TWI420844B - Method and apparatus for antenna mapping selection in mimo-ofdm wireless networks - Google Patents

Description

Antenna mapping selection method and device in MIMO-OFDM wireless network

The present invention relates to wireless communication systems that utilize multiple input multiple output (MIMO) techniques. In particular, the present invention is directed to an optimum setting for multiple antenna arrays that select multiple input multiple output capabilities.

Wireless communication devices having multiple antennas of a diverse architecture arrangement provide various transmission and reception benefits over devices having only a single antenna. The basis of diversity is that the antenna with the best reception is chosen for reception or transmission at any given time. While devices utilizing antenna diversity may have multiple physical antennas, signal processing has only a single set of electronic circuits, also referred to as radio frequency (RF) chains.

Multiple Input Multiple Output Wireless Technology improves antenna diversity with multiple RF chains. Each RF chain can be received and transmitted simultaneously. Thereby, the multiple input multiple output device can achieve higher processing power and eliminate the negative effects of multipath interference. In the transmission device, each radio frequency chain is responsible for transmitting a certain spatial stream. A single frame can be decomposed and multiplexed into multiple spatial streams, which are then reassembled into the receiver.

Multiple Input Multiple Output is one of the most promising technologies in wireless communications. Unlike traditional smart antenna technologies that mitigate unfavorable multipath attenuation and enhance single data stream strength, multiple input multiple output systems utilize multiple path attenuation to simultaneously transmit and receive multiple data streams. In theory, the ability of multiple input multiple output systems increases linearly with the number of transmit and receive antennas. Multiple input multiple output is considered by various wireless data communication standards, such as: IEEE 802.11n and 3GPP Broadband Code Division Multiple Access (WCDMA).

When implementing multiple input multiple outputs, a WTRU may operate in a spatial multiplex mode or a spatial diversity mode. In spatial multiplex mode, the WTRU transmits multiple independent streams of data to maximize data processing capabilities. In contrast, in the spatial diversity mode, the WTRU can transmit a single data stream via multiple antennas. Based on the mode of operation, the WTRU may select a combination of appropriate quality metrics or quality metrics for use in the desired beam combination selection. In general, the m×N channel matrix H system can have the following form:

Wherein, the label below the component h indicates the contribution of various antenna mappings belonging to the antennas a, ..., m of the transmitting WTRU/m and the antennas a, ..., m receiving the WTRU N, ..., m .

The wireless transmission/reception unit can obtain the correction matrix K in a similar manner. The correction of the wireless local area network (LAN) context includes calculating a set of complex correction coefficients that are multiplexed to transmit wireless transmissions on a per-antenna basis and per-sub-carrier basis. / The baseband stream of the receiving unit will equalize the difference in response between the transmission and reception processing paths (until the unknown constant across the antenna).

Please refer to FIG. 1, which is a signal diagram 100 showing channel correction of the prior art. The transmitting WTRU 110 first needs to correct the existing channel between the receiving WTRUs 120. The transmission WTRU 110 transmits a Correction Training Frame (CTF) 131 to the receiving WTRU 120. The receiving WTRU 120 responds to transmit a Probing Entity Packet Data Unit (PPDU) 132. Transmission no The line transmission/reception unit 110 is a channel prediction H 133 for calculating a channel, which is called H (2→1). The transmission WTRU 110 transmits a correction response 134 including a channel prediction H (2→1). Subsequently, the receiving WTRU 120 transmits the corrected training frame 135 to the transmitting WTRU 110 to perform channel prediction. In response, the transmitting WTRU 110 transmits the probe entity packet data unit 136. The receiving wireless transmission/reception unit 120 calculates the channel prediction H (1→2) and calculates the correction matrix K(1→2) and K(2→1) 137 of the channel. Subsequently, the receiving WTRU 120 transmits a correction response 138 having a correction matrix K (1→2) to the transmission WTRU 110. It should be noted that, subsequently, the correction matrix K(1→2) is applied to the transmission WTRU 110 as a fundamental gain or phase correction factor for transmission to the receiving WTRU 120. The correction matrix K (2→1) is applied to the receiving WTRU 120, which also serves as a fundamental gain/phase correction factor for the signal transmission of the receiving WTRU 120 to the transmitting WTRU 110. . At this point, the channel is calibrated and ready for packet exchange.

