TWI479818B - Apparatus and method for computing maximum power reduction for a umts signal - Google Patents

Description

UMTS signal maximum power reduction calculation device and method

This application relates to wireless communications.

In practical amplifier circuits, such as those used in the general mobile telecommunications system (UMTS) wireless transmit receive unit (WTRU) transmit chain, the spectral regeneration is due to non-linear amplifier characteristics. The term spectral regeneration describes an increase in the energy of the out-of-band signal at the output of the power amplifier. The spectral regeneration produced by the nonlinear amplifier effect is mainly generated in the channel adjacent to the desired transmission channel. For UMTS, the requirements for the power amplifier are defined by the adjacent channel leakage ratio (ACLR) of +/- 5 MHz of the desired channel. The following are the amplifier voltage gain characteristics:

v _o ( t )= g ₁ ‧ v _i ( t )+ g ₂ ‧ v _i ( t ) ² + g ₃ ‧ v _i ( t ) ³ +... + g _n ‧ v _i ( t )" (1)

Where g ₁ ‧ vi ( t ) is the linear gain of the amplifier, and the rest (ie, g ₂ ‧ v _i ( t ) ² + g ₃ ‧ v _i ( t ) ³ +... + g _n ‧ v _i ( t ) ⁿ ) represents a nonlinear gain. If the signal carries the modulated third-generation partnership program (3GPP) radio frequency (RF), a nonlinear term is produced as a result of the intermodulation distortion, which produces in-band distortion terms and out-of-band distortion, in-band distortion. This will cause an increase in the error vector magnitude (EVM), while out-of-band distortion will cause an increase in the ACLR. Both of these will cause a decline in the quality of the modulation.

For example, multicode signals in UMTS versions 5 and 6 achieve an increase in peak-to-average power, which results in greater dynamic signal changes. These increased signal changes require stronger amplifier linearization, which results in greater power consumption. Recent results have shown that direct transmission of dB for dB (ie, the ratio of signal peak power to average power, also known as peak-to-average ratio (PAR)) is not effective for amplifier power attenuation. Analysis of the spectrum regeneration of the amplifier shows that the third-order nonlinear gain term ("cubic gain") is the main reason for the increase in ACLR. The total energy of the cubic term depends on the statistical distribution of the input signal.

With the introduction of High Speed Uplink Packet Access (HSUPA), a new method for eliminating amplifier power attenuation, called Cube Metric (CM), was introduced in Release 6. The CM is based on the cubic gain portion of the amplifier. The CM describes the ratio of the cube portion of the observed signal to the 12.2 kbps speech interference signal. The CM is also applicable to High Speed Downlink Packet Access (HSDPA) and HSUPA uplink signals. Statistical analysis shows that the power derating estimated from the CM exhibits a significantly smaller error distribution compared to the power derating based on 99.9% PAR, where the error distribution is between the actual power derating and the estimated power derating. The difference.

The 3GPP specifies a Maximum Power Attenuation (MPR) test indicating that the WTRU's maximum transmit power is greater than or equal to the nominal maximum transmit power, but less than the total amount of the so-called "maximum MPR", where the maximum MPR is a function of the CM of the transmitted signal. . For a given power amplifier, the manufacturer can decide that the device needs to limit its maximum power to some amount, referred to herein as "minimum MPR," which is less than the maximum MPR, but is compatible with 3GPP ACLR. Although "minimum MPR" can be defined as a function of CM, it can alternatively be defined as a function of a certain percentage of PAR. Using a minimum MPR instead of a maximum MPR to limit the maximum power allows the WTRU to transmit with greater maximum power, making the WTRU manufacturer with the smallest MPR more competitive. It is also possible that a WTRU's design can include both a maximum MPR and a minimum MPR, and choose between the two.

Regardless of the choice of maximum MPR or minimum MPR, the key issue is that the WTRU must know the value of CM and/or PAR to calculate the selected MPR and, if so, (ie, if the WTRU is operating near maximum power) Finally, the above values are used to actually set the transmission power. Any multi-code signal (characterized by the transmitted physical channel, its channelization code, and the weight called the beta term) has its specific CM and PAR.

In UMTS, the signal, as well as CM and PAR, can vary in every 2 or 10 millisecond transmission time interval (TTI). It can be seen that for UMTS version 6, there are more than 200,000 combinations of physical channel parameters and quantized beta terms, each of which is referred to as a possible signal. The large number of possible signals makes it possible to form a strictly one-to-one CM or PAR predetermined lookup table as a function of signal characteristics, which is impractical for immediate applications; especially at small low power operating at UMTS data rates In handheld devices. After understanding that the WTRU cannot simply look up the CM or PAR, it needs to measure or estimate it from the characteristic parameters of the signal within a certain allowable error.

