WO2006054659A1

WO2006054659A1 - Communication terminal device and drc signal transmission method

Info

Publication number: WO2006054659A1
Application number: PCT/JP2005/021152
Authority: WO
Inventors: Takeru Usui
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2004-11-18
Filing date: 2005-11-17
Publication date: 2006-05-26
Also published as: JP2006148490A

Abstract

There is provided a communication terminal device for suppressing deterioration of throughput in a high-speed transmission system. In this communication terminal device, an inverse-spread unit (301) executes inverse spread by using a predetermined spread signal for a DRC threshold value component in a reception base band signal. A DRC threshold value detection unit (302) detects a DRC threshold value from the output signal from the inverse-spread unit (301). A DRC signal selection unit (303) selects a DRC value indicating a data rate appropriate for the reception quality CIR of the downstream line measured by a reception quality measuring unit (1710). If the selected DRC value is not smaller than the DRC threshold value, the DRC value is given to a DRC signal generation unit (1712). If the selected DRC value is smaller than the DRC threshold value, the DRC value is not given to the DRC signal generation unit (1712).

Description

Specification

Communication terminal device and DRC signal transmission method

Technical field

[0001] The present invention relates to a communication terminal apparatus and a DRC signal transmission method in a high-speed packet transmission system.

Background art

[0002] Cellular phone network technology cdma2000 used for high speed data transmission HDR (High Data Rate) is standardized by 3GPP2 (3GPP2 C.S0024 Ver.4.0) A high-speed packet transmission system that uses only the data portion to increase the speed is called the lxEV—DO (Evolution Data Only) system. “Lx” means a single carrier.

[0003] This lxEV-DO system is introduced in Patent Documents 1 and 2, for example. Here, the outline of the parts related to the present invention will be described with reference to FIGS.

FIG. 1 is a system diagram illustrating a DRC (Data Rate Control) signal transmission method in a conventional high-speed packet transmission system. In FIG. 1, communication terminal devices (user A, user B, user C), which are mobile devices in the cell of the base station device (BTS), communicate with the base station device at time-division time positions. The station apparatus determines the optimum communication terminal apparatus for transmitting a packet at the time position by the following method.

[0005] Each communication terminal device in the cell receives the common pilot signal (CPICH) transmitted by the base station device, and measures the downlink reception quality CIR (Carrier to Interference Ratio). . Then, each communication terminal apparatus sets a data rate that can be used for packet reception in the measured reception quality, and transmits a DRC signal having a DRC value indicating the data rate to the base station apparatus at a certain cycle.

[0006] Here, the DRC value increases as the reception quality improves, and decreases as the reception quality deteriorates. A communication terminal device with good reception quality can receive a signal with a large number of modulation levels and a low code rate, so a packet with a high data rate is requested by a DRC signal having a high DRC value. be able to. Conversely, the reception quality Since it is difficult for a bad communication terminal device to receive only a packet with a low data rate, only a DRC signal having a DRC value can be transmitted! /.

[0007] The base station apparatus uses the DRC value of the DRC signal transmitted from each communication terminal apparatus at each packet allocation timing, and the communication terminal apparatus that transmits the next packet from the average data rate of each communication terminal apparatus. Determine the data rate. Then, the base station apparatus repeatedly notifies the determined communication terminal apparatus of the ID using a transmission packet notification signal (Preamble) at every packet allocation timing.

[0008] When each communication terminal apparatus detects a transmission packet notification signal addressed to its own ID, the communication terminal apparatus receives the packet data subsequently transmitted at the data rate requested by the DRC signal. .

[0009] By repeatedly performing these processes for each processing time unit, packets can be allocated efficiently, and throughput is increased. In Figure 1, users A and B receive packet allocation, but user C receives no packet allocation. Next, the configuration and specific operation of the conventional base station apparatus and communication terminal apparatus will be described.

FIG. 2 is a block diagram showing a configuration example of the base station apparatus shown in FIG. In FIG. 2, an antenna 1601 is connected to a reception RF unit 1602 and a transmission RF unit 1603 through a duplexer (not shown). Reception RF section 1602 converts a radio signal received by antenna 1601 into a baseband signal and outputs it to despreading sections 1604-1 to 1604 n connected in parallel.

[0011] DRC signal demodulation units 1605-1 to 1605-n are connected to the output terminals of the despreading units 1604-1 to 1604-n in a one-to-one relationship. In other words, the serial circuit of the despreading unit and the DRC signal demodulating unit is provided for each communication terminal device, and the input baseband signal is despread using the spread signal corresponding to the communication terminal device, and the corresponding DRC signal is To restore. The restored DRC signal of each communication terminal apparatus is provided to the user scheduler unit 1606. The allocation buffer unit 1607 stores the average data rate of each communication terminal device.

[0012] The user scheduler unit 1606 uses a scheduling algorithm that uses the restored DRC signal (DRC value) of each communication terminal apparatus at each packet allocation timing or the restored DRC signal (DRC value of each communication terminal apparatus). ) And the allocation buffer section 16 The scheduling algorithm using the average data rate of each communication terminal device stored in 07 gives high priority to communication terminal devices with good reception quality, and conversely low priority to communication terminal devices with poor reception quality. give. Then, the communication terminal device having the highest priority among the priorities given to each communication terminal device is determined as the communication terminal device that transmits the packet at the next packet allocation timing (packet allocation).

[0013] Packet format assigning section 1608 assigns a modulation format corresponding to the data rate to a packet to be transmitted to the communication terminal apparatus determined by user scheduler section 1606, and provides it to adaptive modulation section 1609. Further, the packet format assigning unit 1608 assigns a predetermined modulation format to a signal notifying that the packet has been assigned to the communication terminal apparatus determined by the user scheduler unit 1606, and provides the signal to the transmission packet notification signal generating unit 1612.

[0014] Transmission packet notification signal generation section 1612 generates a transmission packet notification signal to be transmitted to the communication terminal apparatus determined by user scheduler section 1606 in the modulation format assigned by packet format assignment section 1608. The generated transmission packet notification signal becomes a spread signal in spreading section 1613 and is input to signal multiplexing section 1611.

[0015] In addition, adaptive modulation section 1609 applies the packet signal to be transmitted to the communication terminal apparatus determined by user scheduler section 1606 to the modulation format assigned by packet format assignment section 1608, and applies it to the modulation format using a predetermined modulation scheme. Modulate. The modulated packet signal is converted into a spread signal by the spreader 1610 and input to the signal multiplexer 1611.

Further, the pilot signal generated by pilot signal generation section 1614 becomes a spread signal by spreading section 1615 and is input to signal multiplexing section 1611. The signal multiplexing unit 1611 provides the transmission RF unit 1603 with a baseband signal obtained by time-multiplexing the packet signal, the transmission packet notification signal, and the pilot signal. The transmission RF unit 1603 converts the time-multiplexed packet signal, the transmission bucket notification signal, and the pilot signal into a radio signal, and supplies it to the antenna 1601 via a duplexer (not shown).

