KR101347970B1 - Method for receiving of data in mobile communication system - Google Patents

Abstract

The present invention relates to a data receiving method in a mobile communication system, and in particular, a process of calculating a 12-bit sequence of a reception frame of a receiver when receiving a new data frame that does not include a field indicating a higher 4-bit sequence among 12-bit sequences. By proposing a calculation method that considers the possibility of delayed reception, it is possible to calculate a 12-bit sequence of a received frame of an accurate receiver without performing a separate delay detection process.

Sequence number, RLP layer, mobile communication system, data reception, multiplexing layer, physical layer

Description

Receiving data in mobile communication system {METHOD FOR RECEIVING OF DATA IN MOBILE COMMUNICATION SYSTEM}

1 is a block diagram of a protocol structure applied to a data transmission and reception apparatus in a general mobile communication system;

2a shows a frame structure for each protocol of a mobile communication system in the case of an FCH;

2b is a frame structure for each protocol of a mobile communication system for SCH and PDCH;

3 is a flowchart illustrating a data receiving method in a conventional mobile communication system;

4 is a block diagram of an apparatus for transmitting and receiving data in a mobile communication system;

5 is a detailed block diagram of a transmitter in the configuration of FIG. 4;

6 is a flowchart illustrating a data receiving method in a mobile communication system according to an exemplary embodiment of the present invention.

The present invention relates to a data service in a mobile communication system, and more particularly, to a data receiving method in a mobile communication system.

In general, a mobile communication system using a cellular communication method is a representative system of a wireless communication system. Such mobile communication systems use a multiple access scheme to simultaneously communicate with multiple users. As the multiple access scheme, time division multiple access (TDMA), code division multiple access (CDMA) and frequency division multiple access (FDMA) schemes are typically used. Among them, the code division multiple access system has been developed in a form capable of transmitting high-speed packet data in a system mainly providing voice communication according to the rapid development of technology.

1 is a block diagram of a protocol structure applied to a data transmission and reception apparatus in a general mobile communication system. Next, a general protocol structure and an operation according to the structure will be described with reference to FIG. 1.

In FIG. 1, reference numeral 110 denotes a transmitter of a mobile communication system, and reference numeral 120 denotes a receiver of a mobile communication system.

The mobile communication system often transmits high speed data, and in such a case, it is necessary to provide high throughput. In order to provide a high gain ratio, in a radio protocol of a mobile communication system, a radio layer protocol (hereinafter referred to as RLP) layer 111 and 121, a mux layer 113 and 123, and a physical layer The operation of each layer such as the (Physical Layer) 115, 125 becomes a very important factor. In addition, in order to have a high gain rate when transmitting high-speed data in the mobile communication system, mutual interface matching between the layers must be performed, and the flow of information transmitted based on the matching is also an important factor.

The RLP layer 111 arranges at the receiver 120 in the transmission order transmitted from the transmitter 110 by using a sequence sequentially assigned to each RLP frame in the mobile communication system, and receives a frame of a sequence not received. Requests retransmission and recovers unreceived frames.

2A and 2B illustrate a frame structure diagram for each protocol of a mobile communication system. FIG. 2A illustrates a frame structure diagram for the FCH, and FIG. 2B illustrates a frame structure diagram for the SCH and PDCH.

For example, when the transmitter 110 transmits an initial transmission RLP frame by attaching a sequence of X, X + 1, and X + 2, the receiver 120 receives X, X + 2 in the order of X, X + 2. Sort in order of +2, know that X + 1 is missing, and request a retransmission for X + 1. Upon receiving the retransmission request, the transmitter 110 transmits a retransmission RLP frame of X + 1.

The RLP layer 111 uses a 12-bit serial number, but does not include all 12-bit sequences in the RLP header (210 ~ 240), in order to save resources in the wireless environment, the lower 8 bits It may be included only. In this case, the lower 8 bits are defined as 'SEQ', and the upper 4 bits are defined as 'SEQ_HI'.