It is known to measure CM or PAR from actual signals. An important drawback is that the signal must first be generated for measurement. Since the transmit power may eventually be set as a function of CM and/or PAR, setting the power by measurement will require generating a signal or a portion of the signal for at least a period of time prior to transmission. Although this is theoretically feasible, the time delay requirements of UMTS and the actual storage limitations make this approach impractical.

One variation of the above method is to generate and start transmitting signals at the power level calculated from the "guess" of the CM or PAR, and to adjust the transmit power to the second power level in the entire time slot remaining in the subsequent TTI. The combination of the first and second power levels is calculated such that the average power level is close to the power level selected by the CM or PAR prior to the start of the TTI.

In UMTS, there are 15 time slots in a 10 millisecond TTI, but there are only three time slots in a 2 millisecond TTI. Assuming, for example, that the measurement of the CM or PAR requires some portion of a time slot of, for example, a 10 millisecond TTI, the initial power level will be set to be used only for the first time slot, while the remaining 14 time slots are used. The second value. For a 2 millisecond TTI, the initial power level will be set to use the first time slot, which is one-third of the TTI, and the remaining two-thirds of the TTI will use the second value. Obviously, this approach is not consistent, especially in the case of a 2 millisecond TTI. Therefore, there is a need for a method that can determine the CM or PAR before starting to transmit a signal to determine the maximum MPR and/or minimum MPR, and the final transmit power.

A method and apparatus are provided for controlling transmit power using estimates of estimated CM or PAR. This method, as opposed to directly measuring CM or PAR, can be applied to determine the maximum power attenuation value (MPR) or minimum MPR used to calculate the maximum MPR by estimating CM or PAR from the signal parameters. The method of estimating CM or PAR is applicable to any multi-code signal.

The term "wireless transmit/receive unit (WTRU)" as used hereinafter includes, but is not limited to, user equipment (UE), mobile station, fixed or mobile subscriber unit, pager, mobile telephone, personal digital assistant (PDA), computer Or any other type of user device capable of operating in a wireless environment.

The term "base station" as referred to hereinafter includes, but is not limited to, a Node B, a site controller, an access point (AP), or any other type of peripheral device capable of operating in a wireless environment.

FIG. 1 is a block diagram of a WTRU 120 configured to perform the methods disclosed below. In addition to the components contained within a typical WTRU, the WTRU 120 also includes a processor 125 configured to perform the disclosed methods; a receiver 126 in communication with the processor 125; a transmitter 127 in communication with the processor 125; The machine 126 and the transmitter 127 communicate to implement an antenna 128 for transmission and reception of wireless data. The WTRU wirelessly communicates with the base station 110.

A method for estimating a transmission CM and/or PAR of a signal based on a configuration parameter of a signal and using the estimated value to calculate an MPR will be described below. Configuration parameters include the number and type of physical channels and configuration. The configuration can be defined as a combination of channelization code and channel weight (referred to as beta), best used for in-phase (I) and quadrature channel (Q) partial codes. Channel weights (for a given service and data rate), other parameters, the so-called "configurations" below, and all combinations above are determined according to the specifications defined by 3GPP.

A signal can be defined as a combination of a physical channel and a beta term. Every possible signal must be in at least one configuration. This definition can be extended. For example, a subset or a limited range of some or all of the beta terms for one or more physical channels including configuration conditions may be included. The identification of the smallest subset of configuration conditions is subjective, which specifies the minimum CM and/or PAR estimation error that can be received, which in turn is used for the MPR estimation error.

An example of a set of 11 configurations is shown in Table 1. These configurations are limited to allowing up to one DPDCH. Those skilled in the art will appreciate that the configuration is not limited to this. However, it may not be ideal. Empirical results indicate that the resulting less acceptable estimation error, especially the maximum maximum MPR estimation error, is less than or equal to 1.5 dB. Table 1 shows that the configuration is usually defined by three main characteristics: 1) the maximum number of DPDCHs (Nmax DPDCH); 2) whether to start high speed (HS); and 3) the number of E-DPDCHs and the spreading factor (SF) ( E-DPDCH code @SF). Table 2 shows an alternative mapping method. Table 2 shows that some of the conditions originally defined in Table 1 are divided into a plurality of cases, so that less errors than those of Table 1 can be produced. In particular, it indicates that the maximum maximum MPR estimation error is less than or equal to 1.0 dB.

Referring back to Table 1, the HS Chan code column relates to a specific "SF and Orthogonal Variable Length (OV) SF Code" for HS-DPCCH. Note that SF is typically 256, and for OVSF, one of two codes (33 and 64) is used. When the third column (ie HS) shows no ("N") HS, this column is indicated as "unavailable" (N/A).

The E-DPDCH 1, 3 I or Q column indicates that in this section, I or Q, E-DPDCH channels #1 and #3 are displayed, which are used according to the condition of the column.

