JP2007259377A - Radio transmission apparatus and radio transmission power control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain improvement in accuracy of transmission power control by accurately measuring transmission power even when a change point is generated in the transmission power within one transmission slot by offset of a transmission slot between channels in burst transmission of a plurality of channels for each of which a timing of the transmission slot is different, like HSDPA. <P>SOLUTION: A modulation signal is amplified by a variable gain amplifying unit 501 and transmitted out. A part of the transmission output is extracted by a coupler 503 and at a time position when a measurement timing signal is inputted, power measurement is performed by a transmission power measuring unit 504. A gain control unit 506 calculates an error from target transmission power and on the basis of the error, a gain of the variable gain amplifying unit 501 is corrected. A measurement timing generation unit 102 calculates a transmission power change point beforehand on the basis of slot timing information and generates a measurement timing signal so as to measure power in a stable section other than the transmission power change point. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless transmission device and a wireless transmission power control method, and more particularly, to a CDMA that performs transmission power control with high accuracy by correcting the gain of a variable gain amplification unit that amplifies an input modulation signal and outputs a transmission signal. The present invention relates to a wireless transmission apparatus and wireless transmission power control method of the Code Division Multiple Access) method.

  FIG. 5 shows the configuration of a conventional wireless transmission apparatus. The wireless transmission device is configured as follows in order to increase the accuracy of transmission power control. The modulation signal to be transmitted is controlled by the variable gain amplification unit 501 so as to have a target transmission power, and is output as a transmission signal through the power amplification unit 502. A part of the transmission output is extracted by the coupler 503, and transmission power measurement is performed. To the part 504.

  The transmission power measurement unit 504 receives the measurement timing signal output from the timer 505, and the transmission power measurement unit 504 measures the power of the transmission output at the timing when the measurement timing signal is input, and the measurement result is gained. The data is output to the control unit 506. The gain control unit 506 calculates an error between the measurement result measured by the transmission power measurement unit 504 and the target transmission power, and performs variable gain amplification based on a value obtained by averaging the error over a plurality of transmission slots. The gain of the unit 501 is corrected.

  The timer 505 generates a measurement timing signal having a fixed period synchronized with the transmission slot and supplies the measurement timing signal to the transmission power measurement unit 504. In the conventional radio transmission apparatus, as shown in FIG. 6A, the transmission power of the transmission output is determined in advance for each transmission slot, and in order to measure the transmission power in each transmission slot, As shown in (b), the timer 505 is synchronized with the transmission slot and is delayed by a fixed time τ from the beginning of the transmission slot so that the transmission power is measured at a stable time position, avoiding the transmission power change point. Periodic measurement timing signals v1, v2, v3, v4,.

  As a prior art document related to the present invention, a timing signal whose transmission power is stabilized is generated from a rise time of a transmission burst signal, a delay time of a low-pass filter, and the like. Patent Document 1 below describes a transmission power control circuit that controls transmission power by comparing with a reference value.

Automatic level control that controls transmission power by detecting transmission burst timing in the IF signal band, generating transmission power measurement timing based on the information, and comparing the transmission power of the measurement timing with a reference value The apparatus is described in Patent Document 2 below.
JP-A-11-112257 JP-A-6-326683

  As described above, in the conventional wireless transmission device, the timing at which the transmission power changes to the target value is determined in units of transmission slots determined in advance, and therefore the transmission power is measured while avoiding the transmission power change point. In this case, it was possible to measure the transmission power at a stable time position where the transmission power was constant by performing measurement at the time of outputting a periodic measurement timing signal delayed by a fixed time from the head of the transmission slot.

  However, in a wireless transmission device of HSDPA (High Speed Downlink Packet Access) system, as shown in FIGS. 2A and 2B, a plurality of transmission channels # 1, # having different timings at which transmission power changes respectively. 2, and a transmission signal obtained by combining the transmission signals of the plurality of channels is transmitted as a transmission output, as shown in FIG.

  Since the timing shift (offset) between the transmission slot of the transmission channel # 1 and the transmission slot of the transmission channel # 2 is not constant as shown as the offset T1 and the offset T2, as in the conventional wireless transmission apparatus, If the transmission power is measured with the periodic measurement timing signals v1, v2, v3, v4 of 6, the measurement may be performed at the power change point of the transmission output. The accuracy will deteriorate.

