JPWO2006095387A1 - Scheduling method and base station apparatus - Google Patents

Abstract

In a wireless data transmission system in which data is transmitted from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals, the scheduler selects which mobile terminal based on the quality of the received signal at each mobile terminal A mobile terminal that calculates the index value, corrects the index value by the quality variation rate of the received signal, the fading frequency, or the error rate for each CQI, and transmits data based on the corrected index value. select.

Description

  The present invention relates to a scheduling method and a base station apparatus, and more particularly to a scheduling method and a base station apparatus in a wireless data transmission system for transmitting data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals. .

There are several wireless communication systems in which a line is shared by a plurality of users. Here, a W-CDMA (UMTS) mobile communication system will be described as an example. FIG. 17 is a configuration example of a W-CDMA mobile communication system. In the figure, 1 is a core network, 2 is a radio base station controller (RNC), 4 and 5 are demultiplexers, 6 _{1 to} 6 ₅ are radio base stations (RodeB), and 7 is a mobile station. (UE: User equipment) is shown.
The core network 1 is a network for performing routing in the mobile communication system. For example, the core network can be configured by an ATM switching network, a packet switching network, a router network, or the like. The core network 1 is also connected to other public networks (PSTN) or the like so that the mobile station 7 can communicate with a fixed telephone or the like.

The wireless base station controllers 2 and 3, are positioned as higher-level devices of wireless base stations _{61 through 65,} a function of controlling these wireless base stations _{61 through 65} (management of wireless resources used, etc.) I have. In addition, at the time of handover, a handover control function is also provided which receives signals from one mobile station 7 from a plurality of radio base stations under its control, selects data with better quality, and sends it to the core network 1 side. .
The demultiplexers 4 and 5 are provided between the RNC and the radio base station, demultiplex signals received from the RNCs 2 and 3 and addressed to the radio base stations, and output the signals to the radio base stations. Control is performed to multiplex the signals from the stations and deliver them to each RNC side.
The radio base stations 6 _{1 to} 6 ₃ perform radio communication with the mobile station 7 while the radio resources are managed by the RNC 2 and the radio base stations 6 ₄ and 6 ₅ are managed by the RNC 3. The mobile station 7 is located in the radio area of the radio base station 6, thereby establishing a radio line with the radio base station 6 and communicating with other communication devices via the core network 1. Do.
The interface between the core network 1 and the RNCs 2 and 3 is the Iu interface, the interface between the RNCs 2 and 3 is the Iur interface, and the interface between the RNCs 2 and 3 and each radio base station 6 is moved to the Iub interface and the radio base station 6. An interface with the station 7 is referred to as a Uu interface, and a network formed by 2 to 6 devices is particularly referred to as a radio access network (RAN). The line between the core network 1 and the RNCs 2 and 3 is shared for the Iu and Iur interfaces, and the line between the RNCs 2 and 3 and the demultiplexers 4 and 5 is an Iub interface for a plurality of radio base stations. Shared by.
The above is a description of a general mobile communication system. Further, as a technique that enables high-speed downlink data transmission, an HSDPA (High Speed Downlink Packet Access) system may be employed (Non-Patent Document 1). , 2). Here, HSDPA will be briefly described.

・ HSDPA
HSDPA employs adaptive coding and modulation (AMC), for example, QPSK modulation scheme (QPSK modulation scheme) and 16-value QAM scheme (16 QAM scheme) are used for radio base stations and mobile stations. It is characterized by adaptive switching according to the wireless environment.
HSDPA adopts an H-ARQ (Hybrid Automatic Repeat reQuest) system. In H-ARQ, when an error is detected in received data from a radio base station, a mobile station makes a retransmission request (transmission of a NACK signal) to the radio base station. The radio base station that has received this retransmission request retransmits the data, so that the mobile station performs error correction decoding using both the already received data and the retransmitted received data. In this way, in H-ARQ, even if there is an error, the already received data is effectively used, so that the gain of error correction decoding is increased, and as a result, the number of retransmissions is reduced. When an ACK signal is received from a mobile station, data transmission is successful, so retransmission is unnecessary, and the next data transmission is performed.
As shown in FIG. 18, the main radio channels used for HSDPA are (1) HS-SCCH (High Speed-Shared Control Channel), (2) HS-PDSCH (High Speed-Physical Downlink Shared Channel), (3) There is HS-DPCCH (High Speed-Dedicated Physical Control Channel).
HS-SCCH and HS-PDSCH are both shared channels in the downlink direction (that is, the downlink that is the direction from the radio base station to the mobile station), and HS-SCCH is the HS-PDSCH. It is a control channel for transmitting various parameters relating to data to be transmitted. In other words, it is a channel for notifying that data transmission is performed via the HS-PDSCH. As various parameters, for example, modulation scheme information indicating which modulation scheme is used to transmit data by HS-PDSCH, the number of assigned spreading codes (number of codes), and the rate for transmission data There is information such as matching patterns.
On the other hand, HS-DPCCH is an individual control channel (dedicated control channel) in the uplink direction (that is, the uplink from the mobile station to the radio base station), and an error in data received via HS-PDSCH. This is used when the mobile station transmits a reception result (ACK signal, NACK signal) to the radio base station depending on whether or not there is. That is, it is a channel used for transmitting a reception result of data received via the HS-PDSCH. When the mobile station fails to receive data (when the received data is a CRC error, etc.), the NACK signal is transmitted from the mobile station, so that the radio base station executes retransmission control.
In addition, the HS-DPCCH is also used by a mobile station that measures the reception quality (for example, SIR) of a received signal from a radio base station to transmit the reception quality as a CQI (Channel Quality Indicator) to the radio base station. . That is, the CQI is information for the mobile station to report the reception environment to the base station. The CQI takes a value of CQI = 1 to 30, and the block error rate BLER does not exceed 0.1 under the reception environment. Report the CQI value to the base station.
Based on the received CQI value, the radio base station determines whether the downlink radio environment is good or not. If the radio base station is good, the radio base station switches to a modulation method capable of transmitting data at a higher speed. Switch to a modulation scheme for transmitting data (ie, perform adaptive modulation). Actually, the base station holds a CQI table that defines formats with different transmission rates according to CQI = 1 to 30, and the parameters (transmission rate, modulation method, number of multiplexed codes, etc.) according to the CQI value are It is obtained from the table and notified to the mobile station by HS-SCCH.