The E-DPDCH 1,3 Chan code field, if any, relates to the SF and OVSF codes for the E-DPDCH involving channels #1 and #3. For example, configuration case 6 has two E-DPDCHs, labeled #1 and #3, and the remainder of the column is either none (not available) or one (default is "#1"). Most configurations have only one E-DPDCH.

The E-DPDCH 2,4 Chan code column is similar to the above for the case of having two or more E-DPDCHs.

Columns I and Q represent the beta terms in the I and Q sections. In configuration case 6, β _ed relates to E-DPDCH channels #1 and #2, and β _ed3/4 relates to E-DPDCH channels #3 and #4.

Configuration case 0 in Tables 1 and 2 is a known general case where zero maximum MPR is required. For this configuration case, the calculation method for all other configuration cases is not used, but the maximum MPR and/or the minimum MPR is simply set to zero.

Referring to Figure 2, a simple version of the offline process 200 is shown. As will be described in greater detail below in conjunction with FIG. 3, process 200 ultimately calculates and stores parameters for the WTRU to generate a maximum MPR and/or a minimum MPR value. In UMTS, each combination of physical channel and parameters and quantized value β is a possible signal. The quantized value is based on the configuration of the signal. First, all possible signals are mapped to a set of configuration scenarios (210). By using the information (I and Q) given in the two rightmost columns of Table 1, a quantized value (220) can be generated for all possible signals. The CM and/or PAR (230) for all possible signals is measured by transmitter simulation. The measurement of CM and PAR will be described in more detail below.

The pre-calculated term a is optimally determined 240 by using the output of the transmitter simulation 230. Optimally for each of the configuration scenarios defined above, a set of alpha terms for the CM and/or a set of alpha terms for the PAR calculated according to Equation 7 below are determined.

For each configuration, transmitter simulation 230 measures CM and PAR for all possible signals (a mathematical derivation of the estimation of CM and/or PAR will be derived in detail below), where the signal is defined as in 3GPP All possible combinations of beta terms 220 are quantified. The pre-computed alpha term can be determined for a particular configuration situation using a least squares fit method, from all possible signals of the configuration case, or from a typical subset thereof. The calculated alpha term, configuration, and calculated adjustment factor are calculated (240). These values are then written to the WTRU 400 by firmware, software or hardware.

Figure 3 is a flow diagram of the offline initial configuration process (300). The process 300 calculates the alpha term for both CM and PAR and determines the adjustment factor for the configuration. These values are stored in the WTRU (400) for estimating CM and PAR for a given signal.

Referring to Figure 3, a detailed version of the offline process 300 is shown. First, at 310, the configuration is defined based on the characteristics of the physical channel. For example, as shown in configuration case 9 in Table 1, DPCCH, one DPDCH (the largest one DPDCH), HS-DPCCH (ΔACK and ΔCQI are set equal; always send an acknowledgement (ACK) and channel quality indication ( CQI)), E-DPCCH and 2SF@=2 (two E-DPDCHs in SF are equal to 2).

The information (I and Q) in the rightmost two columns of Table 1 were used to determine the required cross-β terms within the individual, square, and component. From the sign of Equation 5 (described below), {β _I1 β _I2 β _I3 }={β _d β _ec β _ed } and {β _Q1 β _Q2 β _Q3 }={β _c β _hs β _ec }( The specification of a specific number is arbitrary). Sixteen such items are defined in Table 3: β _ec , β _ed , β _d , β _c , β _hs , β _ec2 , β _ed2 , β _d2 , β _c2 , β _hs2 , β _ec β _ed , β _ec β _d , β _ed β _d , β _c β _hs , β _c β _ed and β _hs β _ed .

All possible signals of the configuration (ie, all combinations of quantized beta terms for the channel) are then determined (320). For each 3GPP, there are thirty implicit combinations of pairs of values of β _c and β _d , nine explicit values of A _hs =β _hs /β _c , nine values of A _ec =β _ec /β _c And thirty values of A _ed = β _ed / βc, or a total of 72,000 possible signal combinations for each configuration. These 72,900 combinations are not listed here.

Transmitter simulation was used to measure CM and measure 99% PAR (330) for all 72,000 possible signals for each configuration. The measured 145,800 values are not listed here.

Using sixteen pre-computed alpha values for estimating CM and sixteen for estimating PAR using Equation 7 using the measured values of 72,000 possible signals and linear CM and linear PAR for each configuration case A pre-calculated alpha value (340). The symbol term is given in Equations 8 to 7; the numerical value of the α term is given in Table 3. Although it is possible to use only a small subset of 72,900 combinations, assuming that a matrix X with 72,900 rows is needed in the next step, a complete set of the entire 72,900 combinations is used to calculate Table 3 for a configuration.

For each possible signal, the model described by Equations 5 and 6 (described below) is used to estimate the linear CM and the linear PAR (350). The calculation in the form of a matrix is given in Equation 12. Matrix X is the numerator of Equation 5 and includes a normalization function for a single beta term. The matrix Y is a linear CM and a linear PAR measurement multiplied by the denominator of Equation 5; the model of Equation 6 uses a similar form.

