KR20020081521A - Method for transmitting and receiving forward packet in wireless telecommunication system - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a forward packet transmission and reception method in a wireless communication system and a computer-readable recording medium having recorded thereon a program for realizing the method.

2. The technical problem to be solved by the invention

The present invention provides a forward packet transmission and reception method for efficiently using the resources of the forward link by inserting a sub packet error check bit in a wireless communication system, and a computer readable recording medium having recorded thereon a program for realizing the method. box.

3. Summary of Solution to Invention

A forward packet transmission method in a wireless communication system, comprising: a first step of inserting error checking bits per subpacket in a packet configuration of a forward link at a transmitting end; A second step of transmitting, by the transmitting end, a packet including an error checking bit per sub packet to a receiving end; And a third step of transmitting, by the transmitting end, only a corresponding subpacket to the receiving end according to a request for retransmission of an error-occurring frame at the receiving end.

4. Important uses of the invention

The present invention is used in HDR systems and the like.

Description

Method for transmitting and receiving forward packet in wireless communication system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward packet transmission and reception method in a wireless communication system and a computer readable recording medium recording a program for implementing the method, and more particularly, to a code division multiple access (CDMA) mobile communication network. Inspecting secondary packet errors in high data rate (HDR) systems such as next-generation mobile communication networks such as International Mobile Telecommunication (IMT-2000) and Universal Mobile Telecommunication Service (UMTS) The present invention relates to a method for increasing capacity of a forward link through insertion of bits.

1 is an exemplary configuration diagram of a general wireless communication network.

As shown in Fig. 1, a general wireless communication network (e.g., W-CDMA) includes a user equipment (UE) (e.g., asynchronous terminal) 10, a wireless network (RNS :). Radio Network Subsystem (eg, asynchronous radio network) 20 and a wireless communication core network (eg, GSM-MAP core network) 30 are organically connected.

In IS-2000 1X CDMA mobile communication system, HDR system is proposed for high speed data transmission.

A conventional forward packet transmission and reception process in an HDR system is as follows.

As shown in FIG. 2, the length of the forward link packet in the HDR system may be composed of 1024, 2048, 3072, and 4096 bits (2a to 2d), and may be divided into one or two, three, or four subpackets according to a transmission rate. Can be configured. At this time, the secondary packet is composed of a MAC layer packet of 1002 bits transmitted from the Medium Access Contrpl (MAC) layer protocol, which is an upper layer of the physical layer, and a 22-bit padding bit set to '0'. The case consists of a 16-bit frame check sequence and a 6-bit tail instead of the 22-bit padding bits.

When the configured forward packet is transmitted from the access network as shown in FIG. 3 (301), the access terminal decodes the received frame (302,303), and then checks the frame check sequence. (304), if an error occurs, transmits the 'NAK' signal to the access network to request retransmission (305), and if the error does not occur, transmits the 'ACK' signal to successfully transmit the frame. It is informed that it has been received (306).

However, in the related art, when an error occurs in a received frame, there is a problem in that resources of a forward link are inefficiently used because all of the frames need to be retransmitted.

The present invention has been proposed to solve the above problems, and to implement the method and the forward packet transmission and reception method for efficiently using the resources of the forward link through the insertion of the sub-packet error check bit in a wireless communication system Its purpose is to provide a computer readable recording medium having recorded thereon a program.

1 is an exemplary configuration of a general wireless communication network.

2 is a diagram of a forward packet configuration in a conventional HDR system.

3 is a flow chart of a conventional forward packet transmission and reception method.

4 is a diagram illustrating an embodiment of a forward packet according to the present invention;

5 is a flowchart illustrating an embodiment of a method for transmitting and receiving a forward packet according to the present invention.

* Explanation of symbols for the main parts of the drawings

10: mobile station (UE) 20: radio network (RNS)

30: wireless communication core network

According to an aspect of the present invention, there is provided a method of transmitting a forward packet in a wireless communication system, comprising: a first step of inserting error checking bits per subpacket when configuring a packet of a forward link at a transmitting end; A second step of transmitting, by the transmitting end, a packet including an error checking bit per sub packet to a receiving end; And a third step in which the transmitting end retransmits only the corresponding subpacket to the receiving end according to a request for retransmission of an error-occurring frame at the receiving end.

