Wireless transmit/receive unit

Wireless transmitting/receiving unit

This creation is related to wireless communication systems.

Regarding the Evolved Universal Terrestrial Radio Access (E-UTRA) uplink (UL), several launches have been submitted to the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) Working Group 1 (WG1) Power control (TPC) proposal. These proposals can generally be divided into (slow) open loop TPC and slow closed loop or TPC based on channel quality information (CQI).

Open loop TPC is based on path loss measurement and system parameters. The path loss measurement is performed on a wireless transmit/receive unit (WTRU), and the system parameters are provided by an evolved Node-B (eNodeB).

Closed-loop TPC is usually based on TPC feedback information (such as TPC commands) periodically sent from the eNodeB, where the feedback information is usually derived using the signal-to-interference and noise ratio (SINR) measured at the eNodeB.

For example, open-loop TPC can effectively compensate for long-term channel changes (such as path loss and shadowing) without a history of transmit power. However, open-loop TPC usually causes path loss measurement errors and transmit power setting errors. On the other hand, since slow closed loop or CQI-based TPC is based on the feedback signaled from the eNodeB, it is less sensitive to errors in measurement and transmit power settings. However, when there is no feedback available due to the suspension of UL transmission or the suspension of feedback transmission, or when the channel changes drastically, slow closed loop or CQI-based TPC will degrade performance.

For E-UTRAUL, the consideration is to use TPC to at least compensate for path loss and shadows, and/or reduce interference. An enhanced ULTPC solution that combines an open-loop TPC solution and a closed-loop TPC solution with interference mitigation is disclosed here. Closed loop TPC is based on CQI (such as UL permission information or modulation and coding setting (MCS) information). This enhanced ULTPC solution can be used for UL data and control channels. In addition, the proposed enhanced ULTPC solution is also very flexible and adapts to dynamic system/link parameters and channel conditions in order to meet the requirements of E-UTRAUL.

In addition, in the case where the channel and CQI estimation is based on the UL reference signal, in order to avoid bad UL channel and CQI estimation, it is proposed to perform ULTPC for the data channel at a low rate such as 100 Hz (that is, TPC update is performed once every or two hybrid automatic repeat request (HARQ) cycles). For the control signaling associated with the data, assuming that the maximum CQI report rate is once every 1 millisecond transmission time interval (TTI), then the TPC update rate can be increased to 1000 Hz,

The term "wireless transmit/receive unit (WTRU)" referred to below includes but is not limited to user equipment (UE), mobile station, fixed or mobile subscriber unit, pager, cellular phone, personal digital assistant (PDA), computer or Any other user equipment that can operate in a wireless environment. The term "eNodeB" referred to below includes but is not limited to base station, Node-B, cell, site controller, access point (AP) or any other Peripheral devices operating in a wireless environment.

Figure 1 shows a wireless communication system 100 including at least one WTRU 105 and at least one serving eNodeB 110. The WTRU 105 includes a receiver 115, a transmitter 120, a processor 125, and at least one antenna 130. The serving eNodeB 110 includes a transmitter 135, a receiver 140, a processor 145, a mapping table 150, and at least one antenna 155. The WTRU 105 and the eNodeB 110 communicate via the downlink (DL) control channel 160, the UL shared data channel 165, and the UL control channel 170.

The processor 145 in the eNodeB 110 performs the UL interference thermal noise according to the signal received by the receiver 140 (<i>IoT</i>) Measure, and the measured<i>IoT</i>The measurement result is compared with a predetermined threshold value. The processor 145 also generates an interference load indicator, which is broadcast by the transmitter 135 of the eNodeB 110 based on a rule or a trigger. The interference load indicator indicates that it is executed on the eNodeB 110<i>IoT</i>Whether the measurement exceeds a predetermined critical value. When the receiver 115 in the WTRU 105 receives and decodes the interference load indicator, the processor 125 in the WTRU 105 can determine the<i>IoT</i>This state can be used to reduce the inter-cell interference in the eNodeB 110.

When the WTRU 105 is located in a specific cell, it will perform open loop TPC based on system parameters and path loss measurement results. The WTRU 105 reduces the inter-cell interference in the eNodeB 110 according to the interference load indicator, where the eNodeB 110 is in the cell that is adjacent to the specific cell and is the strongest compared to other adjacent cells. The strongest cell refers to the cell for which the WTRU 105 has the highest path gain (that is, the lowest path loss). Then, for the transmit power that may be biased due to open loop errors, the WTRU 105 corrects its transmit power based on the open loop calculation based on the CQI received via the DL control channel 160 and the target SINR, thereby compensating for the open loop error.

