JP2004129085A - Radio communication system, communication terminal, base station, and control information notification method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To notify data information in an up link and perform scheduling operation at a good resource efficiency on the basis of the notified data information in up-link packet communication. <P>SOLUTION: A data amount counter 101 counts the amount of communication data. In a CQI generator 102, a decider 203 determines a necessary rate based on the amount od transmission data. An estimator 201 estimates a line quality based on a transmission power value notified by a transmission ratio section 108. A rate decider 202 determines a transmittable rate based on the line quality. A marge calculator 204 calculates as a margin a differential value obtained by subtracting the communication quality for the necessary rate from a communication quality corresponding to the transmittable rate. A CQI selector 205 selects a CQI which a base station is informed of on the basis of the necessary rate and the margin. The selected CQI is subjected to predetermined transmission processing and then transmitted to the base station. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wireless communication system, a communication terminal device, a base station device, and a control information notification method, and is suitably applied, for example, to a notification unit of quality information or the like on an uplink.
[0002]
[Prior art]
Conventionally, HSDPA (High Speed Downlink Packet Access) has been known as a technique for transmitting packet data at high speed in a downlink. In HSDPA, one physical channel is shared and used by a plurality of communication terminal devices by time division. For this reason, the base station determines to which communication terminal device the information is to be transmitted at a certain time (hereinafter, referred to as “scheduling”) (for example, see Non-Patent Document 1).
[0003]
The scheduling is performed based on the amount of data to be transmitted from the base station apparatus to the communication terminal apparatus, the allowable delay time, the communication quality, and the like. For example, when there is a communication terminal device having a large amount of data to be transmitted or a communication terminal device having a short allowable delay time, it is conceivable to increase the number of codes to be allocated and increase the frequency. Further, it is conceivable to control the determination of the transmission rate in order to reduce the error rate, or to allocate a large number to communication terminal apparatuses having good communication quality in order to improve the throughput. As described above, the base station apparatus determines which communication terminal apparatus should transmit information preferentially.
[0004]
On the other hand, a transmission technique of packet data in an uplink is also being studied, and it is considered that a single physical channel is shared by a plurality of communication terminal apparatuses by time multiplexing or code multiplexing similarly to the downlink. For this reason, it is necessary to allocate which communication terminal apparatus transmits, and this allocation, that is, scheduling is performed on communication quality and the like (for example, information on transmission power under transmission power control and CQI (Channel Quality Indicator)). It is determined by the base station apparatus on the basis of this.
[0005]
Information on the determined scheduling is transmitted to each communication terminal device in communication, and the communication terminal device transmits packet data to the base station device based on the transmitted scheduling information.
[0006]
[Non-patent document 1]
"W-CDMA mobile communication system" supervised by Keiji Tachikawa, Maruzen Co., Ltd., June 25, 2001, p. 403
[0007]
[Problems to be solved by the invention]
However, conventionally, in uplink packet communication, if a communication terminal apparatus does not notify the base station apparatus of a data amount of data to be transmitted and an allowable delay time (hereinafter, these are collectively referred to as “data information”), Has a problem that data information cannot be recognized. For this reason, if the data information is not notified, the base station apparatus cannot perform scheduling in consideration of the data information. For example, when scheduling based on communication quality, despite the small amount of data to be transmitted by the communication terminal device, a large amount of resources may be allocated due to good communication quality, and resources may be efficiently allocated. May not be used. As a result, there is a possibility that the throughput may be reduced.
[0008]
The present invention has been made in view of the above, and discloses a wireless communication system, a base station device, a communication terminal device, and a control information notification method for performing scheduling using resources efficiently in uplink packet communication. The purpose is to provide.
[0009]
[Means for Solving the Problems]
To solve this problem, the wireless communication system of the present invention, the communication terminal device, based on the nature of the data to be transmitted, determines the lowest transmission rate among the transmission rates required to transmit data, The information indicating the surplus quality is transmitted to the base station device together with the information on the determined transmission rate, and the base station device is configured based on the information on the transmission rate transmitted from the communication terminal device and the information indicating the surplus quality. A configuration for performing scheduling is adopted.
[0010]
According to this configuration, since the base station apparatus performs scheduling based on the lowest transmission rate determined by the communication terminal apparatus, scheduling that efficiently uses resources can be performed based on the notified data information. .