To initiate data packet exchange, the transmission WTRU 110 transmits a request 139 to the receiving WTRU 120 in response to transmitting a modulation and coding means (MCS) entity packet data unit 140. The transmission WTRU 110 utilizes a correction matrix K (1→2) to calculate the steering matrix V, and the packet data transfer 142 begins.

Conventional technology does not consider the use of smart antenna technology. Smart antennas, especially beamforming, are used in conjunction with signal processing techniques that control the directionality of the radiation pattern, or the sensitivity of the transmitter or receiver array. When receiving signals, beamforming increases the gain in the desired signal direction and reduces the gain in interference and noise directions. When transmitting a signal, the beamforming system can increase the gain of the direction in which the signal is to be transmitted. When the beamforming capability antenna combines multiple input multiple outputs, the number of available antenna maps increases dramatically.

Number of available antenna maps when the beamforming antenna is included in the WTRU The system can become enormous. In order to optimize the communication link between the two WTRUs, it is necessary to select the appropriate antenna mapping for the transmitter and receiver.

In view of this, the present invention provides a method and apparatus for efficiently utilizing various available antenna mappings for multiple input multiple output capable wireless devices having multiple beamforming antennas.

The present invention is a method and apparatus for selecting an antenna map for a multiple input multiple output enabled wireless communication network. The candidate combinations currently available for antenna mapping are determined based on the long-term channel conditions of the measurements. The antenna mapping is selected via a candidate combination, and the mapping is corrected using a selective antenna mapping of the receiving WTRU. When the mapping correction is selected, the packet data transmission system starts. In another preferred embodiment, the calibration training frame is used for simultaneous or sequential multiple antenna mapping. In addition, the physical layer and media access control (MAC) layer frame format for implementing antenna mapping selection according to the present invention are also disclosed.

110, 310, 410‧‧‧ Transmission wireless transmission/reception unit

120, 320, 420‧‧‧ receiving wireless transmission/reception unit

316A...316N, 326A...326M‧‧‧Multiple antenna

CTF‧‧‧ Correction Training Frame

L-ST‧‧‧Inherited short training field

HT-LTF‧‧‧High processing capacity long training field

HT-SIG‧‧‧High Processing Capability Field

MCS‧‧‧Transformation Control Sequence Field

RA‧‧‧Receiver Address Field

TA‧‧‧Transmitter address field

MSDU‧‧‧Media Access Control Service Data Unit Field

FCS‧‧‧ frame check sequence field

A further understanding of the present invention is explained in detail by the following description of the invention, by way of example, and in conjunction with the accompanying drawings, wherein: FIG. 1 is a schematic diagram showing a channel correction and packet data transfer of the prior art; 1 is a flow chart showing a method of selecting an antenna map according to a preferred embodiment of the present invention; and FIG. 3 is a block diagram showing a system having a wireless network base station (AP) and a wireless transmission/reception unit according to the present invention; 4 is a signal timing diagram showing channel correction and packet data transfer, wherein the antenna mapping selection according to the present invention is utilized; and FIG. 5 is a diagram showing a correction training frame (CTF) for implementing antenna mapping selection according to the present invention. Schematic diagram of a physical packet data unit (PPDU) frame format; FIG. 6 is a schematic diagram showing a probe entity packet data unit (PPDU) frame format for implementing antenna mapping selection according to the present invention; and FIG. 7 is a diagram showing implementation according to the present invention. A schematic diagram of a Probing Entity Packet Data Unit (PPDU) Media Access Control (MAC) frame format for an antenna mapping selection of the invention.