Therefore, the RLP frame may be configured by including both the SEQ field and the SEQ_HI field in the RLP headers 210 to 240. In some cases, only the SEQ field is included in the RLP headers 210 to 240 to configure the RLP frame. Therefore, the receiver 120 performs a process of calculating a 12-bit sequence using only the two fields (ie, SEQ field and SEQ_HI field) or SEQ field. In this case, when the 12-bit sequence is calculated using only the SEQ field, the receiver 120 performs a delay detection process for determining whether the corresponding frame is delayed only for the initial transmission frame. If it is determined that the delay is received, the receiver 120 performs a sequence recalculation process of calculating a 12-bit sequence again to calculate a final sequence.

The RLP frame is divided into a data frame (that is, a frame in which a payload is actually loaded, a 'initial transmission frame' or a 'retransmission frame') and a control frame in which an actual payload is not loaded. As shown in FIG. 2A, the control frame is transmitted and received only through the FCH, and the data frame may be transmitted and received through the FCH, SCH, and PDCH.

The MUX layer 113 multiplexes multiple RLP frames. The MUX header 213 is added to the RLP frame 211 to form the MUX PDU 215. In this case, a form in which a plurality of MUX PDUs are combined is called a MUX SDU 217. When a physical overhead is added to this MUX SDU 217, it becomes one physical frame.

 The transmitter encodes the physical frame thus configured in the encoder 115a and transmits it through the wireless environment.

 On the contrary, the receiver demultiplexes the physical frame decoded by the decoder 125a in units of MUX PDUs 215 in the demultiplexing block (hereinafter referred to as DEMUX) 123, and then removes the MUX head 213 to deliver the decoded physical frame to the RLP layer 121. do.

The RLP layer 121 of the receiver 120 removes the RLP head 213, calculates a serial number, performs delay detection as necessary, and then checks whether the frame is a valid frame using the sequence, and then, in the sequence order. Perform the process of sorting frames.

The RLP layer 121 of the receiver 120 in FIG. 1 has a reception buffer for aligning and storing the received RLP frames, and the transmitter 110 transmits data for storing the data for retransmission and data received from the upper layer. It has a buffer.

3 is a flowchart illustrating a data receiving method in a conventional mobile communication system.

The RLP layers 111 and 121 use 12-bit sequences, but to reduce the overhead of the data frame, the RLP layer 111 of the transmitter 110 does not include the SEQ_HI (high 4 bit sequence) field, and the SEQ (lower 8 bits). A new data frame may be transmitted by including only a sequence field, or may be transmitted by including both SEQ_HI and SEQ.

The RLP layer 121 of the receiver 120 calculates by dividing the L_SEQ (12-bit sequence) of the new data frame received in step 301 into a new data frame including a SEQ_HI field and a new data frame that are not.

  L_SEQ = {L_V (R) + [256 + SEQ-V (R)] mod 256} mod 4096

If the double SEQ_HI field is included, since all information on the 12-bit sequence is received, there is no problem of calculating the L_SEQ. However, for a new data frame that does not include the SEQ_HI field, L_V (R), a variable that manages the sequence of new data frames that the receiver expects to receive next, and the SEQ (lower 8-bit sequence) field of the received new data frame Calculate L_SEQ (12-bit sequence) as shown in Equation 1 above.

After calculating L_SEQ (12-bit sequence), the receiver 120 performs a delay detection (a process of determining whether a delay is received) in step 303 to determine whether the calculated value is correct.

If the delayed frame is not received, the process proceeds to step 307 without resequencing the sequence.

However, when it is determined that the delayed frame is received, the receiver 120 determines that the L_SEQ calculated in step 301 is an incorrectly calculated L_SEQ based on the assumption that L_SEQ is greater than L_V (R), and in step 305, Equation 2 Perform the sequence recalculation process using.