FIG. 3 is a block diagram showing a configuration example of the communication terminal apparatus shown in FIG. In FIG. 3, a reception RF unit 1702 and a transmission RF unit 1703 are connected to an antenna 1701 via a duplexer (not shown). The reception RF unit 1702 converts the radio signal received by the antenna 1701 into a baseband signal, and despreading units 1704, 1 connected in parallel Output to 705 and 1706.

[0018] Despreading section 1704 despreads the data portion in the input baseband signal using a predetermined spread signal, and provides it to adaptive demodulation section 1707. The despreading section 1705 despreads the control information portion in the input baseband signal using a predetermined spread signal, and gives it to the control information demodulation section 1708. Adaptive demodulation section 1707 restores the original data signal from the output of despreading section 1704 in accordance with the control information from control information demodulation section 1708, and provides it to reception processing section 1709. The reception processing unit 1709 extracts information indicating the reception processing status from the data restored by the adaptive demodulation unit 1707 and supplies the information to the packet reception availability information generation unit 17 16.

Despreading section 1706 despreads the pilot signal in the input baseband signal using a predetermined spread signal, and provides the received signal to reception quality measuring section 1710. Reception quality measurement section 171 0 measures reception quality CIR using the reception level of the pilot signal output from despreading section 1706. The DRC signal selection unit 1711 selects a receivable data rate (DRC value) corresponding to the measured reception quality. The DRC signal generation unit 1712 generates a DRC signal having the selected DRC value. The generated DRC signal is modulated by a modulation unit 1713 according to a predetermined modulation method, becomes a spread signal by a spreading unit 1714, and is input to a signal multiplexing unit 1715.

[0020] The packet reception availability information generating unit 1716 receives the reception processing status from the reception processing unit 1709 and generates packet reception availability information (ACK, NACK). The generated packet reception availability information becomes a spread signal in the spreading unit 1717 and is input to the signal multiplexing unit 1715. The pilot signal generated by pilot signal generation section 1718 becomes a spread signal at spreading section 1719 and is input to signal multiplexing section 1715. The signal multiplexing unit 1715 provides the transmission RF unit 1703 with a baseband signal obtained by time-multiplexing the DRC signal, the DRC signal, and the pilot signal. Transmission RF section 1703 converts the time-multiplexed packet signal, transmission packet notification signal, and pilot signal into a radio signal, and supplies it to antenna 1701 via a duplexer (not shown).

Next, with reference to FIG. 4, a conventional downlink packet transmission process performed by the base station apparatus and communication terminal apparatus having the above configuration will be described. In the explanation of the flowchart, the processing procedure is The steps shown are abbreviated as “ST”.

[0022] Upon receiving the pilot signal transmitted by the base station apparatus (ST1801), the communication terminal apparatus measures the downlink reception quality CIR from the reception level of the pilot signal (ST1802), and supports the measured reception quality CIR. The usable data rate is determined as the requested data rate (ST1803). Then, the communication terminal apparatus generates a DRC signal having a DRC value indicating the requested data rate (ST1804) and transmits it to the base station apparatus (ST18 05).

[0023] Upon receiving the DRC signal (ST1806), the base station apparatus calculates the priority of each communication terminal apparatus based on the DRC value or based on the DRC value and the average data rate (ST1807). Then, the packet to be transmitted next time is assigned to the communication terminal apparatus having a high priority (ST18 08). Then, the base station device generates a packet with a modulation format corresponding to the data rate requested by the DRC signal having the assigned communication terminal device power (ST1809), and transmits the packet to the assigned communication terminal device. (ST1810).

[0024] When the communication terminal device receives the packet addressed to itself (ST1811: Yes), it performs packet reception processing (ST1812), and sends an acknowledgment ACK or negative response N ACK to the base station device based on the reception result. Transmit (ST1813).

Here, packet allocation processing (ST1807, ST1808) in the base station apparatus will be described using a specific example. Various scheduling methods for determining communication terminal device priorities have been studied, but here, representative examples are the MaxCIR method (Fig. 5), which determines the communication terminal device priority based on the DRC value, and the DRC value. The Proportional Fairness method (Fig. 6), which determines the priority of communication terminal devices based on the average data rate, is explained.

[0026] FIG. 5 is a diagram showing an example of a bucket assignment result by the MaxCIR method for determining the priority of the communication terminal device based on the DRC value. Fig. 6 is a diagram showing an example of the packet allocation result by the proportional fairness method. In FIGS. 5 and 6, the number of communication terminal devices is “3”. Also, four packet allocation timings # 1 to # 4 are shown.

In FIG. 5, “packet allocation timing”, “DRC value” received from each communication terminal device, and “assigned DRC value” determined are shown as items. In the MaxCIR method, each bucket The DRC value of each communication terminal device is determined as the priority of that communication terminal device. Then, the highest DRC value (priority) among the DRC values (priority) of each communication terminal device is determined as an “assigned DRC value”, and packets are preferentially assigned to the communication terminal devices having this “assigned DRC value”.

That is, at the packet allocation timing # 1, the DRC values of the DRC signals that have received the user A, B, and C forces are “10”, “8”, and “3”, respectively. In this case, the highest DRC value “10” becomes the “assigned DRC value”, and the packet is preferentially assigned to user A who has the “assigned DRC value” “10”. Thereafter, the same applies, and at packet allocation timings # 2, # 3, and # 4, packets are allocated in the order of user B, user A, and user B. User C cannot receive packet allocation at packet allocation timings # 1 to # 4 because the reception environment is poor.

Accordingly, a packet is transmitted to user A at packet allocation timing # 1.

At the next packet allocation timing # 2, the packet is transmitted to the user B. At the next bucket allocation timing # 3, a packet is transmitted to user A. At the next packet allocation timing # 4 (not shown), the packet is transmitted to the user B.

In FIG. 6, as items, “packet allocation timing”, a value “DRCZR (t)” obtained by dividing the D RC value received from each communication terminal device by the average data rate R (t), and the determined “allocation” DR C value "is shown. In the proportional fairness method, at each packet allocation timing, the value “DRCZR (t)” calculated for each communication terminal apparatus is set as the priority of the communication terminal apparatus. Then, the highest priority “DRCZR (t)” in the priority “DRCZR (t)” of each communication terminal device is determined as the “assigned DRC value”, and the communication terminal device having this “assigned DRC value” Preferentially assign packets to.