Equation 13 is optimally used to calculate an estimation error (360) for both CM and PAR. For further description, the distribution of CM estimation errors (in dB) is given in Figures 6A and 6B. The distribution of the PAR error dB form is given in Figures 7A and 7B. Figures 6A and 7A show the model described in Equation 5, while Figures 6B and 7B show the model described in Equation 6.

The required adjustment factor (370) is then determined. It can be seen from the inspection that for the model of Equation 5, the adjustment factor for the maximum MPR, the maximum amplitude positive error in Figure 6A is about 0.54 dB or 1/0.883. If the minimum MPR is the desired result, the adjustment factor using the CM for the minimum MPR, and the maximum amplitude negative error in the 6A diagram is about -0.71 dB. The adjustment factor using PAR for the minimum MPR and the maximum amplitude negative error in Figure 7A is about -0.41 dB. As can be seen from Figures 6B and 7B, the corresponding values for the model of Equation 6 are -0.54 dB, -0.080 dB, and -0.57 dB.

The distribution of the maximum MPR error is determined (380) by using an adjustment factor, which, as calculated above, is consistently 0.54 dB.

Looking at Figure 5A and Figure 5B, the distribution of the maximum MPR error shows that for the two models, the maximum maximum MPR error is 1.5 dB, if it is considered to be small enough (in this case), then theoretically Both models can be used.

As a second criterion, it should be noted that, as shown in FIGS. 5A and 5B, the frequency of occurrence of the maximum error of the model of Equation 5, that is, 9/72900, is lower than the model of Equation 6, ie, 406/72900. Therefore, the model of Equation 5 is selected and the alpha value and the adjustment factor (390) are configured in the WTRU (400). Alternatively, the model of Equation 6 estimates that the CM requires less multiplication, and if this is a significant factor, the model can be selected.

The derivation of the estimated CM and/or PAR is now described. The PAR of the uplink signal is determined according to Equation 2 after the channel weight has been used, but before the root raised cosine and other filters are used.

Wherein β _I is the channel weight for the physical channel in the I part; β _Q is the channel weight for the physical channel in the Q part; N _I is the number of physical channels in the I part; and N _I is in the Q part The number of physical channels.

According to one embodiment, CM _linear , (linear rather than CM in dB form, and no 0.5 dB quantization of 3GPP method) is optimally used as a function related to the pre-filtered PAR _{linear of} Equation 2 for a given configuration. Estimated, as shown in Equation 3:

Where γ _j is the actual weighting factor for each physical channel; n is an integer used to define the indicator of the sum; N _Order is the order of the arbitrary polynomial; Is a normalization function that makes the value independent of any ratio of β.

It is also possible to estimate the PAR _linear at the output of the filter using the same function as in Equation 3, where only the value of the term is different from that for the CM _linear . For any possible signal for a given configuration, using Equation 3 to estimate CM _linear and PAR _linear will typically produce an error between the estimated value and the measured value, which is called the estimation error.

Although N _Order can be chosen to be any positive integer, in one embodiment it is, for example, N _Order = 2. Empirical results show that by using N _Order = 2, the range of estimation errors for all possible signals is an acceptable small range for determining the maximum MPR and the minimum MPR. Therefore, choosing N _Order to be greater than 2 creates additional complexity with no significant performance improvements. Therefore, when N _{Order is} set to 2, Equation 3 is simplified to Equation 4:

Extending Equation 4 yields Equation 5.

The CM _linear described by this equation is substantially equal to a weighted form of a single square weight (weighted by a square root term), an intra-component cross-β term, and an inner product of an alpha term that is not yet known. The formula also applies to PAR _linear , except that the values of the alpha terms are different.

The replacement model described in Equation 5 is represented in Equation 6. The model of Equation 6 removes the single beta term and the associated normalization function (the last term in the numerator of Equation 5). Empirical results show that for some configurations, the model produces less estimation error than the model of Equation 5.

For a given configuration, the value of the alpha term can be determined from: 1) CM _linear and/or PAR _{l inea} using transmitter simulation (230) to measure all or a set of fewer typical possible signals; and 2 Using the known least squares fitting method, given in matrix 7 as Equation:

α=( X ^T X ) ^{- 1} X ^T Y Equation (7)

Where X is a matrix (known as a design or Vandermode matrix), one line per signal, where each element in a row is a square, a single weight, or a numerical value that intersects the beta term within the component. This is determined by replacing the symbols βI and βQ in Equation 5 or Equation 6 with the β term of the specific channel; for the case of having two or four E-DPDCHs, each single and square βed should Only one row of X, not two or four rows; and Y is a column vector with one element per signal, each of which is the measured CM _linear or PAR _linear . Assuming that the alpha term used to estimate the CM or the alpha term used to estimate the PAR is to be calculated, multiply by the signal weighting factor in the denominator of Equation 5 or Equation 6. Alternatively, assuming that the alpha term used to estimate CM and PAR is to be calculated at the same time, Y can be a matrix with two such columns: one for CM _linear and one for PAR _linear .