It should be noted that the CQI refers to the UL grant information (or MCS) signaled by the eNodeB 110 to the WTRU 105 via the DL control channel 160 for UL link adaptation. CQI represents the WTRU-specific UL channel quality that the serving eNodeB 110 returns to the WTRU 105 in the DL control channel 160. In E-UTRA, CQI is provided in the form of UL license information. The target SINR is a WTRU-specific parameter that is determined by the eNodeB 110 and is advertised to the WTRU 105 via higher layer signaling.

WTRU 105 transmit power P for UL shared data channel 165_TxIt is determined in the initial transmission stage according to the DL reference signal 175 transmitted by the transmitter 135 of the eNodeB 110. The DL reference signal 175 has a known transmit power, and the WTRU 105 uses this transmit power to perform path loss measurements. For the TPC inside the cell, the initial transmit power P of the WTRU 105_TxIt is defined in the following way based on the open loop TPC:<i>P</i>_<i>Tx</i>=max(min(<i>SINR</i>_<i>T</i>+<i>PL</i>+<i>IN</i>₀+<i>K,P</i>_<i>max</i>), <i>P</i>_<i>min</i>) Equation (1A) where<i>SINR</i>_<i>T</i>Is the target signal-to-interference-to-noise ratio (SINR) in dB on the serving eNodeB 110, and PL is the path loss in dB from the serving eNodeB 110 to the WTRU 105 (that is, a set point parameter), which includes The shadow is fading. The WTRU 105 measures the path loss based on the DL reference signal 175, where the transmit power of the signal is known on the WTRU 105 via DL signaling. Numerical value<i>IN</i>_<i>0</i>It is the UL interference and noise power in dBm at the serving eNodeB 110. K is the power control tolerance for the serving eNodeB 110 taking into account that the DL reference signal 175 may deviate from the actual transmission power in implementation.<i>P</i>_<i>max</i>and<i>P</i>_<i>min</i>They are the maximum and minimum transmit power levels for the transmission of the WTRU 105 on the UL shared data channel 165 in units of dBm, respectively.

It is assumed that the target SINR for the WTRU 105 (or a subgroup of the WTRU) can be adjusted according to a certain metric on the serving eNodeB 110. The outer loop TPC scheme can be used to adjust the target SINR. Generally, the target SINR is determined based on the target link quality (for example, block error rate (BLER)) of the UL shared data channel 165. In addition, different multipath fading channel states usually require different target SINRs (such as BLER) for specifying target link quality. Accordingly, this metric includes the target link quality (and possibly fading channel quality) for the WTRU 105.

For UL Multiple Input Multiple Output (MIMO), considering that different MIMO modes require different power or SINR for a specified link quality (for example, BLER), the target SINR also depends on the selected MIMO mode. In this case, the WTRU 105 may include multiple antennas 130.

Alternatively, the transmit power of the WTRU 105 can be defined as including the inter-cell TPC, as follows:<i>P</i>_<i>Tx</i>=max(min(<i>SINR</i>_<i>T</i>+<i>PL</i>+<i>IN</i>₀+<i>K</i>+Δ(<i>IoT</i>_<i>S</i>),<i>P</i>_<i>max</i>), <i>P</i>_<i>min</i>) Equation (1B) where the value Δ(<i>IoT</i>_<i>S</i>) Represents the UL load control step length, which is the UL interference load indicator of the strongest (S) neighboring cell (<i>IoT</i>_<i>S</i>)<i>IoT</i>_<i>S</i>The function.

Δ(<i>IoT</i>_<i>S</i>) Select an integer value as follows:

<maths><img file="TWM339161U_D0001.tif" /></maths>

Where δ is a predetermined system parameter, such as δ=-1 or -2<i>dB</i>. By using Δ(<i>IoT</i>_<i>S</i>), which can reduce the interference between adjacent cells. Since the WTRU located in the center of the cell causes less interference to other cells than those at the edge of the cell, the segmentation in the load control step size is considered in the following way:

<maths><img file="TWM339161U_D0002.tif" /></maths>

Where X is the load control factor between the segmented cells.