Although the features of the present invention are described in detail with the specific combinations of the preferred embodiments, the various features or elements may be utilized separately (without requiring or requiring other features and elements of the preferred embodiments), or various features or The elements can also be formed in various combinations (without requiring or requiring other features or elements of the preferred embodiments.

In the following description, a WTRU includes, but is not limited to, a User Equipment (UE), a mobile workstation, a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment. In addition, in the following description, a wireless network base station (AP) includes, but is not limited to, a Node B, a location controller, a base station (BS), or any other type of interface device of a wireless communication environment. In addition, in the following description, the term "antenna mapping" refers to a particular combination of antennas having a particular radio frequency processing chain, or antenna beams (in the case of beamforming antennas).

Please refer to FIG. 2, which illustrates a method 200 of selecting an antenna map in accordance with the present invention. The WTRU selects an antenna map from among candidate combinations of currently available antenna maps (step 210). The WTRU determines whether the antenna mapping is selected for correction (step 220). If it is decided that the selected antenna map is not corrected, the WTRU adjusts the selected antenna map (step 230). It should be noted that the previously corrected antenna mapping correction system may become stale. The correction for selecting the antenna mapping will be described in further detail below. Then, the wireless transmission/reception unit It is determined whether the receiving WTRU has changed its antenna mapping (step 240). If the receiving WTRU has changed its antenna mapping, then the method returns to step 210 to select a new transmitter antenna map, if the situation requires. If it is determined that the receiving WTRU has not changed its antenna mapping, the transmitting WTRU initiates packet data transmission using the selection and correction antenna mapping (step 250). This method returns to step 210 whereby the transmitting WTRU can change its antenna mapping.

Referring to FIG. 3, there is shown a wireless communication system 300 having a first WTRU 310 and a second WTRU 320 for implementing antenna mapping selection in accordance with the present invention. In the following description, the present invention refers to a detailed explanation of the downlink connection transmission by the transmission WTRU/reception unit 310 to the reception WTRU. However, the present invention is equally applicable to uplink connection and downlink connection transmission, wherein the WTRU 310 or the WTRU 320 is a base station (BS), and the present invention is equally applicable to an architecture in which In an ad hoc or mesh network, the WTRU communicates directly with the WTRU.

The WTRU 310 has two radio frequency chains 312A, 312B, a beam selector 314, and a plurality of antennas 316A-316N, wherein N is any integer greater than one, and a correction unit 318. In an exemplary embodiment, antennas 316A-316N are capable of generating multiple beams. The WTRU 320 has two radio frequency chains 322A, 322B, a beam selector 324, and a plurality of antennas 326A-326M, where M is any integer greater than one. In addition, in the exemplary embodiment, at least one of the antennas 326A-326N is capable of generating multiple beams. In particular, please refer to the WTRU 320, which is selected by the beam selector 324 for use in the multi-input multiple-output transmission and reception of the method 200 according to the present invention as described above with reference to FIG. The antenna map is selected based on the control signals output by the beam selector 324 for transmission and reception. Beam selector 324 selects a particular beam based on quality metrics generated and stored in correction unit 328. The combination will be described in further detail below. The WTRU element of the present invention can be integrated into an integrated circuit (IC) or a circuit having a plurality of interconnected elements. It should be understood that although the example embodiment has two RF chains, this is purely for convenience of explanation and any number of RF chains may be utilized.

For ease of explanation, FIG. 3 shows a beamforming antenna that generates three beams, which are transmitted to the wireless transmission/reception unit 310 and the reception wireless transmission/reception unit 320. However, the architecture shown in Figure 3 is provided by way of example only and not limitation. Any combination of antenna types with any number of beams, or antennas that are not beamforming or beam switching types, may also be utilized.