Channel structure FIG. 19 is an explanatory diagram of a channel configuration in HSDPA. In W-CDMA, since a code division multiplexing system is adopted, each channel is separated by a code. CPICH (Common Pilot Channel) and SCH (Synchronization Channel) are downlink common channels, respectively. CPICH is a channel used for channel estimation, cell search, and the like in a mobile station, and is a channel for transmitting a so-called pilot signal. Strictly speaking, the SCH includes a P-SCH (Primary SCH) and an S-SCH (Secondary SCH), and is a channel transmitted in bursts at the first 256 chips of each slot. This SCH is received by a mobile station that performs a three-stage cell search, and is used to establish slot synchronization and frame synchronization and to identify a base station code (scramble code). The SCH is 1/10 the length of one slot, but is shown wider in the figure. The remaining 9/10 is P-CCPCH.
Next, channel timing relationships will be described. Each channel is composed of 15 slots to form one frame (10 ms), and each frame has a length corresponding to 2560 chip length. As described above, since CPICH is used as a reference for other channels, the frame heads of SCH + P-CCPCH and HS-SCCH coincide with the heads of CPICH frames. On the other hand, the head of the HS-PDSCH frame is delayed by 2 slots with respect to HS-SCCH or the like. This is because the mobile station received the modulation scheme information via the HS-SCCH and received the modulation scheme. This is because HS-PDSCH can be demodulated by a demodulation method corresponding to the above. HS-SCCH and HS-PDSCH constitute one subframe with three slots.
HS-DPCCH is an uplink channel, and the first slot thereof receives an ACK / NACK signal indicating the reception result of HS-PDSCH from the mobile station to the radio base station after about 7.5 slots have elapsed since the reception of HS-PDSCH. Used to send to. The second and third slots are used to periodically transmit CQI information for adaptive modulation control to the base station. Here, the CQI information to be transmitted is calculated based on a reception environment (for example, SIR measurement result of CPICH) measured in a period from 4 slots before 1 slot before CQI transmission.

により、指標値C_n(PF)を演算し、指標値C_n(PF)が高いものを選択するという点で、公平性を保ちながら、スループットを向上させる方式である。ただし、(1)式において、R_n は瞬時回線品質、Ave R_n は平均回線品質、1-α、1-βはそれぞれの重み付け係数である。Rn、Ave Rnを回線品質ではなく、回線品質に応じた送信可能なデータ量に置き換えることもある。The scheduler scheduler determines the transmission target (mobile station) and the transmission speed, the modulation method, etc. based on the index value calculated based on the channel quality and the transmission data rate. The scheduler is used in various communication systems. Here, a scheduler applied to a mobile communication system adopting the HSDPA scheme will be described as an example. In HSDPA, since the physical downlink data channel HS-PDSCH described above is shared by a plurality of mobile stations, it is necessary to select a mobile station to be transmitted, and the scheduler is involved in mobile station selection control. FIG. 20 shows a configuration example in the HSDPA system, in which two radio base station devices 6 _{1 to} 6 ₂ are connected to _one radio base station control device 2, and the radio base station device 6 ₁ moves under control. a station 7 ₁ to _7-m and conduct communication, the wireless base station apparatus 6 ₂ is communicating with the mobile station 7 _{(m + 1)} ~7 _n subordinate.
The scheduler SJL of each base station selects a mobile station that transmits data based on CQI and HARQ information (ACK / NACK information) received from the mobile station (mobile station selection control), and receives CQI from the mobile station. Based on the information, the transmission data amount, modulation method, power, etc. are determined, and the channel coding unit CCD is instructed. Further, the scheduler SJL requests the data addressed to each mobile station from the radio base station controller 2 based on the scheduling result (flow control). The radio base station control device 2 holds data addressed to each of the mobile stations 7 _{1 to} 7 _n received via the core network, and transmits the data addressed to the requested mobile station in response to a request from the scheduler SJL. Block buffer section BUF of the base station ₆₁ through 65 ₂ stores each mobile station addressed data transmitted from the wireless base station controller 2, the requested data addressed to the mobile station designated by the instruction from the scheduler SJL The size is input to the channel coding unit CCD. The channel coding unit CCD adds a CRC code for each block to the input data addressed to the mobile station, encodes it for each predetermined number of blocks, modulates it with a modulation method designated by the scheduler, and transmits it to each mobile station. To do.
As a user selection algorithm in the scheduler, the Maximum CIR method and the Proportional Fairness method have been proposed (see Non-Patent Document 3). The Maximum CIR method is a method of selecting a user with good line quality, but it is not assigned to a user with poor line quality and there is no fairness. In contrast, the Proportional Fairness method is

Thus, the index value C _{n (PF)} is calculated, and the one having a high index value C _{n (PF)} is selected, so that throughput is improved while maintaining fairness. However, in equation (1), R _n Is the instantaneous channel quality, Ave R _n is the average channel quality, and 1-α and 1-β are the respective weighting coefficients. Rn and Ave Rn may be replaced with the amount of data that can be transmitted according to the line quality, not the line quality.

[Problem to be Solved by the Invention] In a wireless communication system in which a line is shared by a plurality of users, the scheduler selects a mobile station to be transmitted from a plurality of users based on a scheduling method, and adapts according to downlink quality. Implement modulation control. For this reason, the scheduling scheme has a great influence on the overall cell throughput. The Proportional Fairness method described above in the background art is excellent in improving throughput while maintaining fairness, but still has the following problems.
(1) The Proportional Fairness method makes it easy to select a user whose line quality varies greatly. Proportional Fairness is a method that takes into account both fairness and throughput by using the ratio of instantaneous value to average line quality as an index, while selecting users with severe line quality that seems to be in a poor environment. It's easy to do.
(2) The Proportional Fairness method is not a method that takes into account the data type. Even if the amount of data is the same, the transmission interval may be long if there is no real-time property such as E-mail, but the transmission interval needs to be shortened if the real-time property such as voice is required. . If the characteristics depending on the data type are not taken into consideration at all, the radio resources may be assigned frequently but not to those with high real-time characteristics, while those that do not require real-time characteristics so much. Cannot be used efficiently.
(3) The Proportional Fairness method is not a method that takes into account the error rate for each CQI. In HSDPA, the amount of data to be transmitted is determined according to the line quality (CQI) so as to achieve a target error rate (block error rate = 0.1). However, if the propagation environment varies depending on the location and time, the error rate at the mobile station varies depending on the performance of the terminal. In such a case, it is difficult for all users to make the error rate for each CQI uniform, that is, 0.1, and it is necessary to take this variation into consideration.
(4) The Proportional Fairness method is not a method that takes into account the error rate for each retransmission. In HSDPA, H-ARQ is implemented, and even if there is an error, the gain of error correction decoding is increased by effectively using already received data, and the error rate decreases as the number of retransmissions increases. Become. Therefore, it is necessary to consider the error rate for each retransmission. By the way, the relationship between the number of retransmissions and the error rate (the relationship between the number of retransmissions and the gain) varies depending on the propagation environment. Therefore, it is necessary to take into account the relationship between the number of retransmissions and the error rate according to the propagation environment.
(5) The Proportional Fairness method is not a method that takes into account the uplink radio synchronization state. Although it is assumed that the selection candidate user has established uplink synchronization, it is possible to select a mobile station whose uplink synchronization is not stable. That is, it is possible to select a mobile station that is not in a completely synchronized state but in a forward / backward protected state. Fully synchronized state always means that pilot synchronization is established, and forward protected state means that the pilot synchronization is established once or more from the out-of-synchronization state, and then the state where pilot synchronization is not increased by the number of forward protection stages The state refers to a state in which the pilot synchronization is not increased by the number of backward protection stages after the pilot synchronization is deviated once or more from the complete synchronization state. In the forward / backward protection state, the synchronization state is generally unstable, and in this case, the reception probability of HS-DPCCH data decreases and retransmission processing increases, so that the cell throughput decreases. Therefore, it is necessary to take the uplink synchronization state into consideration.

