JP2002217828A - Transmission power controller and transmission power compression method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission power controller and a transmission power compression method therefor, by which the communication quality of the as a whole is improved in the case of suppressing transmission power from a base station device, in a radio communication system carried out by a TPC (transmission control protocol). SOLUTION: A plurality of calls included in a transmission signal are classified into a plurality of groups on the basis of line types. For example, the calls are classified into line-switching type calls and packet-switching type calls. Next, the power value of the transmission signal is suppressed below the maximum allowable input power value of a power amplifier by suppressing individually the power value of each of the groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention mainly relates to CDMA (C
ode Division MultipleAccess
The present invention relates to transmission power control in a wireless communication system adopting the ss) scheme, and particularly to transmission power control for performing transmission power compression control according to the line type of each channel when the transmission power of a base station device reaches a maximum allowable value. The present invention relates to an apparatus and a transmission power compression method thereof.

[0002]

2. Description of the Related Art In a radio communication system employing a CDMA system, channels are distinguished not by frequency but by code, and all users share the same frequency.

For example, when communication between a base station and a plurality of mobile stations is considered, in the above system, the communication capacity is determined by the transmission power of each mobile station since all mobile stations share the same frequency.

[0004] Here, if each mobile station transmits at a predetermined fixed power value, excessive transmission power will be used depending on the place where communication is performed, which is inefficient.

Therefore, in the conventional system, high-speed transmission power control (Tran) is performed in the uplink and downlink between the base station and the mobile station.
Spher Power Control (TPC) is performed to change the transmission power of each mobile station every moment. Specifically, the SIR (Signal / Inter) of the communication path
reference ratio; desired wave / interference wave power ratio)
Is measured, and the transmission power of each mobile station is controlled so that each call has a constant SIR.

In this control, a mobile station normally measures the SIR of a call used by itself, calculates a difference from a predetermined SIR (target SIR), and sets a TPC inserted in an uplink data header.
The request is transmitted by transmitting a transmission power increase / decrease request (TPC command) in the direction of reducing the difference to the base station using bits, and the base station increases / decreases the amplitude of the transmission signal according to the command.

[0007] By such transmission power control, each call is maintained at a constant SIR, and transmission with excessive transmission power exceeding the SIR is eliminated, thereby improving communication quality and channel efficiency.

[0008] Even in the above-mentioned TPC, a common control channel (Command Control Ch) is used.
The transmission power of a control channel that is commonly used by a large number of users, such as an antenna (CCCH), is kept constant.

[0009]

However, in the above-mentioned conventional transmission power control (TPC), when the amplitude of the transmission signal of each call is increased or decreased according to the TPC, the transmission power of the base station reaches the maximum allowable value. In addition, since the processing for uniformly and uniformly lowering the transmission power of the multiplexed transmission signal for all calls is performed, the requirements of each call cannot be reflected, and the communication quality of the entire system deteriorates. Occurs. Hereinafter, the problem will be described in detail with reference to FIGS.

First, focusing on the downlink from the base station to the mobile station, there is a limit on the transmission power that can be transmitted from the base station in terms of device performance, and if the number of connected mobile stations increases, the transmission power will inevitably increase. Therefore, it can be said that the power limit determines the number of connectable mobile stations. In any case, regardless of the number of mobile stations, as a result of increasing or decreasing the transmission power from the base station according to the TPC, the transmission power may reach a maximum allowable value that cannot be further increased.

[0011] Even under the above-mentioned situation, the TPC continues to function without change. Therefore, according to the TPC, the transmission power may exceed the maximum allowable value and a situation may occur in which the transmission amplifier may be damaged. Therefore, the conventional base station apparatus is provided with an excessive input suppression unit, which is a limiter, for example, at the preceding stage of the transmission amplifier, so that power exceeding an allowable value is not input to the transmission amplifier, and the transmission amplifier is protected from damage. Hereinafter, description will be made with reference to FIG.

FIG. 6 is a schematic configuration diagram showing only the components of the conventional transmission power control device 600 according to the present invention. Here, the transmission power control device is integrated into the base station device. Shall be. The transmission power control device 600 includes a plurality of (for example, N) baseband signal processing units 601, a transmission power control unit 602 provided at a subsequent stage of each baseband signal processing unit 601, and a baseband transmission signal of each call. Baseband signal multiplexing unit 60 for multiplexing
3, an excessive input suppression unit 604, for example, a limiter, a power amplifier 605, for example, an amplifier, and an antenna 606.
And

Each baseband signal processing section 601 performs baseband processing on user data to be transmitted for each call.

Each transmission power control section 602 applies an uplink (Up) to a transmission signal of each call subjected to baseband processing.
(Link; UL) to increase or decrease the amplitude based on the TPC command.

[0015] Baseband signal multiplexing section 603 multiplexes transmission signals of each call.

The over-input suppressing unit 604 is, for example, a limiter. In order to prevent the power amplifier 605 from being damaged, a signal having a power value equal to or larger than the input allowable power value of the power amplifier 605 is prevented from being input to the power amplifier 605. The amplitude of the multiplexed transmission signal is suppressed to a predetermined value or less.

The power amplifier 605 is, for example, an amplifier, and amplifies the multiplexed transmission signal with a constant gain. Antenna 606 radiates a transmission signal.

Next, FIG. 7 and FIG.
This will be described with reference to FIG. FIG. 7 is a graph schematically showing a case where the transmission power compression processing is not performed on an example of the base station transmission power. FIG. 8 is a graph showing the transmission power compression processing performed by the above-described conventional device on the example of the base station transmission power. 7 is a graph schematically showing a case in which is performed. Here, it is assumed that signals are to be transmitted for calls 1 to 5 and that the maximum allowable transmission power value of the base station apparatus is 10 on the vertical axis of the graph. Then, in FIG.
It can be seen that the maximum permissible values at 3 and 6 are exceeded.

As described above, the conventional apparatus collectively compresses the transmission power of the transmission signals for all the calls multiplexed in the preceding stage of the transmission amplifier, so that the transmission signals for all the calls are compressed as shown in FIG. The power is compressed evenly, ie at the same rate.