In such an allocation method, since the average data rate R (t) increases in the communication terminal device to which the packet is allocated, the priority “DRCZR (t)” gradually decreases. On the other hand, the average data rate R (t) decreases in the communication terminal device when the packet is allocated! /, So the priority “DRCZR (t)” gradually increases. As a result, the packet is assigned and V, and the communication terminal device can receive the packet assignment. In this way, with the proportional fairness method, packet allocation for each communication terminal device is possible as much as possible. It will be possible to implement fairly.

In FIG. 6, at packet allocation timing # 1, the priorities “DRC ZR (t)” of users A, B, and C are “10”, “8”, and “3”, respectively, and “allocated DRC value” Becomes "10". At packet allocation timing # 2, user B's priority “DRCZR (t)” “9” becomes “allocation DRC value”, and user C ’s priority “DRCZR (t)” increases from “3” to “4”. On the other hand, the priority “DRCZR (t)” of user A drops greatly from “10” to “5”.

[0033] At packet allocation timing # 3, user A's priority “DRCZR (t)” “7” becomes “allocation DRC value”, and user C's priority “DRCZR (t)” changes from “4” to “5”. On the other hand, the priority “DRCZR (t)” of user B greatly decreases from “9” to “3”. At packet allocation timing # 4, the priority “DRCZR (t)” of users A, B, and C is “2”, “4”, and “6”, respectively, and “allocation DRC value” is the priority that user C has. Degree “DRCZR (t)” “6”.

[0034] In this manner, at the packet allocation timings # 1, # 2, and # 3, user C has a priority “DR CZR (t)” that is significantly lower than that of users A and B. However, in the proportional fairness method, user C's priority “DRCZR (t)” gradually increases, so user C can receive a packet allocation at packet allocation timing # 4.

[0035] By the way, the above is a description on a single carrier system. However, with the increase in required data transmission speed and throughput, it is assumed that such a high-speed packet transmission system will be multi-carrier. . In fact, Qualcomm in the United States is examining a system with multiple lxEV—DO system carriers (2x, 3xEV—DO system) as an option for the IxE V—DO system.

FIG. 7 is a system diagram illustrating a DRC signal transmission method according to the prior art in a multicarrier high-speed packet transmission system. When a broadband system such as the EV-DO system is converted to a multicarrier, the adjacent carriers have a wide bandwidth, so the multipath fading received by each carrier has no correlation. Because of this, as shown in FIG. 7, each communication terminal apparatus (users A, B, and C) in the cell estimates the reception environment in each carrier and transmits the DRC signal for each carrier to the base station. Send to device There is a need to. The base station device needs to check the priority for each carrier and perform packet allocation.

Patent Document 1: Special Table 2004—502328

Patent Document 2: Japanese Patent Laid-Open No. 2002-118514

Disclosure of the invention

Problems to be solved by the invention

[0037] In the lxEV-DO system, which is a conventional high-speed packet transmission system, each communication terminal apparatus needs to transmit a DRC signal to the base station apparatus once at a certain period as described above. The communication terminal device transmits the DRC signal using the same channel. Therefore, as pointed out in Patent Documents 1 and 2, if DRC signal transmissions of multiple communication terminal devices overlap at a certain timing, uplink interference may increase and communication quality may deteriorate.

[0038] Further, as described above, the base station apparatus determines the packet transmission communication terminal apparatus from the DRC signals transmitted from the respective communication terminal apparatuses, and sends the next packet only to the determined communication terminal apparatus. Because it transmits, the majority of other DRC signals that do not allocate packets to the base station are unnecessary at that time. In this regard, Patent Document 1 proposes a method in which each communication terminal apparatus transmits a DRC signal only when base station apparatus power S scheduling is performed. Therefore, the DRC signal unnecessary for the base station device is transmitted.

[0039] Here, the packet allocation processing methods shown in Figs. 5 and 6 are examined in terms of the point that each communication terminal apparatus transmits a DRC signal to the base station apparatus once at a certain period. I understand that.

[0040] In FIG. 5, the communication terminal device C cannot receive the packet allocation at the packet allocation timings # 1 to # 4, but this happens because the reception quality of the downlink is poor at this point. Because. However, conventionally, each communication terminal device reports the DRC value regardless of the possibility of packet assignment, so communication terminal device C has a low possibility of packet assignment, and packet assignment timings # 1 to # 4 Keep sending unnecessary DRC signals Will be. As a result, in the communication terminal apparatus C, processing for generating a DR C signal with low possibility of packet allocation is wasted, and transmission power is wasted.

[0041] Further, since the possibility of packet allocation that user C continues to transmit is low, the DRC signal may cause interference with other communication terminal apparatuses (users A and B). As a result, if, for example, at the packet allocation timing # 1, it is erroneously received that the user C's DRC value of 3 is not "12" but the base station device incorrectly allocates a packet to user C. Will happen. However, since the actual reception quality of user C is inferior, the data cannot be received correctly and the packet is retransmitted. As a result, throughput may be adversely affected.

[0042] In FIG. 6, user C cannot receive a packet assignment because the priority is low at packet assignment timings # 1 to # 3, but priority is given to the progress of packet assignment timings # 1 to # 3. The packet allocation timing # 4 is higher than that of the other communication terminal devices (users A and B), so that packet allocation can be received. However, even in this example, it can be said that the DRC signal transmission at packet allocation timings # 1 to # 3 is useless transmission for user C. In other words, in the example shown in FIG. 6, user C wants to send a DRC signal only at this packet allocation timing # 4.

[0043] As shown in FIG. 7, when the high-speed packet transmission system is converted to multicarriers, each communication terminal apparatus needs to transmit a DRC signal in each carrier. Since the device needs to perform packet allocation processing in each carrier, the communication terminal devices (users A, B, and C) in the cell increase the processing amount and power consumption of DRC signal generation, and In the station equipment, the scheduling load increases by the number of carriers. This can be a major challenge when introducing multi-carrier systems.

[0044] An object of the present invention is to provide a communication terminal apparatus in a high-speed packet transmission system that can be controlled so as not to transmit a DRC signal having a DRC value while suppressing the deterioration of throughput and suppressing packet degradation. And providing a DRC signal transmission method.

Means for solving the problem

[0045] A communication terminal apparatus according to the present invention comprises reception quality measuring means for measuring reception quality of a downlink, A selection means for selecting a data rate of a packet transmitted from the communication partner base station apparatus based on the measured reception quality, and a DRC (Data Rate Control) signal indicating the selected data rate. DRC signal generating means for generating, and transmitting means for transmitting the generated DRC signal to the base station apparatus, wherein the selecting means is configured such that the selected data rate is equal to or higher than a threshold value. The data rate is output to the DRC signal generation means only in the above.

[0046] The DRC signal transmission method of the present invention is based on the reception quality measurement process for measuring the reception quality of the downlink and the data rate of the transmitted packet based on the measured reception quality. A selection step for selecting and selecting, a DRC signal generation step for generating a DRC (Data Rate Control) signal indicating the selected data rate, and the DRC signal generated for the base station apparatus A transmission step of transmitting, and the selection step employs a method of outputting the data rate to the DRC signal generation step only when the selected data rate is equal to or higher than a threshold value.