As described above, an object of the present invention is to provide a scheduling method and a base station apparatus that can solve the problems (1) to (5) and can realize higher throughput based on the Proportional Fairness technique. .
3G TS 25.212 (3rd Generation Partnership Project: Technical Specification Group Radio Access Network; Multiplexing and channel coding (FDD)) 3G TS 25.214 (3rd Generation Partnership Project: Technical Specification Group Radio Access Network; Physical layer procedures (FDD)) IEICE RCS2001-291, pp.51-58, Mar.2002. "Characteristic comparison of scheduling methods focusing on the throughput of each user in high-speed downlink packets"

In the first aspect of the present invention, the scheduler reflects the dispersion value of the channel quality or the fading frequency estimation result in the Proportional Fairness method. This makes it difficult to select a mobile station with a significant fluctuation in channel quality or a high fading frequency.
In addition, in the second invention, the scheduler reflects the required transmission interval according to the data type in the Proportional Fairness method, and the mobile station transmitting data with short required transmission interval (data such as voice with high real-time property) is transmitted. Select with priority.
In the third invention, the scheduler reflects the error rate for each CQI in the Proportional Fairness method and preferentially selects a mobile station that has received a CQI with a low error rate.
In addition, in the fourth invention, the scheduler reflects the error rate for each number of retransmissions in the Proportional Fairness method and preferentially selects a mobile station having a low number of retransmissions.
In the fifth invention, the scheduler reflects whether or not the mobile station is in a completely synchronized state in the Proportional Fairness method, and preferentially selects a completely synchronized mobile station.
According to the first invention, when the channel quality fluctuates severely or the fading frequency is high, the uplink / downlink reception characteristics tend to deteriorate. The rate is lowered and the throughput is improved.
According to the second aspect of the present invention, it is possible to preferentially select a mobile station that transmits / receives data having a short required transmission interval, and not to allocate a line to a mobile station having a long required transmission interval, so that an optimum line allocation according to the data type Is possible.
According to the third aspect, by preferentially selecting a mobile station that has received a CQI with a low error rate, the error rate of the entire cell is lowered and the throughput is improved.
According to the fourth aspect, by preferentially selecting a mobile station having a low number of retransmissions with a low error rate, the error rate of the entire cell is lowered and the throughput is improved.
According to the fifth invention, by preferentially selecting mobile stations that are reliably synchronized, the reception probability of ACK / NACK is improved, and the number of retransmissions associated with DTX reception (no transmission) can be reduced. Throughput is improved. In addition, since the possibility of data transmission based on CQI with low reliability is reduced, it eliminates the cause of throughput reduction such as an increase in error rate when the amount of data is large for the line quality and a decrease in transmission rate when the amount of data is small. it can.

1 is a configuration diagram of a base station apparatus according to a first embodiment. FIG. This is a scheduling processing flow that takes into account the line quality variation (VAR _CQ ). It is a block diagram of the base station apparatus of 2nd Example. This is a scheduling process flow that takes into account the fading frequency fd. It is a block diagram of the base station apparatus of 3rd Example. This is a scheduling process flow that takes into account the required transmission interval according to the data type. It is a block diagram of the base station apparatus of 4th Example. It is the processing flow of the error rate calculation for every CQI by an error rate calculation part. It is memory explanatory data explanatory drawing of an error rate calculation part. This is a scheduling process flow that takes into account the error rate for each CQI. It is a block diagram of a base station apparatus in 5th Example. It is a processing flow of error rate calculation for each number of retransmissions by the error rate calculation unit. This is a scheduling process flow that takes into account the error rate for each CQI. It is a block diagram of the base station apparatus of 6th Example. It is a scheduling processing flow of the sixth embodiment in consideration of the wireless synchronization state. It is a transition diagram between each synchronous state. 1 is a configuration example of a W-CDMA mobile communication system. It is radio channel explanatory drawing used for HSDPA. It is a channel timing explanatory view in HSDPA. It is a structural example of an HSDPA system.

(A) 1st Example FIG. 1: is a block diagram of the base station apparatus of 1st Example. In the first embodiment, the scheduler 15 reflects the variance value of the line quality in the Proportional Fairness method.
The receiving unit 11 of the base station apparatus 10 performs amplification, band limitation, frequency conversion, orthogonal demodulation, AD conversion, and the like of the radio signal received by the antenna and inputs the result to the despreading unit 12.
The despreading unit 12 despreads using a spreading code assigned to the mobile station (mobile terminal) and demodulates the DPCCH (dedicated physical control channel) and HS-DPCCH transmitted from the mobile station, The pilot signal obtained by demodulating the control channel is input to the channel estimation unit 13, and the HS-DPCCH demodulation signal is input to the ACK / CQI decoding unit 14. The channel estimation unit 13 estimates the channel using the pilot signal, and the ACK / CQI decoding unit 14 performs synchronous detection of ACK / NACK and CQI based on the channel estimation value, performs error detection and correction processing, and transmits the HS-DPCCH. The received ACK / NACK and CQI are decoded and output. Similarly, ACK / NACK and CQI sent from all mobile stations are decoded and input to the scheduler 15.
The scheduler 15 calculates an index value based on the Proportional Fairness method and a channel quality variance value for each mobile station, corrects the index value based on the channel quality variance value, and transmits data based on the correction index value. Select the mobile station to be used. Further, the scheduler 15 determines a transmission data amount, a spreading code, a modulation scheme, power, and the like based on the CQI information, and inputs them to the channel coding unit 16, the spreading unit 18, and the transmitting unit 19. Further, the scheduler 15 requests the data addressed to each mobile station from the radio base station controller RNC based on the data retention amount in the buffer unit (flow control).
The radio base station controller RNC holds data addressed to each mobile station received via the core network, and sends the data addressed to the requested mobile station to the base station 10 in response to a request from the scheduler 15. The buffer unit 17 of the base station stores the data addressed to each mobile station transmitted from the radio base station controller RNC, and the channel coding unit with the requested block size of the data addressed to the mobile station designated by the instruction from the scheduler 15 16 The channel coding unit 16 adds a CRC code for each block to the input data addressed to the mobile station and encodes the data for each predetermined number of blocks. The spreading unit 18 spreads the data with the designated spreading code and transmits the data. The unit 19 modulates with the modulation method instructed by the scheduler, converts the frequency to a radio frequency, and transmits it from the antenna to the mobile station.