The antenna can be a switched parasitic antenna (SPA), a phased array antenna, or any type of directional beamforming antenna. Switching parasitic antennas are compact in size and are therefore suitable for use in wireless local area network (WLAN) devices. If the parasitic antenna system is utilized, a single active antenna element can be utilized in conjunction with a single or multiple passive antenna elements. The antenna beam pattern can be adjusted by adjusting the impedance of the passive antenna element, and the impedance adjustment can be implemented by controlling a group of switches that connect the antenna elements. Alternatively, the antenna may also be a composite with multiple antennas, which may all be omnidirectional antennas. For example, three omnidirectional antennas with selected physical intervals can be turned on or off based on control signals from beam selector 324 to define different beam combinations.

For the sake of explanation, please refer to Figure 3. Transmission WTRU 310 (also referred to as a Tx WTRU in the following description) includes two RF chains 312A and 312B. The beam selector 314 is coupled to a plurality of omnidirectional antennas 316A-316N to the RF chains 312A and 312B. In view of this, the number of possible antenna mappings of the transmission WTRU 108 is N times the number of radio chains. The receiving WTRU 320 (also referred to as the Rx WTRU in the following description) also includes two radio frequency chains 322A and 322B. The beam selector 324 is coupled to the plurality of omnidirectional antennas 326A-326M to the RF chains 322A and 322B. As previously described, in a simple example embodiment, each beamforming antenna 326A-326M is capable of forming three directional beams. In view of this, the receiving WTRU 320 has a possible antenna mapping of a total of M times the number of beams multiplied by the number of radio frequency chains. The combination of all possible antenna mappings that can be used for any transmission station is referred to as a "superset," and the size of the _superset is expressed as _Nsuperset . N _superset can be very large and it may not be practical to utilize all available antenna mappings at any given time.

The candidate combinations are sub-combinations of supersets, and the candidate combinations are available for the selected set of antenna maps at any given time. Preferably, the size of the candidate combination is limited to between 8 and 22 antenna maps. The candidate combinations are not static, whereas the candidate combinations are dynamic, and the candidate combinations can change over time to reflect the changed channel conditions. For example, the transmission workstation can continuously or periodically monitor the channel conditions of all antenna mappings in the current candidate combination, and if the measured channel conditions fail to meet the predetermined threshold for a predetermined time, the transmission workstation can modulate the candidate. combination. This can be done by discarding several sets of antenna mappings in the current candidate combination, adding several sets of new antenna mappings, and/or retaining several sets of antenna mappings in the candidate combination. In high speed applications, the candidate combinations can be reduced, or the antenna mapping options can be stopped simultaneously.

In a preferred embodiment of the invention, the WTRU 310 can select any antenna mapping via a candidate combination. The choice of antenna mapping is based on long-term scale. The tracking of the packet-by-packet channel does not need to be implemented, and therefore, the choice of antenna mapping does not track the rapid change (or micro-structure) of the channel. It should be noted that any change in the antenna mapping in the candidate combination occurs outside of any active transmission or reception of the data packet.

Referring to FIG. 3, during operation, the correcting unit 318 of the receiving WTRU 310 measures the beam combination of the selected quality metrics for each antenna beam or the current candidate combination, and outputs the quality metric measurement data to the beam selection. 314. The beam selector 314 selects the desired antenna mapping according to the quality metric measurement, and the receiving wireless transmission/reception unit 320 Material communication. The correcting unit 318 further needs to generate a periodic (or aperiodic) correction detection request as well as a correction training frame and a detection entity packet data unit in response to the correction request. The correcting unit 318 includes a processor that calculates a channel prediction matrix and a correction matrix according to the received detection packet, and a memory that stores the channel prediction matrix and the correction matrix. Preferably, the correction unit implements signal transmission and message delivery compatible with the IEEE standard, such as the IEEE 802.11 family of standards, and in particular, the IEEE 802.11N standard.