As described above, in the conventional device, since the amplitude of the entire transmission signal is collectively compressed, the quality of all calls is affected by deterioration. It is fair to say that reducing transmission power uniformly for all calls is a fair technique in one aspect.However, such a method that does not consider the line type of each call is not efficient as a system, and also as a communication service for users. And not kind.

For example, in the case of voice communication in which communication is performed by circuit switching due to a strict requirement for an allowable delay and a need for immediacy, it is practically difficult to compensate for quality deterioration by using means such as retransmission. In addition, if communication is interrupted due to quality degradation, serious problems may occur if the communication is urgent (for example, communication from an ambulance carrying a sick or injured person to a hospital).

As described above, in a wireless communication system accommodating a plurality of line types having various requirements in a single system, the transmission power of the entire transmission signal from the base station is collectively determined without considering the line types. The conventional method of lowering is not efficient (especially when a circuit-switched type call is included), and may lead to deterioration of communication quality when viewed as a whole system.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and in a wireless communication system in which TPC is performed, a system for controlling transmission power from a base station apparatus when it is necessary to suppress the transmission power. An object of the present invention is to provide a transmission power control device that improves the overall communication quality and a transmission power compression method thereof.

[0024]

According to a first aspect of the present invention, there is provided a transmission power control apparatus including a power amplifying means for amplifying a transmission signal, wherein the power value of an input signal to the power amplifying means is determined by the power amplifying means. A transmission power control device for a wireless communication device that performs control to suppress the input power value to be equal to or less than a maximum allowable input power value of an amplification unit, wherein a classification unit that classifies a plurality of calls included in a transmission signal into a plurality of groups, A power suppressing means for individually suppressing the power value to make the power value of the transmission signal equal to or less than the maximum allowable input power value is adopted.

In this configuration, each call is classified into a plurality of groups by, for example, providing a plurality of baseband signal multiplexing units for multiplexing a part of the transmission signal on a call basis, and arranging the transmission signal of each call to any one of the groups. This can be realized by inputting to the baseband signal multiplexing unit.

According to this configuration, when the transmission power from the base station must be compressed, it is possible to prevent the effect of the transmission power compression from affecting all calls.
Communication quality of the entire system can be improved.

[0027] In the transmission power control apparatus according to a second aspect of the present invention, in the first aspect, the power suppressing means sets an upper limit value of power for each of the groups, and sets the power value of each group to the upper limit value. It adopts a configuration that reduces it.

According to this configuration, the power can be easily suppressed by a device such as a limiter.

The transmission power control apparatus according to a third aspect of the present invention is the transmission power control apparatus according to the second aspect, wherein the classification means classifies the plurality of calls according to a degree of delay permitted by a line type of the call. It adopts the configuration to do.

[0030] In a transmission power control apparatus according to a fourth aspect of the present invention, in the second or the third aspect, the classification means may include:
A configuration is adopted in which the plurality of calls are classified into a call of a circuit switching type and a call of a packet switching type.

A transmission power control apparatus according to a fifth aspect of the present invention is the transmission power control apparatus according to any one of the second to fourth aspects,
The power suppressing means adopts a configuration in which the power upper limit value for a group consisting of packet-switched calls is set smaller than the power upper limit value for a group consisting of circuit-switched calls.

[0032] A transmission power control apparatus according to a sixth aspect of the present invention, in the fourth aspect, employs a configuration in which the power suppressing means reduces only the power value of a group consisting of packet-switched calls.

In these configurations, the degree of delay permitted by the line type can be rephrased as the degree of error tolerance. That is, the line type does not allow the deterioration of the communication quality, and thus the line type can be said to be relatively weak in error resistance, and the communication type can be said to be somewhat tolerable in the deterioration of communication quality and is relatively strong in error. There is a line type. The former is, for example, a circuit-switched call such as voice communication, and the latter is, for example, a packet-switched call such as data communication.

According to these configurations, when the transmission power of the base station apparatus must be compressed, grouping is performed in consideration of the line type of each call, so that error resistance is as low as possible. Only the transmission power of a group consisting of strong calls (for example, packet-switched calls represented by data communication) is suppressed, and calls with relatively low error tolerance (for example, circuit-switched calls represented by voice communication) By suppressing the transmission power of the group consisting of the calls of (a) and (b) as much as possible, it is possible to prevent the communication quality of a call having relatively low tolerance to errors due to transmission power compression from deteriorating.

A transmission power control apparatus according to a seventh aspect of the present invention is the transmission power control apparatus according to any one of the second to sixth aspects,
The power suppressing means employs a configuration in which the power upper limit value for each group is changed according to a change in the number of calls included in the transmission signal and a change in the line type.

In this configuration, the power upper limit can be changed by, for example, using a limiter whose threshold (upper limit) can be changed by external control and changing the threshold according to the line type.

According to this configuration, even if the number of calls constituting the transmission signal and the line type are changed, it is possible to adaptively perform grouping according to the line type.

[0038] In the transmission power control apparatus according to an eighth aspect of the present invention, in the first aspect, the classification means may be configured to divide the plurality of calls into each call to a degree of delay allowed by the line type of the call. Classification is performed based on the priority set accordingly, and the power suppression unit employs a configuration in which the power value of each group is compressed at an individual compression ratio.

[0039] In a transmission power control apparatus according to a ninth aspect of the present invention, in the eighth aspect, the classification means sets a lower level of priority for a call of a line type having a larger allowable delay. The power compression unit may be configured to set the power value of the transmission signal to be equal to or less than the maximum allowable input power value and to determine the compression rate based on the priority such that the lower the priority is, the higher the compression rate is. take.

According to these configurations, line types can be classified more finely without making the device configuration complicated and large-scale, and transmission power compression reflecting the characteristics of each call can be realized. As a result, the communication quality of the entire system is improved.

Further, by compressing a call of a line type having a larger degree of allowable delay at a higher compression rate, it is possible to compress transmission power while maintaining communication quality of a call that does not allow delay.

[0042] In a transmission power control apparatus according to a tenth aspect of the present invention, in the ninth aspect, in the ninth aspect, the classifying means sets a priority of at least one level from the higher priority. The power value of the call is not compressed.

According to this configuration, when the transmission power is compressed, the power value of the high priority call, that is, the call whose communication quality is not allowed to deteriorate, is always maintained. No quality deterioration occurs.