により、回線品質変動量(VAR_CQ)を加味したスケジューリング指標値:C_n(VARCQ)を計算する(ステップ１０４)。(4)式の指標値は(1)式のProportional Fairness手法による指標値に相当するものであり、スケジューリング指標値:C_n(VARCQ) はProportional Fairness手法による指標値を回線品質変動量(VAR_CQ)で補正した値になっている。また、(5)式において、1-β1はC_n(PF)に対する、回線品質変動量の重み付けを示すもので、対象セクタの伝播環境、セクタスループットを考慮し、最適化する。
ついで、スケジューラ１５は、補正指標値C_n(VARCQ) が最も高い移動局を選択し、その移動局向けにデータを送信する(ステップ１０５)。
第１実施例によれば回線品質の変動が激しい移動局を選択しにくくすることにより、セル全体の誤り率が低くなり、スループットが向上する。FIG. 2 is a scheduling process flow that takes into account the line quality variation (VAR _CQ ). First, the channel estimation unit 13 estimates the phase rotation amount and amplitude variation amount in the radio space (channel estimation) based on the DPCCH pilot signal, and inputs the estimated amount to the ACK / CQI decoding unit 14 (step 101). The ACK / CQI decoding unit 14 synchronously detects ACK / NACK and CQI based on the channel estimation value, performs error detection and correction processing, and decodes the HARQ reception result (ACK or NACK) and CQI sent on the HS-DPCCH To the scheduler 15. Similarly, the HARQ reception result (ACK or NACK) sent from all mobile stations is decoded and input to the scheduler 15 (step 102).
The scheduler 15 determines transmission target data (new or retransmission) based on the HARQ reception result (ACK or NACK), and calculates the average channel quality MEAN _CQ and the channel quality fluctuation amount VAR _CQ by the following equations (step 103).
MEAN _CQ = (1-τ) × CQI + τ × MEAN _CQ (2)
VAR _CQ = (1-τ) × (CQI-MEAN _CQ ) ² + τ × VAR _CQ (3)
Channel quality fluctuation amount VAR _CQ, compared past CQI received channel quality and time using the τ forgetting factor to calculate the average value MEAN _CQ, the forgetting factor a variance value of the current CQI from the mean value MEAN _CQ Calculated using τ.
Next, the scheduler 15 uses the CQI of this time, the calculated MEAN _CQ , and the VAR _CQ as follows:

Thus, a scheduling index value: C _{n (VARCQ)} taking into account the line quality fluctuation amount (VAR _{CQ )} is calculated (step 104). The index value in Eq. (4) is equivalent to the index value by the Proportional Fairness method in Eq. (1), and the scheduling index value: C _{n (VARCQ)} is the index value by the Proportional Fairness method as the amount of _channel quality fluctuation (VAR _CQ ) Is the value corrected by. In equation (5), 1-β1 indicates the weighting of the channel quality fluctuation amount for C _{n (PF)} , and is optimized in consideration of the propagation environment and sector throughput of the target sector.
Next, the scheduler 15 selects a mobile station having the highest correction index value C _{n (VARCQ)} and transmits data to the mobile station (step 105).
According to the first embodiment, by making it difficult to select a mobile station whose line quality fluctuates significantly, the error rate of the entire cell is lowered and the throughput is improved.

により、フェージング周波数fdを加味したスケジューリング指標値C_n(fd)を計算する(ステップ２０５)。(7)式の指標値は、(1)式のProportional Fairness手法による指標値に相当するものであり、スケジューリング指標値C_n(fd)はProportional Fairness手法による指標値をフェージング周波数fdで補正した値になっている。また、(8)式において、1-β2はC_n(PF)に対する、フェ−ジング周波数の重み付けを示すもので、対象セクタの伝播環境、セクタスループットを考慮し、最適化する。
ついで、スケジューラ１５は、補正指標値C_n(VARCQ) が最も高い移動局を選択し、その移動局向けにデータを送信する(ステップ２０６)。
フェージング周波数が高い場合、上り／下り受信特性が劣化する傾向にあるが、第２実施例によれば、そういった移動局を選択しにくくすることにより、セル全体の誤り率が低くなり、スループットが向上する。(B) Second Embodiment FIG. 3 is a block diagram of a base station apparatus according to a second embodiment. Components identical with those of the first embodiment shown in FIG. The different points are that a fading frequency estimation unit 21 is provided, and that the scheduler corrects the index value based on the fading frequency and performs scheduling based on the corrected index value. That is, in the second embodiment, the scheduler 15 reflects the fading frequency in the Proportional Fairness method.
FIG. 4 shows a scheduling process flow that takes the fading frequency fd into consideration. First, the channel estimation unit 13 estimates the phase rotation amount and amplitude fluctuation amount in the radio space based on the DPCCH pilot signal (channel estimation), and inputs it to the ACK / CQI decoding unit 14 and the fading frequency estimation unit 21 (step S1). 201). The fading frequency estimation unit 21 estimates the fading frequency fd from the time correlation of the channel estimation result, and notifies the scheduler 15 (step 202). Various fading frequency estimation methods have been proposed. For example, there is a method for estimating a fading frequency using temporal correlation of pilot signals (see Japanese Patent Application No. 2000-179609).
Further, the ACK / CQI decoding unit 14 synchronously detects ACK / NACK and CQI based on the channel estimation value, performs error detection and correction processing, and obtains the HARQ reception result (ACK or NACK) sent on the HS-DPCCH, CQI Is input to the scheduler 15 (step 203). Similarly, HARQ reception results (ACK or NACK) sent from all mobile stations are decoded and input to the scheduler 15.
The scheduler 15 determines the transmission target data (new or retransmission) based on the HARQ reception result (ACK or NACK), and
MEAN _CQ = (1-τ) × CQI + τ × MEAN _CQ (6)
To calculate the average line quality MEAN _CQ (step 204).
Next, the scheduler 15 uses the current CQI, the calculated MEAN _CQ, and the fading frequency fd to

Thus, the scheduling index value C _{n (fd)} taking the fading frequency fd into account is calculated (step 205). The index value in equation (7) corresponds to the index value by the Proportional Fairness method in Equation (1), and the scheduling index value C _{n (fd)} is a value obtained by correcting the index value by the Proportional Fairness method with the fading frequency fd. It has become. In equation (8), 1-β2 indicates the weighting of the fading frequency for C _{n (PF)} , and is optimized in consideration of the propagation environment and sector throughput of the target sector.
Next, the scheduler 15 selects a mobile station having the highest correction index value C _{n (VARCQ)} and transmits data to the mobile station (step 206).
When the fading frequency is high, the uplink / downlink reception characteristics tend to deteriorate. However, according to the second embodiment, by making it difficult to select such a mobile station, the error rate of the entire cell is lowered and the throughput is improved. To do.

