two column vectors and a rank 1 precoding matrix is a preceding vector. When the rank information is overridden from rank 2k raaik L either the first or the second column vector bf the rank 2 matrix can be indicated to be used. [00921 Another scheme for codebook (1) using the above scheme, when the rank is separately indicated, is to use the corresponding PW confirmation and indication scheme table for rank 1, as shown in Table 10A. PM4.. IND MssF-------- Usage 000 Precoding conlirmation Confirm that the eNodeB uses the message preceding information fed back from the WTRU. - 001 Precoding iifornation Inform the WTRU to use preceding or indication message#1 matrix CI. 010 Precoding information Inform the UTRU to use precoding or indication message#2 matrix 02. 011 Precoding informadonf Inform the WTRU to use precoding or indication message#3 matrix C3, 100 Precoding information Inform the WTRU to use precoding or indication message#4 matrix C4. 101-111 Reserved Reserved or used for other purposes. Table 10A: PMI confirmation aad indication scheme for Rank 1 with respect to Codebook (1). - 25 - 9 [00931 For rank 2, corresponding to codebook(1), the PMI.confirmation and indication scheme table, whenrte rankis separately indicated, can be as shown in Table IOB. PMIIND Message Usage 00 Precoding confirmation Confirm that the eNodeB uses the message precoding information fed back from the WTRU. 01 Precoding information Infom the WTRU to use precoding or indication message#1 matrix 05. 10 Precoding information Inform the WTRU to use preceding or indication meseage#2 matrix 06. 11 Reserved Reserqed or used for other purposes. Table 10B - PMI confirmation and indication scheme for Rank 2 with respect to Codebook (1), [0094] As an example, codebook (2) has sixteen preceding vectors for rank 1