The invention's effect

[0047] According to the present invention, since it is possible to control not to transmit the DRC signal that is possessed when the packet allocation possibility is low, it is possible to suppress degradation of throughput. As a result, (1) communication quality improvement by reducing uplink interference amount, (2) processing amount and power consumption reduction in communication terminal equipment, and (3) packet allocation scheduling processing amount reduction in base station equipment Etc. are obtained. In particular, the effects of (2) and (3) are significant in multi-carrier high-speed packet transmission systems that are expected to be used in the future.

Brief Description of Drawings

[0048] [FIG. 1] A system diagram for explaining a DRC signal transmission method in a conventional high-speed packet transmission system.

FIG. 2 is a block diagram showing a configuration example of the base station apparatus shown in FIG.

FIG. 3 is a block diagram showing a configuration example of the communication terminal apparatus shown in FIG.

FIG. 4 is a flowchart for explaining conventional downlink packet transmission processing.

[Fig. 5] A diagram showing an example of conventional packet allocation results by the MaxCIR method that determines the priority of communication terminal devices based on DRC values. 圆 6] A diagram showing an example of a conventional packet allocation result by the Proportional Fairness method that determines the priority of the communication terminal device based on the DRC value and the average data rate

[Fig.7] System diagram for explaining DRC signal transmission method by conventional technology in multi-carrier high-speed packet transmission system

FIG. 8 is a system diagram illustrating a DRC signal transmission method in the high-speed packet transmission system according to the first embodiment of the present invention.

[9] Block diagram showing a configuration example of the base station device shown in FIG.

[10] Block diagram showing a configuration example of the communication terminal device shown in FIG.

圆 11] Flowchart for explaining downlink packet transmission processing according to the first embodiment of the present invention. [Fig. 12] The first embodiment of the present invention is applied to the MaxCIR method for determining the priority of the communication terminal device based on the DRC value. Of an example of packet allocation results

圆 13] A diagram showing an example of a packet allocation result when Embodiment 1 of the present invention is applied to the Proportional Fairness method that determines the priority of a communication terminal device based on the DRC value and the average data rate

FIG. 14 is a system diagram illustrating a DRC signal transmission method in the high-speed packet transmission system according to the second embodiment of the present invention.

[15] Block diagram showing a configuration example of the communication terminal device shown in FIG. 14 (part 1)

[16] Flowchart explaining downlink packet transmission processing according to Embodiment 2 of the present invention (part 1)

[17] Block diagram showing a configuration example of the communication terminal device shown in FIG. 14 (part 2)

[18] Flowchart for explaining downlink packet transmission processing according to Embodiment 2 of the present invention (part 2)

FIG. 19 is a system diagram for explaining a DRC signal transmission method in a multi-carrier high-speed packet transmission system according to Embodiment 3 of the present invention.

[20] Block diagram showing a configuration example of the communication terminal device shown in FIG.

圆 21] Flowchart for explaining downlink packet transmission processing according to Embodiment 3 of the present invention Best Mode for Carrying Out the Invention Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0050] (Embodiment 1)

FIG. 8 is a system diagram illustrating a DRC signal transmission method in the high-speed packet transmission system according to Embodiment 1 of the present invention. In FIG. 8, a communication terminal device (user A) 102, a communication terminal device (user B) 103, and a communication terminal device (user C) 104, which are mobile devices in the cell of the base station device (BTS) 101, The base station apparatus 101 communicates with the base station apparatus 101 at the time-division time position, but the base station apparatus 101 can receive packet allocations such as past packet allocation status and history of DRC signals sent from each communication terminal apparatus. A DRC threshold value 105 that gives a criterion for the possibility is calculated, communicated to each communication terminal device in the cell at a certain period, and optimal for transmitting a packet at that time position Is determined by the following method.

[0051] Each communication terminal apparatus in the cell holds the DRC threshold value 105 transmitted from the base station apparatus 101, receives the common pilot signal (CPICH) transmitted from the base station apparatus 101, and receives the downlink signal. Measure the line reception quality CIR. Then, each communication terminal sets a data rate that can be used for packet reception in the measured reception quality, and when the DRC value indicating the data rate exceeds the DRC threshold 105, the DRC A DRC signal having a value is transmitted to base station apparatus 101.

[0052] Here, the DRC value increases as the reception quality improves, and decreases as the reception quality deteriorates. A communication terminal device with good reception quality can receive a signal with a large number of modulation levels and a low code rate, so the DRC value indicating the data rate corresponding to the measured reception quality is DRC. If the threshold value 105 is exceeded, it is judged that there is a possibility of receiving a knot assignment, and a DRC signal is transmitted, and a packet with a data rate corresponding to the measured reception quality is requested. Conversely, in a communication terminal device with poor reception quality, if the DRC value indicating the data rate corresponding to the measured reception quality exceeds the DRC value and does not exceed the value 105, it is determined that the possibility of receiving packet allocation is low. , Stop sending DRC signals with low DRC values.

In FIG. 8, communication terminal apparatus 102 and communication terminal apparatus 103 transmit a DRC signal because the DRC value indicating the data rate corresponding to the measured reception quality exceeds DRC threshold! /, Value 105. However, since the DRC value indicating the data rate corresponding to the measured reception quality does not exceed the DRC threshold! /, The value 105 does not exceed! /, The communication terminal device C does not transmit the DRC signal! The

[0054] At each packet allocation timing, base station apparatus 101 determines the next packet from the DRC value of the DRC signal transmitted from communication terminal apparatus 102 and communication terminal apparatus 103, and from the average data rate of each communication terminal apparatus. The communication terminal device to be transmitted and the data rate to be used are determined. Then, base station apparatus 101 repeats notifying the determined communication terminal apparatus of the ID using a transmission packet notification signal (Preamble) at every packet allocation timing.

In FIG. 8, it is assumed that communication terminal apparatus 102 and communication terminal apparatus 103 receive packet assignments 106 and 107, respectively. When communication terminal apparatus 102 and communication terminal apparatus 103 detect a transmission packet notification signal (Preamble) addressed to their own ID, they receive the subsequent packet data transmitted at the data rate requested by the DRC signal. Will do.

Next, configuration examples of the base station apparatus and the communication terminal apparatus and the downlink packet transmission processing operation according to Embodiment 1 will be described with reference to FIG. 8 to FIG. FIG. 9 is a block diagram showing a configuration example of the base station apparatus shown in FIG. In FIG. 9, components that are the same as or equivalent to the components shown in FIG. 2 are given the same reference numerals. Here, the parts related to the first embodiment will be described.