The symbol term (rather than its numerical value) for calculating the alpha term for this example in equation (7) is provided below:

The reduced set of possible signals referenced by the above example relates to the situation where the number of signals required to reliably calculate the alpha term may be orders of magnitude less than the number of all possible signals. However, using Equations 12 and 13, the matrix X with all possible signals is used to calculate the estimation error. By limiting the number of signals used to calculate the alpha term in X, no significant savings are created in the off-line processor 200.

The weighting factors used to construct the matrices Y and X, the digital power (the denominators of Equations 5 and 6), and the root mean square magnitude of each signal, as specified in Equations 5 and 6, respectively. The root mean square term in the numerator of Formula 5) may be the same or substantially the same for all signals in a particular embodiment. In this case, it may not be necessary to calculate each signal. Rather, the two weighting factors can be constants common to all signals.

If the ratio of the number β term in the transmitter simulation used to measure CM and/or PAR and then calculate the alpha term is equal to the ratio of the digit β term in the WTRU, the weighting factor can also be removed from Equations 5 and 6. And effectively combined into the alpha term.

By using the processes of Figures 2 and 3, the alpha term for all defined configuration cases, the adjustment factor for each configuration case, and the model capable of minimizing the maximum MPR or minimum MPR, have been Equation 5 and The two models described in 6 are calculated. The model for minimizing the maximum MPR and the minimum MPR is calculated as follows: For the case of the maximum MPR, there are three alternative ways to determine the model that can minimize the maximum MPR estimation error.

In the first alternative, the CM _linear estimated from Equation 5 or 6 should be adjusted such that the adjusted estimated CM is not greater than the value obtained from the actual measurement of the CM. The adjustment factor should be the maximum amplitude positive error for a particular configuration; this factor should be subtracted from the actual estimate. The purpose of this error adjustment is to prevent the CM from being overestimated for any signal.

A second alternative is that the CM _linear estimated from Equation 5 or 6 should be adjusted such that the maximum MPR determined from the adjusted estimated CM is not greater than the maximum MPR obtained from the actual CM measurement. The purpose of adjusting the error in this way is to prevent the maximum MPR from being overestimated for any signal. Here's how to determine the adjustment factor:

1) For each signal in the configuration, the estimated CM is used to determine the estimated MPR (MPR_estimated) and the actual MPR (MPR_true) is determined from the actual CM of the known simulation.

2) Calculate the MPR error (MPR_error) according to Equation 14:

MPR_error = MPR_true-MPR_estimated equation (14)

3) From the signal with the MPR error less than 0, the original adjustment factor (adjustment_factor_raw) is selected according to Equation 15:

adjustment_factor_raw = max (CM_estimated-ceil ( CM_true, 0.5)); equation (15)

Among them, ceil (‧, 0.5) means round up to the nearest 0.5.

4) The final adjustment value is the value of Equation 15 plus a small amount, ε, to ensure that the signal with the largest CM_estimated in Equation 15 is not rounded up to the next 0.5 dB after the adjustment factor is used. In other words, Equation 16 is used to calculate an adjustment factor, where the largest is selected from signals having an MPR error of less than zero.

adjustment_factor = max (CM_estimated-ceil ( CM_true, 0.5)) + ε Equation (16)

A third alternative is to use a smaller magnitude adjustment factor than is used in other alternatives, the selected amount being compromised as a design (eg, preventing the CM from being overestimated only for a particular signal of the configuration).

For the case of calculating a minimum MPR to determine a model that minimizes the minimum MPR estimation error, the estimated CM or PAR should be adjusted such that the adjusted CM or PAR is not less than the actual measured value of the CM or PAR. The adjusted factor should be the negative CM or PAR estimation error for the maximum amplitude of a particular configuration; it should be subtracted from the actual estimate. The purpose of using the adjustment factor in this way is to prevent CM or PAR from being underestimated for any signal. Alternatively, a smaller magnitude negative adjustment factor can be used, the selected amount being compromised as a design (eg, preventing CM from being underestimated only for a particular signal of the configuration).

For each configuration, after any method uses an adjustment factor, it must be evaluated whether the error is small enough for both models. The distribution of measurement errors for a particular configuration is given in Figures 5A, 5B, 6A, 6B, 7A, and 7B. Fig. 5A, Fig. 6A and Fig. 7A show the model described in Equation 5; Fig. 5B, Fig. 6B and Fig. 7B show the model described in Equation 6. Figures 5A and 5B show the distribution of the maximum MPR estimation error for a particular situation. In the 5A and 5B diagrams, the distribution is highly quantized due to the topping ( cei1 ) operation in the maximum MPR calculation.