により、指標値C_n(PF)を補正し(ステップ３０８)、Tx_Int_diffが最小時間差Tx_Int_minより小さければ、次式

により指標値C_n(PF)を補正する(ステップ３０９)。
(12),(13)式は、Proportional Fairness手法による指標値をデータ種別に応じた所要送信間隔で補正した値になっている。なお、1−β3はC_n(PF)に対する、Tx_Int_diffの重み付けを示すもので、対象セクタの伝播環境、セクタスループットを考慮し、最適化することを想定している。また、Tx_Int _minはTx_Int_diffが負値になる場合を考慮し、分母の最小値を規定するためのものであり、極力小さい正値である。
以後、スケジューラ１５は、全移動局について補正指標値C_n(TxInt)を計算し、補正指標値C_n(TxInt)が最も大きい移動局を選択し、その移動局向けにデータを送信する(ステップ３１０)。
第３実施例によれば、所要送信間隔が短いデータを送受信する移動局を優先的に選択し、所要送信間隔が長い移動局に回線を割当てないことにより、データ種別に応じた最適な回線割当が可能となる。(C) Third Embodiment FIG. 5 is a block diagram of a base station apparatus according to a third embodiment. Components identical with those of the first embodiment shown in FIG. The difference is
(1) A transmission interval measuring unit 31 of each mobile station is provided,
(2) Receiving the required transmission interval Tx_Int _target and the minimum time difference Tx_Int _min according to the type of transmission data for each mobile station from the host device,
(3) The scheduler corrects the index value based on the required transmission interval according to the data type, and schedules based on the corrected index value,
It is. In other words, in the third embodiment, the scheduler 15 reflects the required transmission interval according to the data type in the Proportional Fairness method, and transmits the data having a short required transmission interval (data such as voice with high real-time property). Select stations preferentially.
FIG. 6 is a scheduling process flow that takes into account the required transmission interval according to the data type. First, the channel estimation unit 13 estimates the phase rotation amount and amplitude variation amount in the radio space (channel estimation) based on the DPCCH pilot signal, and inputs it to the ACK / CQI decoding unit 14 (step 301). The ACK / CQI decoding unit 14 synchronously detects ACK / NACK and CQI based on the channel estimation value, performs error detection and correction processing, and decodes the HARQ reception result (ACK or NACK) and CQI sent on the HS-DPCCH And input to the scheduler 15 (step 302). Similarly, HARQ reception results (ACK or NACK) sent from all mobile stations are decoded and input to the scheduler 15. The scheduler 15 determines transmission target data (new or retransmission) based on the HARQ reception result (ACK or NACK), and instructs the transmission interval measurement unit 31 to calculate the transmission interval time difference.
The transmission interval measurement unit 31 holds, for each mobile station, a previous transmission time and a required transmission interval Tx_Int _target corresponding to the type of transmission data for each mobile station from the host device in the built-in memory MEM. When a time difference calculation is requested for a predetermined mobile station from the scheduler, the transmission interval measuring unit 31 calculates a time interval Tx_Int from the previous transmission time of the mobile station to the current time (step 303), and then a necessary transmission interval. The difference Tx_Int_diff between Tx_Int _target and the calculated time interval Tx_Int is
Tx_Int_diff = Tx_Int _target -Tx_Int (9)
Is calculated and input to the scheduler 15 (step 304).
Next, the scheduler 15 has the following formula:
MEAN _CQ = (1-τ) × CQI + τ × MEAN _CQ (10)
To calculate the average line quality MEAN _CQ (step 305)
C _{n (PF)} = CQI / MEAN _CQ (11)
Thus, the index value C _{n (PF)} in the Proportional Fairness method is calculated (step 306). If the index value C _{n (PF) is} obtained, the time difference Tx_Int_diff is compared with the minimum time difference Tx_Int _min (step 307). If Tx_Int_diff is greater than the minimum time difference Tx_Int _min ,

To correct the index value C _{n (PF)} (step 308), and if Tx_Int_diff is smaller than the minimum time difference Tx_Int _min ,

Thus, the index value C _{n (PF)} is corrected (step 309).
Expressions (12) and (13) are values obtained by correcting the index value obtained by the Proportional Fairness method at the required transmission interval according to the data type. 1-β3 indicates the weight of Tx_Int_diff with respect to C _{n (PF)} , and is assumed to be optimized in consideration of the propagation environment and sector throughput of the target sector. Further, Tx_Int _min is for defining the minimum value of the denominator in consideration of the case where Tx_Int_diff becomes a negative value, and is a positive value as small as possible.
Thereafter, the scheduler 15, for all the mobile stations to calculate a correction index value C _{n (TXINT),} correction index value C _{n (TXINT)} selects the largest mobile station transmits data to the mobile station for (step 310).
According to the third embodiment, an optimum line allocation according to the data type is selected by preferentially selecting a mobile station that transmits and receives data with a short required transmission interval and not allocating a line to a mobile station with a long required transmission interval. Is possible.

により、指標値C_n(PF)を補正し(ステップ４５７)、BLER_CQI_n,kが最小エラーレートBLER_CQI_minより小さければ、次式

により指標値C_n(PF)を補正する(ステップ４５８)。
(17),(18)式は、Proportional Fairness手法による指標値をＣＱＩ毎にエラーレートで補正した値になっている。なお、1-β4はC_n(PF)に対する、BLER_CQI_n,kの重み付けを示すもので、対象セクタの伝播環境、セクタスループットを考慮し、最適化する。また、BLER_CQI_minはBLER_CQI_n,kが0になる場合を考慮し、分母の最小値を規定するためのものであり、極力小さい正値である。
以後、スケジューラ１５は、全移動局について補正指標値C_{n(BLER_CQI)}を計算し、補正指標値C_{n(BLER_CQI)}が最も大きい移動局を選択し、その移動局向けにデータを送信する(ステップ４５９)。
第４実施例によれば、誤り率の低いＣＱＩを送信した移動局を優先的に選択することにより、セル全体の誤り率が低くなり、スループットが向上する。(D) Fourth Embodiment FIG. 7 is a block diagram of a base station apparatus according to a fourth embodiment, in which components identical with those of the first embodiment of FIG. The difference is
(1) An error rate calculation unit 41 for calculating an error rate of each value of CQI = 1 to 30 is provided,
(2) The minimum block error rate BLER_CQI _min is received from the host device.
(3) The scheduler corrects the index value based on the error rate for each CQI, and schedules based on the corrected index value;
It is. That is, in the fourth embodiment, the scheduler 15 preferentially selects a mobile station having a small error rate by reflecting the error rate for each CQI in the Proportional Fairness method.
FIG. 8 is a processing flow of error rate calculation for each CQI by the error rate calculation unit 41.
Upon receiving notification from the ACK / CQI decoding unit 14 that the mobile station UE # n has been detected within the target cell range (step 401), the error rate calculation unit 41 stores the error in the built-in memory MM1 (see FIG. 9A). Initializing the stored block number TBnum _{n, k} (k = 1 to 30) and error number ERRnum _{n, k} (k = 1 to 30) of the mobile station UE # n to 0, The block error rate BLER_CQI _{n, k} (k = 1 to 30) is initialized to the minimum block error rate BLER_CQI _min (steps 402 to 405).
After that, it is confirmed that the mobile station UE # n exists in the cell area (step 406), and if it exists in the cell area, the first block among the plurality of blocks transmitted in TTI (2mse at subframe interval) is selected. Whether ACK is received, NACK is received, or nothing is received (steps 407 to 408). The base station determines a TF (Transport Format) for each TTI based on the CQI value received from the mobile station, and determines the number of bits per block in the TTI based on the TF.
If ACK is received, the number of blocks TBnum _{n, k} corresponding to the CQI that is the basis of TF determination in the TTI is counted up (step 409), and if NACK is received, it is the basis of TF determination in the TTI. The number of blocks TBnum _{n, k} corresponding to the CQI is counted up and the number of errors ERRnum _{n, k} is counted up (step 410). When nothing is received (DTX reception), the block number TBnum _{n, k} and the error number ERRnum _{n, k} are not changed.
Next, the process waits until the TTI elapses (step 411). When the TTI elapses, the process after the step 406 is executed, and the block number TBnum _{n, k} of the CQI = 1-30 of the mobile station UE # n and the error number ERRnum _{n, k} is obtained and stored in the memory MM1.
FIG. 10 is a scheduling process flow that takes into account the error rate for each CQI.
First, the channel estimation unit 13 estimates the phase rotation amount and amplitude fluctuation amount in the radio space based on the DPCCH pilot signal (channel estimation), and inputs it to the ACK / CQI decoding unit 14 (step 451). The ACK / CQI decoding unit 14 synchronously detects ACK / NACK and CQI based on the channel estimation value, performs error detection and correction processing, and decodes the HARQ reception result (ACK or NACK) and CQI sent on the HS-DPCCH And input to the error rate calculation unit 41 (step 452).
Number block error rate calculation unit 41 in accordance with the CQI TBnum _n, read _k and error count errnum _n, the _k from memory MM1, the following equation
BLER_CQI _{n, k} = ERRnum _{n, k} / TBnum _{n, k} (14)
Thus, the block error rate BLER_CQI _{n, k} corresponding to the current CQI is calculated, and the block error rate, ACK / NACK, and CQI are input to the scheduler 15 (step 453).
The scheduler 15 determines the transmission target data (new or retransmission) based on the HARQ reception result (ACK or NACK), and
MEAN _CQ = (1-τ) × CQI + τ × MEAN _CQ (15)
Thus, the average line quality MEAN _CQ is calculated (step 454). Next, the following formula
C _{n (PF)} = CQI / MEAN _CQ (16)
Thus, the index value C _{n (PF)} in the Proportional Fairness method is calculated (step 455). If the index value C _{n (PF) is} obtained, the block error rate BLER_CQI _{n, k} and the minimum error rate BLER_CQI
Compare with _min (step 456) and if BLER_CQI _{n, k} is greater than the minimum error rate BLER_CQI _min , then