A base station apparatus of a radio communication system according to an eleventh aspect of the present invention employs a configuration having the transmission power control apparatus according to any one of the first to tenth aspects.

According to this configuration, when it is necessary to compress the transmission power from the base station apparatus, it is possible to prevent the influence of the transmission power compression from being applied to all the calls, and to prevent the call quality from deteriorating. Since communication quality can be maintained, communication quality of the entire system can be improved.

A transmission power compression method according to a twelfth aspect of the present invention includes a power amplifying means for amplifying a transmission signal, and the power value of an input signal to the power amplifying means is set to a maximum allowable input of the power amplifying means. What is claimed is: 1. A transmission power control device for a wireless communication device for performing control to suppress power to a value equal to or less than a power value, comprising: a classification step of classifying a plurality of calls included in a transmission signal into a plurality of groups; and individually suppressing a power value for each group. The power value of the transmission signal to be equal to or less than the maximum allowable input power value.

In this method, each call is classified into a plurality of groups by, for example, providing a plurality of baseband signal multiplexing sections for multiplexing a part of the transmission signal on a call-by-call basis. This can be realized by inputting to the baseband signal multiplexing unit.

According to this method, when it is necessary to compress the transmission power from the base station apparatus, it is possible to prevent the influence of the transmission power compression from affecting all calls.
Communication quality of the entire system can be improved.

[0049] A transmission power compression method according to a thirteenth aspect of the present invention is the transmission power compression method according to the twelfth aspect, wherein:
An upper limit of power is provided for each group, and a method of reducing the power value of each group to the upper limit is adopted.

According to this method, the power can be easily suppressed by a device such as a limiter.

[0051] In a transmission power compression method according to a fourteenth aspect of the present invention, in the thirteenth aspect, in the classification step, the plurality of calls are classified according to a degree of delay permitted by a line type of the call. Take the method of doing.

The transmission power compression method according to a fifteenth aspect of the present invention is the transmission power compression method according to the thirteenth or fourteenth aspect, wherein the classifying step includes the step of classifying the plurality of calls into calls whose circuit type is a circuit switching type. A method of classifying calls into packet-switched calls is adopted.

The transmission power compression method according to a sixteenth aspect of the present invention is the transmission power compression method according to any one of the thirteenth to fifteenth aspects, wherein the power suppressing step comprises: A method is adopted in which the value is set smaller than the power upper limit value of a group consisting of circuit-switched calls.

[0054] In a transmission power compression method according to a seventeenth aspect of the present invention, in the fifteenth aspect, the power suppressing step includes:
A method is adopted in which only the power value of a group consisting of packet-switched calls is reduced.

In these methods, the degree of delay permitted by the line type can be rephrased as the degree of error tolerance. That is, the line type does not allow the deterioration of the communication quality, and thus the line type can be said to be relatively weak in error resistance, and the communication type can be said to be somewhat tolerable in the deterioration of communication quality and is relatively strong in error. There is a line type. The former is, for example, a circuit-switched call such as voice communication, and the latter is, for example, a packet-switched call such as data communication.

According to these methods, when the transmission power of the base station apparatus has to be compressed, grouping is performed in consideration of the line type of each call. Only the transmission power of a group consisting of strong calls (for example, packet-switched calls represented by data communication) is suppressed, and calls with relatively low error tolerance (for example, circuit-switched calls represented by voice communication) By suppressing the transmission power of the group consisting of the calls of (a) and (b) as much as possible, it is possible to prevent the communication quality of a call having relatively low tolerance to errors due to transmission power compression from deteriorating.

[0057] In a transmission power compression method according to an eighteenth aspect of the present invention, in any one of the thirteenth to seventeenth aspects, the power suppressing step comprises the steps of: The method employs a method of changing the power upper limit value for each group according to the change of the power.

In this method, the change of the power upper limit can be realized, for example, by using a limiter whose threshold (upper limit) can be changed by external control and changing the threshold according to the line type.

According to this method, even if the number of calls constituting the transmission signal and the type of line change, the grouping can be adaptively performed according to the type of line.

[0060] In a transmission power compression method according to a nineteenth aspect of the present invention, in the twelfth aspect, in the twelfth aspect, the categorizing step includes the step of: Classification is performed based on the priorities set accordingly, and the power suppression step employs a method of compressing the power value of each group at an individual compression rate.

[0061] In the transmission power compression method according to a twentieth aspect of the present invention, in the nineteenth aspect, in the classifying step, a lower level of priority is set for a call of a line type having a larger allowable delay. The power compression step is a method of determining the compression rate based on the priority such that the power value of the transmission signal is equal to or less than the maximum allowable input power value, and the compression rate increases as the priority decreases. take.

According to these methods, it is possible to classify circuit types more finely without making the apparatus configuration complicated and large-scale, and to realize transmission power compression that reflects the characteristics of each call more. Therefore, the communication quality of the entire system can be improved.

Further, by compressing a call of a line type having a larger degree of allowable delay at a higher compression rate, it is possible to compress transmission power while maintaining communication quality of a call that does not allow delay.

[0064] In a transmission power compression method according to a twenty-first aspect of the present invention, in the twentieth aspect, in the classification step, a priority of at least one level within the higher priority is set. The power value of the call is not compressed.

According to this method, when the transmission power is compressed, the power value of the high priority call, that is, the call whose communication quality is not allowed to deteriorate, is always maintained. No quality deterioration occurs.

In the transmission power compression method according to a twenty-second aspect of the present invention, in the nineteenth aspect, in the classifying step, a lower-level priority is set for a call of a line type having a larger allowable delay. The power compression step sets the call to be reduced in order from the call having the lowest priority, and the transmission signal when the power value of the call to be reduced is reduced to the minimum power value at which the call can maintain synchronization. When the power value becomes equal to or less than the maximum allowable input power value, the setting of the call to be reduced is stopped, and the power value of the call other than the call having the highest priority among the calls to be reduced at the time of the stop. Is compressed to the minimum power value at which each call can maintain synchronization, and the power value of the call having the highest priority among the calls to be reduced at the time of the abort is equalized for each call and of the transmission signal. Power value below the maximum allowable input power value Adopt a method of compressing in that compression ratio.