[0011]
The communication terminal device according to the present invention includes a required rate determination unit that determines a lowest transmission rate among transmission rates required for transmitting data, based on a property of data to be transmitted, and information on the determined transmission rate. And a transmitting means for transmitting information indicating the surplus quality to the base station apparatus.
[0012]
According to this configuration, it is possible to make the property of data to be transmitted by the communication terminal device correspond to the information of the transmission rate, and notify the base station device together with the information indicating the channel quality.
[0013]
The communication terminal device of the present invention employs a configuration in which the required rate determining means determines the lowest transmission rate among the transmission rates required for transmission, based on the amount of data to be transmitted.
[0014]
According to this configuration, the amount of data to be transmitted by the communication terminal device can be notified to the base station device in association with the information on the transmission rate.
[0015]
The communication terminal device according to the present invention is characterized in that the required rate determination means determines the lowest transmission rate among transmission rates required for transmission when the allowable delay time of data to be transmitted is less than a predetermined value. take.
[0016]
According to this configuration, the allowable delay time of data to be transmitted by the communication terminal apparatus can be notified to the base station apparatus in association with the information on the transmission rate.
[0017]
The communication terminal apparatus according to the present invention employs a configuration in which the required rate determining means determines a transmission rate required to complete data transmission within an allowable delay time of data to be transmitted.
[0018]
According to this configuration, by notifying the base station apparatus of the information on the transmission rate required to complete the data transmission within the allowable delay time, it is difficult to allocate the scheduling in the base station apparatus and a delay occurs. In such a case, the delay can be avoided.
[0019]
The base station apparatus according to the present invention employs a configuration including scheduling means for performing scheduling based on information on the transmission rate and information indicating the surplus quality transmitted from any of the communication terminal apparatuses having the above configuration.
[0020]
According to this configuration, the base station apparatus performs scheduling based on the information on the transmission rate transmitted from the communication terminal apparatus and the information indicating the surplus quality, so that the base station apparatus can efficiently perform the priority based on the communication quality. Resources can be used.
[0021]
The base station apparatus of the present invention employs a configuration in which the scheduling means performs scheduling for allocating a higher transmission rate exceeding the transmission rate indicated by the information on the transmission rate, based on the information indicated by the surplus quality transmitted from the communication terminal apparatus. .
[0022]
According to this configuration, it is possible to allocate resources corresponding to the maximum possible transmission rate based on communication quality, instead of allocating resources corresponding to the transmission rate requested by the communication terminal device.
[0023]
In the control information notification method of the present invention, the communication terminal apparatus determines a lowest transmission rate among transmission rates required for transmitting data based on a property of data to be transmitted, and a determining step. Transmitting the information representing the surplus quality to the base station device together with the information of the transmission rate, the base station device, the information of the transmission rate and the information representing the surplus quality transmitted from the communication terminal device And a scheduling step of performing scheduling based on the scheduling.
[0024]
According to this method, since the base station apparatus performs scheduling based on the lowest transmission rate determined by the communication terminal apparatus, scheduling that efficiently uses resources can be performed based on the notified data information. .
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
The essence of the present invention is to determine the minimum transmission rate necessary for data to be transmitted by the communication terminal device in uplink packet communication, and to transmit information indicating the surplus quality to the base station device together with information on the determined transmission rate. Notifying, and the base station apparatus performs scheduling based on the notified information. Thereby, data information transmitted by the communication terminal device can be considered, and scheduling using resources efficiently can be performed. In the embodiment of the present invention, the communication terminal apparatus uses the CQI to notify the base station apparatus of the information on the transmission rate and the information on the surplus quality. However, the present invention is not limited to this. Alternatively, the notification may be made using information in place of.
[0026]
(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a communication terminal device 100 according to Embodiment 1 of the present invention. In this figure, the transmission system will be described first.
[0027]
The data amount counting unit 101 counts the data amount of the transmission data, and notifies the CQI generation unit 102 of the counted data amount.
[0028]
The CQI generation unit 102 determines a CQI (Channel Quality Indicator) in consideration of the data amount of the transmission data notified from the data amount counting unit 101 and a transmission power value notified from the transmission wireless unit 108 described later. The CQI represents a transmission rate reflecting communication quality, and can represent several transmission rates by a combination of the number of used codes, a modulation method, a coding rate, and the like. That is, the communication terminal apparatus estimates the uplink quality based on the transmission power of the uplink control channel whose transmission power is controlled, and notifies the base station apparatus using the CQI of the transmission rate at which transmission is possible with the estimated channel quality. Things. The estimation of the channel quality is not limited to this, and any channel quality can be estimated.