Various quality metrics can be used to determine the desired antenna mapping. A physical (PHY) layer, a medium access control (MAC) layer, or a higher level metric is suitable. Preferably, the quality metric includes, but is not limited to, channel prediction, signal noise and interference ratio (SNIR), received signal strength indicator (RSSI), short-term data processing capability, packet error rate (PER), data rate, wireless transmission. / Receive unit operation mode, the size of the maximum eigen-value of the receive channel prediction matrix, or the like.

For convenience of description, the antenna map selection method 200 described with reference to FIG. 2 is shown, and FIG. 4 is a signal timing diagram 400 for antenna mapping selection. The first transmission WTRU 106 transmits the probe entity packet data unit 430 to the reception WTRU 420 using the antenna map p. Subsequently, the transmission WTRU 106 transmits a correction training frame 432 that requires correction. The receiving WTRU 420 currently utilizes the antenna map x, and the receiving WTRU 420 utilizes the probe entity packet data unit 434 transmitted by the antenna map x in response to the corrected training frame 432. The transmission WTRU 410 implements channel prediction 436 for transmitting the antenna mapping of the WTRU 410 and the receiving WTRU 420, that is, the antenna mapping p and the antenna mapping x. The channel prediction matrix H(x→p) is calculated. Transmission WTRU 410 transmits a correction response 438 with corrected channel prediction. Next, the receiving wireless transmission/reception unit 420 transmits the own corrected training frame 440 to the transmission wireless transmission/reception unit 410. Transmission wireless transmission/reception unit 410 responds to detect Entity packet data unit 442. The receiving wireless transmission/reception unit 420 calculates the channel prediction matrix H(x→p) and the correction matrix K(p→x) and K(x→p) 444 of the currently selected antenna mapping by using the sounding entity packet data unit 442. Subsequently, the receiving WTRU 420 transmits a correction response 446 to the transmission WTRU 410, which has a channel correction matrix that the transmission WTRU 410 is interested in, that is, K(p→x) . Then, the antenna map p→x is corrected 448.

Subsequently, the WTRU uses the correction channel to freely start data packet exchange. The transmission WTRU 106 transmits a transmission request (TRQ) 450 to the receiving WTRU 420. The receiving WTRU 420 responds with the probe entity packet data unit 452 transmitted using the antenna map x. Subsequently, the transmission WTRU 110 calculates the steering matrix V based on the correction matrix K(p→x) 454. The transfer of the packet data 456 is then started.

For various reasons, such as: channel conditions (using channel quality metric measurements) or changes in the mobility of any of the WTRUs, for example, the receiving WTRU 420 changes the antenna mapping 458 from x to y. . Subsequently, it is determined whether the antenna map p→y is corrected. In an exemplary embodiment, the antenna map p→y has not been corrected, and therefore, a correction is required. The transmission WTRU 106 transmits the probe entity packet data unit 460 and the subsequent correction training frame 462 using the antenna map p. The receiving WTRU 420 responds with an antenna map y to detect the entity packet data unit 464. The channel prediction matrix H(y→p) 466 occurs in the transmission WTRU 410 and the correction response 468 with the channel prediction matrix is transmitted. Subsequently, the receiving WTRU 420 requires correction 470, and the transmitting WTRU is compatible with the Probing Entity Packet Data Unit 472. The receiving wireless transmission/reception unit 420 calculates a channel prediction matrix H(p→y) and a correction matrix K(p→y) and K(y→p) 474. Subsequently, the correction response 476 is transmitted to the transmission WTRU 104, which has a correction matrix that the transmission WTRU 104 is interested in. Then, the antenna map p→y Corrected and prepared to begin data packet exchange 478.

Subsequently, the data packet switching system begins with the transmitting WTRU/receiving unit 410 requesting the probe 480, and the receiving WTRU 420 responding to transmit the probe entity packet data unit 482 using the antenna map y. Subsequently, the steering matrix V is calculated from the correction matrix K(p→y), and the packet data transfer 486 is then started.