L_SEQ = {4096 + L_V (R)-[256 + V (R) -SEQ] mod 256} mod 4096

After the sequence recalculation process, the receiver 120 determines whether L_SEQ, which is the output of the recalculation process, is a valid sequence (307). If it is a valid sequence, the receiver 120 processes the valid frame in step 309.

However, if the sequence is invalid, the receiver 120 processes the invalid frame in step 311.

 Since the L_SEQ of the new data frame without SEQ_HI is calculated based on the assumption that L_SEQ is larger than L_V (R), the L_SEQ is calculated based on the assumption that L_SEQ is actually less than L_V (R) (when received delayed). Is calculated. Therefore, if it is determined that the delayed new process is received as a new data frame, the L_SEQ is calculated again by performing the sequence recalculation process.

However, this process has the following problems.

First, it is difficult to precisely set the delay detection window size, which is a standard of delay detection, and thus, an error may occur in the delay detection process. For example, in the case of CDMA 1X, the delay detection window size setting is closely related to the parameters such as the F-SCH duration (the period during which the SCH is open) and the MUX option in the F-SCH assignment message. Consideration should also be given to the failure to receive an F-SCH assignment message. The operation method of the F-SCH assignment message is different for each base station (BS), and various parameters are received differently depending on the situation. In the more fatal case, since the parameter value of the F-SCH assignment message that has not been received is not known, it is difficult to precisely set the delay detection window size.

In addition, in case of EVDV, the delay detection window size should be more precise because the frames that are delayed due to HARQ are frequently received, and in other cases, other methods having complicated processing other than delay detection using the delay detection window size should be used.

 If the delay detection window size setting is set larger than the proper value, the incorrectly calculated L_SEQ can be mistaken as the correct value. If the delay detection window size is set smaller than the proper value, the sequence is recalculated by judging the correctly calculated value as the delayed frame. Will calculate the wrong L_SEQ.

Second, if the delay detection is not accurate, the calculation of L_SEQ will be an unintended value, as mentioned above, and the resulting RLP reset or RLP frame mis-ordering may cause frame error ( For example, PPP frame CRC error) may occur, and as a result, the data reception gain rate may be seriously reduced.

Third, there is a problem in that an overhead of having to perform delay detection every frame and recalculating the L_SEQ whenever it is determined that the delayed frame is received.

Fourth, the overhead and the error of L_SEQ calculation cause more serious phenomenon in case of high speed data. For example, 160 new data frames can be received in 20 ms as the worst case in EV-DV. The existing processing method including delay detection has a problem of generating a large load.

Accordingly, an object of the present invention is to provide a data reception method in a mobile communication system considering the possibility of delayed reception in the process of calculating L_SEQ when a new data frame including no SEQ_HI field is received.

It is also an object of the present invention to provide a data receiving method in a mobile communication system that accurately calculates L_SEQ without performing a separate delay detection process.

It is also an object of the present invention to provide a data receiving method in a mobile communication system that accurately calculates L_SEQ without performing a separate delay detection process when receiving high-speed data.

In the method for receiving data in a mobile communication system according to an embodiment of the present invention, in the method for receiving data in a mobile communication system, a process of receiving a frame including a lower sequence without including an upper sequence from a transmitter and at a receiver And determining whether the received frame is delayed by using a new sequence of frames to be received next and the sequence of received frames.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

In the mobile communication system according to the present invention, the data reception method is characterized in that the L_SEQ of a new data frame not including the received SEQ_HI field is not additionally delayed detected. Calculate using Equation 7>.

Before describing <Equation 7>, the definition of terms used in the equation should be preceded.

L_V (N): A variable that manages a 12-bit sequence of the next frame of the last frame received consecutively at the receiver.

-V (N): Lower 8 bits of L_V (N).

-L_V (N) peer: Variable that manages expected L_V (N) of peer RLP.

L_V (R): A variable that manages a 12-bit sequence of new data frames that the receiver expects to receive next.

-V (R): Lower 8 bits of L_V (R).

