WO2006016396A1

WO2006016396A1 - Rate scheduling method and terminal

Info

Publication number: WO2006016396A1
Application number: PCT/JP2004/011439
Authority: WO
Inventors: Michiaki Takano
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2004-08-09
Filing date: 2004-08-09
Publication date: 2006-02-16
Also published as: WO2006016426A1; JPWO2006016426A1

Abstract

A rate scheduling method comprising a rate request transmission step in which, for example, each terminal generates a rate request command depending on the buffer amount of data to be transmitted and transmits the rate request command to a base station by using an FBI field in a DPCCH wireless frame and a rate permission transmission step in which the base station carries out resource allocation according to the rate request command transmitted from each terminal and transmits the result as a rate permission command to each terminal as a reply.

Description

Specification

Rate scheduling method and terminal

Technical field

TECHNICAL FIELD [0001] The present invention relates to a rate scheduling method in a communication system that employs a communication system compliant with 3GPP (3rd Generation Partnership Project), and particularly, when using rate request and rate permission as rate scheduling signaling. TECHNICAL FIELD The present invention relates to a rate scheduling method and a base station that implements the method

[0002] Non-Patent Document 1 discloses an uplink rate scheduling method in 3GPP, a standardization organization for third-generation mobile communication systems, and rate request and rate permission are used as signaling for rate scheduling. .

[0003] Further, Patent Document 1 discloses a dynamic resource allocation method in a digital radio communication system. For example, a predetermined number of DPCHs (Dedicated Physical Channels) depending on a transmission rate for each uplink transmission are disclosed. Signaling information is transmitted in one slot of TTI (Transmission Time Interval), and signaling resources have a data part in addition to TFCI (Transport Format Combination Indicator). It is stated that it is always directed to one subscriber.

[0004] Patent Document 1: Japanese Translation of Special Publication 2003-513531

Non-Patent Document 1: 3GPP TR25. 896V6. 0. 0, PP.19— 21

Disclosure of the invention

Problems to be solved by the invention

[0005] However, the conventional rate scheduling method has a problem that a specific transmission method for a rate request is not specified.

[0006] In addition, since the rate request is transmitted to all base stations (cells, sectors), all base stations (cells, sectors) that have received the rate request allocate resources to the terminal that has transmitted the rate request. There was a problem of reducing throughput.

[0007] The present invention has been made in view of the above, and provides a specific method for transmitting a rate request, and further provides a rate scheduling method capable of improving the throughput as compared with the prior art. Objective.

Means for solving the problem

[0008] In order to solve the above-described problems and achieve the object, in the rate scheduling method according to the present invention, the base station transmits the rate transmitted from each terminal constituting the communication system. A rate scheduling method for allocating uplink resources based on a request command. For example, each terminal generates a rate request command according to a buffer amount of data to be transmitted, and the rate request command A rate request transmission step for transmitting to the base station using an FBI (Feedback Information) field in a DPCCH (Dedicated Physical Control CHannel) radio frame, and a rate at which the base station is transmitted from each terminal. A rate grant transmission step in which resources are allocated based on the request command and the result is returned to each terminal as a rate grant command. It is characterized by including.

The invention's effect

[0009] In the rate scheduling method according to the present invention, the rate request is mapped to, for example, a known channel DPCCH. Specifically, the rate request is transmitted by extending the known FBI field. (Provide specific transmission method of rate request). As a result, there is an effect that reliable transmission can be realized while knock impact compatibility can be secured while reducing the impact in terms of changes from the past.

Brief Description of Drawings

[0010] FIG. 1 is a diagram showing a configuration of a terminal according to a first embodiment for realizing a rate scheduling method that is effective for the present invention.

[Figure 2] Figure 2 shows the radio network controller (RNC) and base station (

It is a figure which shows the signaling flow between Node B) and a terminal (UE).

FIG. 3 is a diagram showing an example of a frame format of a DPCCH radio frame. [FIG. 4] FIG. 4 is a diagram showing a configuration of a terminal according to a second embodiment for realizing a rate scheduling method according to the present invention.

FIG. 5 is a diagram showing an example of a frame format of a DPCCH radio frame.

FIG. 6 is a diagram showing an example of a frame format of a DPCCH radio frame.

FIG. 7 is a diagram showing a configuration of a terminal according to the fourth embodiment for realizing the rate scheduling method according to the present invention.

FIG. 8 is a diagram showing an example of a transport block size formed by a MAC header and a plurality of “MAC-e SDUs”.