-----

ad sixteen rednm c frank 2, 3, and 4. There are sixty four - preceding matrices/vectors in total in codebook 2 as shown in Table 11. The rank 1 preceding matrix is a colhunwector and includes preceding matrices 01-Cic. The rank 2 preceding matri consists of two column vectors and includes - preceding matrices 017-C32. The raniik 3 preceding matrix consists of three colinnt vectors and includes matrices 033-048. The rank 4 preceding matrix consists of four column vectorsiand includes matrices 049-064. The preceding matrix for a lower rank is a subset of the preceding matrix in a higher rank. For instance, Cl is a subset of0 17; which is a subset of 038, which is a subset of C49. RankI Rank2 Rai3 Rank4 C1 C17 C33 C49 02 018 C34 050 C8 C19 C35 051 04 020 036 C52 -26- 05 021 C37 053 06 022 038 054 07 023 C39 C55 CS 024 C40 056 09 C25 C41 057 C10 026 C42 058 el C27 C43 C59 C12 028 C44 COO C13 C29 C45 061 014 030 C46 C62 C15 31 C47 063 016 - C32 - 048 064 Table 11: Codebook 2 [0095] A corresponding table for the PM[ confirmation and indication scheme for Codebook (2) can be as shown in Table 12A - PMI-NDNB-- Message- ----- Utsage.---.-_----_ 0000000 Precoding confirmation Confirm that the eNodeB uses the pnecoding message information fed back from the WTRU. 0000001 Precoding feedback error Inform the WTRU to use precoding matrix X. message 0000010 Precoding information Inform the WTRU to use precoding matrix Y. override message 0000011 - Precoding information or form the WTRU to use precoding matrix C1 0010010 indication message#1 - 64 to C64, respectively. 0010011- Reserved Reserved or used for other purposes. 1111111 Table 12A Joint Coding for PrebDding Confirmation, Indication, Feedback Error and Override Messages. - 27 - 10096] A corresponding able for the PMI confirmation and indication scheme with rank overriding for Codebook (2) can be as shown in Table 12B. PMJND Message Usage 0000000 Precoding Confirm that the eNodeB uses the preceding confirmation message information fed back from the WTRU. 0000001 Precoding feedback Inform the WTRU to use precodingnmatrix error message X. 0000010 Precoding infrmatin Inform the WTRU to use precodingiatrix override mesage Y. 0000011- Precoding information Inform the. WTRU to use precodingmatrix -0010010 or indication message C1 to C64, respectively 1-64- 0010011- Rank information Inform the WTRU to use four preceding 0010110 override fronvrank 4 matrix subsets respectively. to rank 3 0000111- Rank information Inform the WTRU to use six preceding -0011100 ---- -overridefromnank-4---mat-subsetsTespectively;to rank 2 0011101- Rank informad4on Inform the-WTRU to use four precoding 0100000 override fromirank 4 matrix subsets respectively, to rank 1 0100001 - Rank information Inform the WTRU to use three preceding 0100010 override from rank 3 matrix subsets respectively. to rank 2 0100100 - Rank information Inform the WTRU to use three preceding 0100110 override from rank 3 matrix subsets respectively. to rank 1 - 0100111.- Rank information Inform the WTRU to use two preceding 0101000 override from tank 2 matrix subsets (select the first or the second -to rank I column vector) respectively. -28- - 0101001- Reserved Reserved or used.for other puVoses. 1111111 Table 12B: Joint Coding for Precoding Confirmation, Indication, Rank Override and Feedback Error Messages [00971 To save the signaling overhead, one ofthe preceding matrices can be removed from the codebook (2). As an example, if 064 or one of the other matrices is removed, then the scheme reduces to the scheme as shown in Table 12C. PMUND State Usage 000000 Precoding confirmation message Confirm that the eNo4.aeB uses - -the preceding information fed back from the WTRU. 000001- Precoding information or indication Inform the WTRTU to use 111111 message 1 - 61 precoding matrix C1 to 063, respectively. -~~Table-12CModified-Joint Coding-for--Preoding-Confirmaton-and-ndietion--- - Messages. [0098] When each groupphas only one PMI (the PMI or antenna weight - indicator) and the PMIJND is 6et at (n) - 1, it indicates that the nh PM that is used at the eNodeB and the WTRU are not ideniical. ThIs usualy occurs in the event of feedback errors or if the eNodeB overrides the WTRU's feedback. The pib PMI is sent. For example, in Fkgnre 8, if PMI-n is not the same for the eNodeB and the WTRU, PMUND(n) and PMLn are sent by the eNodeB. This increases signaling effciency. [0099] When each groupihas only one PMI (the PMI or antenna weight indicator) and the PMIJIND is set at n =0, it indicates that the n.th PMls that are used at the eNodeB and if the WTRJ are identical. This uaally occurs in the event of no feedback error and if the eNodeB does not override the WTRYs feedback. The nth PMI is not sent, but only the PMIND for the nth PM, i.e., -29 - PMUND(n) is sent, For exaTpl, in Figure 8, if PMI.n is the same for the eNodeB and the WTRU, only the 1-bit PMIJND(n) is sent by the eNodeE. .