  The present invention provides a wireless transmission apparatus that performs burst transmission of a plurality of channels with different timings of radio frames (transmission slots) of transmission signals, such as HSDPA, by offsetting the radio frame (transmission slot) timing between channels. Even when a change point occurs in the transmission power within one radio frame (transmission slot), it is an object to accurately measure the transmission power.

  A radio transmission apparatus according to the present invention includes (1) a variable gain amplification unit that amplifies an input modulation signal, a transmission power measurement unit that measures transmission power of a transmission signal output from the variable gain amplification unit, and the transmission The gain of the variable gain amplifying unit is corrected based on the error between the measurement timing generating unit that instructs the measurement timing of the power measuring unit and the target power instructed by the transmission control unit and the transmission power measured by the transmission power measuring unit. In the wireless transmission device including the gain control unit, the measurement timing generation unit receives, from the transmission control unit, slot timing information indicating the timing of transmission power change in units of transmission slots of each transmission channel, and the slot Based on the timing information, means for calculating the timing of the transmission power change point obtained by combining the transmission signals of the respective transmission channels, and the time position not including the transmission power change point Characterized by comprising a means for outputting a measurement timing signal to instruct the measurement timing in the transmission power measuring unit.

  Further, (2) the measurement timing generation unit inputs gain information including information on the transmission power and the target power measured by the transmission power measurement unit or information on the difference, and based on the gain information, Means for calculating a transient response section of the output of the variable gain amplifier, and means for outputting a measurement timing signal indicating a time position not including the transient response section as a measurement timing to the transmission power measuring section. Features.

  (3) In the wireless transmission device using a timer that instructs the measurement timing of the fixed period as the measurement timing generation unit of (1), the gain control unit may change the transmission power of each transmission channel in the transmission slot unit. Slot timing information indicating the timing of the transmission power is input from the transmission control unit, and based on the slot timing information, means for calculating the timing of the transmission power change point by combining the transmission signals of the respective transmission channels, and Means for discarding the measurement result of the transmission power measured at the time position including the change point, and calculating the error based on the measurement result of the transmission power measured at the time position not including the change point of the transmission power; It is characterized by having.

  In the wireless transmission power control method of the present invention, (4) the input modulation signal is amplified by the variable gain amplification unit, and the transmission power of the transmission signal output from the variable gain amplification unit is measured by the measurement timing generation unit. Based on the error between the target power instructed by the transmission control unit and the transmission power measured by the transmission power measurement unit at the instructed timing, the gain of the variable gain amplification unit is determined as a gain control unit. In the CDMA transmission power control method corrected by the above, in the measurement timing generation unit, slot timing information indicating the timing of transmission power change in units of transmission slots of each transmission channel is input from the transmission control unit, and the slot timing information is On the basis of the process of calculating the timing of the transmission power change point by combining the transmission signals of the respective transmission channels, and the change point of the transmission power. Characterized in that it comprises a step of outputting to the transmission power measurement unit measuring timing signal indicating the no time position as a measurement timing.

  (5) In the CDMA transmission power control method for measuring transmission power at a fixed cycle measurement timing output from a timer, instead of the measurement timing generation unit in (4), the gain control unit Slot timing information indicating the timing of transmission power change for each transmission slot is input from the transmission control unit, and based on the slot timing information, the timing of the transmission power change point obtained by combining the transmission signals of the respective transmission channels is calculated. And discarding the measurement result of the transmission power measured at the time position including the transmission power change point, based on the measurement result of the transmission power measured at the time position not including the transmission power change point, The method includes calculating the error.

  According to the present invention, based on transmission timing information of a plurality of channels having different radio frame (transmission slot) timings, the measurement timing is adaptively changed in a section where the transmission power is stable, and other than the transmission power change point. By generating the measurement timing signal so that the transmission power is measured in a section where the transmission power is constant, the transmission power can be measured with high accuracy, and the accuracy of the transmission power control can be improved.

  Further, a transient response section of the output of the variable gain amplifier is calculated based on the gain information including the measurement value of the transmission power and the target value or information on the difference thereof, and the transmission power is transmitted in a stable section of the transmission power not including the transient response section. By generating the measurement timing signal so as to measure the transmission power, the transmission power can be measured with high accuracy, and the accuracy of the transmission power control can be improved.

