KR100857778B1 - Method for Transmitting and Receiving Using Subpacket - Google Patents

Abstract

The present invention relates to a mobile communication system, and more particularly, to a variable length packet transmission method using a hybrid automatic retransmission request scheme. In the packet transmission method of variable length according to the present invention, when a transmitting end transmits a packet generated from information bits into a plurality of sub packets, each sub packet is transmitted to a receiving end from a fixed position in the packet. Transmission position information is transmitted to the receiving end. One of two indicators is transmitted to the receiving end in the first transmission location information of the transmission location information, and the receiving end determines whether the subpacket transmitted according to the indicator is the first subpacket of the packet.

Subpacket, transmission location information

Description

Method for Transmitting and Receiving Packet Using Subpacket {Method for Transmitting and Receiving Using Subpacket}

1A is a diagram illustrating a configuration of a packet having a fixed length subpacket according to a hybrid automatic retransmission request scheme according to the related art.

FIG. 1B is a view illustrating a process of receiving and reconfiguring fixed length subpackets shown in FIG. 1A

2A is a diagram illustrating a transmission interval of a variable length subpacket according to a hybrid automatic retransmission request scheme according to the prior art;

FIG. 2B is a diagram illustrating a process of receiving and reconstructing variable length subpackets according to a conventional hybrid automatic retransmission request scheme; FIG.

3 is a diagram illustrating a transmission interval of a variable length subpacket according to a hybrid automatic retransmission request scheme according to the present invention.

The present invention relates to a mobile communication system, and more particularly, to a packet transmission and reception method using a subpacket.

In general, the transmission of packet data for a mobile communication system uses a hybrid automatic repeat request (hereinafter, referred to as HARQ).

That is, the HARQ scheme combines an Automatic Repeat Request (hereinafter abbreviated as ARQ) scheme and a Forward Error Correction (hereinafter abbreviated as FEC) to provide reliability and data throughput in data transmission in a communication system. The purpose is to improve throughput.

The ARQ is intended to improve reliability by requiring the receiver to retransmit the same information until the information initially transmitted to the receiver is received without error, and FEC uses an error correction code to generate an error caused by the channel environment. The purpose is to calibrate the receiver.

If the channel environment is always good and there is a low frequency of errors in the information sent, using ARQ alone will suffice.

However, when the channel environment becomes bad, the frequency of errors occurring in the transmitted information increases, and thus the number of times of requesting retransmission increases.

This lowers the data throughput of the system. It is therefore proposed to use FEC with ARQ and this is HARQ.

One type of HARQ is a method using incremental redundancy.                         

In this method, when the transmitting end initially transmits information encoded at a high coding rate to the receiving end, and each time a retransmission is requested from the receiving end, the transmitting end lowers the coding rate and encodes, and then sends only the additional redundancy bits to the receiving end. The decoding is performed by combining with the information already sent.

These added redundancy bits are bits added for error correction or detection of previously sent packet data.

Synchronous incremental redundancy (hereinafter referred to as SIR) and asynchronous incremental redundancy (hereinafter abbreviated as AIR) are used as the HARQ incremental redundancy scheme.

In the SIR method, as shown in FIG. 1A, one packet is formed by encoding and repeating information to be transmitted, and a part of the packet is divided into subpackets having a fixed size and transmitted.

Accordingly, as shown in FIG. 1B, the receiving end reconstructs and decodes the packet using only the received subpackets according to the subpacket ID (sub packet order) received through the control channel.

The AIR method is a method in which a length of each subpacket is changed according to a channel and an environment in a process of dividing a single packet into a plurality of subpackets.

At this time, each subpacket is transmitted from a fixed position in the packet, and the length of the subpacket and information on the position are transmitted to the receiver through a control channel.

2A is a diagram illustrating a transmission interval of a variable length subpacket according to a hybrid automatic retransmission request scheme of the related art. In particular, FIG. 2A illustrates a case in which a sub packet is transmitted at boiling intervals in the AIR scheme.

2B is a diagram illustrating a process of receiving and reconstructing variable length subpackets according to a hybrid automatic retransmission request scheme according to the related art.

Accordingly, as shown in FIG. 2B, the receiving end extracts information about the subpacket through the control channel, and decodes the link packet by connecting / combining with the previously received subpacket through the extracted information.

At this time, the receiving end waits for the first subpacket of the packet, and when receiving the corresponding subpacket, attempts decoding with the subpacket. Thus, if the decoding succeeds, it sends an ACK to the transmitter, and then waits for the first subpacket of another packet.

However, if decoding fails, it sends a NACK to the transmitting end, stores the received subpacket, and waits for the next subsequent subpacket of this subpacket. When the receiving end receives the next waiting subpacket, it attempts to decode by combining the subpacket and the prestored subpacket.

Thus, if the decoding succeeds, it sends an ACK to the transmitter and waits for the first subpacket of another packet. However, if decoding fails, it sends a NACK to the transmitter, stores the received subpacket, and waits for the next consecutive subpacket.                         

The receiving end is waiting for the next consecutive subpacket, and upon receiving the first subpacket of the packet, the receiver abandons the decoding of the previous encoding packet and attempts to decode the new encoding packet using the newly received subpacket. .

The receiving end is waiting for the first transmitted subpacket of the packet. When receiving the successive subpacket, the receiving end discards the received subpacket, sends an ACK to the transmitting end, and waits for the first transmitted subpacket of the new packet.

Such an operation may be possible when the receiving end has information indicating whether or not the received subpacket is the first subpacket of the packet.

In the case of the SIR, since the sub packet ID, which is a sequence of sub packets, is transmitted as control information, it can be seen that the first packet is transmitted first and the rest are consecutive sub packets.