As shown in FIG. 9, in the configuration shown in FIG. 2, the base station apparatus according to Embodiment 1 has a DRC threshold value calculation section 201, a broadcast signal generation section 202, and a spreading section 203. And have been added.

The DRC threshold value calculation unit 201 calculates the DRC threshold value by, for example, the following methods (1) to (5), and provides the calculated DRC threshold value to the notification signal generation unit 202. (1) Based on each DRC signal from the DRC signal demodulating units 1605-1 to 1605-n, the average value of all the received DRC values in the past several times is calculated and used as the DRC threshold value. (2) Calculate the average value of all received DRC values in the past several times, and set the average value plus an offset as the DRC threshold value. (3) Allocation buffer unit The average value of the past several packet allocation DRC values accumulated in 1607 is calculated and used as the DRC threshold value. (4) Allocation buffer unit Calculates the average value of the past several packet allocation DRC values accumulated in 1607 and adds an offset to the average value. This is the DRC threshold. (5) Further, determine the DRC threshold by combining the methods (1) to (4). For example, the lower one of the DRC threshold value calculated by method (1) and the DRC threshold value calculated by method (3) is the DRC threshold value! /.

In the notification signal generation unit 202, a signal for notifying each communication terminal device of the DRC threshold calculated by the DRC threshold calculation unit 201 is generated by, for example, the following methods (1) to (3): . That is, (1) DRC threshold information is inserted into a transmission packet notification signal (Preamble) placed at the head of packet data. (2) Embed DRC threshold information in another downlink channel. (3) Embed DRC threshold information in a new broadcast channel.

[0060] Spreading section 203 converts the broadcast signal generated by broadcast signal generation section 202 into a spread signal and provides it to signal multiplexing section 1611. As a result, the packet signal, the transmission packet notification signal, the pilot signal, and the DRC threshold notification signal are time-multiplexed and transmitted toward the cell.

Next, FIG. 10 is a block diagram showing a configuration example of the communication terminal apparatus shown in FIG. In FIG. 10, the same or similar components as those shown in FIG. 3 are denoted by the same reference numerals. Here, the part related to the first embodiment will be described.

[0062] As shown in FIG. 10, the communication terminal apparatus according to the first embodiment has a configuration shown in FIG. 3, to which a despreading section 301 and a DRC threshold detection section 302 are added, and A DRC signal selection unit 303 is provided instead of the DRC signal selection unit 1711.

[0063] Despreading section 301 performs despreading using a predetermined spread signal according to the DRC threshold component in the baseband signal input from reception RF section 1702. The DRC threshold value detection unit 302 also detects the DRC threshold value for the output signal power of the despreading unit 301.

[0064] DRC signal selection section 303 selects a DRC value indicating a data rate suitable for downlink reception quality C IR measured by reception quality measurement section 1710, and selects the selected DRC value and DRC threshold value detection section. The DRC threshold detected by 302 is compared with the value, and when the selected DRC value is equal to or greater than the DRC threshold value, the selected DRC value is given to the DRC signal generation unit 1712. When the selected DRC value is smaller than the DRC value, the selected DRC value is not given to the DRC signal generation unit 1712.

Next, referring to FIG. 11, a base station apparatus and a communication terminal apparatus configured as described above are used. The downlink packet transmission process performed in this way will be described. In FIG. 11, the same or similar processing steps as those shown in FIG. 4 are denoted by the same reference numerals. Here, the description will focus on the parts related to the first embodiment.

In FIG. 11, a DRC signal transmission availability determination process (ST401) is inserted between the requested data rate determination process (ST1803) and the DRC signal generation process (ST1804) shown in FIG.

In the DRC signal transmission availability determination process (ST401), the requested data rate determination process (ST180)

It is determined whether the DRC value indicated by the data rate determined in 3) exceeds the DRC threshold sent by the base station equipment, and if DRC value ≥ DRC threshold (ST401: Yes) The DRC signal generation process (ST18

Go to 04). As a result, a DRC signal having a predetermined DRC value corresponding to the reception quality is transmitted to the base station apparatus.

On the other hand, if DRC value <DRC threshold value (ST401: No), the process returns to pilot signal reception processing (ST1801). In other words, it is determined that there is no possibility of receiving packet allocation, and transmission of a DRC signal having a predetermined DRC value corresponding to the received quality is stopped.

In FIG. 11, a DRC threshold value calculation process (ST402, ST403) is inserted between the packet allocation process (ST1808) and the packet generation process (ST1809) shown in FIG. Instead of transmission processing (ST1810), transmission processing (ST404) is performed.

[0070] In the DRC threshold calculation process (ST402, ST403), for example, the allocation result in the packet allocation process (ST 1808) is stored in a buffer (ST402), and the stored past allocation history power DRC threshold is stored. Calculate (ST403). As a result, each communication terminal apparatus in the cell transmits a DRC threshold value in addition to the packet (ST404).

Here, with reference to FIG. 12 and FIG. 13, description will be given of how packet allocation processing is performed in the base station apparatus as a result of enabling the communication terminal apparatus to control transmission of the DRC signal. FIG. 12 is a diagram showing an example of a packet allocation result when Embodiment 1 of the present invention is applied to the MaxCIR method for determining the priority of the communication terminal apparatus based on the DRC value. FIG. 13 shows the implementation of the present invention in the proportional fairness method for determining the priority of the communication terminal device based on the DRC value and the average data rate. It is a figure which shows an example of the packet allocation result at the time of applying 1. In FIG. 12 and FIG. 13, “DRC threshold” is added to the items shown in FIG. 5 and FIG.

In FIG. 12, “DRC threshold” indicates an average value of all received DRC values when the past several times are set to once (that is, the previous time). That is, the “DRC threshold” shown in FIG. 12 is calculated as an average value of all DRC values received at that time at each packet allocation timing.

In FIG. 12, in the example of packet allocation timing # 1, the received DRC value is “10”, “8”, “3”, so the average DRC value is “7”. The base station apparatus reports this average DRC value “7” to all communication terminal apparatuses as a DRC value at the next packet allocation timing # 2.

[0074] Each user transmits a DR C signal only when the DRC value to be transmitted is equal to or greater than the DRC threshold value "7". Therefore, at allocation timing # 2, communication terminal apparatus A and communication terminal apparatus B Because the DRC value is greater than or equal to the DRC threshold, the communication terminal device C that transmits the DRC signal does not transmit the DRC signal because the DRC value is less than the DRC threshold. Thereafter, the communication terminal apparatus C does not transmit a DRC signal until the reception quality is improved and the possibility that a packet is allocated becomes high. However, the packet allocation result is the same as that shown in Fig. 5.

In FIG. 13, “DRC threshold” indicates the priority DRCZR of the user who performed packet allocation.