The strongest neighbor cell is determined on the WTRU 105 based on the path loss measurement from a single neighbor cell to the WTRU 105, where the strongest neighbor cell is the cell adjacent to the cell currently serving the WTRU 105 Among the cells, the neighboring cell with the lowest path loss to the WTRU 105.

By introducing Δ(<i>IoT</i>_<i>S</i>), can reduce inter-cell interference (such as inter-cell TPC), especially for the strongest neighboring cells. For the inter-cell TPC, the eNodeB will measure the UL interference (in a regular or periodic form), and then determine whether the measured interference level exceeds a predetermined threshold. The final UL interference status is using<i>IoT</i>_<i>S</i>(I.e. load indicator) and broadcast from eNodeB 110 (in a regular or periodic form). For example, if the interference exceeds this threshold, then<i>IoT</i>_<i>S</i>It is set to 1. In this way, since the eNodeB 110 will encounter too much inter-cell interference in the UL, the eNodeB 110 will instruct the WTRU in the neighboring cell to reduce its transmit power by a certain amount. otherwise,<i>IoT</i>_<i>S</i>Will be set to 0, so that the eNodeB 110 will receive the current UL interference level, so that the WTRU in the neighboring cell does not need to reduce its transmit power. The WTRU 105 decodes the load indicator received from the strongest neighbor cell, and then follows the command (<i>IoT</i>_<i>S</i>). If<i>IoT</i>_<i>S</i>Decode to 1, then the transmit power of the WTRU 105 is reduced by Δ(<i>IoT</i>_<i>S</i>), that is, Δ(<i>IoT</i>_<i>S</i>)&lt;0 dB. If<i>IoT</i>_<i>S</i>Decoded as 0, then Δ(<i>IoT</i>_<i>S</i>)=0 dB.

Assuming that each cell periodically broadcasts UL interference load bits (similar to the relative grant in High Speed Uplink Packet Access (HSUPA)), so the WTRU 105 can decode the indication from the selected strongest neighbor cell Symbol bit. The WTRU 105 can determine whether it is at the edge of the cell or inside the cell based on the path loss ratio between the serving cell and the strongest neighboring cell. Alternatively, the load control factor x between the segmented cells can be defined as follows:

<img file="TWM339161U_D0003.tif" />

After the initial transmission phase, during which the WTRU 105 starts to implement its TPC immediately after powering on (similar to random access channel (RACH) processing) or establishing a session connection, the WTRU's transmit power is calculated as follows:<i>P</i>_<i>tx</i>=max(min(<i>SINR</i>_<i>T</i>+<i>PL</i>+<i>IN</i>₀+<i>K</i>+αf(<i>CQI, SINR</i>_<i>T</i>),<i>P</i>_<i>max</i>), <i>P</i>_min)Equation (5) where f(<i>CQI, SINR</i>_<i>T</i>) Is a closed loop correction factor based on UL CQI (such as UL permit information or MCS information) and the corresponding target SINR. The weighting factor α can be determined according to the channel status and CQI availability (or UL transmission suspension), where 0<img file="TWM339161U_D0004.tif" />α<img file="TWM339161U_D0005.tif" />1. For example, if there is no UL CQI (UL permission or MCS information) available from eNodeB 110 due to lack of scheduled UL data transmission, then the weighting factor α will be set to zero. Otherwise, the weighting factor α will be set to 1. Although for the sake of simplicity, the weighting factor α is set to 0 or 1, but the alternative embodiment also includes an adaptive α value that is compatible with the channel status and the UL/DL channel configuration.