According to this method, transmission power is compressed step by step from low priority calls, thereby realizing transmission power compression without compressing transmission power of high priority calls as much as possible. it can.

Also, for a call whose transmission power is compressed, the transmission power after compression is set to a minimum value such that synchronization is not lost with respect to the call, so that the minimum synchronization can be ensured even after transmission power compression. can do.

[0069]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The same components are denoted by the same reference numerals throughout the drawings.

(Embodiment 1) First, a transmission power control apparatus 100 and a transmission power compression method thereof according to Embodiment 1 of the present invention will be described using FIG. FIG. 1 is a schematic configuration diagram schematically showing a portion related to the present invention of transmission power control apparatus 100 according to Embodiment 1 of the present invention. Note that the transmission power control apparatus 100 according to the present embodiment is characterized by having a plurality of baseband signal multiplexing units, and as an example, is integrated in a base station apparatus in a wireless communication system.

First, the configuration will be described. The transmission power control device 100 includes a plurality of (here, for example, N) baseband signal processing units 101 and a plurality of baseband signal processing units 10.
1 and a distribution unit 103 for grouping the baseband transmission signals of each call into groups.
A plurality of (here, for example, two) baseband signal multiplexing sections 104 for multiplexing the baseband transmission signals of each grouped call for each group, and a plurality of baseband signal multiplexing sections 104 For example, an over-input suppression unit 105 that is a limiter and an over-input suppression control unit 106 that instructs a threshold (upper limit) in each over-input suppression unit 105.
Multiplexing unit 1 for multiplexing the output of each over-input suppressing unit 105
07, a power amplifier 108, for example, an amplifier, and an antenna 109.

The baseband signal processing section 101 performs baseband processing on user data to be transmitted for each call.

Each transmission power control section 102 transmits an uplink (Up) signal to a transmission signal of each call subjected to baseband processing.
(Link; UL) to increase or decrease the amplitude based on the TPC command.

The distribution unit 103 obtains information on the line type of each call from, for example, a radio network controller outside the apparatus, and classifies the input transmission signals of each channel into a plurality of groups based on the line type. , And output to a different baseband signal multiplexing unit 104 for each group. In the present embodiment, as an example, classification is made into two groups, and the classification criteria are based on whether the line type is a circuit-switched type or a packet-switched type.

Each baseband signal multiplexing section 104 multiplexes a plurality of input baseband transmission signals. In the present embodiment, as described above, for example, the transmission signal of each call is 2
It is assumed that two baseband signal multiplexing sections 104 are provided to classify the baseband signal into two groups. Although any number of baseband signal multiplexing units 104 can be provided, it is preferable that the number of baseband signal multiplexing units be two or more in view of the purpose of the present embodiment in which transmission signals of each call are classified into a plurality of groups.

The over-input suppressing section 105 is, for example, a limiter and is provided at a stage subsequent to each of the baseband signal multiplexing sections 104, and controls the amplitude of the input signal based on a threshold (upper limit) relating to the amplitude which can be controlled from the outside. Suppress below the threshold. In the present embodiment, the excess input suppression unit 105 suppresses the amplitude of the transmission signal multiplexed for each group with the threshold value specified by the excess input suppression control unit 106 as the upper limit.

The over-input suppression control unit 106 acquires information about the line type of each channel from, for example, a radio network control station outside the apparatus, and individually sets the threshold value in each over-input suppression unit 105 based on the line type. To instruct.

The determination of the threshold value by the over-input suppression control unit 106 is performed in order to protect the power amplifier 108 from damage.
Any method may be used as long as the amplitude of the transmission signal after being multiplexed by the multiplexing unit 107 with respect to the transmission signals of all calls is equal to or smaller than the allowable input value of the power amplifier 108. For example, if the allowable input power value of the power amplifier 108 is 1, the threshold value can be determined so that the power value of each group becomes 0.2 and 0.8.

In this embodiment, the excessive input suppression control unit 1
06 suppresses the amplitude as much as possible for the group to which the circuit-switched call is classified, and suppresses the transmission power by suppressing only the amplitude of the group to which the packet-switched call is classified, if possible. It is set to be equal to or less than the allowable input value of the power amplifier 108.

The multiplexing section 107 multiplexes the output of each over-input suppressing section 105 and outputs the multiplexed output to the power amplifier 108. Power amplifier 108 amplifies the multiplexed transmission signal with a constant gain. Antenna 107 radiates a transmission signal.

Next, the operation of transmission power control apparatus 100 according to the present embodiment will be described. The transmission signal of each call that has been subjected to baseband processing by each baseband signal processing unit 101 and subjected to TPC processing by each transmission power control unit 102 is input to any one baseband signal multiplexing unit 104 by the distribution unit 103. Are grouped into circuit-switched lines and packet-switched lines.

The transmission signals multiplexed for each group by baseband signal multiplexing section 104 are output to multiplexing section 107 after the amplitude is suppressed to below a threshold by excessive input suppressing section 105. The threshold is set to the excessive input suppression control unit 1
06 and may vary from group to group. That is, when transmission power from the base station apparatus must be suppressed (ie, when excessive input to the transmission amplifier occurs), transmission power compression processing can be performed at a different compression ratio for each group.

As described above, in the present embodiment, the transmission signal is divided into a plurality of groups for each call, and the transmission power is compressed for each group when excessive input occurs. Compression does not affect the transmission power of other groups. That is, the transmission power compression of some calls does not affect the transmission power of other calls, and the range affected by the transmission power compression is limited, so that the communication quality of all the calls is degraded by the transmission power compression. Can be prevented.

Thus, as in the above example, each call is grouped into a circuit-switched type and a packet-switched type on the basis of the line type, and when an excessive input occurs, transmission of the packet-switched group which is relatively resistant to errors is performed. Compress power only,
By not compressing the transmission power of a circuit-switched type group that requires immediacy and is not likely to degrade communication quality, transmission power can be reduced while maintaining the communication quality of a circuit-switched type call. it can.

In the above example, the case where calls are classified into two groups has been described, but the number of groups is arbitrary. For example, by providing four processing systems including a baseband signal multiplexing unit 104 and a subsequent over-input suppressing unit 105, the number of groups is set to four, so that circuit-switched calls can be used for more urgent voice communication and other communication. , The packet-switched call is further classified into those with a large delay time and those with a small delay time, and the compression rate of the transmission power is changed stepwise, so that finer control is possible.