[0029]
In the CQI according to the present embodiment, the transmission rate and the amount of data to be transmitted are associated with each CQI value, and a table that is a correspondence table is held in the CQI generation unit. CQI generating section 102 determines a CQI value based on this table, and outputs the determined CQI value to transmission packet generating section 104. Details of the CQI generation unit 102 will be described later.
[0030]
The buffer 103 temporarily holds the input transmission data, and outputs the held data to the transmission packet generation unit 104 based on the scheduling information output from the report value extraction unit 113 described later. The transmission packet generation unit 104 is configured into transmission packet transmission units based on the transmission data output from the buffer 103, and then outputs the data to the encoding unit 105. Similarly, the CQI value output from CQI generating section 102 is also output to encoding section 105 after having a configuration necessary for transmission.
[0031]
After the transmission data output from the transmission packet generation unit 104 is encoded by the encoding unit 105, the modulation unit 106 performs modulation processing. The modulated transmission data is output to spreading section 107. Here, coding section 105 and modulation section 106 perform coding processing and modulation processing at the coding rate and modulation scheme indicated by MCS allocation information output from report value extraction section 113 described later, respectively.
[0032]
Spreading section 107 spreads the transmission data output from modulation section 106. The spread transmission data is output to transmission radio section 108, subjected to predetermined radio processing (up-conversion, D / A conversion, etc.), and transmitted to the base station apparatus via antenna AN. In addition, the value of the transmission power of the control channel subjected to the transmission power control, which is processed by the wireless transmission unit 108, is notified to the CQI generation unit 102.
[0033]
Next, the receiving system of the communication terminal device 100 will be described. In communication terminal apparatus 100, reception radio section 109 receives a signal transmitted from the base station apparatus via antenna AN. The reception radio section 109 performs predetermined radio processing (down conversion, A / D conversion, etc.) on a signal (reception signal) received via the antenna AN. The signal after the radio processing is output to despreading section 110. Despreading section 110 despreads the received signal output from receiving radio section 109 using a spreading code, and demodulates the signal after despreading in demodulating section 111. The demodulated received signal is output to decoding section 112. Decoding section 112 decodes the received signal demodulated by demodulation section 111, and outputs the result to report value extraction section 113.
[0034]
Report value extracting section 113 extracts a report value reported by the base station apparatus from the decoded received data. The extracted report value includes scheduling information and MCS allocation information. The scheduling information is output to the buffer 103, and the MCS allocation information is output to the coding unit 105 and the modulation unit 106. Here, the scheduling information is information indicating permission to transmit packet data to the communication terminal device. The MCS allocation information is information for determining a coding rate and a modulation scheme. Here, the MCS allocation information will be described as information for determining a modulation scheme and a coding rate, but the present invention is not limited to this, and may be any parameter related to a transmission rate determined by the base station apparatus.
[0035]
Next, details of CQI generation section 102 will be described. FIG. 2 is a block diagram showing an internal configuration of CQI generation section 102 according to Embodiment 1 of the present invention. In this figure, channel quality estimating section 201 estimates uplink quality based on the transmission power value notified from transmitting radio section 108, and notifies the transmittable rate determining section 202 of the estimation result.
[0036]
Transmittable rate determining section 202 determines a transmission rate that can be realized with the uplink quality estimated by channel quality estimating section 201. That is, if the line quality is good, it is possible to increase the transmission rate, and if the line quality is bad, it is necessary to lower the transmission rate. From this, it can be said that the transmission rate and the line quality generally correspond. Here, the maximum transmission rate among the transmission rates that are equal to or lower than a predetermined error rate is determined. Since the determined transmission rate is determined from the transmission rates set in the communication terminal device 100, the determined transmission rate roughly indicates the line quality. The determined transmittable rate is notified to margin calculating section 204.
[0037]
The required rate determination unit 203 determines a required transmission rate for the amount of data waiting for transmission output from the data amount counting unit 101. That is, when transmitting data with a large data amount, transmission at a low transmission rate requires a long time until transmission is completed. Therefore, transmission at a high transmission rate at which transmission is possible is more efficient. Also, transmitting data with a small amount of data at an unnecessarily high transmission rate requires a lot of resources, thereby lowering the throughput. The required rate determining unit 203 also determines the required rate from the transmission rates set in the communication terminal device 100, similarly to the transmittable rate determining unit 202. The determined required rate is notified to the margin calculation unit 204.