FIG. 9 is a diagram showing an example of a transport block size formed by a MAC header and a plurality of “MAC-e SDUs”.

Explanation of symbols

[0011] 1 Rate request generator

2 Frame, assembly part

3 Transmitter

4 Receiver

5 Frame disassembly part

11 Buffer management section

12 Judgment part

21 Channel coding section

22 Channel decoding part

31 TrBK generator

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of a rate scheduling method and a terminal according to the present invention will be described in detail based on the drawings. Note that the present invention is not limited to this embodiment.

Embodiment 1.

FIG. 1 is a diagram showing the configuration of a terminal according to Embodiment 1 that implements the rate scheduling method according to the present invention, and shows the rate request generation configured by a notch amount management unit 11 and a determination unit 12. A forming unit 1, a frame assembling unit 2, a transmitter 3, a receiver 4, and a frame disassembling unit 5 are provided.

[0014] Here, the operation of the entire communication system including the terminal will be described. FIG. 2 is a diagram showing a signaling flow (control signal flow) between a radio network controller (RNC), a base station (Node B), and a terminal (UE) constituting the communication system of the present embodiment.

[0015] First, the RNC notifies the base station and the terminal of the TFCS upper limit and the TFC S start position as an initial setting (step S1, step S2). The above TFCS upper limit represents the maximum value of TF CS (Transport Format Combination Set), and the base station and the terminal are controlled so as not to exceed this upper limit. The TFCS start position indicates the default value of TFCS used for uplink data transmission.

[0016] After the initial setting, the terminal transmits a rate request to the base station (step S3). This rate request is a command indicating UP, DOWN, or KEEP. If you want to send more data than the TFCS start position, use UP, and if you want to send data about the same as the TFCS start position, use KEEP. If you want to send a smaller amount of data than the TFCS start position, send DOWN as a rate request.

[0017] After that, the base station performs scheduling by inputting rate requests from a plurality of terminals, and transmits the scheduling result to each terminal as a rate permission (step S4). This rate permission is also a command indicating UP, DOWN, and KEEP. To allow data transmission by incrementing the TFCS start position by one step (a predetermined amount of data for one step). DOWN is sent to allow data transmission with UP reduced by one step from the TFCS start position, and KEEP is sent as rate permission to permit data transmission at the same level as the TFCS start position. To do.

[0018] Thereafter, the same operations as in steps S3 and S4 are repeatedly executed, and the transmission rate is controlled by the accumulation of the TFCS start position and the rate permission command.

[0019] When transmitting data, the terminal transmits TFRI (Transport

Format Resource Indicator) is transmitted (step S5). This TFRI is an indicator that represents at least four of the modulation scheme, the number of codes, the transport block size, the spreading factor, and the code rate of simultaneously transmitted data. The base station is in this TFRI Therefore, the received data of the terminal is demodulated, and the CRC (Cyclic Redundancy Check) of the received data is determined (the CRC generated from the received data is compared with the CRC included in the received data). If there is an error, NAK is transmitted to the terminal as ACK / NAK (step S6).

[0020] Thus, in the communication system of the present embodiment, the base station can control the TFCS for the terminal within a range that satisfies the TFCS upper limit.

Next, the operation of the terminal when executing the signaling flow of FIG. 2 will be described in detail using the configuration of FIG.

[0022] The buffer amount management unit 11 monitors the buffer amount of data to be transmitted as an uplink. This buffer amount is supplied to the determiner 12 as buffer amount information periodically (every predetermined time elapses) or when a predetermined amount of data is specified in advance. If the ACK / NAK signal is ACK, the buffer that stores the corresponding data is released and the buffer amount is updated.

The determiner 103 compares the buffer amount information from the buffer amount management unit 11 with a predetermined threshold value. For example, when “buffer amount> threshold”, UP is set as “buffer amount”. When “Threshold” is selected, DOWN is output. When “Buffer amount = threshold”, KEEP is output. Note that the UP, DOWN, and KEEP determination methods are not limited to this. For example, the above threshold value is set as the first threshold value, and the second threshold value (“first threshold value> 2), and when “buffer amount> first threshold value”, UP is set. When “first threshold value> buffer amount> second threshold value” is set, KEEP may be output if “second threshold> buffer amount”, DOWN. The determination unit 103 supplies +1 for UP, 0 for K EEP, and -1 for DOWN to the frame assembly unit 2.