  Further, the transmission power measurement is periodically performed in synchronization with the transmission slot timing, the transmission power change point is calculated based on the transmission slot timing information, the transmission power measurement value measured in the section including the transmission power change point is discarded, By using a transmission power value measured in a stable section of power that does not include a transmission power change point, an accurate transmission power value can be obtained, and the accuracy of transmission power control can be improved.

  FIG. 1 shows a configuration of a CDMA communication apparatus according to the present invention. As shown in the figure, in the present invention, slot timing information is input from the transmission control unit 101 to the measurement timing generation unit 102. The slot timing information is timing for each transmission slot at which the transmission power of each transmission channel is set and controlled to a target value, that is, transmission power change timing information.

  In addition, gain information is input from the gain control unit 506 to the measurement timing generation unit 102 in order to accurately calculate the transient response section of the output of the variable gain amplification unit 501. The gain information is information including the measurement value of the transmission power obtained from the transmission power measurement unit 504 and the information on the target value of transmission power obtained from the transmission control unit 101, or the difference information thereof.

  The measurement timing generation unit 102 calculates the transmission power change point and the transient response section of the variable gain amplification unit 501 associated with the transmission power change from the slot timing information and the gain information, so that the transmission power becomes stable. A measurement timing signal for the section is generated, and the measurement timing signal is input to the transmission power measurement unit 504.

  Here, the slot timing notified by the slot timing information (transmission power change timing) is not constant, and the measurement timing generation unit 102 adapts to the slot timing information that changes for each transmission slot, and changes the transmission power change point. A section that does not include is calculated and a measurement timing signal in the section is output.

  For example, for the offset T1 of the transmission channel # 2 shown in FIG. 2B, the measurement timing signals w1 and w2 at timings earlier than the transmission power change point by the transmission slot 201 are generated, and for the offset T2, The measurement timing signals w3 and w4 are generated at a timing delayed from the transmission power change point by the transmission slot 202.

  Whether the measurement timing signal is shifted forward or backward with respect to the transmission power change point is more stable in the stable section where the transmission power is constant in front of the change point and the stable section where the transmission power is constant behind the change point. An adaptive selection is made so that the measurement timing signal is generated in the longer section. It should be noted that the stable section where the transmission power is constant is calculated including the transient response section of the output of the variable gain amplifier 501.

  The transmission power measurement unit 504 performs transmission output power measurement in synchronization with the measurement timing signals w1, w2, w3, and w4 output from the measurement timing generation unit 102, thereby changing the transmission power as shown in FIG. It is possible to avoid the transient response section of the point and the output of the variable gain amplifying unit 501 and perform highly accurate power measurement in a section where the transmission power is constant and stable.

  The measurement result of the transmission power measured by the transmission power measurement unit 504 is input to the gain control unit 506, and the gain control unit 506 calculates an error between the measurement result of the transmission power and the target power, and a plurality of the errors are calculated. Based on the average value over the slot, the gain of the variable gain amplifying unit 501 is corrected. By so doing, it is possible to perform transmission power control with high accuracy in a wireless transmission device in which the timing of transmission slots is not constant.

  Moreover, it can be set as the structure shown in FIG. 3 as 2nd Embodiment different from the above-mentioned 1st Embodiment. In the second embodiment, as shown in FIG. 3, the transmission power measuring unit 504 is configured to transmit periodic measurement timing signals v1, v2, v3, which are output from the timer 505, similarly to the configuration shown in FIG. The transmission output power is measured in synchronization with v4,..., and the transmission output power measurement value is input to the gain control unit 302.

  The slot timing information is input from the transmission control unit 301 to the gain control unit 302. The gain control unit 302 calculates the power change point of the transmission output based on the slot timing information, and the transmission control power among the measured power values of the transmission output is transmitted. The measurement result measured in the section including the power change point is excluded, the error from the target power is calculated using the measurement result measured in the section not including the transmission power change point, and the error spans multiple slots. Based on the average value, the gain of the variable gain amplifier 501 is corrected.

  FIG. 4 shows a specific example of the transmission output power measurement timing according to the second embodiment. In the figure, the transmission channels # 1 and # 2 to be measured and the transmission output as a combined output thereof are shown in FIG. Of the transmission power measurement results measured with periodic measurement timing signals v1, v2, v3, and v4 that are delayed by a fixed time τ from the beginning of the transmission slot of transmission channel # 1, measurement is performed with the measurement timing signals of v1 and v2. Since the result is obtained by measuring the section including the transmission power change point, it is excluded, and the error is calculated using the measurement result of the measurement timing signals of v3 and v4 to correct the gain of the variable gain amplifier 501. .