To correct the index value C _{n (PF)} (step 457), and if BLER_CQI _{n, k} is smaller than the minimum error rate BLER_CQI _min ,

Correcting an index value C _{n (PF)} (step 458).
Expressions (17) and (18) are values obtained by correcting the index value obtained by the Proportional Fairness method with the error rate for each CQI. 1-β4 indicates the weighting of BLER_CQI _{n, k with} respect to C _{n (PF)} , and is optimized in consideration of the propagation environment and sector throughput of the target sector. BLER_CQI _min is for defining the minimum value of the denominator in consideration of the case where BLER_CQI _{n, k} is 0, and is a positive value as small as possible.
Thereafter, the scheduler 15, for all the mobile stations to calculate a correction index value C _{n (BLER_CQI),} correction index value C _{n (BLER_CQI)} selects the largest mobile station transmits data to the mobile station for (step 459).
According to the fourth embodiment, by preferentially selecting a mobile station that has transmitted a CQI having a low error rate, the error rate of the entire cell is lowered and the throughput is improved.

(E) Fifth Embodiment FIG. 11 is a block diagram of a base station apparatus in the fifth embodiment, and the same reference numerals are given to the same parts as those in the first embodiment of FIG. The difference is
(1) An error rate calculation unit 51 for calculating an error rate of each value of the number of retransmissions = 1 to 15 is provided,
(2) The minimum block error rate BLER_transmit _min is received from the host device.
(3) The scheduler corrects the index value based on the error rate for each retransmission, and schedules based on the corrected index value;
It is. That is, in the fifth embodiment, the scheduler 15 reflects the error rate for each number of retransmissions in the Proportional Fairness method and preferentially selects a mobile station with a low error rate.
FIG. 12 is a processing flow of error rate calculation for each number of retransmissions by the error rate calculation unit 51.
Upon receiving notification from the ACK / CQI decoding unit 14 that the mobile station UE # n has been detected within the target cell range (step 501), the error rate calculation unit 51 stores the error rate calculation unit 51 in the built-in memory MM2 (see FIG. 9B). ACK number ACKnum _{n, k} (k = 1 to 15) and NACK number NACKnum for error rate calculation of stored mobile station UE # n
_{n, k} (k = 1 to 15) is initialized to 0, and the block error rate BLER_transmit _{n, k} (k = 1 to 15) is initialized to the minimum block error rate BLER_transmit _min (steps 502 to 505).
Thereafter, it is confirmed that the mobile station UE # n exists in the cell range (step 506). If the mobile station UE # n exists in the cell range, the first block among the plurality of blocks transmitted in TTI (2mse at subframe interval) is determined. Whether ACK is received, NACK is received, or nothing is received (steps 507 to 508).
If ACK is received, ACKnum _{n, k} is counted up according to the number of retransmissions (step 509). If NACK is received, NACKnum _{n, k} is counted up (step 510). If nothing is received (DTX reception), ACKnum _{n, k} , NACKnum _{n, k}
Do not change.
Next, the process waits until the TTI elapses (step 511). When the TTI elapses, the process after the step 506 is executed, and the number of retransmissions of the mobile station UE # n = 1 to 15 ACKnum _{n, k} , NACKnum _{n, k} is obtained and stored in the memory MM2.

により、指標値C_n(PF)を補正し(ステップ５５７)、BLER_transmit_n,kが最小エラーレートBLER_transmit_inより小さければ、次式

により指標値C_n(PF)を補正する(ステップ５５８)。
(22),(23)式は、Proportional Fairness手法による指標値を再送回数毎にエラーレートで補正した値になっている。なお、1-β5はC_n(PF)に対する、BLER_transmit_n,kの重み付けを示すもので、対象セクタの伝播環境、セクタスループットを考慮し、最適化することを想定している。また、BLER_transmit_minはBLER_transmit_n,kが0になる場合を考慮し、分母の最小値を規定するためのものであり、極力小さい正値である。
以後、スケジューラ１５は、全移動局について補正指標値C_{n(BLER_ transmit)}を計算し、補正指標値C_{n(BLER_ transmit)}が最も大きい移動局を選択し、その移動局向けにデータを送信する(ステップ５５９)。
第５実施例によれば、誤り率の低い再送回数の移動局を優先的に選択することにより、セル全体の誤り率が低くなり、スループットが向上する。FIG. 13 is a scheduling process flow that takes into account the error rate for each CQI.
First, the channel estimation unit 13 estimates the phase rotation amount and amplitude variation amount in the radio space (channel estimation) based on the DPCCH pilot signal, and inputs it to the ACK / CQI decoding unit 14 (step 551). The ACK / CQI decoding unit 14 synchronously detects ACK / NACK and CQI based on the channel estimation value, performs error detection and correction processing, and decodes the HARQ reception result (ACK or NACK) and CQI sent on the HS-DPCCH And input to the error rate calculation unit 41 (step 552).
The error rate calculation unit 51 reads ACKnum _{n, k} and NACKnum _{n, k} according to the number of retransmissions from the memory MM2 _, and calculates
BLER_transmit _{n, k} = NACKnum _{n, k} / (ACKnum _{n, k} + NACKnum _{n, k} ) (19)
Then, the block error rate BLER_transmit _{n, k} corresponding to the current number of retransmissions is calculated, and the block error rate, ACK / NACK, and CQI are input to the scheduler 15 (step 553).
The scheduler 15 determines the transmission target data (new or retransmission) based on the HARQ reception result (ACK or NACK), and
MEAN _CQ = (1-τ) × CQI + τ × MEAN _CQ (20)
Thus, the average line quality MEAN _CQ is calculated (step 554). Next, the scheduler 15 has the following formula:
C _{n (PF)} = CQI / MEAN _CQ (21)
Thus, the index value C _{n (PF)} in the Proportional Fairness method is calculated (step 555).
If Motomare index value C _{n (PF),} the scheduler 15 compares the magnitude of the block error rate BLER_transmit _{n, k} and the minimum error rate BLER_transmit _min (step _556), BLER_transmit _{n, k} is the minimum error rate BLER_transmit _in If larger, the following formula

