KR100311525B1 - Method for assigning common packet channel efficiently - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a next generation communication system, and in particular, when allocating a common packet channel (CPCH) in a random access method of next generation mobile communication, an empty portion of an acquisition indication channel (AICH). part).

To this end, in the present invention, in the random access procedure of the next generation mobile communication, the empty-part and the collision protection preamble (CD) of the acquisition indication channel (AP-AICH) for the access preamble (AP) used in the downlink are used. A method of allocating a common packet channel (CPCH) to a user side (UE) more efficiently by using an empty part of a capture indication channel (CD-AICH).

Description

Method for assigning common packet channel efficiently

The present invention relates to a next generation communication system, and more particularly, to a method of using an empty part of an acquisition indication channel (AICH) when allocating a common packet channel (CPCH) in a random access method of next generation mobile communication. .

Recently, ARIB in Japan, ETSI in Europe, T1 in the US, TTA in Korea, and TTC in Japan are the core networks of the existing Global System for Mobile Communications (GSM), which provides multimedia services such as voice, video and data. The next generation of mobile communication system based on wireless access technology was envisioned.

In order to present technical specifications for the next generation evolved mobile communication system, they agreed to joint research, and the project for this was called Third Generation Partnership Project (hereinafter abbreviated as 3GPP).

3GPP includes three major technical research areas.

The first is the 3GPP system and service sector, which is a study of the structure and service capabilities of the system based on the 3GPP specification.

Second, it is a research area for Universal Terrestrial Radio Access Network (UTRAN), where the Universal Terrestrial Radio Access Network (UTRAN) is based on W-CDMA according to Frequency Division Duplex (FDD) mode. Radio Access Network (RAN) using TD-CDMA according to Time Division Duplex (TDD) mode.

Third, it is a research section for core network that has evolved from the second generation mobile communication globalization system (GSM) and has third generation networking capability such as mobility management and global roaming.

In the above-described technical research divisions of 3GPP, a research section for a global radio access network (UTRAN) describes definitions and descriptions of a transport channel and a physical channel.

One common transport channel (CPCH), which is one of the transport channels, is used for the uplink and is used to transmit relatively medium or small packets, and is mapped to a physical common packet channel (PCPCH), which is a physical channel. do.

The common packet channel (CPCH) relates to a dedicated channel (DCH), which is a downlink transmission channel that provides power control for the uplink common packet channel (CPCH), wherein the dedicated channel (DCH) is a physical channel. It is mapped to a dedicated physical control channel (DPCCH).

Since the 3GPP system using these channels is asynchronous, a random access scheme is applied in order for multiple user equipments (UEs) to transmit signals effectively.

For a user side (UE) transmitting a packet in a random access scheme (Contention), the network side (UTRAN: Universal Mobile Terrestrial Radio Access Network) allocates an available common packet channel (CPCH) to the user side (UE). .

1 illustrates a scenario of allocating a common packet channel (CPCH) according to the prior art.

Referring to FIG. 1, first, all UEs in a cell are broadcast channels (BCHs), which are downlink transmission channels that are mapped and transmitted with a primary common control physical channel (PCCPCH), which is a downlink physical channel. Receive access information through Channel). In this case, the access information transmitted through the broadcast channel (BCH) indicates which access slot is available in the current cell and also relates to an access preamble signature.

Accordingly, each UE may start transmission at the correct time offset number with respect to the frame boundary of the broadcast channel (BCH) transmitted by the primary common control physical channel (PCCPCH) in the current cell.

Thereafter, the various UEs select one of the 16 access preamble symbols of the access preamble signature set by using the received access information, and match the access preamble according to the start of the available uplink access slot. The AP transmits an access preamble to the network side (UTRAN). In this case, the UE uses a random access channel (RACH).

After that, the UE waits for a certain time for an Acquisition Indicator (AI) for the transmitted access preamble. If the AI does not arrive at the UE, the UE transmits it. The access preamble is transmitted to the network side (UTRAN) repeatedly by a predetermined threshold number while the power is raised to a predetermined level.