[0024] The frame assembling unit 2 incorporates the rate request command generated based on the above UP, DOWN, and KEEP into a DPCCH (Dedicated Physical Control CHannel) radio frame. FIG. 3 is a diagram showing an example of a frame format of a DPCCH (Dedicated Physical Control CHannel) radio frame. The period of the DPCCH radio frame is, for example, 10 ms as shown in FIG. 3, and one frame is composed of 15 slots (# 0 # 14). One slot is PILOT, TFCI, FBI (Feedback Information), TPC ( Each field consists of 10 bits. The FBI has a 3-bit configuration and consists of an S field for SSDT (Site Selection Diversity Transmission), a D field for Diversity, and an E field for E-DCH.

Specifically, the frame assembling unit 2 transmits a rate request command using, for example, the E field (1 bit).

[0026] Transmitter 3 executes spreading modulation, DPDCH, etc., multiplexing with other channels, filtering, conversion processing to radio frequency, and transmits the radio frequency band signal generated by these processing to the base station . Note that although the rate request in FIG. 2 is focused here, TFRI and data transmitted at the same time are also transmitted as other channels.

[0027] On the other hand, the receiver 4 performs conversion to baseband signals, filtering, demultiplexing of DPCCH signals, and despreading processing on radio frequency band signals transmitted from the base station, and the results are obtained. Supply to frame disassembly 5. The frame decomposition unit 5 extracts an AC K / NAK signal from the DPCCH and supplies the extraction result to the buffer amount management unit 11. Here, the power S, rate permission, and traffic data channel focusing on ACK / NAK in Fig. 2 are transmitted as other channels multiplexed on the DPCCH signal.

[0028] Thus, in this embodiment, the rate request is mapped to DPCC H, which is a known channel. Specifically, the rate request is transmitted by extending the known FBI field ( Providing specific transmission method for rate requests). As a result, it is possible to achieve reliable transmission while reducing the impact of changes and points from the past, and to ensure knock word compatibility.

In FIG. 3, the FBI (3 bits) is used for transmission in the order of the S field, the D field, and the E field, but this is not limiting, and this transmission order is arbitrary. Also, all three bits can be used as the E field by deactivating SSDT and Diversity in the upper message. Also, the 3 bits of FBI may be 2 bits or 1 bit.

[0030] Embodiment 2.

FIG. 4 is a diagram illustrating the configuration of the terminal according to the second embodiment that implements the rate scheduling method that is advantageous for the present invention. In addition to the configuration of FIG. 1 according to the first embodiment, FIG. And a channel decoding unit 22. The overall operation of the system is the same as in Fig. 2 above. In the present embodiment, operations different from those of the first embodiment will be described.

FIG. 5 is a diagram illustrating an example of a frame format of the DPCCH radio frame. In FIG. 3, the rate request command is 1-bit data. In this embodiment, 15-bit data is used. Since 15 bits are transmitted, one command is used for one frame. Specifically, the channel coding unit 21 shown in FIG. 4 uses, for example, a secondary Golay code as a method of extending 1 bit (+1, 0, _1) to 15 bits.

[0032] Also, regarding the ACK / NACK, the base station side transmits 1 bit to 15 bits, and the channel decoding 22 decodes the received data into the original 1-bit information.

[0033] Thus, in this embodiment, the transmission side performs channel coding processing on the rate request command and the ACKZNAK command, and the reception side obtains the channel coding gain. Quality transmission can be realized

[0034] Embodiment 3.

Next, processing of the terminal according to the third embodiment will be described. The terminal configuration is the same as that of the second embodiment described above. Here, only processing different from the second embodiment will be described.

FIG. 6 is a diagram illustrating an example of a frame format of the DPCCH radio frame. In the second embodiment described above, the rate request command has been expanded from 1 bit to 15 bits. In this embodiment, the channel coding unit 21 transmits the rate request command to 1 bit as shown in FIG. (E field is any 1 bit in 15 bits) and the remaining 14 bits are transmitted as “Active Set ID”. “Active Set ID” is an identifier representing a communicable set of base stations, cells, and sectors) in the system.

[0036] Then, the base station recognizes whether the received rate request is addressed to itself based on the "Active Set ID", and discards the rate request not addressed to itself. This avoids useless allocation of rate permits. Also, set the “Active Set ID” By transmitting together with the network request, unnecessary radio resource allocation by the base station can be avoided, so that the throughput (system capacity) can be further increased.