However, in the case of the AIR in which the control information transmits the position of the subpackets not in the order of the subpackets, it is not possible to determine whether the subpackets are the first packets to be transmitted.

Accordingly, an object of the present invention has been made in view of the above-described problems of the prior art, and has been described in detail. It is to provide a transmission method.

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Hereinafter, a configuration and an operation according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.
The present invention provides a packet receiving method applied to a system for performing communication using at least one subpacket corresponding to one packet, the method comprising: receiving a subpacket, and receiving the subpacket prior to the subpacket Receiving a control signal indicating whether to delete all one subpacket or to combine and decode a subpacket received before the subpacket and the subpacket, and to perform decoding on the subpacket according to the signal. A step is made.
In addition, the present invention provides a packet transmission method applied to a system for performing communication using at least one subpacket corresponding to one packet, the method comprising: transmitting a first subpacket corresponding to one packet; Transmitting a control signal indicating whether to delete all subpackets received before the first subpacket or to combine and decode the subpacket received before the subpacket and the subpacket from the receiving end; And receiving a signal indicating whether or not it has been decoded.

The present invention proposes two methods for the receiver to determine whether a transmitted subpacket is a first subpacket of an arbitrary packet in a packet transmission consisting of variable length subpackets.

First, a method of including 1 bit of control information in a control channel for notifying a receiver whether a subpacket transmitted by a transmitter is a first subpacket of an arbitrary packet.

That is, a field called NC_IND (NEW / CONTINUE Indication) is added to the control information channel. If NC_IND is 0, it is determined that the packet is the first packet transmitted.

Second, a method of modifying control information including where a subpacket transmitted by a transmitting end is transmitted from is a packet.

That is, one of the control information is a method used to indicate that the first sub-packet is not transmitted.

However, if two bits are used to indicate the transmission location of a subpacket as in the prior art, it is difficult to select an appropriate transmission location because there are three indicating subpacket transmission locations.

Thus, the present invention proposes a method of indicating a transmission position of a subpacket using 3 bits.

3 is a diagram illustrating a transmission interval of a variable length subpacket according to a hybrid automatic retransmission request scheme according to the present invention.

Referring to FIG. 3, in the present invention, P0 (000) and P7 (111) are first transmitted to inform the receiving end of the transmission position of a subpacket using 3 bits and whether or not it is the first subpacket of the subpacket. Position, and the remaining P1 (001), P2 (010), P3 (011), P4 (100), P5 (101), and P6 (110) indicate the remaining transmission positions. Here, P0 is used only for the first subpacket of the packet, and P7 is used only for the packet that is not the first subpacket.

Therefore, the receiving end receives the transmission position information of the 3-bit subpacket from the transmitting end, and if it is P0 (000), determines that the packet is the first subpacket transmitted. It is determined that it is not.

The first method and the second method use the same control information, but the difference between the sub packet transmission positions of the second method and the sub packet transmission positions of the second method is 7 different.

As described above, in the present invention, the receiving end may determine whether or not the transmitted subpacket is the first transmitted packet, thereby enabling the receiving end to perform a correct operation.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the examples, but should be defined by the claims.

Claims (17)

In the packet receiving method applied to a system for performing communication using at least one subpacket corresponding to one packet, Receiving a subpacket; Receiving, via a control channel, a control signal indicating whether to delete all subpackets received before the subpackets, or to decode the subpackets received before the subpackets and the subpackets; And According to the signal, performing decoding on the sub packet; Packet receiving method comprising a. The method of claim 1, Performing the decoding, And decoding according to the control signal by combining the subpacket and the subpacket received before the subpacket. The method of claim 2, The control signal value is a packet receiving method, characterized in that '1'. The method of claim 1, Performing the decoding, The method according to the control signal, characterized in that to delete all the sub-packet received before the sub-packet, decoding using the sub-packet. The method of claim 4, wherein The control signal value is a packet reception method, characterized in that '0'. The method of claim 1, The control signal may include whether to delete all subpackets received before the subpackets, or decode the subpackets received before the subpackets and the subpackets, and include predetermined packet transmission position information. Packet receiving method characterized in that. The method of claim 6, The control signal is a packet receiving method, characterized in that having a 3-bit length. The method of claim 7, wherein Performing the decoding, And when the control signal value is (000), delete all subpackets received before the subpacket. The method of claim 1, If the decoding is successful, further comprising the step of transmitting a successful (ACK) signal packet receiving method. The method of claim 2, If the decoding fails, further comprising the step of transmitting a NACK signal. The method of claim 1, The communication system is a packet receiving method, characterized in that the Hybrid Automatic Repeat Request (HARQ). The method of claim 1, Wherein each step is performed at a mobile station. A packet transmission method applied to a system for performing communication using at least one subpacket corresponding to one packet, Transmitting the first subpacket to which one packet corresponds; Transmitting, by a receiver, a control signal indicating whether to delete all subpackets received before the first subpacket or to combine and decode a subpacket received before the first subpacket and the first subpacket; And Receiving from the receiving end a signal indicating whether the first subpacket has been successfully decoded Packet transmission method comprising a. The method of claim 13, When the first subpacket is a first subpacket of the subpackets corresponding to the one packet, the control signal is a signal for deleting all the subpacket received before the first subpacket, characterized in that Packet transmission method. The method of claim 14, The control signal value is a packet transmission method, characterized in that '0'. The method of claim 13, When the first subpacket is not the first subpacket transmitted among the subpackets corresponding to the one packet, the control signal is a signal informing that the first subpacket and the previously received subpacket are combined and decoded. Packet transmission method characterized in that. The method of claim 16, The control signal value is a packet transmission method, characterized in that '1'.

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