(Embodiment 2) Next, a transmission power control apparatus 2 according to Embodiment 2 of the present invention will be described with reference to FIGS.
00 and its transmission power compression method will be described. FIG.
Is a transmission power control device 20 according to Embodiment 2 of the present invention.
FIG. 3 is a schematic configuration diagram schematically showing a portion related to the present invention of FIG. 3, and FIG. 3 is a flowchart showing a transmission power control method of a transmission power control device 200 according to Embodiment 2 of the present invention.
FIG. 4 is a detailed flowchart of the transmission power compression method of the transmission power control method. FIG. 5 is a diagram illustrating an example of the base station transmission power by the transmission power control apparatus 200 according to the present embodiment. It is a graph which shows the case where processing was performed typically. The transmission power control apparatus 200 according to the present embodiment is characterized in that the transmission power is compressed by performing weighting processing on the amplitude of the transmission signal of each call, and as an example, the transmission power control apparatus 200 is integrated in the base station apparatus in a wireless communication system. Shall be incorporated as

The present embodiment further advances the concept of grouping according to the first embodiment. That is,
In the first embodiment, when the number of groups is increased to perform control that more finely reflects the characteristics of each call, baseband signal multiplexing section 104 and subsequent over-input suppressing section 10
Since the number of systems consisting of five may be increased, mounting is easy, but there is a demerit that the configuration becomes large. Therefore, in the present embodiment, the priority based on the line characteristics is determined for each call, and the transmission power compression ratio of each call is determined according to the priority. The communication quality of a circuit-switched call is not degraded.

First, the transmission power control device 2 will be described with reference to FIG.
00 will be described. The same components as those in transmission power control apparatus 100 according to Embodiment 1 have the same reference numerals, and a detailed description thereof will be omitted. The transmission power control device 200 includes a plurality of (here, for example, N) baseband signal processing units 101 and each of the baseband signal processing units 10.
1; a transmission power control unit 102 provided at a subsequent stage; a power compression unit 201 for compressing transmission power of a transmission signal; a priority information control unit 206; a priority information storage unit 207, for example, a memory; A power amplifier 108;
The power compression unit 201 includes an antenna 109, a baseband signal storage unit 202 including at least a memory, a power compression control unit 203 that controls signal processing in the power compression unit 201, and a single unit that multiplexes an input signal. It includes one baseband signal multiplexing unit 204, an excessive input detection unit 205, and a weighting processing unit 208 that performs a weighting process based on the priority set for each call to the transmission signal of each call.

The baseband signal storage unit 202 includes at least a memory, stores the baseband signal of each call subjected to the baseband signal processing and the TPC processing, and according to the request of the power compression control unit 203, Outputs the data stored in.

The power compression control unit 203
1 is controlled, and the baseband signal of each call stored in the baseband signal storage unit 202 is stored in the over-input detection unit 2.
In response to the control signal from the control unit 05, the signal is output to the baseband signal multiplexing unit 204 or the weighting processing unit 208. The priority information control unit 206 requests the priority information, obtains the priority information from the priority information control unit 203, and outputs the
Information about the degree of over-input from step 05 is obtained, a weighting coefficient is calculated from the priority information and the degree of over-input, and the calculated weighting coefficient is output to the weighting processing unit 208. Further, the output destination of the baseband signal multiplexing unit 204 is changed according to the control signal from the excessive input detecting unit 205.

[0091] Baseband signal multiplexing section 204 multiplexes the input signal. Further, the output destination is switched between the excessive input detection unit 205 and the power amplifier 108 according to a control signal from the power compression control unit 203.

[0092] Over-input detection section 205 determines whether or not the transmission signal multiplexed by baseband signal multiplexing section 204 becomes over-input. That is, it is determined whether or not the amplitude value of the input transmission signal exceeds the allowable input value of the power amplifier 108. If the allowable input value is not exceeded, the excessive input detection unit 205 outputs the transmission signal to the power amplifier 108 as it is. If the allowable input value is exceeded, the excessive input detection unit 205
Notifies the power compression control unit 203 of the fact that an excessive input has been detected and the degree thereof (difference from the allowable input value).

The priority information control unit 206 acquires information on the priority determined for each call based on the line type and line characteristics of each channel from, for example, a radio network control station outside the apparatus, and is, for example, a memory. It is stored in the priority information storage unit 207. Also, in response to a request from the power compression control unit 203, the priority information is read from the priority information storage unit 207 and output to the power compression control unit 203.

[0094] Weighting processing section 208 performs weighting processing on the input transmission signal of each call with a weighting coefficient for each call instructed by power compression control section 203, and outputs the result to baseband signal multiplexing section 204.

Next, the transmission power compression method according to this embodiment will be described with reference to FIG.

The transmission signal of each call which has been subjected to baseband processing by each baseband signal processing section 101 and subjected to TPC processing by each transmission power control section 102 is temporarily stored in baseband signal storage section 202 and immediately subjected to power compression control. The signal is read out by the unit 203 and output to the baseband signal multiplexing unit 204 without weighting (S3).
01). At this time, the transmission signal is not output to weighting processing section 208, and the output destination of baseband signal multiplexing section 204 is set to excess input detection section 205 by a control signal from power compression control section 203.

Next, the unweighted transmission signal is multiplexed by the baseband signal multiplexing section 204 and output to the excess input detecting section (S302).

Next, whether the multiplexed transmission signal is in an over-input state is determined by the over-input detection section 205 (S303). If no excessive input is detected, the signal is output to the power amplifier 108 as it is (S308), and the processing for the transmission signal ends without performing power compression.

If an over-input is detected in S303, the over-input detection fact and the degree of the over-input detection
5 to the power compression control unit 203. The input signal to be detected is discarded and is not output to the power amplifier 108.

When the power compression control unit 203 is notified that an over-input has been detected, the priority information for each call is stored by the priority information control unit 206 in response to a request from the power compression control unit 203. It is read from the unit 207 and output to the power compression control unit 203 (S304).