[001001 A PA[ indicator may be sent along with, attached to, or embedded in the existing control signaling. Figure 9 shows that PMI validation signaling is attached to a control signaling. Figure 10 shows that PM! validation signaling is inserted in a control signaling; Alternatively, the PMI indicator may be samit using a separate signaling or a, stand alone signaling. [00101] The PMI validatiem messages may be signaled to the WTRU via control signaling or a dedicated: reference signal (RS). Alternatively, part of the validation message may be sent via control signaling and part of the validation message may be sent via a dedicated reference signal, For example, the preceding confirnation part may be sent via control signaling and the precodittg indication part may be sent via dedicated reference signal. The PMI indicator signaling may be applied to ,both the control signaling and the dedicated reference signal and be used toreduce the amount of control signaling overhead . or dedicated RS overhead. When dedicated reference signals are used to send th e -- _PM.salidation-messages,-.seveaLformns-forndedicatedreference-signals-mayhe -- used, such as preceded pilots. The use of the PMI indicator to reduce dedicated RS is described as follows. [00102] New downlinkPIfl indicator signaling for dedicated refrense signal 100103] When the PMIND is set to 1 (a negative confirmation message), it indicates that at least one of the multiple PMVIs used at the eNodeB and the WTRU are not identical, This Usually occurs in the event of feedback errors or Lf the eNodeB overrides the WTRt's feedback. All dedicated reference signals that carry PMs are sent by the eNadeB. The PMIUIND is set to 1 and is also sent by - the eNodeB. [00104] When the PMIID is set to 0 (a positive confirmation message), it indicates that all of the multiple PMIs used at the eNodeB and the WTRU are identical. This usually occurs in the event of no feedback error and ifthe eNode3 -30does not override the WTRU'F feedback. All dedicated reference signals that carry PMls are not sent by the &NodeB, but only the 1-bit PMIND that is set to 0 is sent by the eNodeB. [00105] Most-of the time, all of the multiple PMIs used at the eNodeB arid the WTRU are identical and dedicated reference signals are not transmitted, buLt only the 1-bit PMIND that isi set to 0 is sent by the eNodeB. Therefore, this signaling scheme significantly reduces the overhead of dedicated referene signals. [00106] PMlI indicator signaling may be applied to both single user (S~) MIMO and multi-user (MU) MIMIO for reduced signaling overhead. In SI UMIMO, only the PMI indicatortfor one WTRU is sent by the eNodoB in a sub band or a frequency-and timeresoarce. n*MU-MIMO, inultiple PMIindicatois for multiplo- WTRUs-that share the same sub-band or the same frequency and time resource are sent by the eNodeB. It is, therefore, a simple extension fronm SU-MIMO. [001071 In MU-M10, itiassumedthatK WI'RUs exist. An eNodeB sends _- ----- iultipilEMIlyalidation signaaeacofwhichhasone-rmltiple-P-MIs-for-each- - -_ _ WTRU (WTRU 1, WTRU 2, . WTRU 10. The eNodeB sends multiple PMI! indicators to the WTRUs. Eack WTRU receives one PMI indicator if no group PMI is used as shown in FigureA, or multiple PMI indicators if group PMIs area used for the WTRU as shown in Figures 5-8. [00108] In the case that the PMbs are the same at the eNodeB and the kth WTRU, the eNodeB sends a lit PMI indicator to the km VTRU. In case that the PAIs are not the same for the eNodeB and the kmk WTRU, the eNodeB sends the PMI indicator denoted by PMIIND& and PMIs denoted by PMIN of the kt WTRU to the k t WTRU. 100109] For example, if the PMls are not the same for the eNodeB and the - first WTRU, but the same for a other WTRUs, then the 1-bit PMUIND) and PMIO are sent to the first WTRU by the eNodeB and the 1-bit PMIIND1IW) for k=2,3,..-,K are sent to all other>WTRUs by the eNodeB. Alternatively in MU MIMO, the eNodeB sends multiple PI indicators, each for one group ofWTRUs. - ~31 - The eNodeB may also send ons PMI indicator for all WTRUs. For MU-MIMO, the preceding schemes and usage can be generalized as described earlier. [00110] For two users simultaneously supported in the same RB or RBGQit is assumed there is one stream per user, i.e., each WTRU sees a rank 1 transmission for itself. Further suppose there are eight beamformingvectors C1, C2, ... , C8 in the beamforming codebook. Table 13 describes this scheme: If PMIIND 0 (a positive coniflmation message), it indicates that the eNodeiB confirms that the WTRU's feedback is used at the eNodeB (Caes'ca). A 8-bit PMI indicates seven possible inter&ring beaxdforming vectors of the other user, C, j=1,2,...,8 and Qj # Caeia. One bit combination (111) is reserved. If PMIIND 1, it indicates that the eNodeB will not use the WTtIU's feedback and a different beamforming vector will be used. A 8-bit PM! indicated eight possible beamforming vectors (C, j=1,2....,8) for the desired user, There is no separate indication for an interfering beamforming vector unless the signaling overhead is - allowed to increase. PMI-ITDI PM (1 bit) (3 bits) --- - -fConfirmation- ----------- mdistfion-Message)-------- Messa e) _ 0 000 - 110 forj=i,2,, and - j #Ca a 111 Reserved 1 000* C1. 001 C2 .010 ca 011 C4 100 - 05 101 06 110 07 111 08 Table 13: Separate Coding for Confirmation and Indication Messages - 32 - [00111] Another option issthe use of a default beamforming vector for the desired user when the PMIJN] is 1 (a negative confirmation message) and Usea S-bit PMI to indicate seven possible interfering vectors similar to the case whcn -PMITND 0. [00112] Similarly, for a four user MU-IvMO and rank 1 per user, a schenie is described in table 14, PMIND PMI. (I bit) (6 bits) 0 000000 -100010 35 combinations C4 Cj, Ck, for i, j, k = 1 icj<k and C, Cj, Ck # Cesirca 100011 - 111111 reserved 1 000- 111 C, i= 1,2,..,8 (First 3 bits indicate the vectc;Dr) 000 - 111 - 8 combinations (Last 3 bits indicate the -(2 C0, cO), -interferevte vector for (jk 1,2,.

