KR100407937B1 - parameter determinating Method for downlink rate matching - Google Patents

Abstract

The present invention relates to a method for determining a parameter for a variable rate matching pattern in a downlink rate matching algorithm of a mobile communication, in particular, using wideband code division multiple access (hereinafter, abbreviated as W-CDMA) in a next generation mobile communication. In the present invention, the data size (length) of the coded composite transport channel obtained by rate matching for all transport channels as much as possible in order to determine the amount to be repeated or punctured by downlink variable rate matching is actual. In the procedure for checking whether the physical channel is larger than the data size (length), the comparison step is omitted and only the result of the "Z equation" is temporarily determined. It provides a parameter determination method for downlink variable rate matching, which is used to correct the value of. Also, the discontinuous transmission (DTX) indication bit inserted in the CCTrCH is minimized for all transport channel and all transport format combinations. New rate matching rate calculated to be Temporarily determined using Is used to determine the amount to be repeated or punctured by downlink variable rate matching, and eventually provides a parameter determination method for downlink variable rate matching without using the "Z equation".

Description

Parameter determinating method for downlink rate matching

The present invention relates to the next generation mobile communication, and more particularly, to a method for determining a parameter for a variable rate matching pattern among downlink rate matching algorithms of a mobile communication using a W-CDMA scheme.

In recent years, the Third Generation Partnership Project (hereinafter abbreviated as 3GPP) is a more advanced next generation movement based on the core network and wireless access technology of the mobile communication globalization system that provides multimedia services such as voice, video and data. The technical specification for the communication system is presented.

Among the 3GPP technical research areas, the research on the global radio access network (UTRAN) describes definitions and explanations of transport channels (TrCH) and physical channels (PhCH). In particular, the technical specification (TS) describes the definition and description of multiplexing, channel coding, and interleaving according to the frequency division duplex (FDD) mode.

Here, a channel coding and transport channel multiplexing structure in downlink according to the 3GPP radio access network (RAN) standard will be described.

1 is a block diagram illustrating a channel coding and transport channel multiplexing structure in a downlink according to a 3GPP radio access network (RAN) standard, wherein a downlink data stream delivered from a higher layer is transmitted on a radio link. It is encoded to provide. Herein, data streams exchanged with higher layers are called transport blocks, and a set of these transport blocks is called a transport block set.

In the downlink, procedures such as error detection and correction, rate matching, interleaving, and mapping of transport channels to physical channels are performed along with encoding of the data stream.

A transmission channel (TrCH) is one channel transmitted from a higher layer, and a period of a transmission channel is called a transmission time interval (hereinafter, referred to as a TTI). That is, the downlink data stream is descended in TTI units, and the TTI is 10 ms, 20 ms, 40 ms, or 80 ms, depending on the transmission channel characteristics.

The coding structure of the downlink data stream varies according to the type of service. When a real user requests several services at the same time, it is natural that several transport channels must exist at the same time.

The following describes in more detail the channel coding and transport channel multiplexing structure in the downlink shown in FIG.

First, a CRC bit for cyclic redundancy check (hereinafter referred to as CRC) is added to each transport block (S1). This is for error detection.

Next, all transport blocks during each TTI are successively connected. If the number of bits of the transport block is larger than the coding length, code block division is performed after the transport block is connected (S2).

Next, channel coding is performed. After the channel coding, rate matching for repeating or puncturing bits on a transmission channel is performed in units of TTIs (S4).

Current downlink rate matching patterns include a fixed rate matching pattern that performs puncturing and repetition at fixed positions, and a variable rate matching pattern that can flexibly change the puncturing and repetitive positions.

When the receiving side determines the bit rate in the decoding process, the variable rate matching pattern first decodes a Transport Format Combination Indicator (TFCI) field among fields belonging to the received frame and uses rate matching information obtained thereby.

If the downlink rate matching is a fixed rate matching pattern, a discontinuous transmission (hereinafter abbreviated as DTX) indication bit insertion procedure is performed immediately after rate matching (S5). This fills the radio frame with meaningless bits to equalize the size (length) of the radio frame, which is then used by the interleaver, where the length of the input data stream is used in the first ^ST interleaving (S6). This is to fill up to the last column of the last row by making it a multiple of the column number of.