Correction factor f(<i>CQI, SINR</i>_<i>T</i>) Is used to compensate open-loop TPC related errors, which include path loss measurement errors mainly due to the imperfect reciprocity of UL and DL in frequency division duplex (FDD), and due to the WTRU 105 transmitter 120 Damage caused by nonlinear power amplification. In addition to path loss as a set point parameter, eNOdeB 110 can also prompt correction factors to adjust TPC-related system parameters, such as SINR,<i>IN</i>_<i>0</i>And K, these parameters are also set point parameters. For example, when the eNodeB 110 must adjust the target SINR for a designated WTRU 105 and then let the WTRU 105 know about the adjustment, the eNodeB 110 may adjust the CQI (UL grant) for the WTRU 105 accordingly, instead of directly signaling the target SINR to WTRU 105. Considering that the UL CQI represents the SINR received on the eNodeB 110, the correction factor is calculated by the WTRU 105 based on the UL CQI (UL grant or MCS information) from the serving eNodeB 110. For example, f(<i>CQI, SINT</i>_<i>T</i>)=<i>SINR</i>_<i>T</i>-<i>E</i>{<i>SINR</i>_<i>est</i>(<i>CQI</i>))(dB) Equation (6) where<i>SINR</i>_<i>est</i>(<i>CQI</i>) Represents the SINR estimate received by the eNodeB, which is derived by the WTRU 105 from the UL CQI feedback based on the SINR-to-CQI mapping table signaled via the higher layer of the serving eNodeB 110.<i>E</i>{<i>SINR</i>_<i>est</i>(<i>CQI</i>)} represents the average value of the estimated SINR with respect to time, thus:<i>E</i>{<i>SINR</i>_<i>est</i>(<i>CQI</i>^<i>k</i>)}=ρ<i>E</i>{<i>SINR</i>_<i>est</i>(<i>CQI</i>^<i>k</i>^-1)}+(1-ρ)<i>E</i>{<i>SINR</i>_<i>est</i>(<i>CQI</i>^<i>k</i>)) Equation (7) where<i>CQI</i>^<i>k</i>Represents the k-th received CQI, ρ is the average filter coefficient, and 0<img file="TWM339161U_D0006.tif" />ρ<img file="TWM339161U_D0007.tif" />1。

For the correction factor given by the difference between the target SINR and the estimated SINR (derived from the reported CQI) as described above, the correction factor usually represents the open-loop TPC-related error that needs to be compensated.

ENodeB signaling for the proposed TPC scheme

Target SINR level<i>SINR</i>_<i>T</i>Is a WTRU (or WTRU subgroup) specific parameter as a function of the distance from eNodeB 110 to WTRU 105 (eg path loss) and/or specified quality requirements such as BLER. This parameter can be used by eNodeB 110 The signal is announced to the WTRU 105. Generally, the eNodeB 110 uses the mapping table 150 to map the target quality (for example, BLER) to the target SINR value. How to generate this mapping table is a proprietary solution of the eNodeB (or carrier operator). The target SINR can be adjusted through the outer loop mechanism. The signaling of the target SINR is done through in-band L1/2 control signaling when it is adjusted.

Power control tolerance<i>K</i>It is an eNodeB-specific parameter mainly used for DL reference signals, and the power control tolerance K may be signaled by the eNodeB 110 to the WTRU 105. For example, because the DL reference signal 175 is transmitted at a constant transmit power level, and this level can be learned on the WTRU via higher layer signaling, the DL reference signal 175 can be used for the path loss measurement of the WTRU 105. However, the actual transmit power of the DL reference signal 175 may be different from the signaled power value due to the eNodeB's proprietary scheme. In this case, the power offset will be between the actually used transmit power and the transmit power advertised in a semi-static manner via the broadcast channel (BCH). Correct<i>K</i>In other words, it is likely to be semi-static and announced via the broadcast channel (BCH). The WTRU 105 uses this information for its UL/DL path loss calculations. It should be noted that although the power control tolerance is assumed<i>K</i>It is signaled separately with other parameters, but it can also be embedded in the target SINR that is<i>SINR</i>_<i>T</i>In, thus:<i>SINR</i>_<i>T</i>(After embedding)=<i>SINR</i>_<i>T</i>+<i>K</i>(<i>d</i>B) Equation (8) In this case, it is not necessary for K to be explicitly signaled to the WTRU 105.

To total UL interference and noise level<i>IN</i>_<i>0</i>In other words, it is averaged over all sub-carriers (or radio bearers (RB)) or subsets of sub-carriers in use, and this level can be signaled by the eNodeB 110 to the WTRU 105. This level is measured/derived by the eNodeB 110 (and can be advertised via the BCH). The update rate of this signaling is usually relatively low. The eNodeB 110 uses eNodeB proprietary solutions such as noise estimation technology to measure/estimate in a regular manner.<i>IN</i>_<i>0</i>。

For maximum and minimum UL transmit power levels<i>P</i>_<i>max</i>and<i>P</i>_<i>min</i>In other words, these levels may be signaled to the WTRU 105 by the eNodeB 110. In addition, these levels may be parameters based on the WTRU's capabilities, or they may be explicitly signaled by the eNodeB 110.