The value is obtained by subtracting the value “3” from (t). At packet allocation timing # 1, communication terminal apparatuses A, B, and C transmit DRC signals as usual. Since each priority D RC / R (t) is “10” “8” “3”, the assigned DRC value is “10”, and the DRC threshold value is “7”. The base station apparatus reports the value “7” to each communication terminal apparatus as the DRC threshold value at the next packet allocation timing # 2.

[0076] At the next packet allocation timing # 2, only the communication terminal apparatus B with the priority value "7" or higher transmits a DRC signal. Since the priority DRCZR (t) of the communication terminal device B at this time is “9”, the value “6” obtained by subtracting the value “3” from this is the DRC threshold value. The base station apparatus reports the value “6” to each communication terminal apparatus as a value when performing DRC at the next packet allocation timing # 3. [0077] At the next packet allocation timing # 3, only the communication terminal apparatus A with the priority value "6" or higher transmits a DRC signal. Since the priority DRCZR (t) of the communication terminal device A at this time is “7”, the value “4” obtained by subtracting the value “3” from this is the DRC threshold value. The base station apparatus reports the value “4” to each communication terminal apparatus as a value when performing DRC at the next packet allocation timing # 4.

[0078] Communication terminal device C does not transmit a DRC signal at packet allocation timings # 2 and # 3, but the priority gradually increases, and at packet allocation timing # 4, DRC threshold "4" As described above, a DRC signal is transmitted. Thus, even when the proportional fairness method is used, the packet allocation result is the same as that shown in FIG.

[0079] As described above, according to the first embodiment, the base station apparatus performs DRC and informs each communication terminal apparatus of the value so that the communication terminal apparatus can determine the packet allocation possibility. Therefore, each communication terminal device has a good reception quality and a high possibility of packet allocation according to uniform judgment criteria, and only the communication terminal device transmits a DRC signal, so that the communication quality is poor and the packet allocation possibility is low. The terminal device can perform control not to transmit a DRC signal. Therefore, a communication terminal apparatus having a low packet allocation possibility does not need to perform a wasteful process for generating a DRC signal and does not waste a transmission power.

[0080] Further, since the uplink interference component is reduced, the communication quality can be improved. Furthermore, in addition to reducing the scheduling load, the base station apparatus reduces the occurrence of packet retransmission due to erroneous detection of the DRC value, thereby suppressing throughput degradation. In addition, even if the DRC signal transmission restriction according to the first embodiment is applied, the packet allocation results are the same as those in the conventional example (Figs. 5 and 6). Throughput can be maintained.

[0081] (Embodiment 2)

FIG. 14 is a system diagram illustrating a DRC signal transmission method in the high-speed packet transmission system according to the second embodiment of the present invention. In FIG. 14, a base station apparatus (BTS) 701 performs the same packet allocation operation with the same configuration as the base station apparatus shown in the conventional example (FIG. 1). On the other hand, the communication terminal device 702, the communication terminal device 703, and the communication terminal device 704, which are mobile devices in the cell, each assign a packet for DRC signal transmission of its own device. It is now possible to autonomously estimate the packet allocation possibility from the situation and perform transmission control to determine the power of transmitting DRC signals! /

[0082] Various methods can be considered as a method for each communication terminal apparatus to autonomously estimate the packet allocation possibility from the packet allocation status for its own DRC signal transmission and to determine whether or not to transmit the DRC signal. Force Here, the following methods (1) and (2) will be described.

[0083] (1) Among the DRC values that have been transmitted in the past, the DRC value for which the packet was actually assigned is also the DRC value that is N levels below the DRC threshold shown in the first embodiment. And FIG. 15 shows a configuration example of a communication terminal apparatus that implements this method, and FIG. 16 shows the overall operation (downlink packet transmission processing) including the base station apparatus.

[0084] (2) The DRC threshold shown in Embodiment 1 is the value when the probability that packets are actually allocated falls below N% among the DRC values transmitted in the past. . FIG. 17 shows a configuration example of a communication terminal apparatus that implements this method, and FIG. 18 shows an overall operation (downlink packet transmission processing) including the base station apparatus.

First, a configuration example and overall operation (downlink packet transmission processing) of the communication terminal apparatus when the method (1) is used will be described. FIG. 15 is a block diagram showing a configuration example of the communication terminal apparatus shown in FIG. 14 (part 1). FIG. 16 is a flowchart for explaining the overall operation (downstream packet transmission processing) including the base station apparatus (part 1).

In FIG. 15, components that are the same as or equivalent to the components shown in FIG. 3 are given the same reference numerals. Here, parts related to the second embodiment will be described. As shown in FIG. 15, the communication terminal apparatus (part 1) according to the second embodiment has a DRC signal transmission determination unit 801, a transmission DRC signal buffer unit 802, and a minimum in accordance with the configuration shown in FIG. An allocation DRC value selection unit 803 is added.

[0087] DRC signal transmission determining section 801 first provides the DRC value to be transmitted acquired from DRC signal selecting section 1711 as well as to DRC signal generating section 1712 and also to transmission DRC signal buffer section 802. The transmission DRC signal buffer unit 802 monitors the processing result of the reception processing unit 1709, and when processing is performed on a packet assigned to the transmitted DRC value received from the DRC signal transmission determination unit 801, Stores the transmitted DR C value that received the packet assignment. [0088] The minimum allocated DRC value selection unit 803 sets the minimum DRC value “D RCmin” among the transmitted DRC values that have received the packet allocation accumulated in the transmission DRC signal buffer unit 802 as described above. This is selected and given to the DRC signal transmission judgment unit 801. Needless to say, the minimum allocated DRC value selection unit 803 starts the selection operation when the transmission DRC signal buffer unit 802 stores the transmitted DRC value values that have received the packet allocation.

[0089] When the DRC signal transmission determination unit 801 receives the DRC value “DRC min” from the minimum allocation DRC value selection unit 803, the DRC signal transmission determination unit 801 also determines the DRC value in the N stages as the “DRC threshold” Compares the magnitude relationship with the DRC value to be transmitted input from the selection unit 1711, and when the DRC value to be transmitted is equal to or greater than the “DRC threshold value”, the DRC value to be transmitted is set to the DRC signal. This is given to the generation unit 1712. Also, the DRC signal transmission determination unit 801 gives the DRC value to be transmitted to the DRC signal generation unit 1712.

Next, with reference to FIG. 16, description will be given of downlink packet transmission processing performed by the base station apparatus and communication terminal apparatus configured as described above. In FIG. 16, the same reference numerals are given to the processing procedures that are the same as or equivalent to the processing procedures shown in FIG. Here, the description will focus on the parts related to the first embodiment.

In FIG. 16, a DRC signal transmission availability determination process (ST901) is inserted between the required data rate determination process (ST1803) and the DRC signal generation process (ST1804) shown in FIG. In FIG. 16, a minimum allocation DRC value determination process (ST902 to ST904) is added.