In another preferred embodiment, the correction of multiple antenna mapping occurs sequentially prior to the transfer of the data packets. Similar to the correction signal transmissions 430 through 448 shown in FIG. 4, the receiving WTRU may utilize the multiple antenna mapping selected via its current candidate combination in response to correcting the training frame. The resulting correction matrix can be stored for future reference. For example, the transmitting WTRU may select the antenna map f and transmit the corrected training frame to the receiving WTRU that requires correction. The receiving WTRU may sequentially respond with a set of antenna maps q, r, s selected through its currently available candidate combinations to detect the entity packet data unit. Before the transfer of the packet data, the transmission WTRU receives the antenna mapping f→q, f→r, f→s to correct the channel, and stores the correction matrix in the memory for future reference. If the receiving WTRU changes its antenna mapping to, for example, the antenna mapping r, the transmitting WTRU can retrieve the appropriate correction matrix via the memory and does not need to perform correction again to start the data packet transmission. .

Alternatively, the correction of multiple antenna mappings may occur in parallel (that is, simultaneously) to reduce signal transmission. In the preferred embodiment, the single sounding entity packet data unit utilizes a selective antenna mapping (e.g., mapping b) for transmission by the transmitting wireless transmission/reception unit. The receiving WTRU having the currently available antenna mappings t, u, v responds to the single correction training frame by using the available antenna mappings t, u, v, and each group of antennas maps b→t, b→u, The correction matrix of b→v is calculated. In this way, the correction signal transmission required is reduced, thereby reducing the correction delay and increasing the processing capability.

In another preferred embodiment, wherein the wireless communication system is compatible with the IEEE 802.X standard, the Probing Entity Packet Data Unit includes a Modulation Control Sequence (MCS) bit field. The Modulation Control Sequence (MCS) bit field is a Media Access Control (MAC) Information Element (IE), which indicates the current selection of the receiving WTRU antenna mapping candidate combination size and the current selection of the receiving WTRU. Antenna mapping. Preferably, the modulation control sequence (MCS) bit field has a length of 5 bits. Optionally, the modulation control sequence (MCS) bit field has a unit cell "run length indicator" that allows the transmitting WTRU to request the receiving WTRU to change its antenna mapping. Currently a candidate combination.

The transmitting WTRU may require the receiving WTRU to change its antenna mapping candidate combination. For example, if the transmitting WTRU cannot find the antenna mapping of the receiver, the quality requirements are met. In this case, if the receiving WTRU is able to change its candidate combination, the receiving WTRU may indicate that its antenna mapping candidate combination will be changed immediately using the New Media Access Control (MAC) management frame.

When the transmitting WTRU is trying to change its candidate combination based on various possible reasons (for example, if the transmitting WTRU cannot find its own antenna mapping in the current candidate combination to meet its quality requirements), then The transmitting WTRU may transmit a Medium Access Control (MAC) management frame to indicate a candidate combination change to the receiving WTRU. Subsequently, the transmitting WTRU may immediately change the antenna mapping candidate combination and select a suitable antenna mapping for transmission via the mapping in the new candidate combination.

Alternatively, the transmitting WTRU may require the receiving WTRU to completely disable its antenna mapping. This requirement can be transmitted to the receiving WTRU using the physical packet data unit. Upon receipt of a physical packet data unit having such a request, the receiving wireless transmission/reception unit may or may not be compatible with such requirements. The compatibility system can be represented by the receiving wireless transmission/reception unit in the sounding entity packet data unit. When receiving wireless transmission When the receiving unit is compatible with this requirement, the currently selected antenna mapping of the receiving WTRU becomes static and unchangeable.