UL CQI (such as UL license information or MCS information) is initially signaled for UL link adaptability (such as adaptive modulation coding (MCS)) (its maximum signaling rate is once per TTI, such as 1000 Hz) ), and the UL CQI may be signaled to the WTRU 105 by the eNodeB 110.

UL CQI (e.g., UL grant information) is WTRU-specific feedback information signaled by the eNodeB 110 to the WTRU 105. Although UL CQI was originally used for UL link adaptability, it is also used for the closed-loop part of the proposed combined open-loop and closed-loop TPC. Generally, CQI (UL grant) is derived based on UL channel conditions (such as SINR measurement results at eNodeB 110) and SINR-CQI mapping rules, which means that UL CQI represents the SINR measured at eNodeB 110. Therefore, once the WTRU 105 receives the CQI and is given a mapping rule for SINR-CQI mapping at the eNodeB 110, the WTRU 105 can interpret the received CQI into an SINR estimate. The estimated SINR is then used to calculate the correction term according to equation (6).

The eNodeB 110 uses the CQI mapping rule (or the deviation between the CQI and the measured SINR) to implement the generation of the CQI feedback, and the rule may be signaled by the eNodeB 110 to the WTRU 105. In addition, this rule or parameter can also be combined into the target SINR. In this case, explicit signaling of rules (or parameters) is not needed.

Since the above TPC scheme does not require additional feedback TPC commands in addition to the system parameters listed above, this includes the target SINR and the cell interference/noise level that can be broadcast (or directly signaled) to the WTRU at a very slow rate. Standard and reference signaling transmission power and constant, therefore, this scheme is very advantageous. In addition, the above-mentioned TPC scheme is designed to be very flexible and compatible with dynamic system/link parameters (target SINR and inter-cell interference load status) and channel status (path loss and shadow fading), thereby achieving E-UTRA Demand. In addition, the above-mentioned TPC scheme is also compatible with other link adaptation schemes, such as AMC, HARQ, and adaptive MIMO.

Although the solution proposed here is to use UL CQI (such as UL license information) for the proposed closed-loop component (such as correction factor) of the combined open-loop and closed-loop TPC of E-UTRA UL, as an alternative, eNOdeB 110 It is also possible to signal a correction command embedded in the UL grant information to the WTRU 105 explicitly. In this case, the WTRU 105 may use this explicitly signaled correction command for the closed loop correction factor (possibly in combination with UL CQI). In addition, if the serving eNodeB 110 coordinates the inter-cell interference with other cells, and adjusts the target SIR accordingly or possible<i>P</i>_<i>max</i>To merge them, the proposed TPC can also be used to reduce interference between cells.

In order to achieve accurate UL channel estimation (for UL data/control signaling demodulation) and CQI estimation (for UL scheduling and link adaptability), it is ideal to adjust the UL reference signal transmission power at a relatively fast rate , In order to deal with bad channel and/or system conditions as quickly as possible. Even if the UL TPC for the data channel proposed above updates the WTRU transmit power at a slower rate (considering the UL AMC per 1 millisecond TTI), an update rate of up to 100 Hz can be achieved (for example, every Or update once for two HARQ cycle periods), thereby avoiding bad UL channel and CQI estimation. The update rate is controlled by the WTRU 105, so it is preferable that the WTRU 105 can update each time a CQI is received.

For UL control signaling, the WTRU 105 will use the aforementioned combined TPC scheme with the following deviations. When UL CQI is available and the maximum CQI report rate is once every 1 millisecond TTI, then a fast TPC update rate (for example, 1000 Hz) will be used. In this case, the correction factor f(<i>CQI, SINR</i>_<i>T</i>) Can be expressed as follows: f(<i>CQI, SINR</i>_<i>T</i>)=<i>SINR</i>_<i>T</i>-<i>SINR</i>_<i>est</i>(<i>CQI</i>)(dB) Equation (9) where<i>CQI</i>It is the latest UL CQI. In addition, the weighting factor is set equal to 1 (α=1). This will result in a combined open loop and CQI-based TPC. When no UL CQI is available, the CQI-based TPC part will be disabled (that is, α=0). And this will only produce an open loop TPC.