It is a figure which shows the structure of the radio | wireless transmitter by this invention. It is a figure which shows the transmission output and power measurement timing in this invention. It is a figure which shows the structure of the radio | wireless transmitter of the 2nd Embodiment of this invention. It is a figure which shows the transmission output and electric power measurement timing of the 2nd Embodiment of this invention. It is a figure which shows the structure of the conventional radio | wireless transmitter. It is a figure which shows the conventional transmission output and electric power measurement timing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Transmission control part 102 Measurement timing signal generation part 501 Variable gain amplification part 502 Power amplification part 503 Coupler 504 Transmission power measurement part 506 Gain control part

Claims (5)

A variable gain amplifier for amplifying an input modulation signal;
A transmission power measuring unit that measures the transmission power of the transmission signal output from the variable gain amplification unit;
A measurement timing generation unit for instructing measurement timing of the transmission power measurement unit;
Based on the error between the target power instructed from the transmission control unit and the transmission power measured by the transmission power measurement unit, the gain control unit for correcting the gain of the variable gain amplification unit,
The measurement timing generation unit inputs slot timing information indicating the timing of transmission power change in transmission slot units of each transmission channel from the transmission control unit, and based on the slot timing information, transmits a transmission signal of each transmission channel. Means for calculating the timing of the combined transmission power change point, and means for outputting to the transmission power measurement unit a measurement timing signal instructing a time position not including the transmission power change point as a measurement timing. A wireless transmitter characterized by the above.   The measurement timing generation unit inputs gain information including information on the transmission power measured by the transmission power measurement unit and the target power or information on the difference thereof, and based on the gain information, the variable gain amplification unit 2. A means for calculating an output transient response section, and a means for outputting a measurement timing signal indicating a time position not including the transient response section as a measurement timing to the transmission power measuring section. The wireless transmission device according to 1. A variable gain amplifier for amplifying an input modulation signal;
A transmission power measuring unit that measures the transmission power of the transmission signal output from the variable gain amplification unit;
A timer for instructing a measurement timing of a fixed period to the transmission power measurement unit;
Based on the error between the target power instructed from the transmission control unit and the transmission power measured by the transmission power measurement unit, the gain control unit for correcting the gain of the variable gain amplification unit,
The gain control unit receives slot timing information indicating the transmission power change timing of each transmission channel in units of transmission slots from the transmission control unit, and synthesizes transmission signals of the transmission channels based on the slot timing information. The means for calculating the timing of the transmission power change point and the measurement result of the transmission power measured at the time position including the transmission power change point are discarded and measured at the time position not including the transmission power change point. And a means for calculating the error based on the measured transmission power. The input modulation signal is amplified by the variable gain amplification unit, and the transmission power of the transmission signal output from the variable gain amplification unit is measured by the transmission power measurement unit at the timing indicated by the measurement timing generation unit, and transmission control is performed. In the CDMA transmission power control method for correcting the gain of the variable gain amplification unit by the gain control unit based on the error between the target power instructed by the unit and the transmission power measured by the transmission power measurement unit,
The measurement timing generation unit inputs slot timing information indicating the timing of transmission power change for each transmission channel of each transmission channel from the transmission control unit, and based on the slot timing information, transmits a transmission signal of each transmission channel. Including a step of calculating a timing of a combined transmission power change point and a step of outputting a measurement timing signal indicating a time position not including the transmission power change point as a measurement timing to the transmission power measurement unit. A featured CDMA transmission power control method. The input modulation signal is amplified by the variable gain amplification unit, and the transmission power of the transmission signal output from the variable gain amplification unit is measured by the transmission power measurement unit at the fixed cycle measurement timing output from the timer, and transmitted. In the CDMA transmission power control method for correcting the gain of the variable gain amplifier by the gain controller based on the error between the target power instructed by the controller and the transmission power measured by the transmission power measuring unit,
In the gain control unit, slot timing information indicating the transmission power change timing of each transmission channel for each transmission slot is input from the transmission control unit, and based on the slot timing information, a transmission signal of each transmission channel is synthesized. The process of calculating the timing of the transmission power change point and the measurement result of the transmission power measured at the time position including the transmission power change point are discarded, and the measurement result is measured at the time position not including the transmission power change point. A CDMA transmission power control method, comprising: calculating the error based on the measured transmission power.

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