[0038]
The margin calculation unit 204 determines whether the required rate determined based on the amount of data to be transmitted is equal to or less than the transmittable rate determined based on the channel quality. If the required rate is equal to or less than the transmittable rate, a difference obtained by subtracting the communication quality corresponding to the required rate from the communication quality corresponding to the transmittable rate, that is, how much margin as surplus quality is calculated. . The calculated margin is notified to the CQI selection unit. In the present embodiment, when the required rate exceeds the transmittable rate, only the transmittable rate is notified to the base station apparatus, so that the margin is not calculated.
[0039]
CQI selection section 205 has a table as shown in FIG. 3, and the base station apparatus has the same table. In this table, CQI values are set to 0 to 34, and the number of codes, modulation scheme, coding rate, and margin are associated with each CQI value. CQI selecting section 205 selects a CQI based on the required rate notified from required rate determining section 203 and the margin notified from margin calculating section 204. Here, since the selected CQI includes information on a required rate and a margin, the actual channel quality of the communication terminal apparatus 100 can be roughly represented from the communication quality indicated by the information. Here, the value of the margin indicates how high the actual quality is (surplus quality) than the transmittable rate.
The selected CQI value is output to transmission packet generating section 104.
[0040]
FIG. 4 is a block diagram showing a configuration of base station apparatus 400 according to Embodiment 1 of the present invention. In this figure, the transmission system will be described first.
[0041]
The CQI extracting section 401 has a table shown in FIG. 3, and extracts a CQI from received data decoded by a decoding section 413 described later. In the table of FIG. 3, the communication quality is improved as the CQI value goes from 0 to 34, and the priority assigned by the scheduler unit 402 described later increases as the CQI value increases.
[0042]
CQI extracting section 401 extracts a CQI from the received signal, and outputs the extracted CQI to scheduler section 402 and MCS allocating section 403.
[0043]
Based on the CQI of communication terminal apparatus 100 output from CQI extracting section 401, scheduler section 402 performs scheduling in consideration of the priority from the margin value. Information indicating the contents of the scheduling, that is, information indicating which communication terminal apparatus is to be given transmission permission, is output to transmission packet generation section 405.
[0044]
MCS allocating section 403 allocates a modulation scheme and a coding rate (MCS: Modulation and Coding Scheme) for each communication terminal apparatus based on the CQI notified from CQI extracting section 401. The MCS allocation result of the communication terminal device whose transmission is permitted by the scheduler unit 402 is output to the transmission packet generation unit 405, the demodulation unit 412, and the decoding unit 413. Note that the MCS is not allocated to all communication terminal devices, and the amount of resource usage changes depending on the allocated MCS. Therefore, information is exchanged between the scheduler unit 402 and the MCS allocation unit 403.
[0045]
The buffer 404 temporarily stores the input transmission data, and then outputs the transmission data to the transmission packet generation unit 405. The transmission packet generation unit 405 generates a transmission packet using the transmission data output from the buffer 404 and the information output from the scheduler unit 402 and the MCS allocation unit 403, and outputs the transmission packet to the encoding unit 406.
[0046]
After the transmission data output from the transmission packet generation unit 405 is encoded by the encoding unit 406, the modulation unit 407 performs modulation processing. The modulated transmission data is output to spreading section 408. Spreading section 408 spreads the transmission data output from modulating section 407 using a spreading code assigned to the communication terminal apparatus. The spread transmission data is output to transmission radio section 409, subjected to predetermined radio processing (up-conversion, D / A conversion, etc.), and transmitted to the communication terminal device via antenna AN.
[0047]
Next, the receiving system will be described. In base station apparatus 400, reception radio section 410 receives a signal transmitted from the communication terminal apparatus via antenna AN. The reception radio section 410 performs predetermined radio processing (down conversion, A / D conversion, etc.) on a signal (reception signal) received via the antenna AN. The signal after the radio processing is output to despreading section 411.
[0048]
Despreading section 411 despreads the received signal output from radio receiving section 410 using a spreading code, and demodulates the signal after despreading in demodulating section 412. The demodulated received signal is output to decoding section 413. Decoding section 413 decodes the received signal demodulated by demodulation section 412 to obtain received data. Further, it outputs the decoded received signal to CQI extracting section 401. Here, demodulation section 412 and decoding section 413 respectively perform demodulation and decoding according to the assignment result in MCS assignment section 403.