For the UL shared data channel 165, the WTRU 105 will determine its transmit power based on the combined open loop and CQI-based TPC with a slower update rate of 100 Hz. In the initial transmission and 1 or when the available UL CQI cannot be obtained from the eNodeB 110, for example, in the transmission suspension procedure, the CQI-based transmit power control part will be disabled, and only the open loop TPC will be used.

For the UL shared data channel 165, the WTRU 105 determines its transmit power based on the combined open loop and CQI-based TPC at a faster update rate such as 1000 Hz. When the available UL CQI cannot be obtained from the eNodeB 110, for example, in the transmission suspension procedure, the CQI-based transmission power control part will be disabled, and only the open loop TPC is used.

The eNodeB 110 broadcasts system parameters associated with the TPC, including its reference signal transmission power level, interference level, and power tolerance. In addition, the eNodeB 110 also signals to the WTRU 105 the WTRU-specific parameters associated with the TPC, including the target SINR, the WTRU maximum power level, and the minimum power level. The signaling is controlled by the in-band L112 layer. The signaling is done. The outer loop can be used to adjust the target SINR.

Figure 2 shows a flowchart of a TPC program 200 that can be implemented by the system 100 of Figure 1. In step 205, the initial UL transmission phase is implemented. The WTRU 105 executes an open-loop intracellular TPC procedure based on path loss based on the system parameters provided by the serving eNodeB 110 to set the transmit power for the initial UL transmission phase (for example, similar to the RACH procedure), where the system parameters can be SINR,<i>IN</i>_<i>0</i>、<i>K</i>And the transmission power of the DL reference signal 175 (step 210). In step 215, the normal UL transmission phase is implemented. The WTRU 105 will execute an open-loop intracellular TPC procedure based on path loss based on the system parameters provided by the serving eNodeB 110, and will execute a closed loop based on the UL CQI (UL permission information) provided by the serving eNodeB 110 (based on CQI) Intracellular TPC program (step 220). Alternatively, the WTRU will base the load indicator (<i>IoT</i>) To execute based on<i>IoT</i>The intracellular TPC program (step 225). In step 230, the WTRU 105 will set the transmit power of at least one UL channel (for example, UL shared data channel 165, UL control channel 170) according to the value generated in step 220.

Although the features and elements of this creation are described in a specific combination in the preferred embodiment, each feature or element can be used alone without the other features and elements of the preferred embodiment, or in Used in various situations in combination with or without other features and elements of this creation. The method or flowchart provided in this creation can be implemented in a computer program, software, or firmware executed by a general-purpose computer or processor, where the computer program, software, or firmware is included in a computer-readable storage medium in a tangible manner In, examples of computer-readable storage media include read-only memory (ROM), random access memory (RAM), register, buffer memory, semiconductor memory device, internal hard disk, and removable disk. Such as magnetic media, magneto-optical media, and optical media such as CD-ROM discs and digital versatile discs (DVD).

For example, suitable processors include: general-purpose processors, special-purpose processors, traditional processors, digital signal processors (DSP), multiple microprocessors, one or more microprocessors associated with the DSP core, Controller, microcontroller, dedicated integrated circuit (ASIC), field programmable gate array (FPGA) circuit, any kind of integrated circuit (IC) and/or state machine.

The processor associated with the software can be used to implement a radio frequency transceiver for use in a wireless transmit and receive unit (WTRU), user equipment, terminal, base station, radio network controller, or any kind of host computer. WTRU can be used in conjunction with modules implemented in hardware and/or software, such as cameras, camera modules, video circuits, speaker phones, vibration devices, speakers, microphones, TV transceivers, hands-free headsets, keyboards, Bluetooth<img file="TWM339161U_D0008.tif" />Module, frequency modulation (FM) radio unit, liquid crystal display (LCD) display unit, organic light-emitting diode (OLED) display unit, digital music player, media player, video game console module, Internet browser and / Or any kind of wireless local area network (WLAN) module.

<p>100. . . Wireless communication system</p><p>200. . . TPC program</p><p>105 (WTRU). . . Wireless transmitting/receiving unit</p><p>110 (eNodeB). . . Service Evolved Node B</p><p>130, 155. . . antenna</p>

By reading with reference to the attached drawings, you can better understand the previous overview and the subsequent detailed description, among which:

Figure 1 shows a wireless communication system including WTRU and eNodeB; and

Figure 2 shows the flow chart of the TPC program implemented by the system in Figure 1.