0 ,8, iczj.k combinations) and C1, C C<A #Cdeaea Table 14: Separate Codingor Confrrmation and Indication Messages [00113] If some bind of restriction is imposed, the number of vector combinations can be reduced and thus the number of bits can be reduced. For example, if the rule indicates that only certain combinations are allowed, fo, instance CI, C2, C3, C4 can be oombined together as a group, and C5, C6, C7, C8 can be combined together as afgroup. But the group C1, C2, C3, C4 cannot be -33combined with the group 05, G, C7, C8. For example, Cl can be combined with - 02, C3, or C4 but cannot be tombined with 05, 06, C7, or 08. Combination restriction requirements may -he rules to meet unitary properties or a unitary beamforming requirement [00114] As an example, assume that Cl is the beamforming vector for the desired user and that the restriction rule is used. The vector combinations can be reduced to seven combinations; For two users, only combinations [C1, C2], [Ci, C31, and [CI, C4] are allowed. For three users only [W1, C2, C3], [CL, C2, 041, and [01, 03, 04] are allowed. For four users only [CL, C2, C3 C41 is allowed. Table 15 summarizes this particular scheme with restrictions: - Two WTRUs S1-(C, C3) 82=(C1, 03), 85=(01, 04) Three WTRUs 34-(01, C2, C3), 35=(01, 02, C4), S6=(C1, C3, C4) Four WTRUs 7--(01, C2, CS, C4) Table 15: Beamforming Vector Combinations (Assuming C1 is the Desired Vector) - - than 01 used for the desired' user. The PM confirmation and indication messages can be jointly coded and the corresponding PMI confirmation and indication scheme can be the following. If PMIJND =000, conrfim the WTRU's feedhbdck. If PILIIND=00, inform the WTRJ that 02 is the interfering beamforming vector. If PMI.ND=010, inform the WTRU that C3 is the - interfering beamforming vector, and so on as shown in Table 16. If PMI_IND=111, inform the WTRU that 02, C3, and C4 are the interfering beamforinng vectors. PMUJND Messages or States (Confinnation/Indication Messages) 000 Confirm 001 C2 010 - C3 011 04 -34- 1)2 FAY 100 02, C3 101 02, C4 110 C3, C4 111 I02, C3, C4 Table 16: Joint Coding for Precoding Confnation and Indication Messages [00116] Another alternative is to have PIIND=000 as the coarirmation message and PMI_IND=001-111 as the indication messages to indicate the seven possible desired vectors. Thenseven vectors or matrices are selected or pre selected from 01-CS. Similar; tables can be built for different beamforminig vectors other than C1 for a desired user. [00117] Joint coding may be performed for the preceding cdniistida message, the precoding information, or the indication messages, which may or may not include rank information. In addition, joint coding may also be performed for the rank overrideunessages, the feedback error messages, or other MIMO related information and;messages. ~0018] Sigure--4-shows. a-wirelesscommuniaionsystem-wit-muitipieeNodeBs 1113 implementing the embodiments as described. Each eNodeB 1113 provides communication coverage for a particular geographic area comonly referred to as cells and shown as idealized hexagons. The term "cell" can refers to its coverage area dependings on the coptext-i- which the term is used. T improve system capacity, an oNodeB coverage area may be partitioned into multiple smaller areas, e.g., three smaller areas. WTRTs 1111 maybe dispersed tltoughout the coverage area. -35- [00119] EMBODIMENTS 1. A method for reducing signaling overhead for a Wireless Transmit/Receive Unit (WTR), in a multiple-input multiple-output MIMO wireless communications by .using preceding confirmation and preceding information or indication in the form of a validation message, the method comprising; using the validation message to indicate the kind ofprecoding information used at an evolved Node B (eNodeB) wherein the validation message comprises of at least one bit; the validation message provides precoding confirmation message and indication message and validation message could be composed of one confirmation memage andaone-inidication message using separate coding; validation message could also be a single message that indicates confirmation, information, override or error message using joint coding; and indication message can ho a preceding information indication message or rank override message or a feedback error message or a combination and can indicate proving informaionfotringleuser $U-MMOnd-can-alsoindicate --- desired preceding information; interfering preceding information or both for multi user MU-MIMO. 2. The method of enbodiment 1, wherein the preceding information may also contain preceding matrices or ranks or other breeding related information or a combination of all. S3. The method of embodiment 1, wherein the validation message. comprises of at least two of a confirmation message and an indication message, a feedback error message and an'override error message. 4. The method of embodiment 1, wherein the preceding confirmation and indication messages (validation message) can be separately encoded or jointly encoded. 5. The method of em1odiment 1, wherein when the validation message is separately coded or encoded, the validation message itself consists oftwo parts; a confirmation part and an indication part. - 36 - 6. The method of embodiment 5, wherein the confirmation part uses one bit or a plurality of bitsAto carry a positive confiration message or a negative confirmation message. 7. The method of embodiment 6, wherein a positive confirmation message is used to inform the WTRU that precodinginformation used at eNodeR is exactly the same as the preceding information fed back from the W