[0049]
Next, operations of communication terminal apparatus 100 and base station apparatus 400 having the above configurations will be described. Referring to FIG. 2, communication terminal apparatus 100 counts the amount of data to be transmitted to base station apparatus 400 by data amount counting section 101 and notifies CQI generating section 102 of the counted data amount. Further, the transmission power value of the signal processed by transmission radio section 108 is reported to CQI generation section 102. CQI generating section 102 generates a CQI to be notified to the base station apparatus based on the data amount and the transmission power value. Hereinafter, the operation of CQI generation section 102 will be described in detail.
[0050]
In channel quality estimating section 201, uplink channel quality is estimated based on the transmission power value of the uplink control channel whose transmission power has been controlled, and the estimated channel quality information is reported to transmittable rate determining section 202.
[0051]
In transmission available rate determination section 202, the maximum transmission rate among the transmission rates available for transmission is determined based on the estimated uplink channel quality. The determined transmittable rate is notified to margin calculating section 204.
[0052]
The required rate determining unit 203 determines a transmission rate required for transmission based on the data amount counted by the data amount counting unit 101. That is, the required rate reflects the amount of transmission data.
[0053]
The margin calculator 204 determines whether the required rate is equal to or less than the transmittable rate. If the required rate is equal to or lower than the transmittable rate, a surplus of the channel quality estimation value with respect to the required rate is calculated as a margin. That is, this margin corresponds to a difference obtained by subtracting the communication quality corresponding to the transmittable rate from the communication quality corresponding to the required rate. If the required rate exceeds the transmittable rate, only the transmittable rate is notified to the base station apparatus, and therefore no margin is calculated.
[0054]
The CQI selection unit 205 selects a CQI value from the required rate notified from the required rate calculation unit 203 and the margin notified from the margin calculation unit 204 based on the table shown in FIG. For example, referring to FIG. 3, if the required rate is a transmission rate indicating a CQI value of “15” and the margin is −2 [dB], a CQI value of “17” is selected. The required rate indicates the minimum rate at which the amount of data transmitted by the communication terminal device can be transmitted, and the margin indicates how good the uplink channel quality is from the quality indicated by the required rate. Thus, the information on the required rate and the margin roughly represents the actual line quality in the communication terminal device 100.
[0055]
After the selected CQI value is output to transmission packet generation section 104, a transmission packet is generated together with the transmission data. The CQI value inserted in the transmission packet is transmitted to the base station device after performing a predetermined transmission process.
[0056]
Referring to FIG. 4, the base station apparatus receives a packet including the CQI transmitted from the communication terminal apparatus, performs predetermined reception processing on the received packet, and obtains decoded reception data. The table shown in FIG. 3 is stored in CQI extracting section 401, and CQI included in the received data is extracted in CQI extracting section 401. The CQI includes necessary rate and margin information as described above. That is, it indicates the amount of data transmitted by the communication terminal apparatus and how good the uplink channel quality is from the quality indicated by the required rate. The value indicated by the extracted CQI is notified to the scheduler unit 402.
[0057]
In the scheduler unit 402, scheduling is performed in consideration of the priority based on the CQI value notified from the CQI extraction unit 401. For example, a user with a high margin can be preferentially assigned. This allows the scheduler unit 402 to allocate resources for the required rate, so that scheduling using the resources can be performed efficiently. Further, when the transmission rate is determined based only on the communication quality, if only the necessary rate not considering the communication quality as described above is notified to the base station apparatus, the communication quality may be determined to be poor. And the priority may be lowered. However, by being notified of the margin, it is possible to know how good the communication quality is actually from the communication quality indicated by the required rate, and to avoid a decrease in the priority. For example, when the actual uplink channel quality is good and the amount of transmission data is small, the required rate is low but the margin is large, so that a decrease in the priority order is avoided. For this reason, the transmission from the communication terminal device can be terminated early, and the number of communication terminal devices to be processed can be reduced by excluding this communication terminal device from scheduling.
[0058]
As described above, according to the embodiment of the present invention, by including the data amount transmitted by the communication terminal device in the CQI, the data amount can be notified to the base station device. In addition, since the CQI indicates the margin, the uplink channel quality can be roughly expressed by the communication quality indicated by the required rate and the communication quality indicated by the margin. Therefore, the priority when scheduling is performed by the base station apparatus is taken into consideration. Can be easier. Thereby, especially when transmitting a small amount of data in a state of good communication quality, scheduling can be performed so as to use resources efficiently.