L_SEQ: 12-bit sequence of the receiver frame at the receiver.

-l_seq: 12-bit sequence of transmission frame of the transmitter.

L_V (S): A variable that manages a 2-bit sequence of a new data frame transmitted next by the transmitter.

-SEQ: Low 8 bit sequence out of 12 bit sequence.

-SEQ_HI: High 4 bit sequence out of 12 bit sequence.

4 shows a block diagram of a data transmission and reception apparatus in a mobile communication system, and FIG. 5 shows a detailed block diagram of a transmitter in the configuration of FIG.

In FIG. 4, reference numeral 400 is used to describe a sequence representation method in the RLP layers 111 and 121 of the transceivers 110 and 120 of the mobile communication system. Although 12-bit serial numbers are used in the RLP layers 111 and 121 of the transceivers 110 and 120 of the mobile communication system, in order to save resources in a wireless environment, all 12-bit sequences are RLP headers. If only the lower 8 bits are included without being included in (210 to 240), the lower 8 bits are represented by 'SEQ' 410 and the upper 4 bits are represented by 'SEQ_HI' 420. Hereinafter, the sequence is denoted by upper 4 bits / lower 8 bits.

In FIG. 4, the transmitter 110 transmits 2/52 frames at sequence number 2/44, but the receiver 120 has shaded portions of sequence numbers 2/44, 2/45, 2/46 and 2 It can be seen that frames of / 50 and 2/51 have not been received.

FIG. 5 is a detailed block diagram of a transmitter. When the following Equation 3 is satisfied, the SEQ_HI field must be filled and transmitted.

[4096 + l_seq-L_V (N) peer] mod 4096> 255

That is, the RLP layer 111 of the transmitter 110 may omit SEQ_HI by omitting only when the sequence of the transmission frame is 255 or less than the L_V (N) peer.

As an example, FIG. 5 illustrates a case in which a new data frame having a sequence of 2/53 includes only SEQ in a RLP header and a case in which both SEQ and SEQ_HI are included.

In the case of FIG. 5, since Equation 3 is not satisfied, a new data frame may be configured by including only 53 as SEQ without omission of 2 as SEQ_HI.

In another example of FIG. 5, a retransmission data frame having a sequence of 2/47 may also omit 2 as SEQ_HI and transmit only 47 as SEQ, with the same rules as in the case of a new data frame.

5 shows that if Equation 3 is satisfied, both the new data frame and the retransmission data frame must include both SEQ and SEQ_HI.

As shown in FIG. 4, since the transmitter 110 receives the L_V (N) transmitted from the receiver 120 and updates its value to the L_V (N) peer value, the RLP layer 111 of the transmitter 110 is The L_V (N) peer managed and the L_V (N) managed by the RLP layer 121 of the receiver 120 satisfy Equation 4 below.

[4096 + L_V (N) -L_V (N) peer] mod 4096 <2048

In Equation 4, the L_V (N) peer managed by the RLP layer 111 of the transmitter 110 may not be larger than the L_V (N) managed by the RLP layer 121 of the receiver 120. .

As mentioned above, since the RLP layer 111 of the transmitter 110 omits and transmits SEQ_HI only when the transmission sequence is less than 255 less than the L_V (N) peer, the RLP layer 121 of the receiver 120 is transmitted. The L_SEQ of the new data frame not including the received SEQ_HI field always satisfies Equation 5 according to Equations 3 and 4.

 [4096 + L_SEQ-L_V (N)] mod 4096 <256

Equation (5) means that L_SEQ of a new data frame received without including SEQ_HI in the RLP layer 121 of the receiver 120 cannot always be greater than 256 than L_V (N).

Therefore, if the L_SEQ is calculated as shown in Equation 6 below, it is precisely calculated not only when the L_V (R) is larger than the L_V (R) but not smaller than the L_V (R). I can make it.