T

RU. 8. The method of erabodiment 6, wherein a negative confinnation message is used to infbrm WEIRU that the precoding information used at the eNodeB is not the same as -the precoding information fed back from the WTRU. - 9. The method of embodiment 6, wherein the indication part uses 8t -least one bit to carry a two or more indication messages. 10. The method of embodiment 6, whereinrthe indication jiart indicates to the WTRU that different prer.oding information is being used at the eNodeRl. 11. The method of embodiment 3, wherein when the validation message is jointly coded or encoded, the validation message combines the confirmation part and the indication part. ___ . _1A2dnmthod.-for-ra~dncing -signaling-ov-erhead--for-a-Wireless-- Transmit/Receive Unit (WTRU), in a multiple-input multiple-output MIMV) wireless communications by using precoding confirmation and precoding information or indication, the method comprising transmitting. a preceding matrix inde -{rMI). that includes. antenn weights and beamforming weights to an evolved Node-B (eNodeB); and receiving a validation message from the eNodeB as a PMI indicator that includes information about its antenna weights. 13. The method of eambodiment 12 wherein the part of validation - message is sent to the WTRU via a dedicated reference signal and the part &f validation message is sent to the WTRU via control signaling scheme. 14. The method of enbodiment 12 wherein the eNodeB sends only a preceding confirmation message or PM indicator when the PMI of the WVRT and-a PMI of the eNodeB are identical. :37- 15. The method of embodiment 12 wherein the eNodeB sends to the WTRU a PMI indicator with it$ PIP when the PMI of the WTRU and a PMI of the eNodeB are not identical or when the PMI of the WTRU is overridden by the PWl of the eNodeB or when a feedback error occurs. 16. The method of embodinent 12 wherein PMI indicator size is one bit or more than one bit, can represent state confirmations and can be any arbitrary value depending upon design choice. 17. A method for reducing signaling overhead for a Wireless ITransmit/Receive Unit (WTRU), in a multiple-input multiple-output MIMO wireless communications by using preceding confirmation and preceding information or indication, the method comprising: transmitting a pluralityf precoding matrix indices (PMI) that includes antenna weights and beamforrdng weights to an eNodeB; receiving a validation massage from the eNode B as an individual PMI indicator for each PMI that inobhdes information about its antenna weights, 18. The method of embodiment 12 wherein the part of validation * esg ssett~hWR-i--ddctdreference signal- and-the-part-ef --- validation message is sent to the WTRU via control signaling scheme. 19 The method of embodiment 17 wherein the eNodeB sends only a PMI indicator when the PMIof the WTRU and a PMI of the eNodeB are identical. 20. The method of embodiment 17 wherein the Node-B sends to the WTRU a PMI indicator with ittPMI when at least one of the PMIs of the WTRU and at least une of the PMIs of the eNodeB are not identical or when the PMI of the WTRU is overridden by the PMI of the eNodeB or when a feedback error occurs. 21. The method of emledim~ent 17, wherein PMI indicator size is one bit or more than one bit, can represent state confirmations and can be any arbitrary value depending upon design choice. 22. A method for reducing signaling overhead for a Wireless Transit/Receive Unit (WTRU), in a multiple-input multiple-output MIMO -38 wireless communications by i using preceding confirmation and precoding - information or indication, the method comprising: transmitting a plurality of preceding matrix indexes PVH that are separated into groups that inchades antenna weights and beamfonning weights to a eNodeB; receiving from the eNodeRa validation message as an individual PMI indicator for each group of PlIs that includes information about its antenna weights. 23. The method of embodiment 22 wherein the part of validation message is seitt to the WTRU via a dedicated reference signal and the part of validation message is sent to the WTRU via control signaling scheme. - 24. The method of eibodiment 22 wherein the eNodeB sendt'only a PMI indicator that includes the PMI indicators of all groups when the PMIs st the WTRU and a PMI of the griup at eNodeB are identicaL 25. The method of embodiment 22 wherein the eNodeB sends to the WTU a PM indicator with itsi PII when at least one of the PMIs of groups of - --... theAVTRLamd.atleast-one-ofthaeM~s ofthe-groups-at-eNodeE-arenot-identie--- or when the PMI of the WTRU is overridden by the PM of the eNodeB or when a feedback error occurs. - 26 The method of embodiment 22 wherein each group of PMI indicators - or each PMI indicator hagone- bit or more-,-than one bit-to indicate whether antenna weights are same for eNodeB and WTRU. - 27. The method of embodiment 22 when each group has only one PW. 28. A method of eitherof embudiments 1, 12, 17, or 22 to send the PM1I indicator without modifying the existing control signaling wherein the PMI is either attached to or embedded into existing control signaling. 29. A method for reducing signaling overhead in multiple-input - - multiple-output 34V4O wirelesacommunications by use ofa validation message that includes preceding confimation and preceding information or indication ,messages, and the validation message comprises of:: a confirmation message having one bit; - 39-- TI a confirmation messagehaving more than one bits; one possible sab-Iessage for an indication message having at least one bit showing the different possible precoding information; one possible sub-messaga for an override message having at least one bt showing the different overridetules for precoding; and - one possible sub-message for feedback error message having at least one bit showing different precoding rules to handle feedback error. 30. An evolved Node B eNodeB for reducing signaling overhead between a Wireless Transmit/Receive Unit (WTRU) and the eNodeB, in a multiple-input multiple-ontput MIMO wireesscommunications by using precoding confirmation and precoding information or indication in the form of avalidation message, the eNodeB configured-te transmit the validation message to indicate the kind of precoding information used at the eNodeE wherein the validation message comprises of at least one bit; the validation message provides confirmation message and indication - - messageaand-vaidation-message-could-be-composed of-one-confirmationmessageand one indication message using separate coding; validation message could also be a single message that indicators confirmation, information, overide or error message using joint coding; and . indication message can be a precodinginformation indication message or rank override message or a feedback error message or a combination and can indicate preceding informationfor single user SU-MIMO and can also indicate desired precoding information; interfering preceding infonnation or both for multi user MU-MIMO. 31. The eNode of embodiment 30, wherein the preceding information - may contain precodin matrices or ranks or other precoding related information - or a combination of aI. 32. The eNodeB of enibodnient 30, wherein the validation message comprises a combination of at least two of a confirmation message, an indication . message, a feedback error message aind an override error message. -40- 33. The eNodeB of embodiment 30, whereinthevalidation message can be separately coded or encoded or jointly coded or encoded. 34. The eNodeB of embodiment 30, wherein when the precodiig confirmation and indication messages (validation message) is separately coded or encoded, the validation message itself consists of two parts: a confirmation part and an indication part. 35. The eNodeB of embodiment 34, wherein the confirmation part uses one bit or more than one bitto carry a positive-confirmation message or 'a negative confirmation message, 36. The eNodeB of embodiment 34, wherein a positive conhrinatioa message is used to inform the WTRU that preceding information used at eNodeB is exactly the same aa-the-preceding information fed back from the WTRU. 37. The eNodeB of embodiment 34, wherein a negative confirmation message is used to inform WTRU that the precoding information used at the eNodeB is not the same as the Precoding information fed back from the WTR-. 