On the other hand, in the case of the variable rate matching pattern, the DTX indication bit insertion procedure immediately after the rate matching is not performed. This is because the parameter of rate matching is set such that the length itself of the rate-matched output data stream is a multiple of the number of columns of the interleaver used.

Next, the data stream of the transport channel is divided into predetermined radio frame units (S7). This is done when the TTI is longer than the radio frame unit.

Next, several transport channels through which all of the above procedures are performed are multiplexed with each other to form one data stream (S8). The multiplexed data stream is inserted through a coded composite transport channel (hereinafter referred to as CCTrCH), when the next downlink rate matching is a variable rate matching pattern. It is mapped to a plurality of physical channels (PhCH # 1, PhCH # 2, ....) through the physical channel division (S10) and the second interleaving (S11).

However, in the case of a variable rate matching pattern, it is important to determine the amount of repetition or puncturing by rate matching so that the DTX indication bit inserted when the transmission rate of CCTrCH is maximized for all transport channel and all transport format combinations is minimized. Do.

The following describes a procedure for determining an amount to be repeated or punctured by rate matching when downlink rate matching is a variable rate matching pattern.

Prior to this, the amount of repetition or puncture by rate matching ( ) May be determined according to the size of the physical channel and the service of the transport channel. This is because several transmission channels are multiplexed with each other and transmitted through a physical channel.

In general, the amount of data that can be transmitted over a physical channel in the downlink ( ) Is not determined by the combination of transport channels, but is already assigned and fixed at a higher layer.

To determine the amount to be repeated or punctured by downlink variable rate matching, first, a temporary variable for all transport channels and all transport format combinations Calculate as follows.

Where subscript Is an index representing the number of the transport channel. Also subscript Is an index representing transport format combinations.

The amount that is repeated or punctured by rate matching so that the DTX indication bit inserted when the transmission rate of CCTrCH becomes maximum is minimum. Decide temporarily. To this end, for all transport channels and all transport format combinations, the new rate matching rate ensures that the DTX indication bits inserted in the CCTrCH are minimized. Is calculated by the following equation.

Also temporarily Is calculated by the following equation.

Then calculated above The data size (length) of the CCTrCH obtained by rate matching for all transport channels as possible using Check for greater than by the following procedure.

"for all j in TFCS do ---------- for all transport format combinations

---- transport format combination CCTrCH bit rate for bits in 10ms

if then

for to do ------------------ for all transport channels

------ By the Z equation Obtained from

if then

end-if

end-for

end-if

end-for "

As can be seen from the above inspection procedure, if the data size (length) of the CCTrCH obtained by rate matching is the data size (length) of the actual physical channel, If greater, then temporarily determined using the "Z equation" Fix the value of.

"

, (i = 1,…, I) "

The value was fixed using the "Z equation" described above. The value of is determined as the amount to be repeated or punctured by downlink variable rate matching.

As described so far, the interrogation procedure performed to determine the amount of repetition or puncture by downlink variable rate matching, i.e. the data size (length) of the CCTrCH obtained by rate matching for all transport channels, Data size (length) of the actual physical channel The procedure for checking for greater than " By using "", rate matching allows the amount of data to be transmitted to be less than the amount of data that can be transmitted over the actual physical channel.

However, the DTX identification bit is unnecessarily inserted because it is not sending as much data as possible.

In addition, since the "Z equation" is used to determine the amount to be repeated or punctured by downlink variable rate matching, there is a problem in that a large amount of calculation is performed.

An object of the present invention is to solve the above problems, and to determine the amount of repeated or punctured by downlink variable rate matching, the data size (length of CCTrCH) obtained by rate matching for all transport channels as much as possible. ) Skips the comparison step and temporarily sets only the result of the "Z equation" in the procedure of checking whether the) is greater than the data size (length) of the actual physical channel. To provide a parameter determination method for downlink variable rate matching used to correct the value of.