Figures 6A and 6B show the intensity of the CM estimation error; Figure 6A has a narrower intensity than the 6B diagram. The distributions in Figures 6A and 6B and the distributions in Figures 7A and 7B are substantially continuous. Figures 7A and 7B show the error strength of the estimated PAR. In order to calculate the maximum MPR, the maximum maximum MPR error should be within the desired limits. Alternatively, the difference between the limit positive and negative CM measurement errors within the desired limits can be taken as a criterion. However, the best is to use the largest maximum MPR error. In order to calculate the minimum MPR using CM or PAR, the difference between the extreme positive and negative measurement errors should be within the required range.

For maximum MPR, the result of using the adjustment factor according to the first alternative is that no signal has an overestimated MPR, but some signals have an underestimated MPR. The result of using the adjustment factor according to the second alternative is that no signal has a CM with an overestimation, but some signals have a CM that is underestimated. In particular, a signal with the largest positive CM error will have a correctly estimated CM, and a signal with a negative CM error of the largest amplitude will have a CM that is too low estimated due to the difference between the maximum amplitude positive and negative CM errors, other The signal will have a CM that is too low estimate due to some smaller amount.

For the minimum MPR, the result of using the adjustment factor is that no signal will have a CM or PAR that is underestimated; and some signals have an overestimated CM or PAR. In particular, a signal with the largest positive CM or PAR error will have a correctly estimated CM or PAR; a signal with the largest amplitude positive CM or PAR error will have been due to the difference between the positive and negative CM errors of the maximum amplitude. Highly estimated CM or PAR.

There are two possible problems with estimating errors: First, due to deliberate underestimation and overestimation of CM and PAR, the calculated minimum MPR may exceed the calculated maximum MPR. In this case, the WTRU may not be able to select a value for the MPR that is guaranteed to meet the requirements of both MPR and ACLR, such as the 3GPP standard. Second, the greater the difference between the maximum amplitude positive and negative estimation errors, the greater the difference between the minimum MPR obtained according to the method and the minimum MPR obtained from the measurement, thereby reducing the maximum achievable Transmit power.

Two possible measures for the above problem are: 1) the above compromise can be used by selecting the replacement adjustment factor, so that for some possibly smaller signal sets, the calculated MPR is not applicable; and 2) the specific The configuration is divided into two or more configurations, which results in a smaller estimation error. For example, if the analysis indicates that the largest beta term produces the greatest estimation error for a particular physical channel, then these beta terms are used to establish a separate configuration.

Once a set of configuration scenarios has been defined and the alpha terms and adjustment factors have been calculated for all configuration scenarios, they are best stored in the WTRU's table.

Referring to Figure 4, the WTRU 400 is shown. Before each TTI begins transmission, the appropriate configuration is selected to configure the data provided by the Media Access Control (MAC) layer of the transport block. In order to define the set of configuration conditions given in Table 1, the selection is made according to the combination of physical channels used to transmit the transport block, and possibly the E-DPDCH spreading factor.

Regardless of whether the MPR computing device (430) calculates the maximum MPR, the minimum MPR, or both, and if the device calculates the minimum MPR using PAR, the CM _{linear is} estimated according to Equation 17, which is Equation 5 and the like. The simplified form of Equation 6:

Wherein N and D are the numerator and denominator of Equation 5 or Equation 6, respectively, and the CM α term of the configuration case determined above is used. Equation 11 is used to estimate PAR _linear , but CM _{linear is} replaced with PAR _linear and the PAR α term of the configuration case is used. The CM _linear and/or PAR _{linear are then} converted to the dB form.

If the MPR computing device (430) calculates the maximum MPR, the selected adjustment factor (in dB) for calculating the maximum MPR is subtracted from the estimate of the CM in dB form. This gives the CM value used to calculate the maximum MPR.

If the MPR computing device (430) calculates the minimum MPR using the CM, the selected adjustment factor (in dB) for calculating the minimum MPR is subtracted from the estimate of the CM in dB form. The result of this is that the minimum MPR is calculated using the CM value.

If the MPR computing device (430) calculates the minimum MPR using PAR, the selected adjustment factor (dB) for calculating the minimum MPR using PAR is subtracted from the estimate of the PAR in the form of dB, the result of which is used to calculate the minimum MPR. .

If the MPR computing device (430) calculates the maximum MPR, the maximum MPR is optimally calculated from 3GPP. If the MPR calculation device calculates the minimum MPR, the minimum MPR is optimally calculated according to the specifications of the power amplifier.

If the device calculates the maximum MPR or the minimum MPR, not both, the calculated maximum MPR or minimum MPR is output as the MPR value used to set the transmission power. A device that calculates both the maximum MPR and the minimum MPR can select an intermediate value as the MPR value for setting the transmit power and remain consistent with the standards and manufacturer's recommendations.