38. The eNodeB of embodiment 34, wherein the indication part uses at - -~--least oehit tosarryztwxomormore~indication~messages- 39. The eNodeB of embodiment 34, wherein the indication part indicates to the WTRU that different preceding information is being used at the eNodeB. 40. -The 1 d of_emboditent 34-,, -wherein, when .the-tvalidation message is jointly coded or encoded, the validation message combines the confirmation part and the indication part into a single part or field. 41. An evolved Node iB (eNodeB) for reducing signaling overhead, operating in multiple-input mfdtiple-output MIMO wireless communications ,suitable for preceding confirmation and preceding information or indication and configured to: receive a precoding matri index (PMI) from a Wireless Transmit'Receive Unit (WTRU) that includes theTWTRUs antenna weights; transmit a -validation message to the WTRU as a PV[ indicator tha, includes information about its awn antenna weights. -41 - 42. The eNodeB of embodiment 41 wherein.the validation message ris - sent to the WTRU via a dedicated reference signal or via control signaling scheme. 48. The eNodeB of embodiment 41 wherein the eNodeB sends only! a PMI indicator when the PMI of the WTRU and a PM[ of the eNodeB are identical. 44. The eNodeB of embodiment 41 wherein the Node-B sends to the WTLRU a PMI indicator with it PMI when the PMI of the WTRU and a PMI of the eNodeB are not identical orwhen the PMI of the WTRU ia overridden by the PMI of the eNodeB or when a feedback error occurs. 45. The eNodeB of er'oodiment 41 wherein PMI indicator size is one bt or more than one bit, can represent state conairiatios-and can be iny arbitray value depending upon design choice. 46. An evolved Node! B (eNodeB) fbr reducing signaling overhead, operating in multiple-input rmltiple-output MIMO wireless communications suitable for precoding confmation and preceding information or indication ani .onflg red to: ...... ... ... receive a plurality of prcoding matrix indices (PAIs) from a Wireless Transmit/Receive Unit (WTRU) that iacindes the WTRUs antenna weights; and transmit a .validation message to the WTRU as an individual PMI indicator that includes inform ion abont its ownntennaweights. 47. The method of embodiment 46 wherein the part of validation message is sent to the WTRU via a dedicated reference signal and the part 6f validation message is sent to the WTRU via control signaling scheme. 48. The eNodeB of embodiment 46 wherein the eNodeB sends only a PAI indicator when the PAMof the WTRU and a PMI of the eNodeB are . identical. 49. The eNodeB of enbodiment 46 wherein the eNodeB sends to the . WTRU a PMI indicator with its-PMI when at least one of the PAMIs of the WTRU - and at least one of the PMIs of the eNodeB are not identical or when the PMi oF -42 the WTRU is overridden by the PMI of the eNodeB or when a feedback error occurs, 50. The eNodeB of embodiment 46 wherein PMI indicator size is one bit or more than one bit, can represent stat-e confirmations and can be any arbitray value depending upon design cnoice. 51. The eNodeB of embodiment 46 configured to send the PMjI indicator without modifying the existing control signaling wherein the PM! is either attached to or embedded into existing control signaling, 52. An evolved Node- B (eNodeB) for reducing signaling overhead, operating in multiple.-input multiple-output IMO wireless communications suitable for preceding confirmation and preceding information or indication and confignred to:- - - . receive a plurality of preceding matrix indices (PMIs) from a Wireless TransmitReceive Unit (WTRU) that are separated into groups that includes the WTRUs antenna weights; and transmit a validation message to the VTRU as an individual PMI indicator~foruach gronpof _Es-that.includes-infomation-about-its-own- antenna weights, 53. The eNodeB of embodiment 52, wherein part of validation message is sent to the WTRU via a dedicated reference signal and the part ofvallidation message is sent to the-WITRUI via .control-signalingscheme. 54. The eNodeB of embodiment 52, wherein the eNodeB sends only a PMI indicator that includes th6 PMI indicators of all groups when the PM~s at the WTRU and a PMI of the group at eNodeB are identical. 55. The eNodeB of enbadiment 52 wherein the eNodeB sends to the WTRU a PMI indicator with itsPMI when at least one of the MIls of groups of the WTRRU and at least one of th- PIs of the groups at eNodeB are not identical or when the PMI of the WTRUis overridden by the PMJ ofthe eNodeB or When a feedback error occurs. -43- 56. The eNodeB of isembodinent 52 Wherein each group of PMil indicators or each PMI indicator has one bit or more than one bit to indicate whether antenna weights are same for eNodeB and WTRU. 57. The eNodeB of embodiment 52 wherein each group has only one PML 58. The eNodeB of embodiment 52 configured to send the PMI indicator without modifying the eistinig control signaling wherein the PMI is either attached to or embedded into existing control signaling. 59. An evolved Node B (eNodeB) for reducing signaling overhead, operating in multiple-input multiple-output MIMO wireless communications having a transceiver and processor fbr precoding confirmation and precodirg information or indication and, nigured to gsner-ate a vaRidation message that includes preceding matrix information PAU, and the validation message comprises: a confirmation message having one bit; or a confirmation message having more than one bit; one possib -_me g r i action eg v -atleast-ne bitshowing the different possible precoding information; one possible sub-message for an override message having at least one bit - showing the different override rules for preceding; and one possible sub-messagefor feedback ere anessage having.aV least one bit showing different preeodingsrules to handle feedback error. 60. A wireless transruit/receive unit (WTRU) for reducing signaling - overhead between an evolved-Node B and the WTRU, in a multiple-input multiple.-output MIMO wirelesstommunications by using preceding confirmation and preceding information or indication in the form of a validation message, the WTRU configured to: receive the validation message to indicate the kind of precoding information used at the eNodeBwherein the validation message comprises of a least one bit; -44the validation message provides preceding confirmation message and . indication message and vaRdation message could be composed of one confirmation message and oneindication message using separate coding; - validation message cold also be a single message that indicates confirmation, information, override or error message using joint coding; and indication message can be a preceding information indication message or rank override message or a feedback error message or a combination and cen indicate precoding information for single user SU-MIMO and can also indicate desired preceding information; interfering precoding information or both ftr multi user MU-MIMO. 6L The WTRU of erMbodiment 60, wherein the validation message comprises a combination of at igs-t1 twe of: a confriation message, an idication message, a feedback error message and an override error message. 62. The WTRU of embodiment 60, wherein the precoding information and indication messages valuationn message) can be separately encoded 6r jointly encoded. 63, The WTIJof em ien_6Alwhereinwhen-he-vaidatio-mege is separately coded or encoded, the validation message itselfeonsists of two parts: a confirmation part and an indication part. 64. The WTRU ofembodiient 63, wherein the confirmation part uses one bit- or more tlan one bitto sarry a positive-carnftmation message or a negative confirmation message. 