Another object of the present invention is a new rate matching rate calculated to minimize the DTX indication bits inserted in the CCTrCH for all transport channel and all transport format combinations. Temporarily determined using Is used to determine the amount to be repeated or punctured by downlink variable rate matching, and eventually provides a parameter determination method for downlink variable rate matching without using the "Z equation".

A feature of the parameter determination method for downlink rate matching according to the present invention for achieving the above object is that, when the data rate of the physical channel is maximized in variable rate matching, a discontinuous transmission (DTX) is added. Calculating a parameter value of the number of bits punctured or repeated in the transmission unit time such that the number of displayed bits is minimized, and performing rate matching using the calculated parameter value for a plurality of transport channels. Comparing the length of the output data stream with the data length of the transmittable physical channel, and if the data length of the transmittable physical channel is larger, changing the calculated parameter value to a predetermined value. Advantageously, the DTX indication bits use a pre-calculated rate matching rate. It is inserted into the data length of a coded composite transport channel obtained by the rate matching for a number transport channel and a number of transport format combinations. More preferably, the determined value is a predetermined transmission time interval of the multiple transport channel. (TTI) is determined to be smaller than the data length of the transmittable physical channel while maintaining a multiple of the length of the radio frame. The calculated parameter value is also a property of rate matching provided by a higher layer, before the rate matching. The calculated value is calculated based on the number of bits during the transmission unit time and the number of frames during the transmission unit time. Preferably, the determined value is calculated by a Z equation. It is determined to be a multiple of the number of columns of the interleaver used.

1 is a block diagram illustrating a channel coding and transport channel multiplexing structure in downlink according to the 3GPP Radio Access Network (RAN) standard;

Hereinafter, a preferred embodiment of a parameter determination method for downlink rate matching according to the present invention will be described with reference to the accompanying drawings.

In the present invention, the amount of data that can be transmitted through the downlink physical channel to which variable rate matching is applied is maximized. To this end, it is necessary to appropriately determine the amount of repeated or punctured by downlink variable rate matching. The present invention proposes the following two methods. To determine the amount of repeated or punctured by downlink variable rate matching of the present invention. As a first solution for this, the data size (length) of the CCTrCH obtained by rate matching for all the transport channels as much as possible is the data size of the actual physical channel (data length of the transmittable physical channel). Temporary variable by "Z equation" in the procedure to check if greater than Parameters obtained from And the number of radio frames during TTI, the transmission time unit of all transmission channels Is the product of Temporarily Omit the procedure of comparing with the value of. Transfer format The number of bits repeated or punctured during each TTI for the transport channel belonging to

That is, calculated by the above equation 3 The data size (length) of the CCTrCH obtained by rate matching for all transport channels as much as possible using is the data size of the actual physical channel (data length of the transmittable physical channel). In the process of checking for greater than " "It doesn't go through steps.

Accordingly, in the present invention, calculated by Equation 3 above By the following inspection procedure, the data size (length) of the CCTrCH obtained by rate matching for all the transmission channels as much as possible is the data size of the actual physical channel (data length of the transmittable physical channel). Check for greater than

"for all j in TFCS do ---------- for all transport format combinations

---- transport format combination CCTrCH bit rate for bits in 10ms

if then

for to do ------------------ for all transport channels

------ By the Z equation Obtained from

end-for

end-if

As can be seen from the above inspection procedure, if the data size (length) of the CCTrCH obtained by rate matching is the data size of the actual physical channel (data length of the transmittable physical channel) If greater, then temporarily determined using the "Z equation" Fix the value of.

"

"

Where i = 1,… , I, whose value has been fixed using the "Z equation" The value of is determined as the amount to be repeated or punctured by downlink variable rate matching. And the RM is a rate matching attribute for transport channels. However, the RM is an indeterminate rate matching attribute provided by a higher layer. In the first scheme of the present invention, as shown above, only the result of the "Z equation" is temporarily determined. It is used to correct the value of so that the amount of data to be transmitted through rate matching is smaller than the data length that can be transmitted through the actual physical channel.

In the present invention, as a second method for determining the amount of repetition or puncturing by downlink variable rate matching, conventionally, a large amount of computational "Z equation" is used while allowing DTX indication bit insertion. Equation "is not used.