[0092] In the DRC signal transmission availability determination process (ST901), the DRC value force indicated by the data rate determined in the required data rate determination process (ST180 3) is obtained in the minimum allocation DRC value determination process (ST90 02 to ST904). Minimum DRC value “DRCmin” force It is determined whether or not the DRC value under the N stage is exceeded. If DRC value ≥DRCmin—N (ST901: Yes), there is a possibility that the packet can be assigned. The process proceeds to the DRC signal generation process (ST1804). As a result, a DRC signal having a predetermined DRC value corresponding to the reception quality is transmitted to the base station apparatus.

On the other hand, when DRC value <DRCmin—N (ST901: No), the process returns to pilot signal reception processing (ST1801). In other words, it is determined that there is no possibility of receiving the packet allocation. Stops sending a DRC signal with a predetermined DRC value corresponding to the signal quality to the base station.

[0094] In the minimum allocation DRC value determination process (ST902 to ST904), when a packet addressed to its own device is detected (ST1811), it is checked whether or not the packet is an allocated packet (ST902). If the packet is a packet (ST902: Yes), the transmitted DRC value that is the target of packet allocation is stored in the buffer (ST903). Then, the smallest DRC value “DRCmin” is selected from the packet allocation DRC values stored in the notifier, and is given to the DRC signal transmission availability determination process (ST901) (ST904).

Next, a configuration example and overall operation (downlink packet transmission process) of the communication terminal apparatus when using the method (2) will be described. FIG. 17 is a block diagram showing a configuration example of the communication terminal apparatus shown in FIG. 14 (part 2). FIG. 18 is a flowchart for explaining the overall operation (downstream packet transmission process) including the base station apparatus (part 2).

In FIG. 17, components that are the same as or equivalent to the components shown in FIG. 3 are given the same reference numerals. Here, parts related to the second embodiment will be described. As shown in FIG. 17, the communication terminal apparatus (part 2) according to the second embodiment has the DRC signal transmission judgment unit 1001, the transmission DRC signal buffer unit 1002, and the DRC value for each configuration in the configuration shown in FIG. An allocation probability calculation unit 1003 is added.

[0097] DRC signal transmission determining section 1001 first provides the DRC value to be transmitted acquired from DRC signal selecting section 1711 to DRC signal generating section 1712 and also to transmission DRC signal buffer section 1002. . The transmission DRC signal buffer unit 1002 stores the transmitted DRC value received from the DRC signal transmission determination unit 801, monitors the processing result of the reception processing unit 1709, and receives the assigned packet. This information is added to the transmitted DRC value.

[0098] The allocation probability calculation unit 1003 for each DRC value indicates the actual packet allocation probability among the transmitted DRC values accumulated in the transmission DRC signal buffer unit 1002 as described above for each transmitted DRC value. And provided to the DRC signal transmission judgment unit 1001.

[0099] When the allocation probability for each DRC value is input from the allocation probability calculation unit 1003 for each DRC value, the DRC signal transmission determination unit 1001 determines the DRC value that is N% lower than that as the "DRC threshold". I will. Then, the DRC value to be transmitted input from the DRC signal selection unit 1711 is given to the transmission DRC signal buffer unit 1002, and the magnitude relationship between the DRC value to be transmitted and “DRC threshold V, value” is compared. When the DRC value to be transmitted is greater than or equal to “DRC threshold, value”, the DRC value to be transmitted is given to the DRC signal generation unit 1712.

Next, with reference to FIG. 18, description will be given of downlink packet transmission processing performed by the base station apparatus and communication terminal apparatus configured as described above. In FIG. 18, the same or similar processing procedures as those shown in FIG. 4 are given the same reference numerals. Here, the description will focus on the parts related to the first embodiment.

In FIG. 18, a DRC signal transmission availability determination process (ST1101) is inserted between the required data rate determination process (ST1803) and the DRC signal generation process (ST1804) shown in FIG. In FIG. 18, an allocation probability calculation process (ST1102 to ST1104) is added.

[0102] In the DRC signal transmission availability determination process (ST1101), the allocation probability obtained in the DRC value power allocation probability calculation process (ST1102 to ST1104) indicated by the data rate determined in the requested data rate determination process (ST18 03) It is determined whether the DRC value is less than the force N%, and if the allocation probability is ≥N% (ST1101: Yes), it is determined that there is a possibility of receiving the packet allocation and the DRC signal generation process Proceed to (ST1804). As a result, a DRC signal having a predetermined DRC value corresponding to the reception quality is transmitted to the base station apparatus.

[0103] On the other hand, if the allocation probability is <N% (ST1101: No), the process returns to the pilot signal reception process (ST1801). That is, it is determined that there is no possibility of receiving packet allocation, and transmission of a DRC signal having a predetermined DRC value corresponding to the reception quality to the base station apparatus is stopped.

[0104] In the allocation probability calculation process (ST1102 to ST1104), when a packet addressed to its own device is detected (ST1811), it is checked whether the packet is an allocated packet (ST1102), and the transmitted DRC value and The relationship with the presence / absence of packet allocation is stored in the buffer (ST1103). Then, the allocation probability is calculated based on the transmitted DRC value accumulated in the notifier, and is given to the DRC signal transmission availability determination process (ST1101) (ST1104).

[0105] As described above, according to the second embodiment, the communication terminal apparatus autonomously estimates the packet allocation status with respect to its own DRC signal transmission, and estimates the possibility of packet allocation. Since transmission control for determining whether or not to transmit a signal is performed, the estimation accuracy of packet assignability is somewhat inferior to that of Embodiment 1, but the same operation and effect as Embodiment 1 can be obtained. it can.

[0106] Power! According to the second embodiment, the base station apparatus does not need to report the DRC threshold value as in the first embodiment! Therefore, the processing load should not be increased! When you are done!

[Embodiment 3]

In this third embodiment, a multi-carrier high-speed packet transmission system that will be used in the future will be described. As described above, when a broadband system such as an EV-DO system is converted to a multicarrier, the adjacent carriers have a wide bandwidth, and the multipath fading received by each carrier has no correlation. For this reason, each communication terminal device, which is a mobile device, needs to estimate the reception environment of each carrier and transmit a DRC signal for each carrier to the base station device. The base station apparatus needs to check the priority for each carrier and perform packet allocation.

[0108] Therefore, in order to realize a high-speed packet transmission system using multiple carriers (EV-DO system using multiple carriers), each communication terminal device increases the amount of DRC signal generation and power consumption. In the base station apparatus, it is an urgent task to prevent the scheduling load from increasing by the number of carriers.