In order to achieve the above object, the present invention provides a method for receiving a forward packet in a wireless communication system, wherein, when a forward link frame is received, a strength of a received signal is measured at a receiving end to compare the received signal with a predetermined threshold. First step; A second step of checking a frame check sequence after decoding a received frame when the strength of the received signal is greater than the predetermined threshold value according to the comparison result of the first step; And a third step of generating an information bit of a subpacket in which an error occurs and requesting the transmitting end to retransmit only the corresponding subpacket according to the check result of the second step.

In addition, the present invention may further comprise a fourth step of decoding a received frame and then checking a frame check sequence when the strength of the received signal is less than the predetermined threshold as a result of the comparison in the first step; And as a result of the check in the fourth step, when an error occurs, a NAK signal is transmitted to the transmitter to request retransmission, and when an error does not occur, a frame transmitted by transmitting an ACK signal to the transmitter is transmitted. And further comprising a fifth step indicating that the reception was successful.

In addition, the present invention further comprises a sixth step of informing that the transmitted frame has been successfully received by transmitting a success (ACK) signal to the transmitter when an error does not occur as a result of the inspection of the second step. It is done.

The present invention for achieving the above object comprises a first function for inserting error checking bits per sub-packet in the packet configuration of the forward link at the transmitting end of the wireless communication system having a processor for forward packet transmission; A second function of transmitting, by the transmitting end, a packet including an error checking bit per sub packet to a receiving end; And a computer-readable recording medium having recorded thereon a program for realizing a third function of retransmitting only a corresponding subpacket to the receiver in response to a request for retransmission of an error-occurring frame at the receiver.

In order to achieve the above object, the present invention provides a receiving end of a wireless communication system having a processor for receiving a forward packet, when receiving a forward link frame, measuring the strength of the received signal at the receiving end and A first function of comparing a predetermined threshold; A second function of checking a frame check sequence after decoding a received frame when the strength of the received signal is greater than the predetermined threshold according to a comparison result of the first function; And a computer-readable recording medium having recorded thereon a program for realizing a third function for generating an information bit of an error subpacket and retransmitting only the subpacket according to a result of the inspection of the second function. to provide.

The present invention also provides a fourth function for decoding a received frame and then checking a frame check sequence when the strength of the received signal is less than the predetermined threshold as a result of the comparison of the first function; And as a result of the inspection of the fourth function, when an error occurs, a NAK signal is transmitted to the transmitter to request retransmission, and when an error does not occur, a frame is transmitted by transmitting a success (ACK) signal to the transmitter. A computer readable recording medium having recorded thereon a program for further realizing a fifth function of informing successful reception is provided.

The present invention also provides a program for further realizing a fourth function of notifying that a transmitted frame has been successfully received by transmitting a success (ACK) signal to the transmitting end when no error occurs as a result of the inspection of the second function. Provide a computer readable recording medium having recorded thereon.

According to the present invention, in the HDR system proposed for high-speed data transmission under an IS-2000 1X CDMA mobile communication network environment, a data packet of a forward link may consist of one or multiple subpackets. By inserting and transmitting and retransmitting only the corresponding subpacket when an error of the forward packet occurs, the resource increase effect can be obtained by suppressing resource waste of the forward link due to the entire packet retransmission.

That is, the present invention inserts and transmits an error check bit per subpacket when configuring a packet on a forward link, so that even if an error occurs, the error check bit of the secondary packets is checked instead of retransmitting all the frames. By retransmitting only the corresponding secondary packet, it is possible to minimize capacity waste of the forward link and to increase capacity.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The structure of the forward packet proposed by the present invention is as shown in FIG.

As shown in FIG. 3, the structure of the forward packet proposed by the present invention changes the existing subpacket structure (see FIG. 2) to add 12-bit packet error check bits instead of 22-bit padding bits and the rest. Only 10 bits are inserted as padding bits (4b to 4d).

Since the access terminal uses the frame check sequence of the last subpacket to determine whether the received frame is in error, the packet error check bit is composed of 12 bits, and the polynomial shown in Equation 1 below is used.

g (x) = x ¹² + x ¹¹ + x ¹⁰ + x ⁹ + x ⁸ + x ⁴ + x + 1

5 is a flowchart illustrating a method of transmitting and receiving a forward packet according to the present invention.