Please refer to FIG. 5, which is a schematic diagram showing the format of a physical packet data unit frame of the calibration training frame entity packet data unit 500 according to the present invention. It should be noted that although the frame format shown in FIG. 5 is compatible with the IEEE 802.11N standard, the present invention is also applicable to any IEEE standard. The calibration training frame is used to require channel correction via the detection packet transmission of the receiving WTRU. The calibration training frame entity packet data unit 500 has an inheritance short training field (L-STE) 510, which is followed by a high processing capability long training field (HT-LTF) 520 and a high processing capability frame field (HT). -SIG) 530, and data field 540. The Inherit Short Training Field (L-STF) 510 has the same format as the Inherited (pre-802.11N) short training field. The High Processing Capability Training Field (HT-LTF) 520 is defined in the 802.11N Entity (PHY) layer and is used for multiple input multiple output transmission training. The High Processing Capability Field (HT-SIG) 530 is defined in the field of 802.11N and indicates the size of the selection modulation and coding means and the Medium Access Control (MAC) Service Data Unit (MSDU).

The Modulation Control Sequence (MCS) field 535 includes information related to correction and antenna mapping selection, such as: (1) representation of a selected antenna map for transmission of a physical packet data unit; (2) complete candidate combination order or parallel detection Representation of the requirements; (3) representation of the requirement to change the size of the candidate combination; (4) request to receive the updated run length bit of the WTRU antenna mapping candidate combination; and (5) receive the wireless transmission / The receiving unit temporarily maintains the representation of the requirements for antenna mapping selection.

Please refer to FIG. 6, which is a schematic diagram showing the format of the frame of the detecting entity packet data unit 600. Similarly, it should be noted that although the frame format shown in FIG. 6 is compatible with the IEEE 802.11N standard, the present invention is also applicable to any IEEE standard. The detection entity packet data unit has: inheritance short training field (L-STE) 610, high processing capability long training field (HT-LTF) 615, high processing capability frame field (HT-SIG) 620, modulation Control Sequence (MCS) field 625, which follows a plurality of additional high processing capability long training fields (HT-LTF) 630 ₁ to 630 _N , and a data field 635. The High Processing Capability Field (HT-SIG) 620 includes: 2 bits representing the size of the candidate combination, and a total number of high processing capability long training fields (HT-LTF) 630 included in the entity packet data unit. 5 bits. In view of this, the high processing capability long training field (HT-LTF) of each group of antenna mappings of the candidate combination may be included in the entity packet data unit. Preferably, as previously described, the candidate combinations can be as small as 1 and as large as 32. Each group of high processing capability long training fields (HT-LTF) 615 and 630 of the entity packet data unit utilizes different antenna mapping transmissions selected through the candidate combinations. The selected antenna mapping used to transmit the first high processing capability long training field (HT-LTF) 615 and data field 635 is represented in the modulation control sequence (MCS) field 625. The Modulation Control Sequence (MCS) field may also include additional bits to indicate: (1) the sustain/release requirements of the continuation antenna mapping selection of the receiving station; (2) the antenna mapping changes in response to the previous reception of the sustain/release request Confirmation; (3) confirmation of the previous reception request of the calibration training frame for the complete candidate combination search; and (4) confirmation of the previous reception request of the correction training frame for changing the candidate combination size.

Please refer to FIG. 7, which is a media access control (MAC) frame format 700 for the data frame of the probing entity packet data unit of FIG. The Media Access Control (MAC) field includes: Frame Control Field 705, Period/Identification Code Field 710, Receiver Address (RA) Field 715, Transmitter Address (TA) Field 720, Media Access Control (MAC) Service Data Unit (MSDU) field 725, and Frame Check Sequence (FCS) field 730. In a preferred embodiment of the present invention, a Medium Access Control (MAC) Service Data Unit (MSDU) field 725 may include a bit, thereby indicating a hold/release confirmation of an antenna mapping change in response to receiving a hold/release request. As previously discussed with reference to Figure 5 and the Modulation Control Sequence (MCS) field 535. By reducing candidate combination updates, the correction and correlation signal transmission can be reduced, thereby increasing processing power.

Although the features of the present invention are described in detail with the specific combinations of the preferred embodiments, the various features or elements may be utilized separately (without requiring or requiring other features and elements of the preferred embodiments), or various features or The elements can also be formed in various combinations (without requiring or requiring other features or elements of the preferred embodiments.