[0037] In FIG. 6, the "Active Set ID" is 14 bits and the rate request is 1 bit, and the bit distribution is changed with the total number of bits maintained at 15. Moyo.

[0038] Embodiment 4.

FIG. 7 is a diagram showing a configuration of a terminal according to the fourth embodiment that implements the rate scheduling method according to the present invention, and includes a TrBK generation unit 31. The overall operation of the system is the same as in Fig. 2 described above. In the present embodiment, only operations different from those in the first to third embodiments will be described.

The TrBK generation unit 31 incorporates the rate request command into the transport block. FIG. 8 is a diagram illustrating an example of a transport block size formed by a MAC header and a plurality of “MAC-e SDUs”. The transport block is formed by the MAC header, “MAC_e SDU”. Collect multiple “MAC_e SDUs” together with the payload. In addition, a plurality of “MAC—e PDUs” are mapped to “MAC—e SDU”, and SID (corresponding to SID—SID in FIG. 8), N (corresponding to N-1N), F (F— Equivalent to F)

l k l k l k

It is In this embodiment, a rate request (rate request)

1 rate request

(equivalent to k) is mapped as 1-bit information immediately before F, for example, and the signal thus generated is supplied to the channel coding unit 21.

[0040] In the channel coding unit 21, for the signal obtained as described above, for example, C

Carry out RC with RC, turbo coding, rate matching, interleaving, etc.

[0041] Thus, in the present embodiment, a rate request is transmitted using MAC signaling. This makes it possible to achieve highly reliable transmission compared to transmission in the physical layer.

[0042] In this embodiment, the rate request command is not limited to 1 bit. For example, as in Embodiment 3 described above, the transmission is performed including the "Active Set ID". (See Figure 9).

Industrial applicability

As described above, the rate scheduling method according to the present invention is useful for a communication system that employs a 3GPP-compliant communication method, and in particular, a communication system that uses rate request and rate permission as a rate scheduling signal. And suitable for the terminals constituting the communication system.

Claims

The scope of the claims

[1] In a rate scheduling method in which a base station performs uplink resource allocation based on a rate request command transmitted from each terminal constituting a communication system, a buffer for data to be transmitted by each terminal A rate request transmission step that generates a rate request command according to the volume and transmits the rate request command to the base station using an FBI (Feedback Information) field in a DPCCH (Dedicated Physical Control CHannel) radio frame. When,

The base station performs resource allocation based on a rate request command sent from each terminal, and returns the result to each terminal as a rate permission command.

A rate scheduling method comprising:

[2] Each terminal is

As an initial setting, a rate for receiving an upper limit value of the transmission data amount and a reference value for the transmission data amount, and requesting transmission of a data amount exceeding the reference value (below the upper limit value) based on the buffer amount A request command, a rate request command for requesting data transmission equivalent to the reference value, or a rate request command for requesting transmission of a data amount less than the reference value are transmitted. The rate scheduling method according to Item 1.

3. The rate scheduling method according to claim 1, wherein the rate request command is transmitted using a predetermined 1 bit of the FBI field.

[4] The rate request command is transmitted using a predetermined 1 bit (number of bits corresponding to all slots) of FBI finale in all slots constituting the DPCCH radio frame. The rate scheduling method according to Item 1.

[5] Predetermined FBI field in one slot constituting the DPCCH radio frame

1 bit is used to send the rate request command,

Furthermore, information for indicating a cell or a sector is transmitted using a predetermined 1 bit (the number of bits corresponding to the remaining slot) of the FBI field in the remaining slots constituting the DPCCH radio frame. The rate scheduling method according to claim 1, wherein:

[6] In the rate scheduling method in which the base station performs uplink resource allocation based on a rate request command transmitted from each terminal constituting the communication system, each terminal is configured to buffer data to be transmitted. A rate request transmission step of generating a rate request command according to the amount, and transmitting the rate request command to the base station using a transport block in MAC signaling;

The base station performs resource allocation based on a rate request command sent from each terminal, and returns a rate permission transmission step for returning the result to each terminal as a rate permission command;

A rate scheduling method comprising:

[7] Each terminal is

As an initial setting, a rate for receiving an upper limit value of the transmission data amount and a reference value for the transmission data amount, and requesting transmission of a data amount exceeding the reference value (below the upper limit value) based on the buffer amount A request command, a rate request command for requesting data transmission equivalent to the reference value, or a rate request command for requesting transmission of a data amount less than the reference value are transmitted. Item 6. The rate scheduling method according to item 6.