Actually, it is not necessary to fully estimate the value of CM, but only need to detect whether the estimated CM value is higher or lower than one or more threshold values. A possible threshold test can be provided by slightly modifying Equation 17, such as Equation 18, which has the advantage of avoiding the partitioning operation in Equation 17.

Where CM _linearT is a specific threshold of CM _linear ; The operator is a critical value test, and if the inequality is "true", it indicates that the CM _{linear is} greater than the CM _linearT .

Table 4 is derived from Table 6.1A of 3GPP TS 25.101, which shows an efficient algorithm given in the form of C language, which sets the value of max_MPR_dB and the critical value. The linear equivalent of the adjustment factor is chosen for use in calculating the maximum MPR.

The special device algorithm used to calculate the minimum MPR is similar to the calculation of the maximum MPR. Depending on the number, there is likely to be only one CM and/or PAR threshold and can be calculated using a similar algorithm.

Returning to Fig. 4, FIG. 4 is a WTRU 400 configured for wireless communication that receives and processes digital user data and control data by a scaling circuit 450 to digitally scale the data to set its relative transmit power. The digital user profile can be encoded into a channel such as a Dedicated Physical Data Channel (DPDCH) or an Enhanced DPDCH (E-DPDCH). The control material can be encoded into a channel such as a Dedicated Physical Control Channel (DPCCH), a High Speed DPCCH (HS-DPCCH), or an Enhanced DPCCH (E-DPCCH). The scaling circuit 450 operates in each of these channels.

The scaled data is filtered by filter device 460, and the filtered data is converted to an analog signal by analog to digital converter (DAC) 470 and transmitted by radio transmitter 480 through antenna (Tx) 490. The WTRU's transmitter has an adjustable (i.e., power controllable) overall transmit power, as well as a scalable single channel input, as represented by the analog gain term and the digital gain term, respectively, in FIG. Other forms of controllable transmission equipment can also be used.

The transmission power and overall transmission power of a single channel are set by the transmission power control unit 440 according to a procedure defined in 3GPP. The nominal maximum transmit power is determined by the WTRU power level or the network. The maximum transmit power of the WTRU power level is defined in 3GPP. The WTRU may automatically limit its maximum transmit power using a maximum MPR or a smaller device-specific minimum MPR, which is a value within the range defined by 3GPP.

The transmit power control unit 440 uses a plurality of parameters to set the transmit power. One of these parameters is MPR. To calculate the MPR, the configuration is first defined in terms of offline configuration parameters, which are obtained according to the description of Figures 2 through 3 above (410). For the case after the identification, the adjusted estimated CM and/or PAR (420) is calculated based on the following.

The MPR (430) is set according to the value for the maximum MPR and/or the minimum MPR. Optimally, the maximum MPR and/or minimum MPR is calculated by processing device 430 based on the adjusted CM and/or PAR estimate (420), or the adjusted MPR estimate. If it is calculated based on the adjustment to the MPR, the CM and/or PAR are no longer adjusted.

The WTRU 400 may be configured to calculate either or both of the MPRs; and calculate the minimum MPR from either CM or PAR, such that any combination may be selected for use. The estimate of CM and/or PAR may be a function of a pre-calculated value represented by an alpha term, or a function of the desired correlated channel power (beta term) of the transmitted signal, where the specific function of the beta term Is based on the specific entity parameters of the signal. The adjustment to this estimate can be from a pre-computed item.

In order to calculate one or two MPRs in the WTRU 400, first, for a TTI, with a configuration example of the signal, the channel weight of its MAC-es is β _c = 15, β _d = 6, and A _h s = β _hs / β _c = max (Δ _ACK and Δ _CQI ) = _15/15 , A _ec = β _ec / β _c = _15/15 , A _ed , = β _ed / β _c = 95/15. An example of this signal is the signal U in R4-060176, 3GPP TSG RAN 4 Meeting #38.

Second, by using digital scaling, the WTRU 400 calculates the following digital channel weights: β _c = 22, β _d = 9, β _hs = 22, β _ec = 22, β _ed = 200. These weights take up the desired ratio and their sum of squares is the required constant.

Third, by using α _CM and β in Table 3, the estimation of the digital channel weight and CM _linear is calculated using Equation 5, which is 1.0589, which is equal to 0.2487 dB.

Fourth, the CM estimate is adjusted by subtracting 0.54 dB to obtain about -0.29 dB. Alternatively, in a linear form, the estimate is adjusted by multiplying 1.0589 by 0.883, yielding about 0.93.

Fifth, the linear adjustment estimate of CM is 0.94 less than the first linear threshold in Table 4; therefore, the maximum MPR is calculated to be 0 dB.