First, when an access terminal receives a forward link frame (502), it measures the strength (Pr) of the received signal (503) and then compares the value with a threshold (504).

As a result of the comparison, when the intensity Pr of the received signal is smaller than the threshold, the same operation as that of FIG. 2 is performed. That is, after decoding the received frame (505) and checking the frame check sequence (506), if an error occurs, the 'NAK' signal is transmitted to the access network to request retransmission ( 507 and 501, when no error occurs, a ACK signal is transmitted to inform that the transmitted frame has been successfully received (508).

As a result of the comparison, when the strength Pr of the received signal is greater than the threshold, the received frame is decoded (510), the frame check sequence is checked (511), and if there is an error, each subpacket is again. The packet error check bit is checked (512), and a sub packet without error is stored, and the sub packet having an error generates information bits of the corresponding sub packet to request retransmission (513, 501). That is, if the received signal strength is below a certain level, the probability of error occurring in the packet error check bit increases. In this case, the entire packet needs to be retransmitted. Only when the received signal has a certain level or more, retransmission for each subpacket is performed. By doing so, the reliability of the received signal is maintained. In addition, unlike the conventional '0' or '1' that was repeatedly transmitted 128 times when transmitting an ACK channel that transmits an error of a received frame, as shown in [Table 1], 1-bit error bit and 3-bit retransmission are performed. By repeatedly transmitting the 4-bit signal composed of the information bits of the required sub-packet 32 times, the access network can know whether there is an error and the information of the corresponding sub-packet. Error status and retransmission request packet information bits are shown in Table 1 below.

Bit No One 2 3 4 Contents '1' if retransmission is required. '0' if retransmission is required.

Ex) 0000: No frame error

1101: Error in 1st, 3rd, 4th sub-packet

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

As described above, the present invention can insert unnecessary error checking bits for each subpacket during forward link packet transmission, thereby preventing unnecessary resource waste of the forward link due to retransmission of the entire packet when an error occurs in the packet. It is possible to increase the reliability by requiring retransmission only when the measured value is greater than or equal to a certain threshold value. In addition, the packet error check bit of the present invention can remove the confusion that may occur in the access terminal by using the number of bits and the generator polynomial differently from the frame error check sequence, and the message on the received packet error By repeatedly transmitting the information of the secondary packet with an error to the access network, the capacity of the forward link can be increased while maintaining reliability regardless of the channel and the user environment.

Claims (15)