[0109] Although the methods of the first and second embodiments described above are also effective measures, the method of the third embodiment is considered to be relatively easy to introduce compared to the first and second embodiments. Indicates. That is, FIG. 19 is a system diagram illustrating a DRC signal transmission method in a multi-carrier high-speed packet transmission system according to Embodiment 3 of the present invention.

In FIG. 19, base station apparatus (BTS) 1201 has a conventional single carrier configuration for a plurality of carriers, and it is assumed that packet allocation is performed for each carrier. On the other hand, in each communication terminal apparatus 1202, 1203, 1204 in the cell, a DRC signal having a DRC value indicating a data rate determined from the reception quality of each downlink is transmitted to the base station apparatus (BTS) 1201 by the corresponding carrier. When transmitting, a DRC signal corresponding to a predetermined carrier having good reception quality is transmitted. [0111] Specifically, each of the communication terminal devices 1202, 1203, 1204 transmits (1) a DRC signal corresponding to the carrier having the highest reception quality, or (2) a higher number having good reception quality. Each DRC signal corresponding to the carrier is transmitted.

FIG. 20 is a block diagram showing a configuration example of the communication terminal apparatus shown in FIG. In FIG. 20, a reception RF unit 1302 and a transmission RF unit 1303 are connected to an antenna 1301 via a duplexer (not shown). The receiving RF unit 1302 is connected to carrier receiving units 1304-1 to 1304 -N that receive baseband signals in parallel. The transmission RF unit 1303 is connected to carrier transmission units 1305-1 to 1305 -N that output baseband signals in parallel.

[0113] Carrier receiving units 1304-1 to 1304-N have the same configuration, and are each despreading units 1704 to 1706, adaptive demodulation unit 1707, control information demodulation unit 1708, and reception processing unit shown in FIG. 1709 and a reception quality measuring unit 1710.

[0114] Carrier transmission units 1305-1 to 1305-N have the same configuration, and each includes DRC signal generation unit 1712, modulation unit 1713, spreading unit 1714, and packet reception availability information generation unit shown in FIG. 1716, a spreading unit 1717, a pilot signal generating unit 1718, a spreading unit 1719, and a signal multiplexing unit 1715 are provided.

A transmission DRC signal selection unit 1306 is provided between the carrier reception units 1304-1 to 1304 -N and the carrier transmission units 1305-1 to 1305 -N. The transmission DRC signal selection unit 1306 receives the measurement results of the reception quality measurement units 1710 of the carrier reception units 1304-1 to 1304-N, and the DRC signal corresponding to the carrier having the highest reception quality or the reception quality A DRC signal corresponding to a good upper number carrier is supplied to a corresponding DRC signal generation unit 1712 of each DRC signal generation unit 1712 of the carrier transmission units 1305-1 to 1 305 -N.

Further, the processing results of the reception processing units 1709 of the carrier reception units 1304-1 to 1304 -N are supplied to the packet reception availability information generation unit 1716 of the carrier transmission units 1305-1 to 1305 -N.

[0117] Next, downlink packet transmission processing in a multicarrier high-speed packet transmission system will be described with reference to FIG.

[0118] In the communication terminal apparatus, for each carrier, packet reception processing (ST1401), received packets Reception quality measurement processing using signals (ST1402), and data rate determination processing (ST1403) corresponding to the measured reception quality. Then, each DRC value indicating the data rate obtained for each carrier is compared (ST1404), for example, a DRC signal of the top N carriers with good reception quality is generated and transmitted to the base station apparatus (ST1405). .

[0119] In the base station device, for each carrier, DRC signal reception processing (ST1406), priority calculation processing of each communication terminal device based on the received DRC value (ST1407), and communication to a communication terminal device with high priority Packet allocation processing (ST1408), transmission packet generation processing (ST1409) in a modulation format according to the DRC value, and packet transmission processing (ST1410) are performed.

[0120] In the communication terminal device, processing for detecting reception of a packet addressed to the own device (ST 1411), reception processing of the packet addressed to the own device (ST1412), and response (ACK, NACK) transmission based on the reception processing result for each carrier Processing (ST1413) is performed.

[0121] As described above, according to Embodiment 3, in a high-speed packet transmission system using multicarriers, each communication terminal apparatus transmits a DRC signal corresponding to a predetermined carrier having good reception quality. Therefore, each communication terminal device suppresses an increase in the processing amount and power consumption of DRC signal generation, and the base station device suppresses an increase in the scheduling load allocated to the packet by the number of carriers. it can.

[0122] Power! Therefore, according to Embodiment 3, in a high-speed packet transmission system using multicarriers, only a specific communication terminal device cannot monopolize multiple carriers and receive packets! / It is also possible to maintain fairness between communication terminal devices.

[0123] In this specification, the lxEV—DO system has been described in mind, but in addition to the HSDPA (High Speed Downlink Packet Data Access) system, which is a high-speed packet transmission system for the mobile phone network W—CDMA. Similarly, it goes without saying that the present invention can be applied.

[0124] This specification is based on Japanese Patent Application No. 2004-335013 filed on Nov. 18, 2004. All this content is included here.

Industrial applicability

[0125] The present invention is suitable for use in a communication terminal apparatus in a high-speed packet transmission system. In particular, for multi-carrier high-speed packet transmission systems that are expected to be used in the future. It is useful.

Claims

The scope of the claims

[1] reception quality measuring means for measuring the reception quality of the downlink,

A selection means for selecting a data rate of a packet transmitted from a base station apparatus of a communication partner based on the measured reception quality!

DRC signal generation means for generating a DRC (Data Rate Control) signal indicating the selected data rate;

Transmitting means for transmitting the generated DRC signal to the base station apparatus,

The communication terminal apparatus, wherein the selecting means outputs the data rate to the DRC signal generating means only when the selected data rate is equal to or greater than a threshold value.

[2] When the base station apparatus power packet is transmitted by multicarrier,

The reception quality measuring means measures downlink reception quality for each carrier, and the selecting means selects a data rate for each carrier based on the measured reception quality, and only a data rate equal to or higher than a threshold value is selected. The communication terminal device according to claim 1, wherein the communication terminal device outputs the signal to the DRC signal generation means.

3. The communication terminal apparatus according to claim 1, wherein the threshold value is a value notified from the base station apparatus.

4. The communication terminal apparatus according to claim 1, wherein the threshold value is a value obtained by estimating a packet assignability in the communication terminal apparatus.

[5] A reception quality measurement process for measuring the reception quality of the downlink,

A selection step of selecting a data rate of a packet transmitted from a base station apparatus of a communication partner on the basis of the measured reception quality;

A DRC signal generation step of generating a DRC (Data Rate Control) signal indicating the selected data rate;

A transmission step of transmitting the generated DRC signal to the base station device,

The DRC signal transmission method, wherein the selecting step outputs the data rate to the DRC signal generating step only when the selected data rate is equal to or higher than a threshold value.