65. The WTRU of embodiment 60, wherein a positive confirmation message is used to inform the WTRU that preceding information used at eNodeB is exactly the same as the preceding information fed back from the WTRU, 66, The WTRU of embodiment 60, wherein a negative confirmation message is used to inform WTIU that the precoding information used at the eNodeB is not the same as the precoding information fed back front the WTRJ. 67. The WTRtJ of embodiment 63, wherein the indication part uses one bit or more than one bit to carry a two or more indication messages. -45 - 68. The WTRU ofembodiaent 64, wherein the indication part indicates to the WTRU that different pnicoding information is being used at the eNodeB. 69 The WTRU of embodiment 64, wherein when the validation message is jointly coded or encoded, th validation message combines the confirmation part and the indication part. 70. . A wireless tranmilt/receive unit WTRU for reducing signaling overhead, operating in mutiple-input multiple-output MIMO wireless communications having a tranceiver and processor and processor for preceding confirmation and precoding information or indication and configured to generate a validation message that includes precoding matrix information PfI, and the validation message comprises; a confirmation message having one 'bit; or -- = a confirmation message having at least one bit; one possible sub-message for an indication message having at least one bit showing the different possible preceding information; one possible sub-message for an override message having at least one bit showing the different override rules for preceding; and. .. .. one possible sub-message for feedback error message having at least one bit showing different preceding rules to handle feedback error. 71. A wireless transmit/receive nit (WTIRU) for reducing signaling overhead, operating .in muli nut UPmttiple-otpnt-MMO wireless communications, having a transceiver and a processor for preceding confirmation and preceding infonnation or indication and configured to: transmit a preceding matrix index (PHI) to an evolved Node B (eNodeB) that includes the WTRTJs antenna weights; receive a validation message from the eNodel as a.PMI indicator that includes information about its own antenna weights. 72. The WTRU of embodiment 71, wherein part of validation message is received via a dedicated reference signal and the part of validation message is received via control signaling scheme. -46- - 73, The WTRU of embodiment 72, wherein the WTRU receives only a preceding confirmation or PMIidicator when the PMI ofthe WT-U and PMI of the eNodeB are identical. 74. The WTRU of embodiment 71, wherein the WTRU receives a PMI indicator with its PMI when the PMI ofthe WTRU and a PM[ ofthe eNodeB are not identical or when the PMT of the WTRU is overridden by the PI of the eNodeB or when a feedback error occurs, 75. The WTRU of embodiment 71, wherein PMI indicator size is one hit or more than one bit, can represent state confirmations and can be any arbitrary value depending npon design choice. 76. The WTRU ofembadiment 71, wherein part ofvalidationmessage-is received by the transceiver via a-dedicatedoference signal--and the part of. validation message is received via control signaling scheme. 77. A wireless transmit/receive unit (WTRU) for rbdncing signaling overhead, operating in multiple-input muiltiple-output M[MO wireless communications, having a transceiver and a processor for precoding confirnatioa _~ndpredinginformationor-ndication and-configured-to: ------ - transmit a plurality ofprecoding matrix indices (PMs) to an evolved Node B (eNodeB) that includes the WTRUS antenna weights; and receive a validation mei-sage from the eNodeB as an individual PMI indicator that includes-information about. eNodeBs own. antenna weights: . 78. The WTRU of embodiment 77, wherein part of validation message is received by the transceiver via a dedicated reference signal or via control signaling scheme. 79. The WTRU of embodiment 77, wherein the WTRU receives only a PMI indicator from the eNodeB when the PMI of the WTRU and a PMI of the eNodeB are identical. 80. The WTRU of embodiment 77, wherein the WTRU receives a Plva indicator with eNodeBs PMI -when at least one of the PMIs of the WTRT and at . least one of the PMIs of the eNodeB are not identical or when the PMI of the . WTRU is overridden by the PM ofthe eNodeB or when a feedback error occurs. -47- 81. The WTRU of emibodiment 80, wherein PMI indicator size is one bit or more than one bit, can represent state confirnations and can be any arbitrary value depending upon design choice. 82. A wireless transmit/receive unit (WTRU) for reducing signaling overhead, operating in multiple-input multiple-output MIMO wireless communications, having a transceiver and a processor for precoding matria indication and configured to: transmit-a plurality of preceoding matriz indices (PMIs) to an evolved Node B (eNodeB) that are separatedtinto groups that includes the WTRUs antenna weights; and receive a validation message from the eNodeB as an individual PMI indicator for each group of -PIMs thatincludea information about its 'own antenna weights. 83. The WTRU of embodiment 82, wherein part ofvalidation message is received by the transceiver via a dedicated reference signal and the part of validation message is received via control signaling scheme. - ----- 84. The WTVR ofmoodcent_82,_ wherenthaW2'RK receives only a PMI indicator from the eNodeB that includes the PMJ indicators of all groups when the PMIis at the WTRU and a PAI of the group at eNodeB are - identical. 85. -The WTTU of enahodiment 8?,whereinetheVTRI receives a PM - indicator from eNodeB with itsPMI when at least one of the PMIs of groups of the WTRU and at least one of the PMIs of the groups at eNodeB are not identical or when the PMI of the WTRU is overridden by the PMI of the eNodeB or when a feedback error occurs. 86. The WTRU ofembadiment 82, wherein each group of PAI indicators or each PIVU indicator has one bit or more than one bit to indicate whether antenna weights are same for tNodeB and WTRU. 87. The WTRU of embodiment 82, wherein each group has only one PAI. -48 - 88. The WTRU of embodiment 82 configured to receive the PlNI indicator roma the eNodeB wherein the PMI is either attached to or embedded into existing control signaling. [00120] Although the features and elements of the present invention are described in the prefered embadiments in particular combinations,each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention, The methods or flow charts provided in the present invention may be i-cplemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium focr execution by a general purpose, computer or a processor. Examples of computer readable storage mediums include a read onlynemaory ROM, a randm access memory RAM, a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto optical media, and optical medIa such as CD-ROM disks, and digital versatile disks DVDs. [001211___Suitlepmaoinldesywayofexampleaenerlpurpse processor, a special purpose processor, a conventional processor, a digital signal processor DSP, a plurality of microprocessors, one or more microprocessors in association with a DSP core, a crnatroller, a microcontroller, Application Specific Integrated Circuits ASIQs, Field Programmable Gate-ArraysFPGAeicuit, any other type of integrated circuit '[C, and/or a state machine. [00122] A processor in association with software may be used to implemert a radio frequency transceiver for use in a wireless transmit receive unit WTRU, Wireless Transmit/Receive Unit WTRU, terminal, base station, radio network controller RNC, or any host computer. The WTRU may be used in conjunction with modules, implemented in Kardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth@ module, a frequency modulated FM radio unit, a liquid crystal display LCD display unit, an organic light-emitting diode OLED display unit, a -49 digital music player, a medisplayer, a video g e player module, an Interret browser, and/or any wireless bai area network WAN medult 650-