In the forward packet transmission method in a wireless communication system, A first step of inserting error checking bits per sub-packet in the packet configuration of the forward link at the transmitting end; A second step of transmitting, by the transmitting end, a packet including an error checking bit per sub packet to a receiving end; And A third step in which the transmitting end retransmits only the corresponding subpacket to the receiving end according to a request for retransmission of an error-occurring frame at the receiving end; Forward packet transmission method in a wireless communication system comprising a. The method of claim 1, The receiving end, When the frame error occurs, by checking the error check bit of the sub-packet, and requesting the transmitting end to retransmit only the corresponding sub-packet in error, the forward packet transmission method in a wireless communication system. The method according to claim 1 or 2, The first step is, 12. A method of transmitting a forward packet in a wireless communication system, comprising changing a subpacket structure of an existing forward packet to add a 12-bit packet error check bit instead of a 22-bit padding bit and inserting only the remaining 10 bits as padding bits. The method of claim 3, wherein The packet error check bit, Since the receiving end uses the frame check sequence of the last sub-packet of the forward packet to determine whether the received frame is an error, the wireless terminal comprises a packet error check bit composed of 12 bits and is generated by the following equation. Forward packet transmission method in system. g (x) = x ¹² + x ¹¹ + x ¹⁰ + x ⁹ + x ⁸ + x ⁴ + x + 1 The method of claim 4, wherein The receiving end, In requesting retransmission for each subpacket when a forward frame error occurs, the sub-packet retransmission is requested to the transmitting end only when the received signal has a magnitude greater than or equal to a predetermined threshold, and information about the retransmission subpacket is measured. The forward packet transmission method of the wireless communication system, characterized in that configured to transmit with the error to the transmitting end. In a forward packet receiving method in a wireless communication system, When receiving a forward link frame, a first step of measuring a strength of a received signal at a receiving end and comparing the received signal with a predetermined threshold; A second step of checking a frame check sequence after decoding a received frame when the strength of the received signal is greater than the predetermined threshold value according to the comparison result of the first step; And A third step of requesting the transmitting end to retransmit only the corresponding subpacket by generating an information bit of an error subpacket according to the result of the check of the second step Forward packet receiving method in a wireless communication system comprising a. The method of claim 6, A fourth step of decoding a received frame and then checking a frame check sequence when the strength of the received signal is less than the predetermined threshold as a result of the comparison in the first step; And As a result of the check in the fourth step, when an error occurs, a NAK signal is transmitted to the transmitting end to request retransmission, and when an error does not occur, an ACK signal is transmitted to the transmitting end so that the transmitted frame is successful. 5th step to let you know that the The forward packet receiving method in a wireless communication system further comprising. The method of claim 6, A fourth step of informing that the transmitted frame has been successfully received by transmitting an ACK signal to the transmitting end when an error has not occurred as a result of the checking of the second step; The forward packet receiving method in a wireless communication system further comprising. The method according to any one of claims 6 to 8, The third step is The secondary packet without an error is stored, and the secondary packet having an error is generated by generating information bits of the corresponding secondary packet and retransmitted to the transmitting end. When the strength of the received signal is less than or equal to the predetermined threshold, the packet error check bit is stored. A method of forward packet reception in a wireless communication system according to claim 1, wherein the entire packet is retransmitted because the probability of an error is increased, and retransmission is performed for each subpacket only when the received signal has a strength greater than or equal to the predetermined threshold. The method of claim 9, The transmitting end, In the wireless communication system, a subpacket structure of an existing forward packet is changed and 12 packet error check bits are added instead of 22 bit padding bits, and only the remaining 10 bits are inserted as padding bits and transmitted to the receiving end. Forward packet reception method. The method of claim 10, The packet error check bit, Since the receiving end uses the frame check sequence of the last sub-packet of the forward packet to determine whether the received frame is an error, the wireless terminal comprises a packet error check bit composed of 12 bits and is generated by the following equation. Method for receiving forward packet in system. g (x) = x ¹² + x ¹¹ + x ¹⁰ + x ⁹ + x ⁸ + x ⁴ + x + 1 For forward packet transmission, to a transmitting end of a wireless communication system having a processor, A first function of inserting error checking bits per sub-packet in the packet configuration of the forward link at the transmitting end; A second function of transmitting, by the transmitting end, a packet including an error checking bit per sub packet to a receiving end; And A third function in which the transmitting end retransmits only the corresponding subpacket to the receiving end according to a request for retransmission of an error-occurring frame at the receiving end; A computer-readable recording medium having recorded thereon a program for realizing this. At the receiving end of a wireless communication system having a processor for forward packet reception, A first function of, when receiving a forward link frame, measuring the strength of the received signal at the receiving end and comparing the strength of the received signal with a predetermined threshold; A second function of checking a frame check sequence after decoding a received frame when the strength of the received signal is greater than the predetermined threshold according to a comparison result of the first function; And A third function of requesting the transmitting end to retransmit only the corresponding subpacket by generating an information bit of a subpacket in error according to a result of the inspection of the second function A computer-readable recording medium having recorded thereon a program for realizing this. The method of claim 13, A fourth function of decoding a received frame and then checking a frame check sequence when the strength of the received signal is smaller than the predetermined threshold as a result of the comparison of the first function; And As a result of the check of the fourth function, when an error occurs, a NAK signal is transmitted to the transmitting end to request retransmission, and if an error does not occur, a ACK signal is transmitted to the transmitting end to transmit the frame successfully. 5th function to inform you that it has been received by A computer-readable recording medium that records a program for further realization. The method of claim 13, A fourth function of notifying that the transmitted frame has been successfully received by transmitting an ACK signal to the transmitting end when an error has not occurred as a result of the inspection of the second function; A computer-readable recording medium that records a program for further realization.