Claims (15)

A method for antenna selection for a wireless transmit/receive unit (WTRU), the method comprising: selecting an antenna map from a candidate combination of antenna maps, wherein an antenna map comprises a radio frequency (RF) chain, selected from the group consisting of Combining an antenna of the plurality of antennas of the at least one beamformed antenna with a combination of an antenna element selected from the plurality of antenna beams associated with the antenna; correcting the selected antenna map, wherein the correcting comprises: transmitting an indication to initiate the correction Receiving a sounding entity layer packet data unit (PPDU) in response to the transmission of the indication to start correction; and predicting a channel associated with the selected antenna map based on the received PPDU; generating a correlation based on the predicted channel a steering matrix of the antenna beam mapped to the selected antenna; and transmitting a data packet to the other WTRU using the corrected selected antenna mapping and the steering matrix. The method of claim 1, wherein an antenna comprises a plurality of omnidirectional physical antennas, and the selecting comprises selecting an omnidirectional physical antenna from the plurality of omnidirectional physical antennas. The method of claim 1, wherein the candidate combination of antenna mappings comprises a sub-combination of all possible antenna mappings. The method of claim 3, wherein the adjusting comprises adding an antenna map to the candidate combination of the antenna map or removing at least one of the antenna map from the candidate combination of the antenna map. The method of claim 1, wherein the adjusting is performed in response to a change in a channel condition. The method of claim 5, wherein a change in one channel condition comprises a long term change. The method of claim 1, wherein the selecting comprises analyzing a quality metric for each antenna mapping in the candidate combination of antenna mappings. The method of claim 1, wherein the selecting comprises: correcting the first antenna map if the first antenna map is not corrected. The method of claim 8, wherein the correcting comprises: transmitting the first probe entity packet data unit by using the first antenna mapping; and transmitting a first correction training frame indicating a first correction request; Receiving a second sounding entity packet data unit indicating a second antenna map; generating a first channel prediction of the first antenna map, and a second channel prediction of the second channel map; using the first channel Predicting a first channel prediction matrix with the second channel prediction; transmitting a first correction response including the first channel prediction matrix; receiving a second correction training frame indicating a second correction request; transmitting a first The third detecting entity packet data unit; and receiving a second corrected response including a second channel prediction matrix. The method of claim 1, wherein the selecting comprises: reselecting the candidate from the candidate combination of the antenna mapping under a condition that a second antenna mapping of another wireless transmitting/receiving unit is not corrected An antenna mapping. The method of claim 1, wherein: the selecting comprises selecting a plurality of antenna maps; and the correcting comprises correcting each of the selected antenna maps. The method of claim 1, wherein the WTRU is an IEEE 802.11 WTRU. A wireless transmit/receive unit (WTRU) comprising: a radio frequency chain configured to process a signal; a beam selector configured to select an antenna map from a plurality of currently available antenna maps, wherein the selected antenna map includes a radio frequency chain And a combination of an antenna selected from a plurality of antennas including at least one beamforming antenna, and an antenna beam selected from a plurality of antenna beams associated with the antenna; a correction unit configured to correct the selected antenna mapping, Transmitting an indication to initiate correction, responding to the transmission of the indication to initiate correction, receiving a sounding entity layer packet data unit (PPDU), and predicting a channel associated with the selected antenna map based on the received PPDU; a pilot unit configured to generate a steering matrix associated with the antenna beam of the selected antenna map based on the predicted channel; and a transmitter configured to transmit using the corrected selected antenna map and the steering matrix A data packet is addressed to another WTRU. A WTRU as claimed in claim 13 wherein: the beam selector is configured to select a plurality of antenna maps; and the correction unit is configured to correct each of the selected antenna maps. A WTRU as claimed in claim 13 wherein the WTRU is an IEEE 802.11 WTRU.