Summarized by Figure 8, a process 800 for setting transmit power by the WTRU 400 to calculate the MPR is shown. The adjustment factor and the pre-calculated alpha value are determined and processed in the offline processor (810) depending on the configuration. These values are stored in the WTRU 400 to assist the WTRU 400 in identifying configuration conditions (820). Once the configuration is determined, the adjusted estimated CM and/or PAR (830) is calculated. By using these adjusted estimates, the maximum MPR and the minimum MPR (840) are calculated and the MPR is set. The MPR, theoretical maximum power, and power control commands are combined (850) to set the transmit power (860).

Although the features and components of the present invention are described in the preferred embodiments of the specific combination, each of the features and components may be used separately without the other features and components of the preferred embodiment, and each Both features and components can be used in different combinations with or without other features and components of the invention. The method or flowchart provided by the present invention can be implemented in a computer program, software or firmware executed by a general purpose computer or processor, wherein the computer program, software or firmware is tangibly embodied in a computer readable storage medium. Examples of computer readable storage media include read only memory (ROM), random access memory (RAM), scratchpad, cache memory, semiconductor memory device, internal hard disk, and mobile disk. Optical media, magneto-optical media, and optical media such as CD-ROM discs and digital versatile discs (DVDs).

Suitable processors include, for example, general purpose processors, special purpose processors, conventional processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, control , microcontroller, dedicated integrated circuit (ASIC), field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC) and/or state machine.

The software related processor can be used to implement a radio frequency transceiver for a wireless transmit receive unit (WTRU), a user equipment (UE), a terminal, a base station, a radio network controller (RNC), or any host computer. The WTRU may be used in conjunction with modules implemented in hardware and/or software, such as cameras, camera modules, video phones, speaker phones, vibration devices, speakers, microphones, television transceivers, hands-free headsets, keyboards, Bluetooth Module, frequency modulation (FM) wireless unit, liquid crystal display (LCD) display unit, organic light emitting diode (OLED) display unit, digital music player, media player, video game module, internet browser and / or any wireless local area network (WLAN) module.

110. . . Base station

120, 400, WTRU. . . Wireless transmitting and receiving unit

125. . . processor

126. . . Receiver

127. . . transmitter

128. . . antenna

200. . . Offline process

300. . . Offline initial configuration process

440. . . Transmit power control unit

450. . . Scaling circuit

460. . . Filter device

470, DAC. . . Analog to digital converter

480. . . Radio transmitter

490, Tx. . . antenna

CM. . . Cubic measure

MPR. . . Maximum power attenuation

PAR. . . Peak-to-average ratio

A more detailed understanding of the present invention can be obtained from the description of the preferred embodiments.

1 is a functional block diagram of a wireless transmit receive unit (WTRU) in accordance with the present invention;

Figure 2 is a block diagram of a simplified version of the offline processor;

Figure 3 is a detailed flow chart of the offline initial configuration process;

Figure 4 is a block diagram of a WTRU in accordance with an embodiment;

5A and 5B are two diagrams of the model for Equation 5 and the model of Equation 6, respectively, showing the distribution of the maximum MPR estimation error;

6A and 6B are two diagrams of the model for Equation 5 and the model of Equation 6, respectively, showing the distribution of CM estimation errors;

FIGS. 7A and 7B are two diagrams of the model for Equation 5 and the model of Equation 6, respectively, showing the distribution of the PAR estimation error; and FIG. 8 is a flowchart of the method of setting the transmission power.

400, WTRU. . . Wireless transmitting and receiving unit

440. . . Transmit power control unit

450. . . Scaling circuit

460. . . Filter device

470, DAC. . . Analog to digital converter

480. . . Radio transmitter

490, Tx. . . antenna

CM. . . Cubic measure

MPR. . . Maximum power attenuation

PAR. . . Peak-to-average ratio

Claims (4)

A wireless transmit/receive unit (WTRU), comprising: a circuit configured to calculate a first maximum power attenuation (MPR) and a second MPR; wherein the first and second MPRs are based on an uplink for the one of the WTRUs At least one modulation type of the link transmission is calculated; the circuit is further configured to select the first or second MPR; the circuit is further configured to modify one of the maximum output power of the WTRU to return to the first or selected a second MPR; and the circuitry is further configured to transmit the uplink transmission when an output power does not exceed the modified maximum output power. The wireless transmit/receive unit (WTRU) of claim 1, wherein the second MPR is calculated based on at least one adjustment factor. A method for calculating a first maximum power attenuation (MPR), the method comprising: calculating, by a wireless transmit/receive unit (WTRU), the first MPR and a second MPR, wherein the first and second MPRs Calculating based on at least one modulation type for one of the uplink transmissions of the WTRU; selecting the first or second MPR by the WTRU; modifying, by the WTRU, one of the maximum output power of the WTRU to return to the selected one One or second MPR; and transmitting the uplink transmission when an output power does not exceed the modified maximum output power. The method of claim 3, wherein the second MPR is calculated based on at least one adjustment factor.