8. The rate scheduling method according to claim 6, wherein the rate request command is transmitted using a predetermined 1 bit of the transport block.

9. The rate scheduling method according to claim 6, wherein the rate request command and information for indicating a cell or a sector are transmitted using a predetermined plurality of bits of the transport block.

[10] In a terminal constituting a wireless communication system together with a base station that performs uplink resource allocation,

Buffer amount management means for monitoring the buffer amount of data to be transmitted;

A determination means for generating a rate request command based on a determination result of the buffer amount and a predetermined threshold value defined in advance;

The rate request command is sent to DPCCH (Dedicated Physical Control CHannel) A transmission means that is incorporated into the FBI (Feedback Information) field in the line frame, performs a predetermined transmission process, and transmits.

A terminal comprising:

[11] As an initial setting, an upper limit value of the transmission data amount and a reference value of the transmission data amount are received.

The buffer amount is compared with the threshold and value, and when “buffer amount> threshold, value”, a rate request command for requesting transmission of a data amount exceeding the reference value (below the upper limit value). If “buffer amount = threshold”, a rate request command for requesting data transmission equivalent to the above reference value is generated. If “buffer amount = threshold”, the reference value is generated. 11. The terminal according to claim 10, wherein the terminal generates a rate request command for requesting transmission of a data amount less than.

[12] As an initial setting, an upper limit value of the transmission data amount and a reference value of the transmission data amount are received.

As the above threshold, the first threshold, the value and the second threshold, and the value (“first threshold, value> second threshold”) are set, and “buffer amount> first” is set. In the case of “threshold”, a rate request command for requesting transmission of the data amount exceeding the reference value (below the upper limit value) is generated, If `` value '', a rate request command for requesting data transmission equivalent to the reference value is generated, and if `` second threshold> buffer amount '', transmission of data amount less than the reference value is performed. 11. The terminal according to claim 10, wherein a rate request command for requesting is generated.

[13] The transmission means includes:

11. The terminal according to claim 10, wherein the rate request command is incorporated into a predetermined 1 bit of the FBI field.

[14] The transmission means includes:

An encoding process is performed so as to form the rate request command with a predetermined 1 bit (number of bits corresponding to all slots) of FBI feedback in all slots constituting the DPCCH radio frame. The terminal according to claim 10.

[15] The transmission means includes: The rate request command is embedded in a predetermined 1 bit of the FBI field in one slot constituting the DPCCH radio frame,

Further, the information for indicating a cell or sector is incorporated into a predetermined 1 bit (the number of bits corresponding to the remaining slot) of the FBI field in the remaining slot constituting the DPCCH radio frame. The terminal according to claim 10.

[16] In a terminal constituting a wireless communication system together with a base station that performs uplink resource allocation,

The rate request command is incorporated into a transport block in MAC signaling, and is transmitted by performing a predetermined transmission process;

A terminal comprising:

[17] As an initial setting, an upper limit value of the transmission data amount and a reference value of the transmission data amount are received.

The buffer amount is compared with the threshold and value, and when “buffer amount> threshold, value”, a rate request command for requesting transmission of a data amount exceeding the reference value (below the upper limit value). If “buffer amount = threshold”, a rate request command for requesting data transmission equivalent to the above reference value is generated. If “buffer amount = threshold”, the reference value is generated. 17. The terminal according to claim 16, wherein the terminal generates a rate request command for requesting transmission of a data amount less than.

[18] As an initial setting, an upper limit value of the transmission data amount and a reference value of the transmission data amount are received.

As the above threshold, the first threshold, the value and the second threshold, and the value (“first threshold, value> second threshold”) are set, and “buffer amount> first” is set. In the case of “threshold”, a rate request command for requesting transmission of the data amount exceeding the reference value (below the upper limit value) is generated, and “first threshold value> buffer amount> second threshold value” is generated. In the case of “value”, a rate request command for requesting data transmission equivalent to the reference value is generated, and in the case of “second threshold> buffer amount” 17. The terminal according to claim 16, wherein the terminal generates a rate request command for requesting transmission of a data amount less than the reference value.

[19] The transmission means includes:

The terminal according to claim 16, wherein the rate request command is incorporated into a predetermined bit of the transport block.

[20] The transmission means includes:

17. The terminal according to claim 16, wherein the rate request command and information for indicating a cell or a sector are incorporated in a predetermined plurality of bits of the transport block.