That is, the new rate matching rate calculated to minimize the DTX indication bit inserted in the CCTrCH for all transport channel and all transport format combinations. Temporarily determined using By using the value of to determine the amount to be repeated or punctured by the downlink variable rate matching, the calculation is thus not to use a complex "Z equation".

To this end, for all transport channels and all transport format combinations, the new rate matching rate is such that the DTX indication bits inserted in the CCTrCH are minimized. Is calculated by Equation 2 previously described.

After that, for every transport channel and all transport format combinations, Is calculated by the following equation.

After that, for every transport channel and all transport format combinations, Is calculated by Equation 3 already described above.

Then calculated by Equation 3 above The data size (length) of the CCTrCH obtained by rate matching for all transport channels as much as possible using is the data size of the actual physical channel (data length of the transmittable physical channel). Check for greater than by the following procedure.

"for all j in TFCS do ---------- for all transport format combinations

---- transport format combination CCTrCH bit rate for bits in 10ms

if then

end-if

end-for "

As can be seen from the above inspection procedure, if the data size (length) of the CCTrCH obtained by rate matching is the data size of the actual physical channel (data length of the transmittable physical channel) If greater, temporarily set using the "Z equation" Unlike the conventional method of correcting the value of, the above test procedure is obtained by using Equation 4 below. The value of is determined as the amount to be repeated or punctured by downlink variable rate matching.

Finally, in the second method for determining the amount of repetition or puncture by downlink variable rate matching, the data size (length) of the CCTrCH obtained by rate matching is the data size of the actual physical channel (data length of the transmittable physical channel). If greater than the number of radio frames during the TTI of all transport channels The data stream size (length) to be finally transmitted is the data size of the actual physical channel (data length of the transmittable physical channel) while maintaining a multiple of the length of the data stream. Becomes smaller.

In the case of the downlink variable rate matching pattern according to the present invention, the rate matching parameter is set such that the length itself of the rate-matched output data stream is a multiple of the number of columns of the interleaver used. In 1 ^ST Interleaving, the DTX indication bit inserted in the CCTrCH can be minimized so that the length of the input data stream is a multiple of the number of columns of the interleaver used.

As described above, in the present invention, in the downlink variable rate matching algorithm, the rate of the rate-matched output data stream is a multiple of the number of columns of the interleaver used in the first ^ST interleaving. The parameter of the match is set more simply.

In addition, the length of the rough output data stream, the rate matching by the value set in the parameter, because a multiple of the in-line number (Column) of the interleaver used in the first interleaved (1 ^ST Interleaving), and simpler sikineunde multiplexing several transport channels, DTX indication bits inserted in the CCTrCH can be minimized.

Claims (6)

In variable rate matching, Calculating a parameter value of the number of punctured or repeated bits in the transmission unit time such that when the data rate of the physical channel is maximized, the number of additional Discontinunous Transmission (DTX) indication bits is minimized; For multiple transport channels, comparing the length of the rate-matched output data stream with the data length of the transmittable physical channel using the calculated parameter value; And when the data length of the transmittable physical channel is larger, changing the calculated parameter value to a predetermined value. 2. The data length of a coded composite transport channel according to claim 1, wherein the DTX indication bits are obtained by the rate matching for multiple transport channel and multiple transport format combinations using a precomputed rate matching rate. Method for determining a parameter for downlink rate matching, characterized in that inserted in. The method of claim 1, wherein the determined value is determined to be smaller than the data length of the transmittable physical channel while maintaining a multiple of the number of radio frames during a predetermined transmission time interval (TTI) of the multiple transmission channels. Parameter determination method for downlink rate matching. The method of claim 1, wherein the calculated parameter value is calculated based on an attribute of a rate matching provided by an upper layer, the number of bits during the transmission unit time before the rate matching, and the number of frames during the transmission unit time. A method for determining parameters for downlink rate matching, characterized by the above-mentioned. The method of claim 1, wherein the determined value is calculated by a Z equation. 2. The method of claim 1, wherein the determined value is determined such that the length of the output data stream is a multiple of the number of columns of interleavers used.