Next, the power compression control unit 203
From the priority information and the degree of over-input transmitted from the over-input detection unit 205, a weighting coefficient for each call for preventing transmission power from being over-input by a weighting process for each call is calculated (S305). ). This calculation processing will be described later in detail.

When the weighting coefficient is calculated, the transmission signal stored in the baseband signal storage unit 202 where the excessive input is detected is read out again by the power compression control unit 203, and this time, Is output. At this time, the transmission signal is not output to baseband signal multiplexing section 204. Further, the weighting coefficient of each call calculated in S305 is output from power compression control section 203 to weighting processing section 208. The baseband signal multiplexing unit 2
The output destination of 04 is set in the power amplifier 108 by the control signal from the power compression control unit 203. Further, the power compression control unit 203 causes the baseband signal storage unit 202
The data relating to the transmission signal in the
2 is ready for the next data entry. Then, the weighting processing section 208 performs weighting processing on the transmission signal using the calculated weighting coefficient (S3).
06) Thus, individual transmission power compression for each call is realized.

The weighted transmission signal is output to baseband signal multiplexing section 204 and multiplexed (S30).
7) Output to the amplifier (S308), and the process ends.

Next, with reference to FIG.
An example of a weighting coefficient determination algorithm (corresponding to S304 and S305 in FIG. 3) performed by step S03 will be described. The algorithm according to the present embodiment is:
It is assumed that a call that does not degrade communication quality has a higher priority, and if transmission power must be compressed (when excessive input occurs), the transmission power of a call with a lower priority is compressed in order. Is characterized by determining a weighting coefficient.

A call with a high priority is a call of a line type having a low tolerance to errors, for example, a circuit-switched voice communication in which an allowable delay request is strict and immediacy is required.
A low-priority call is a call of a line type that is relatively resistant to errors. For example, packet-switched data communication that has a relatively large margin for delay requests due to having error correction means such as retransmission requests. And so on.

First, when an over-input is detected by the over-input detection unit 205 and transmitted to the power compression control unit 203 to that effect, the power compression control unit 203 starts a compression algorithm.

First, the power compression control section 203 stores the transmission signal in which the excessive input is detected in the baseband signal storage section 2.
02, and the power value of each call (that is, the amplitude of each call) is obtained from the transmission signal. Further, priority information for each call is obtained from the priority information control unit 206. And
The power compression control 203 creates a table relating to the priority and the power value for each call (S40).
1).

Next, the data in the table created in S401 is rearranged using the priority as a key (S401).
402), the priority of the call having the lowest priority at that time (not limited to one call) is set to the priority to be reduced (hereinafter, referred to as “priority Pri”).

Next, based on the information on the degree of over-input transmitted from over-input detection section 205, a reduction target indicating how much the transmission power of the transmission signal should be reduced to be below the maximum allowable value of the transmission amplifier. The electric energy _Pobj is calculated (S404).

Next, when the transmission power of all calls having the priority Pri is compressed to a minimum power value that does not cause synchronization, the compressed power amount is reduced to the target power amount _Pobj.
Is calculated and determined (S405).

When the determination result in S405 reaches the target reduction power amount _Pobj , it is understood that only the transmission signal of the call having the priority Pri at that time should be subjected to transmission power compression. Therefore, the transmission power of the call having the priority Pri at that time is changed by the power compression control unit 203,
A weighting factor is determined so that the target power consumption is reduced from each call of the priority Pri at an equal rate proportional to the power value of each call (S408).

If the determination result in S405 does not reach the target reduction power amount P _obj , the transmission power of the transmission signal of the call having the priority Pri at that time is set to the minimum power value that does not cause the synchronization to be lost. The table is updated to that effect (S406). After the table is updated, the "priority Pri" setting is released for the call for which the power value is set to the minimum value, and the call from which the "priority Pri" has been released is one step lower than the original priority. The priority of the call having the higher priority is newly set to "priority Pri" (S4).
07). Then, again in S404, the target reduction power amount P
_obj is recalculated. In the processing of S404 to S407, the determination result in S405 is that the reduction target power amount P
_It repeats until it reaches _obj .

The above algorithm is an example in the transmission power compression method according to the present embodiment, and is not limited to the above processing. For example, when a plurality of priorities are to be reduced, as in the above example, the transmission power to the call having the highest level of priority among the calls to be reduced is compressed at a uniform compression ratio, The transmission power of a call having a priority other than the highest level among the calls to be reduced can be compressed to the respective minimum values. However, the lower the priority of the call according to the priority level, the higher the compression ratio. May be compressed.

Further, in the above example, the case where the transmission power of the call having the priority Pri is set to the minimum power value that does not cause the synchronization to be lost has been described. However, the transmission power may be set to zero (zero). That is, when it is required to absolutely maintain the communication quality of a high priority call even when the transmission power capacity of the base station device is very imminent, the transmission is performed in ascending priority order. It is also possible to employ an algorithm for setting the power to zero, that is, disconnecting the line.

In any of the processing methods, by compressing the transmission power from the lower priority for each call as in the present embodiment, the call with the higher priority is not affected by the transmission power compression, and the communication quality is reduced. Does not deteriorate. It is clear that any number of priority levels and levels can be provided.

FIG. 5 shows an example of the processing result of the transmission power compression method according to the present embodiment. FIG. 5 shows a case where transmission power compression processing is performed by the transmission power control device 200 according to the present embodiment on the same example as the above-described example of the base station transmission power shown in FIG. 7 in order to facilitate comparison. FIG. Therefore, conditions;
5, the maximum allowable transmission power value of the base station apparatus is assumed to be 10 on the vertical axis of the graph, and the maximum allowable transmission power value exceeds the maximum allowable value at times 2, 3, and 6. It is assumed that this is the same as in the case of No. 7.

In FIG. 5, call 1 is the highest priority call, call 5 is the lowest priority call,
It is assumed that calls 2 to 4 are all calls of the same level of intermediate priority.

Under such an assumption, in FIG. 5, at times 2 and 3, only the transmission power of call 5 is compressed, so that the total transmission power falls to 10 or less. On the other hand, at the time 6, the total transmission power does not fall below 10 by simply compressing the transmission power of the call 5,
After setting the transmission power to the call to the minimum value, the transmission powers of the lower priority calls 2 to 4 are evenly compressed. At any time, the transmission power of the call 1 having the highest priority is constant, and is not affected by the transmission power compression. That is, communication quality is maintained.