[0059]
In this embodiment, since the amount of data that can be stored in the buffer is limited, the CQI may be generated when the amount of data stored in the buffer exceeds a predetermined value. At this time, a necessary transmission rate is determined for a data amount necessary to prevent the data amount from exceeding the allowable data amount of the buffer.
[0060]
Further, in the present embodiment, margin calculating section 204 associates the margin with a value obtained by subtracting the communication quality corresponding to the required rate from the communication quality corresponding to the transmittable rate. The subtracted value may correspond to the margin. Instead of the communication quality corresponding to the transmittable rate, a value obtained by subtracting the communication quality corresponding to the required rate from the estimated quality may correspond to the margin.
[0061]
Further, although the present embodiment has been described using the table shown in FIG. 3, as shown in FIG. 5, a combination of an ID table showing a transmission rate and an ID table showing a margin may be used.
[0062]
(Embodiment 2)
In this embodiment, a case will be described where the allowable delay time of data transmitted by a communication terminal device is made to correspond to CQI.
[0063]
FIG. 6 is a block diagram showing a configuration of communication terminal apparatus 600 according to Embodiment 2 of the present invention. However, in this figure, portions common to FIG. 1 are denoted by the same reference numerals as in FIG. 1, and detailed description thereof will be omitted. FIG. 6 differs from FIG. 1 in that the data amount counting unit 101 is changed to an allowable delay time measuring unit 501. Hereinafter, the allowable delay time is the time remaining until the transmission data is transmitted.
[0064]
Allowable delay time measuring section 501 measures the allowable delay time from the time spent in transmission data waiting for transmission, and outputs the measurement result to CQI generating section 102.
[0065]
FIG. 7 is a block diagram showing an internal configuration of CQI generation section 102 according to Embodiment 2 of the present invention. However, in this figure, portions common to FIG. 2 are denoted by the same reference numerals as in FIG. 2, and detailed description thereof will be omitted. In the required rate determination unit 701, based on the allowable delay time measured by the allowable delay time measurement unit 501, when the allowable delay time is shorter than a certain value, the base station apparatus receives the signal within the allowable delay time. The lowest rate (required rate) among the possible transmission rates is determined. The required rate is determined in this way to indirectly indicate that the allowable delay time is not so long. As long as the amount of data can be transmitted in one transmission, a transmission rate based on the amount of data may be used as the required rate.
[0066]
The CQI generated by CQI generation section 102 is inserted into a packet together with transmission data in transmission packet generation section 104 to generate a packet. The generated packet is transmitted to the base station device after performing a predetermined transmission process.
[0067]
Since the configuration of the base station apparatus according to Embodiment 2 of the present invention is the same as that of FIG. 4, a description will be given with reference to FIG.
[0068]
In the base station apparatus, a predetermined reception process is performed on the packet transmitted from communication terminal apparatus 600, and the reception data decoded by decoding section 413 is output to CQI extraction section 401. CQI extraction section 401 extracts a CQI included in the received data. The extracted CQI includes information of a requested transmission rate and a margin for determining actual communication quality. The CQI extracting unit 401 notifies the extracted CQI to the scheduler unit 402.
[0069]
The scheduler unit 402 performs scheduling of the communication terminal device in consideration of the priority based on the CQI notified from the CQI extraction unit 401. This allows the scheduler unit 402 to allocate resources for the required rate, so that scheduling using the resources can be performed efficiently. Further, when the transmission rate is determined based only on the communication quality, if only the required rate that does not represent the actual communication quality is notified to the base station apparatus, there is a possibility that the communication quality is determined to be poor. Yes, the priority may be lowered. However, by being notified of the margin, it is possible to know how good the communication quality is actually from the communication quality indicated by the required rate, and to avoid a decrease in the priority.
[0070]
As described above, according to the embodiment of the present invention, the allowable delay time of the data transmitted by the communication terminal apparatus is indirectly transmitted using the CQI, whereby the allowable delay time can be notified to the base station apparatus. Also, by expressing the margin in CQI, the uplink channel quality can be roughly expressed by the communication quality indicated by the required rate and the communication quality indicated by the margin, so that the priority when scheduling is performed by the base station apparatus is maintained. be able to. Thereby, scheduling can be performed so as to use resources efficiently.
[0071]
(Embodiment 3)
In this embodiment, a case will be described in which the base station apparatus performs scheduling to assign a high rate based on margin information.
[0072]
Since the configuration of the base station apparatus according to Embodiment 3 of the present invention is the same as that of the base station apparatus shown in FIG. 4, description will be made with reference to FIG.