Claims (22)

1. A method for signaling control information for a Wireless Transmit/Receive Unit, WTRU, the method including: sending, by the WTRU, a plurality of precoding matrix indexes, PMIs, or 5 codebook values, as feedback; receiving, by the WTRU, a message including (1) a single bit PMI indicator in a first field, and (2) only a single PMI in a second field or only a single codebook value representing only the single PMI in the second field, the second field being separate from the first field; and 10 processing, by the WTRU, at least the single bit PMI indicator, the single bit PMI indicator indicating whether to use the PMIs or codebook values sent as the feedback.

2. The method of claim 1, wherein the processing of the at least single bit PMI indicator includes joint decoding of the single bit PMI indicator and the single 15 PMI or the single codebook value received from an evolved NodeB (eNB).

3. The method of claim 2, wherein the joint decoding of the single bit PMI indicator and the single PMI or the single codebook value decodes a fixed length bit segment.

4. The method of claim 1, further including processing the single PMI or the 20 single codebook value on the condition that the single bit PMI indicator indicates that an evolved NodeB sending the message is not using the precoding matrixes associated with the feedback PMIs.

5. A method implemented by an evolved Node B (eNB), the method including: 25 receiving, by the eNB from a wireless transmit/receive unit (WTRU), a precoding report including a plurality of precoding matrix indexes (PMIs) or codebook values, as feedback; generating a single bit PMI indicator indicating whether precoding according to the PMIs or codebook values sent as the feedback; and 52 sending a message including (1) the generated single bit PMI indicator in a first field, and (2) only a single PMI in a second field or only a single codebook value representing only the single PMI in the second field, wherein the second field is separate from the first field. 5

6. The method of claim 5, further including joint coding the single bit PMI indicator and the single PMI or the single codebook value to be sent to the WTRU.

7. The method of claim 5, wherein the joint coding includes coding: (1) the PMI indicator, and (2) the single PMI or the single codebook value, as a fixed 10 length bit segment.

8. The method of any one of the preceding claims, further including determining whether to use: (1) precoding matrices associated with the feedback PMIs or feedback codebook values; or (2) a precoding matrix associated with the single PMI or single codebook value for communications. 15

9. The method of any one of the preceding claims, wherein the single bit PMI indicator indicates the eNB is using or is to use precoding reported from the WTRU.

10. The method of any one of the preceding claims, wherein the single bit PMI indicator has a first logic level indicating precoding according to precoding 20 feedback and a second logic level indicating not precoding according to the precoding feedback.

11. The method of any one of the preceding claims, wherein the message includes a first bit for the single PMI indicator and a bit segment for the single PMI or single codebook value that indicates precoding information used by the eNB. 25

12. A Wireless Transmit/Receive Unit, WTRU, configured to signal control information, including: a processor and transmitter/receiver unit configured to: 53 send a plurality of precoding matrix indexes, PMIs, or codebook values, as feedback; receive a message including (1) a single bit PMI indicator in a first field, and (2) only a single PMI in a second field or only a single codebook value 5 representing only the single PMI in the second field, the second field being separate from the first field; and process at least the single bit PMI indicator, the single bit PMI indicator indicating whether to use the PMIs or codebook values sent as the feedback. 10

13. The WTRU of claim 12, wherein the WTRU is configured to determine whether to use: (1) precoding matrices associated with the feedback PMIs or feedback codebook values; or (2) a precoding matrix associated with the single PMI or single codebook value for communications.

14. The WTRU of claim 12, wherein the WTRU is configured to process the 15 received message including a first bit associated with the single bit PMI indicator and a bit segment associated with the single PMI or the single codebook value, the bit segment indicating precoding information used by an evolved NodeB.

15. The WTRU of claim 12, wherein the bit segment indicates a single codebook value to be used by the WTRU on condition that the first bit indicates 20 the evolved NodeB is not using precoding reported from the WTRU.

16. The WTRU of claim 12, wherein the WTRU is configured to joint decode the single bit PMI indicator and the single PMI or the single codebook value received from an evolved NodeB.

17. An evolved Node B (eNB), including: 25 a processor and a transmit/receive unit configured to: receive, from a wireless transmit/receive unit (WTRU), a precoding report including a plurality of precoding matrix indexes (PMIs) or codebook values, as feedback; 54 generate a single bit PMI indicator indicating whether precoding according to the PMIs or codebook values sent as the feedback; and send a message including (1) the generated single bit PMI indicator in a first field, and (2) only a single PMI in a second field or only a single 5 codebook value representing only the single PMI in the second field, wherein the second field is separate from the first field.

18. The eNB of claim 17, wherein the processor is configured to determine whether to use: (1) precoding matrices associated with the feedback PMIs or feedback codebook values; or (2) a precoding matrix associated with the single 10 PMI or single codebook value for communications.

19. The eNB of claim 17, wherein the message includes a first bit for the single PMI indicator and a bit segment for the single PMI or single codebook value that indicates precoding information used by the eNB.

20. The eNB of claim 17, wherein the single bit PMI indicator indicates the 15 eNB is using or is to use precoding reported from the WTRU.

21. The eNB of claim 17, wherein the processor is configured to joint code the single bit PMI indicator and the single PMI or the single codebook value to be sent to the WTRU.

22. The eNB of claim 17, wherein the processor is configured to code: (1) the 20 PMI indicator, and (2) the single PMI or the single codebook value, as a fixed length bit segment. INTERDIGITAL TECHNOLOGY CORPORATION WATERMARK PATENT AND TRADE MARKS ATTORNEYS P32496AU01