However, if the acquisition indicator (AI) for the access preamble is delivered through the acquisition indication channel (AICH), which is a downlink physical channel, the user side (UE) again returns a Collision Detection Preamble (CD) to the physical common packet channel ( PCPCH).

Here, when the network side UTRAN transmits the acquisition indicator AI, the access preamble signature information of the received access preamble is included in the acquisition indicator AI and transmitted. In this case, the frame structure of the acquisition indication channel (AICH) used for transmission to the user side (UE) in accordance with the start time of the downlink access slot is shown in FIG. The acquisition indication channel (AICH) in FIG. 2 will be described below.

The reason why the UE, which receives the acquisition indicator AI through the acquisition indication channel AICH, transmits the collision protection preamble CD to the physical common packet channel PCPCH is different from the UEs. At the same time, when the same access preamble is used, the acquisition indicator (AI) may be received on the same acquisition indication channel (AICH). Therefore, the UE (UE) has already reselected one access preamble symbol from an access preamble signature set and another access preamble symbol set, and then matches the start point of the available uplink access slot. The collision protection preamble (CD) is transmitted to the network side (UTRAN).

The network side (UTRAN) then selects a relatively strong transmit power for the collision protection preambles (CDs) of different preamble symbols transmitted simultaneously from multiple user sides (UEs) and then captures the indicator for the collision protection preamble (CDs). (AI) is transmitted to the corresponding UE on the acquisition indication channel (AICH).

At the same time, the network side (UTRAN) acquires an acquisition indicator (AI) including information on a common packet channel (CPCH) to be allocated to the user side (UE) in the form of a code to the user side (UE) in the acquisition indication channel (AICH). send.

Thereafter, packet data is transmitted through an uplink common packet channel (CPCH). However, prior to packet data transmission, a power control preamble is exchanged between the UE and the network UTRAN for a predetermined time.

2 is a diagram illustrating a frame structure of a general acquisition indication channel (AICH).

The frame of the acquisition indication channel (AICH) is 10 ms long and is composed of eight access slots (AS).

Each access slot AS is 20 symbols long (1.25 ms), and each access slot AS is divided into two parts. This is the capture indicator (AI) portion of 16 symbols long (1 ms) and the empty-part of 4 symbols length (0.25 ms).

This acquisition indication channel (AICH) is spread with 256 lengths of channelization codes, such as spreading / scrambling for other channels in the downlink, and then scrambled with a unique scrambling code for each cell.

In the scenario of allocating a conventional common packet channel (CPCH) described above, the acquisition indication channel (AP-AICH) for the access preamble (AP) and the acquisition indication channel (CD-AICH) for the collision protection preamble (CD) Acquisition indication channel (CA-AICH) was used to transmit allocation information for the common packet channel (CPCH).

Accordingly, the network side UTRAN is conventionally used in addition to the acquisition indication channel code used for the acquisition indicator AI for the access preamble AP and the acquisition indication channel code used for the collision protection preamble CD. Acquisition indication channel code for providing allocation information for this common packet channel (CPCH) to the user side (UE) is further used.

In addition, after the acquisition indicator (AI) for the collision protection preamble (CD) is transmitted to the corresponding UE (UE) through the acquisition indication channel (CD-AICH), the allocation information for the common packet channel (CPCH) is acquired. Since it is provided to the user side (UE) through -AICH, the user terminal (UE) has a disadvantage in that it takes a long time to transmit its own packet data by actually being assigned a common packet channel (CPCH).

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned matters, and more efficiently by using an empty part of the acquisition indication channel (AICH) used in the downlink in the random access procedure of the next generation mobile communication. A method of allocating a common packet channel (CPCH) to a UE) is provided.

A feature of the common packet channel (CPCH) allocation method according to the present invention for achieving the above object is that the network side (UTRAN) assigns a common packet channel (CPCH) to the multiple user side (UE), the downlink physical channel The allocation information for the common packet channel (CPCH) is inserted into the empty portion of the ACI, and is repeatedly transmitted to each UE.