[0073]
In the base station apparatus, a predetermined reception process is performed on the packet transmitted from the communication terminal apparatus, and the reception data decoded by decoding section 413 is output to CQI extraction section 401. CQI extraction section 401 extracts a CQI included in the received data. The extracted CQI includes information on a required rate in consideration of an allowable delay time and a margin for determining actual communication quality.
[0074]
However, when the required rate is determined based on the allowable delay time as in the second embodiment, there is a possibility that transmission data having an allowance for the allowable delay time exists in the buffer 103. In this case, the required rate may be low even though the communication quality is good.
[0075]
Therefore, the scheduler unit 402 can allocate a high rate according to the actual quality calculated from the required rate and the margin, instead of the required rate notified by the communication terminal apparatus.
[0076]
As described above, in the present embodiment, when the communication terminal apparatus determines the required rate in consideration of the permissible delay time, the base station apparatus can perform scheduling for allocating a transmission rate at which communication can be performed with a quality including a margin. it can.
[0077]
In the present embodiment, the transmission data amount and the allowable delay time may be considered simultaneously from the CQI. In this case, if it is indicated that the transmission data amount is also taken into consideration, it is not necessary to use the transmission rate with the margin plus the quality, so that it is notified that the request rate is determined by the transmission data amount. As a result, the base station apparatus can perform scheduling in consideration of the transmission data amount and the allowable delay time.
[0078]
(Embodiment 4)
In this embodiment, a case is described in which, using a minimum required transmission rate and margin, a communication terminal apparatus notifies a base station apparatus that transmission of data to be transmitted must be completed within an allowable delay time. explain.
[0079]
FIG. 8 is a block diagram showing a configuration of communication terminal apparatus 800 according to Embodiment 4 of the present invention. However, parts in FIG. 8 common to FIG. 1 are denoted by the same reference numerals as in FIG. 1, and detailed description thereof will be omitted. This figure differs from FIG. 1 in that an allowable delay time measuring unit 501 is added.
[0080]
Data amount counting section 101 counts the data amount of the transmission data, and outputs the counted data amount to CQI generation section 102. Allowable delay time measuring section 501 measures an allowable delay time of transmission data, and outputs the measured allowable delay time to CQI generating section 102.
[0081]
CQI generating section 102 determines the required rate based on the data amount output from data amount counting section 101 and the allowable delay time output from allowable delay time measuring section 501, and transmits the transmission rate output from transmission radio section 108. A margin is determined based on the power value. A CQI is generated according to the determined required rate and the margin.
[0082]
FIG. 9 is a block diagram showing an internal configuration of CQI generating section 102 according to Embodiment 4 of the present invention. 9 that are the same as in FIG. 2 are assigned the same reference numerals as in FIG. 2, and detailed descriptions thereof are omitted. In this figure, a required rate determination unit 901 determines a minimum transmission rate (required rate) required to transmit data to be transmitted within an allowable delay time, and determines the determined required rate in the margin calculation unit 204 and the margin calculation unit 204. Notify to CQI selection section 205. For example, the required rate for transmitting a data amount of 100 bits is 10 kbps if the allowable delay time is short and 10 ms. Conversely, if the allowable delay time has a margin and is 100 ms, the required rate is 1 kbps. In this example, the transmission rate when transmitting continuously is shown.
[0083]
The required rate determined in this way represents the minimum rate for completing data transmission within the allowable delay time. As a result, a delay may occur in a case where assignment is difficult, such as when the line condition is poor, but the base station apparatus can perform the assignment with the delay avoided based on the required rate. .
[0084]
Note that the required rate in the present embodiment is not based on the transmission data amount or the presence of data within a certain allowable delay time. Therefore, it can be distinguished by the presence of data within the transmission data amount or a certain allowable delay time, or by adding a signal indicating these in the case of the present embodiment.
[0085]
As described above, according to the present embodiment, by notifying the base station apparatus of the minimum rate for the communication terminal apparatus to complete data transmission within the allowable delay time, the base station apparatus Since the assignment can be performed by the assignment, it is possible to perform the assignment while avoiding the delay even when the assignment is difficult.
[0086]
Although the above embodiments have been described using a combination of a data rate and a margin as the CQI, in short, the communication terminal apparatus needs to have a minimum transmission rate based on data information and a maximum possible transmission rate based on communication quality. Any information indicating the transmission rate is acceptable. The maximum possible transmission rate based on the communication quality may be information indicating the communication quality, and various contents to be combined as the CQI are conceivable.