To correct the index value C _{n (PF)} (step 557), and if BLER_transmit _{n, k} is smaller than the minimum error rate BLER_transmit _in ,

Thus, the index value C _{n (PF)} is corrected (step 558).
Expressions (22) and (23) are values obtained by correcting the index value obtained by the Proportional Fairness method with the error rate for each retransmission. 1-β5 indicates the weighting of BLER_transmit _{n, k with} respect to C _{n (PF)} , and is assumed to be optimized in consideration of the propagation environment and sector throughput of the target sector. BLER_transmit _min is for defining the minimum value of the denominator in consideration of the case where BLER_transmit _{n, k} is 0, and is a positive value as small as possible.
Thereafter, the scheduler 15, the correction index value C _n of the _{(BLER_ transmit)} was calculated for all the mobile stations, and selects a correction index value C _{n (BLER_ transmit)} is the largest mobile station transmits data to the mobile station for (Step 559).
According to the fifth embodiment, by preferentially selecting a mobile station having a low error rate and the number of retransmissions, the error rate of the entire cell is lowered and the throughput is improved.

(F) Sixth Embodiment FIG. 14 is a block diagram of a base station apparatus according to a sixth embodiment. Components identical with those of the first embodiment of FIG. The difference is
(1) A synchronization state monitoring unit 61 that monitors the uplink radio synchronization state of the mobile station and inputs the monitoring result to the scheduler 15 is provided.
(2) A synchronization state storage unit 62 for storing the synchronization state of each mobile station is provided,
(3) The scheduler schedules considering the radio synchronization state of the mobile station,
It is. The synchronization state monitoring unit 61 monitors whether synchronization is established or lost using a pilot included in the dedicated physical control channel DPCCH transmitted from the mobile station. That is, since the pilot is a known pattern, the received pilot and the known pilot are compared, and if the difference is small, it is determined that synchronization is established, and if the difference is large, it is determined that synchronization is lost. Since this difference corresponds to the channel estimation value, the synchronization state monitoring unit 61 monitors the synchronization state based on the channel estimation value.

In the sixth embodiment, the scheduler 15 preferentially selects a fully synchronized mobile station, and selects a forward / backward protected UE only when there is no fully synchronized mobile station. FIG. 15 shows a scheduling process flow of the sixth embodiment in consideration of the wireless synchronization state. Note that MAX_UE_SEL is the number of selectable mobile stations. The number of mobile stations that can be selected is generally determined by the remaining power and code resources. However, since the explanation of the algorithm is not mainly used here, the number of mobile stations that can be selected is determined by some method, and this scheduling is performed based on that. A mobile station is selected using a method.
The synchronization state monitoring unit 61 monitors whether all mobile stations UE # n (n = 1 to N) existing in the target cell are in a completely synchronized state or a forward / backward protected state.
UE_SYNC [k1] = UE # n
And if it is in front / rear protection
UE_NOSYNC [k2] = UE # n
(Steps 601 to 608). FIG. 16 is a synchronization state transition diagram, and the synchronization state storage unit 62 stores whether the mobile station is in an out-of-synchronization state, a forward protection state, a complete synchronization state, or a rearward protection state.
Out-of-synchronization state: A state in which the mobile station belongs first, and communication with this mobile station is not possible. When synchronization is established even once, it shifts to the forward protection state.
-Forward protection state: Communication with the mobile station is possible before the transition to the fully synchronized state. When synchronization is established N1 times in succession, it will be in the fully synchronized state, and once it is out of sync, it will be in the out of synchronization state. N1 is set to an optimum value according to the external environment such as the propagation environment and the characteristics of the device.
Fully synchronized state: A state where communication with a mobile station is possible stably. If synchronization is lost even once, it will shift to the backward protection state.
Backward protection state: Communication with the mobile station is possible at the stage where there is a possibility of shifting to out of synchronization. When synchronization is lost N2 times (determined by the system) continuously, it will be out of synchronization, and once synchronization is established, it will transition to full synchronization. Note that N2 is set to an optimum value according to the external environment such as the propagation environment and the characteristics of the device.

In a state in which the synchronization state of each mobile station is stored in the synchronization state storage unit 62, the channel estimation unit 13 estimates the amount of phase rotation and amplitude variation in the radio space based on the DPCCH pilot signal (channel estimation). ) And notifies the ACK / CQI decoding unit 14 of the estimation result.
The ACK / CQI decoding unit 14 decodes ACK / NACK and CQI and transmits them to the scheduler 15. The scheduler 15 determines transmission target data (new or retransmission) based on the HARQ reception result (ACK / NACK).
Next, the scheduler 15 uses the decoded CQI to
MEAN _CQ = (1-τ) × CQI + τ × MEAN _CQ (24)
To calculate the average line quality MEAN _CQ and
C _{n (PF)} = CQI / MEAN _CQ (25)
To calculate the index value C _{n (PF)} in the Proportional Fairness method. Thereafter, the index value C _{n (PF)} of all target mobile stations is calculated in the same manner.
At this time, the mobile station that is the object of calculation of the above C _{n (PF)} is determined by comparing the total number of UEs K1 stored in UE_SYNC [k1] with MAX_UE_SEL. That is,
If K1 ≧ MAX_UE_SEL, only the mobile station stored in UE_SYNC [k1], that is, the mobile station in the complete synchronization state is targeted. On the other hand, if K1 <MAX_UE_SEL, all mobile stations are targeted (mobile stations stored in UE_SYNC and UE_NOSYNC, respectively).