Although the embodiments of the present invention have been described above, the transmission power control apparatus according to the present invention is not limited to the mode in which the transmission power control apparatus is integrally incorporated in the base station apparatus as in the above-described example. It can be located anywhere on the system as long as it controls the transmission power of the device.

Further, the present invention is not limited to the CDMA system as described above, and is not limited to the FDMA (Frequen
cy Division Multiple Access
ss) method or TDMA (Time Division)
In the Multiple Access method, the present invention is also applicable to a case where a technique called so-called common amplification, in which a plurality of signals transmitted from different radio frequencies are combined and amplified collectively, is applied.

[0121]

As described above, according to the transmission power control apparatus according to the first aspect of the present invention, when the transmission power from the base station apparatus must be compressed, the influence of the transmission power compression is reduced. Since all calls can be prevented, communication quality of the entire system can be improved.

Further, according to the transmission power control device of the second aspect of the present invention, the power can be easily suppressed by a device such as a limiter.

Further, according to the transmission power control apparatus according to claims 3 to 6 of the present invention, when the transmission power of the base station apparatus has to be compressed, the transmission power of the base station apparatus should be considered in consideration of the line type of each call. In order to perform the division, only the transmission power of a group consisting of calls that are relatively resistant to errors (eg, packet-switched calls) is suppressed as much as possible, and calls that are relatively weak against errors (eg, circuit-switched calls) are suppressed. By minimizing the transmission power of the group consisting of (call) as much as possible, it is possible to prevent the transmission quality from deteriorating the communication quality of the call having relatively weak error resistance due to transmission power compression.

Further, according to the transmission power control apparatus of the present invention, even if the number of calls constituting the transmission signal and the line type are changed, the groups are adaptively classified according to the line type. Can be.

Further, according to the transmission power control apparatus according to claims 8 and 9 of the present invention, it is possible to classify the line types more finely without making the apparatus configuration complicated and large-scale.
Since transmission power compression reflecting the characteristics of each call can be realized, communication quality of the entire system is improved.
Also, by compressing a call of a line type having a larger allowable delay with a higher compression ratio, the transmission power can be compressed while maintaining the communication quality of a call that does not allow a delay.

Further, according to the transmission power control apparatus according to the tenth aspect of the present invention, when compressing the transmission power, the power value of the high priority call, that is, the call for which the deterioration of the communication quality is not allowed, is always maintained. Therefore, the communication quality of the call does not deteriorate due to transmission power compression.

Further, according to the base station apparatus of the radio communication system according to the eleventh aspect of the present invention, when the transmission power from the base station apparatus must be compressed, the influence of the transmission power compression affects all calls. The communication quality of the entire system is improved because the communication quality of a call that does not want to degrade the communication quality can be maintained.

Further, according to the transmission power compression method according to the twelfth aspect of the present invention, when the transmission power from the base station apparatus must be compressed, the effect of the transmission power compression affects all calls. Therefore, the communication quality of the entire system can be improved.

Further, according to the transmission power compression method according to the thirteenth aspect of the present invention, the power can be easily suppressed by a device such as a limiter.

Further, according to the transmission power compression method according to the fourteenth to seventeenth aspects of the present invention, when the transmission power of the base station apparatus has to be compressed, the transmission power of the base station apparatus is taken into consideration in consideration of the line type of each call. In order to perform the division, only the transmission power of a group consisting of calls that are relatively resistant to errors (eg, packet-switched calls) is suppressed as much as possible, and calls that are relatively weak against errors (eg, circuit-switched calls) are suppressed. Call)
By suppressing the transmission power of the group consisting of as much as possible, it is possible to prevent the transmission power compression from deteriorating the communication quality of a call that is relatively weak in error.

Further, according to the transmission power compression method according to claim 18 of the present invention, even if the number of calls constituting the transmission signal and the line type are changed, the grouping is adaptively performed according to the line type. Can be.

Further, according to the transmission power compression method according to the nineteenth and twentieth aspects of the present invention, it is possible to classify the line types more finely without making the device configuration complicated and large-scale, Can be realized, so that the communication quality of the entire system can be improved. Also, by compressing a call of a line type having a larger degree of allowable delay at a higher compression ratio,
The transmission power can be compressed while maintaining the communication quality of a call that does not allow delay.

According to the transmission power compressing method of the present invention, when compressing the transmission power, the power value of the high-priority call, that is, the call whose communication quality is not allowed to deteriorate is always maintained. Therefore, the communication quality of the call does not deteriorate due to the transmission power compression.

Further, according to the transmission power compression method according to claim 22 of the present invention, the transmission power of a high priority call is compressed as much as possible by gradually compressing the transmission power from low priority calls. It is possible to achieve transmission power compression without performing the above. Also, for a call whose transmission power is compressed, by setting the transmission power after compression to a minimum value that does not cause synchronization loss for the call, it is possible to ensure the minimum synchronization even after the transmission power is compressed. it can.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a transmission power control device 100 according to Embodiment 1 of the present invention.

FIG. 2 is a schematic configuration diagram of a transmission power control device 200 according to Embodiment 2 of the present invention.

FIG. 3 is a flowchart showing a transmission power control method of transmission power control apparatus 200 according to Embodiment 2 of the present invention.

FIG. 4 is a detailed flow chart of a transmission power compression method among transmission power control methods of transmission power control apparatus 200 according to Embodiment 2 of the present invention.

FIG. 5 is a graph schematically showing a case where transmission power compression processing is performed by the transmission power control device 200 according to the present embodiment for an example of base station transmission power.

FIG. 6 is a schematic configuration diagram showing only components of the conventional transmission power control device 600 according to the present invention.

FIG. 7 is a graph schematically showing a case where transmission power compression processing is not performed on an example of base station transmission power.