[0087]
Further, in each of the above embodiments, the data amount and the allowable delay time have been described. However, the present invention is not limited to this, and information representing characteristics of data, for example, information of QoS (Quality of Service) is considered. It is also possible to determine the CQI.
[0088]
Further, in each of the above embodiments, if the content indicated by the margin is simply that the user wants to transmit early, it is also possible to use a signal that the user wants to transmit earlier instead of the margin.
[0089]
【The invention's effect】
In the uplink packet communication, the communication terminal device determines the minimum transmission rate required for data to be transmitted, notifies the base station device of information representing the communication quality together with the information of the determined transmission rate, and is notified. By performing scheduling by the base station apparatus based on the information, data information transmitted by the communication terminal apparatus can be considered, and scheduling using resources efficiently can be performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a communication terminal device according to Embodiment 1 of the present invention.
FIG. 2 is a block diagram showing an internal configuration of a CQI generation unit according to Embodiment 1 of the present invention.
FIG. 3 is a table showing information corresponding to respective CQI values according to the first embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of a base station apparatus according to Embodiments 1, 2, and 3 of the present invention.
FIG. 5 is a table showing information corresponding to respective CQI values according to the first embodiment of the present invention.
FIG. 6 is a block diagram showing a configuration of a communication terminal device according to Embodiment 2 of the present invention.
FIG. 7 is a block diagram showing an internal configuration of a CQI generation section according to Embodiment 2 of the present invention.
FIG. 8 is a block diagram showing a configuration of a communication terminal apparatus according to Embodiment 4 of the present invention.
FIG. 9 is a block diagram showing an internal configuration of a CQI generation section according to Embodiment 4 of the present invention.
[Explanation of symbols]
101 Data amount counting unit
102 CQI generator
103, 404 buffer
104, 405 transmission packet generation unit
105, 406 Encoding unit
106, 407 modulator
107, 408 diffusion unit
108, 409 Transmission radio section
109, 410 receiving radio section
110, 411 Reverse diffusion unit
111, 412 demodulation unit
112, 413 decoding unit
113 Report value extractor
201 Line quality estimator
202 Transmission available rate determination unit
203, 701, 901 Required rate determination unit
204 Margin calculator
205 CQI selector
401 CQI extraction unit
402 scheduler section
403 MCS allocator
501 Allowable delay time measurement unit

Claims (8)

The communication terminal device determines a lowest transmission rate among transmission rates required for transmitting data, based on a property of data to be transmitted,
Transmitting information indicating the surplus quality together with the information on the determined transmission rate to the base station apparatus,
The radio communication system, wherein the base station apparatus performs scheduling based on the information on the transmission rate and the information indicating the surplus quality transmitted from the communication terminal apparatus. Based on the nature of the data to be transmitted, required rate determination means for determining the lowest transmission rate among the transmission rates required to transmit the data,
Transmitting means for transmitting information representing the surplus quality to the base station apparatus together with the information on the determined transmission rate,
A communication terminal device comprising: 3. The communication terminal device according to claim 2, wherein the required rate determining means determines a lowest transmission rate among transmission rates required for transmission based on a data amount of data to be transmitted. The said required rate determination means determines the lowest transmission rate among the transmission rates required for transmission, when the permissible delay time of the data to be transmitted is less than a predetermined value. Communication terminal device. 3. The communication terminal device according to claim 2, wherein the required rate determination means determines a transmission rate required to complete data transmission within an allowable delay time of data to be transmitted. A base station apparatus, comprising: scheduling means for performing scheduling based on transmission rate information transmitted from the communication terminal apparatus according to any one of claims 2 to 5 and information representing surplus quality. . 7. The scheduling method according to claim 6, wherein the scheduling means performs scheduling for allocating a higher transmission rate exceeding a transmission rate indicated by the transmission rate information, based on information indicated by the surplus quality transmitted from the communication terminal apparatus. Base station device. The communication terminal device, based on the nature of the data to be transmitted, a required rate determination step of determining the lowest transmission rate among the transmission rates required to transmit the data,
A transmitting step of transmitting information indicating the surplus quality together with the information of the determined transmission rate to the base station apparatus,
A control information notification method, comprising: a scheduling step of performing scheduling based on the transmission rate information transmitted from the communication terminal apparatus and the information indicating the surplus quality.

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