When the calculation of the index values of all target mobile stations is completed, the scheduler 15 selects a mobile station according to the lower processing flow (steps 701 to 704) in FIG. That is, until k reaches the mobile station selectable number (MAX_UE_SEL) or until the total number of mobile stations stored in UE_SYNC is reached, the mobile stations in the synchronization state UE_SYNC are selected in descending order of C _{n (PF)} . At this point, when the number of mobile station selections reaches MAX_UE_SEL (YES in step 704), the mobile station selection at that TTI is terminated. If not, the process proceeds to step 801 to select a mobile station from the forward / backward protection state UE_NOSYNC.
That is, the scheduler 15 follows the lower processing flow (steps 801 to 804) of FIG. 15 until k reaches the mobile station selectable number (MAX_UE_SEL) or the total number of mobile stations existing in the target cell. Until reaching (k1 + k2), the mobile stations in the forward / backward protection state UE_NOSYNC are selected in descending order of C _{n (PF)} . At this time, when the number of UEs selected reaches MAX_UE_SEL, or when all mobile stations belonging to the target cell are selected, UE selection at that TTI is terminated.
According to the sixth embodiment, it is possible to improve the reception probability of ACK / NACK by preferentially selecting mobile stations that are reliably synchronized, and to reduce the number of retransmissions associated with DTX reception (no transmission). Throughput is improved. In addition, since the possibility of data transmission based on CQI with low reliability is reduced, it eliminates the cause of throughput reduction such as an increase in error rate when the amount of data is large for the line quality and a decrease in transmission rate when the amount of data is small. it can.
Although the case where the present invention is applied to the HDDPA has been described above, the present invention is not limited to such an HDDPA, and a wireless transmission of data from a network side to a predetermined mobile station via a wireless line shared by a plurality of mobile stations. It can be applied to a data transmission system.
Further, although the individual embodiments have been described above, the embodiments can be combined as appropriate.

Claims (16)

In a scheduling method in a wireless data transmission system for transmitting data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals,
Based on the quality of the received signal at each mobile terminal, calculate an index value of which mobile terminal to select,
Obtaining the quality variation rate, correcting the index value by the quality variation rate,
Selecting a mobile terminal to send data based on the correction index value;
A scheduling method characterized by the above. In a scheduling method in a wireless data transmission system for transmitting data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals,
Based on the quality of the received signal at the mobile terminal, calculate an index value of which mobile terminal to select,
Find the fading frequency at the mobile terminal,
The index value is corrected by the fading frequency,
Selecting a mobile terminal to send data based on the correction index value;
A scheduling method characterized by the above. In a scheduling method in a wireless data transmission system for transmitting data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals,
Based on the quality of the received signal at the mobile terminal, calculate an index value of which mobile terminal to select,
Obtain the required transmission interval of data to be transmitted to the mobile terminal,
Correcting the index value by the required transmission interval;
Selecting a mobile terminal to send data based on the correction index value;
A scheduling method characterized by the above. Scheduling in a wireless data transmission system that transmits data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals, and performs retransmission control when an error is detected in the data received by the mobile terminal In the method
Based on the quality of the received signal at the mobile terminal, calculate an index value of which mobile terminal to select,
Calculating an error rate in the mobile terminal with the received signal quality;
The index value is corrected by the error rate,
Selecting a mobile terminal to send data based on the correction index value;
A scheduling method characterized by the above. The error rate is calculated based on signals indicating normal reception and abnormal reception transmitted from the mobile terminal,
The scheduling method according to claim 4, wherein: Scheduling in a wireless data transmission system that transmits data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals, and performs retransmission control when an error is detected in the data received by the mobile terminal In the method
Based on the quality of the received signal at the mobile terminal, calculate an index value of which mobile terminal to select,
Calculate the error rate at the mobile terminal for each retransmission,
The index value is corrected by the error rate,
Selecting a mobile terminal to send data based on the correction index value;
A scheduling method characterized by the above. The error rate is calculated based on signals indicating normal reception and abnormal reception transmitted from the mobile terminal,
The scheduling method according to claim 6, wherein: In a scheduling method in a wireless data transmission system for transmitting data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals,
Based on the quality of the received signal at the mobile terminal, calculate an index value of which mobile terminal to select,
Detect the uplink radio synchronization status of the mobile terminal,
A mobile terminal that transmits data is preferentially selected based on the index value from mobile terminals that are in a synchronized state.
A scheduling method characterized by the above. In a base station apparatus in a wireless data transmission system that transmits data to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals,
A receiving unit for receiving data indicating the quality of a received signal at each mobile terminal from the mobile terminal;
Based on the received signal quality, an index value indicating which mobile terminal is selected for each mobile terminal is calculated, a variation rate of the received signal quality is obtained, and the index value is corrected by the variation rate of the received signal quality And a scheduler that selects a mobile terminal that transmits data based on the correction index value;
A base station apparatus comprising: In a base station apparatus in a wireless data transmission system that transmits data to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals,
A receiving unit for receiving data indicating the quality of a received signal at each mobile terminal from the mobile terminal;
A fading frequency calculation unit for calculating a fading frequency in the mobile terminal;
Based on the received signal quality, an index value indicating which mobile terminal is selected for each mobile terminal is calculated, the index value is corrected by the fading frequency of the mobile terminal, and data is calculated based on the correction index value. A scheduler that selects the mobile terminal to send,
A base station apparatus comprising: In a base station apparatus in a wireless data transmission system that transmits data to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals,
A receiving unit for receiving data indicating the quality of a received signal at each mobile terminal from the mobile terminal;
A transmission interval acquisition unit for acquiring a necessary transmission interval of data to be transmitted to the mobile terminal;
An index value indicating which mobile terminal to select for each mobile terminal based on the received signal quality is calculated, the index value is corrected based on the necessary transmission interval, and data is transmitted based on the corrected index value Scheduler to select the device,
A base station apparatus comprising: A base in a wireless data transmission system that transmits data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals and performs retransmission control when an error is detected in the data received by the mobile terminal In the station equipment,
A receiving unit for receiving data indicating the quality of a received signal at each mobile terminal from the mobile terminal;
An error rate calculator for calculating an error rate in a mobile terminal with the received signal quality;
A scheduler that calculates an index value for selecting a mobile terminal based on the received signal quality, corrects the index value based on the error rate, and selects a mobile terminal that transmits data based on the correction index value;
A base station apparatus comprising: The error rate calculation unit calculates the error rate based on signals indicating normal reception and abnormal reception transmitted from a mobile terminal,
The base station apparatus according to claim 12. A base in a wireless data transmission system that transmits data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals and performs retransmission control when an error is detected in the data received by the mobile terminal In the station equipment,
A receiving unit that receives data indicating the quality of a received signal in each mobile terminal and the number of retransmissions from the mobile terminal;
An error rate calculation unit for calculating an error rate in the mobile terminal for each retransmission,
A scheduler that calculates an index value for selecting a mobile terminal based on received signal quality of the mobile terminal, corrects the index value based on the error rate, and selects a mobile terminal that transmits data based on the correction index value;
A base station apparatus comprising: The error rate calculation unit calculates the error rate based on signals indicating normal reception and abnormal reception transmitted from a mobile terminal,
The base station apparatus according to claim 14. In a base station apparatus in a wireless data transmission system that transmits data from a network side to a predetermined mobile terminal via a wireless line shared by a plurality of mobile terminals,
A receiving unit for receiving data indicating the quality of a received signal at each mobile terminal from the mobile terminal;
A synchronization detector for detecting the uplink radio synchronization state of the mobile terminal;
A scheduler that calculates an index value for selecting a mobile terminal based on the received signal quality of the mobile terminal, and that preferentially selects a mobile terminal that transmits data based on the index value from mobile terminals that are in a synchronized state;
A base station apparatus comprising:

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