FIG. 8 is a graph schematically showing a case where a transmission power compression process is performed on the example of the base station transmission power by the conventional device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 transmission power control device 101 baseband signal processing unit 102 transmission power control unit 103 distribution unit 104 baseband signal multiplexing unit 105 over input suppression unit 106 over input suppression control unit 107 multiplexing unit 108 power amplifier 109 antenna 200 transmission power control device 201 Power compression section 202 Baseband signal storage section 203 Power compression control section 204 Baseband signal multiplexing section 205 Excessive input detection section 206 Priority information control section 207 Priority information storage section 208 Weighting processing section

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Seigura Onoe NTT Docomo, 2-1-1-1, Nagatacho, Chiyoda-ku, Tokyo (72) Inventor Takehiro Nakamura Machiji Nagata, Chiyoda-ku, Tokyo No. 11-1, NTT Docomo Co., Ltd. (72) Inventor Mikio Iwamura 2-1-1, Nagatacho, Chiyoda-ku, Tokyo, Japan NTT Docomo Co., Ltd. (72) Inventor Yoshiaki Ohto 2-11-1, Nagatacho, Chiyoda-ku, Tokyo F-term in NTT Docomo (reference) 5K022 EE01 EE21 5K060 CC04 CC11 DD04 FF06 HH06 HH32 HH39 LL01 5K067 AA03 AA23 CC10 DD11 EE02 EE08 GG

Claims (22)

[Claims] 1. A wireless communication apparatus comprising: a power amplifying means for amplifying a transmission signal; and performing control for suppressing a power value of an input signal to the power amplifying means to be equal to or less than a maximum allowable input power value of the power amplifying means. A transmission power control device, comprising: a classifying unit that classifies a plurality of calls included in a transmission signal into a plurality of groups; and individually suppressing power values of the respective groups to allow the power value of the transmission signal to be equal to the maximum allowable value. A transmission power control device, comprising: a power suppression unit that controls the input power value to be equal to or less than the input power value. 2. The transmission power control apparatus according to claim 1, wherein said power suppressing means sets an upper limit value of power for each group, and reduces the power value of each group to the upper limit value. 3. The transmission power control apparatus according to claim 2, wherein said classification means classifies said plurality of calls according to a degree of delay allowed by a line type of said call. 4. The transmission according to claim 2, wherein the classifying means classifies the plurality of calls into a call of which circuit type is a circuit-switched type and a call of a packet-switched type. Power control device. 5. The power limiter according to claim 1, wherein the power upper limit for a group of packet-switched calls is set smaller than the power upper limit of a group of circuit-switched calls. 5. The transmission power control device according to any one of 2 to 4. 6. The transmission power control device according to claim 4, wherein said power suppression means reduces only the power value of a group consisting of packet-switched calls. 7. The power limiter according to claim 2, wherein the power suppression unit changes the power upper limit value for each group according to a change in the number of calls included in a transmission signal and a change in the line type. A transmission power control device according to one of the claims. 8. The classifying unit classifies the plurality of calls based on a priority set according to a degree of delay permitted by a line type of the call for each call, The transmission power control device according to claim 1, wherein the power value of each group is compressed at an individual compression rate. 9. The classifying means sets a lower priority level for a call of a line type having a larger allowable delay, and the power compressing means sets a power value of the transmission signal to the maximum allowable input power value. 9. The transmission power control device according to claim 8, wherein the compression ratio is determined based on the priority such that the lower the priority, the higher the compression ratio. 10. The transmission power according to claim 9, wherein said classifying means does not compress the power value of a call for which a priority of at least one level within the higher priority is set. Control device. 11. A base station apparatus for a wireless communication system, comprising the transmission power control apparatus according to claim 1. 12. A wireless communication apparatus having a power amplifying means for amplifying a transmission signal and performing control for suppressing a power value of an input signal to the power amplifying means to a maximum allowable input power value of the power amplifying means or less. A transmission power control apparatus, comprising: a classification step of classifying a plurality of calls included in a transmission signal into a plurality of groups; and individually controlling power values of the groups to allow the power value of the transmission signal to be equal to the maximum allowable value. A transmission power compression method, comprising: a power suppression step of setting the input power value to a value or less. 13. The transmission power compression method according to claim 12, wherein in the power suppressing step, an upper limit value of power is provided for each group, and the power value of each group is reduced to the upper limit value. 14. The transmission power compression method according to claim 13, wherein said classifying step classifies said plurality of calls according to a degree of delay allowed by a line type of said call. 15. The transmission according to claim 13, wherein the classifying step classifies the plurality of calls into a call of which circuit type is a circuit switching type and a call of a packet switching type. Power compression method. 16. The power limiting step according to claim 1, wherein the upper limit of power for a group of packet-switched calls is set smaller than the upper limit of power for a group of circuit-switched calls. 16. The transmission power compression method according to any one of 13 to 15. 17. The transmission power compression method according to claim 15, wherein said power suppressing step reduces only the power value of a group consisting of packet-switched calls. 18. The power limiting step according to claim 13, wherein the power upper limit value for each group is changed according to a change in the number of calls included in a transmission signal and a change in the line type. A transmission power compression method according to claim 1. 19. The classifying step classifies the plurality of calls on the basis of a priority set according to a degree of delay permitted by a line type of the call for each call, The transmission power compression method according to claim 12, wherein the power value of each group is compressed at an individual compression rate. 20. The classifying step, wherein a lower level of priority is set for a call of a line type having a larger allowable delay, and the power compressing step sets the power value of the transmission signal to the maximum allowable input power value. 20. The transmission power compression method according to claim 19, wherein the compression ratio is determined based on the priority so that the compression ratio becomes higher as the priority becomes lower. 21. The transmission power according to claim 20, wherein the classification step does not compress a power value of a call for which a priority within at least one level from the higher priority is set. Compression method. 22. The classifying step sets a lower priority level for a call of a line type having a larger allowable delay, and the power compressing step sets the calls having the lowest priority in the order of the call to be reduced in order from the call having the lowest priority. Setting, the power value of the transmission signal when the power value of the call to be reduced is reduced to the minimum power value at which the call can maintain synchronization becomes equal to or less than the maximum allowable input power value. Suspending the call setup, compressing the power values of the calls other than the call having the highest priority among the reduction target calls at the time of the suspension to the minimum power value that allows each call to maintain synchronization, Compressing the power value of the call having the highest priority among the reduction target calls at the time of suspension at a compression rate that is equal for each call and the power value of the transmission signal is equal to or less than the maximum allowable input power value. 20. The transmission power pressure according to claim 19, wherein: Method.