  L_SEQ = {L_V (N) + [256 + SEQ-V (N)] mod 256} mod 4096

 That is, conventionally, L_SEQ is first calculated as shown in Equation 1 under the assumption that L_V (R) is large, and a separate delay detection process is required to check whether this assumption is correct. If it is determined that the data frame is new, the sequence recalculation process is executed, whereas the data receiving method according to the embodiment of the present invention does not have a separate delay detection process. In the data receiving method according to an embodiment of the present invention, it is possible to directly determine whether or not to directly receive a delay by using Equation 7 used when checking sequence validity using the sequence calculated by Equation 6.

  [4096 + L_V (R) -L_SEQ] mod 4096 <2048

If the calculated L_SEQ satisfies Equation 7, it is not a delayed frame, otherwise it is a delayed frame. Therefore, it is possible to determine whether to receive delay when checking sequence validity without any additional routine.

6 is a flowchart illustrating a data receiving method in a mobile communication system according to an exemplary embodiment of the present invention. A method of receiving data at a receiver in a mobile communication system will be described with reference to FIG. 6.

First, when the RLP frame is received by the RLP layer 121, the receiver 120 calculates the equation as shown in Equation 6 in step 601. If L_SEQ is calculated as shown in Equation 6, the L_SEQ is calculated not only when it is larger than L_V (R) (when the frame is not delayed) but also when it is smaller than L_V (R) (when delayed). Can be.

In addition, the receiver 120 checks whether the frame is valid in step 603. Checking whether the frame is valid determines whether a delay is directly received by Equation (7). If the calculated L_SEQ satisfies Equation 7, it is not a delayed frame, otherwise it is a delayed frame.

That is, if the delayed frame is not received, the receiver 120 determines that the frame is valid and processes the valid frame in step 605. However, in case of a delayed received frame, the receiver 120 processes an invalid frame in step 607.

In the present invention that operates as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

According to the present invention, when a new data frame including no SEQ_HI field is received, L_SEQ can be accurately calculated without considering a delay detection process by considering the possibility of delay reception in calculating L_SEQ. This increases the data reception gain rate, so that the terminal user can download the content at a faster and lower price, and the base station can quickly operate the limited resources by providing the service more quickly. In addition, the omission of the delay detection process eliminates the risk of error of the delay detection itself, and may omit the delay detection processing routine, the parameter management processing routine for the delay detection window, the sequence recalculation processing routine, and the like. This can simplify the processing of the RLP receiver, which can act as a bottle neck when processing data services from a software point of view, thereby reducing the load on the CPU and effectively processing high-speed data services.

In addition, the present invention can determine whether to receive a delay when checking the sequence validity without an additional routine.

Claims (5)

In the method for receiving data in a mobile communication system, Receiving a frame including a lower sequence of 8 bits from a transmitter, the upper sequence of 4 bits of the sequence of 12 bits; Determining whether the frame is delayed without a delay detection process according to whether the sequence of the frame satisfies Equation 8 below; And When the following Equation 8 is satisfied, the method comprising the step of determining that the frame is not a delayed frame, the data receiving method in a mobile communication system, &Quot; (8) &quot;  [4096 + L_V (R) -L_SEQ] mod 4096 <2048 Where L_V (R) represents a variable that manages the 12-bit sequence of the new data frame that the receiver expects to receive next, and L_SEQ represents the 12-bit sequence of the receiver's received frame. delete The method of claim 1, The sequence of frames is Method for receiving data in a mobile communication system, characterized in that calculated by <Equation 9> &Quot; (9) &quot;   L_SEQ = {L_V (N) + [256 + SEQ-V (N)] mod 256} mod 4096 Here, L_SEQ represents a 12-bit sequence of the received frame, L_V (N) represents a variable for managing a 12-bit sequence of the next frame of the last frame consecutively received at the receiver, SEQ represents a sequence number, V ( N) represents the lower 8 bits of the L_V (N). delete The method of claim 1, If the <Equation 8> is not satisfied further comprising the step of determining a delay received frame data receiving method in a mobile communication system.

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