Preferably, in inserting the allocation information into the blank portion, the codes are orthogonal to each other among the codes transmitted through each downlink access slot.

Another feature of the present invention for achieving the above object is that (a) the user side (UE) to the network side is assigned the access preamble (AP) in order to be assigned a common packet channel (CPCH) required for its packet data transmission (BRAN) and (b) the network side (UTRAN) receiving the access preamble sends the allocation information for the common packet channel (CPCH) through a blank portion of an acquisition indication channel (AP-AICH). Providing to the user side (UE), (c) transmitting the collision protection preamble (CD) to the network side (UTRAN) by the user side (UE) receiving the channel allocation information, and (d) the collision protection preamble The network side (UTRAN) receiving the (CD) provides the UE with the remaining allocation information for the common packet channel (CPCH) through a blank portion of another acquisition indication channel (CD-AICH). Is done.

Preferably, in the step (b) of providing the channel allocation information, the allocation information of the currently assignable common packet channel (CPCH) is provided through a blank portion of the acquisition indication channel (AP-AICH), and (d In step), allocation information provided through the blank portion of the acquisition indication channel (AP-AICH) is repeatedly provided through the blank portion of the another acquisition indication channel (CD-AICH).

Here, each of the provided allocation information is inserted into each blank portion in the form of a code, and a plurality of codes for indicating the allocation information are used in which a symbol equal to the symbol length of the blank portion is orthogonally phase shifted.

In the step (b) of providing the channel allocation information, a plurality of common packet channels (CPCHs) that can be currently allocated are grouped, and then the allocation information for the corresponding channel group is allocated to a blank portion of the acquisition indication channel (AP-AICH). In step (d), information on a corresponding allocated channel belonging to the channel group is provided through a blank portion of the another acquisition indication channel (CD-AICH).

Herein, the allocation information for the channel group and the information on the allocation channel are respectively inserted in the blank portions in the form of codes, and the sign indicating the allocation information for the channel group and the sign indicating the information on the allocation channel are Orthogonal to each other.

1 illustrates a scenario of allocating a common packet channel (CPCH) according to the prior art.

2 shows a frame structure of a general acquisition indication channel (AICH).

3 is a diagram illustrating a scenario of allocating a common packet channel (CPCH) according to the present invention according to the present invention.

4 is a diagram illustrating an acquisition indication channel (AICH) structure for transmitting common packet channel (CPCH) allocation information according to a first embodiment of the present invention.

5 is a diagram illustrating an acquisition indication channel (AICH) structure for transmitting common packet channel (CPCH) allocation information according to a second embodiment of the present invention.

Hereinafter, an exemplary embodiment of an efficient common packet channel (CPCH) allocation method according to the present invention will be described with reference to the accompanying drawings.

In the present invention, the acquisition indicator (AI) in the acquisition indication channel (hereinafter referred to as AP-AICH) for the access preamble (AP) and the acquisition indication channel (hereinafter referred to as CD-AICH) for the collision protection preamble (CD). The allocation information for the common packet channel (CPCH) is inserted into each empty part except for the part) and provided to the UE.

As a result, in the present invention, the information on the common packet channel (CPCH) currently allocated by the network side (UTRAN) is included in the blank portion of the 4-symbol length of the AP-AICH and the 4-symbol length of the CD-AICH. ) To provide.

3 is a diagram illustrating a scenario of allocating a common packet channel (CPCH) according to the present invention according to the present invention.

Referring to FIG. 3, first, all UEs in a cell receive access information through a broadcast channel (BCH), which is a downlink transmission channel that is mapped and transmitted with a primary common control physical channel (PCCPCH), which is a downlink physical channel. do. In this case, the access information transmitted through the broadcast channel (BCH) indicates which access slot is available in the current cell and also relates to an access preamble signature.

Accordingly, each UE may start transmission at the correct time offset number with respect to the frame boundary of the broadcast channel (BCH) transmitted by the primary common control physical channel (PCCPCH) in the current cell.

Thereafter, the various UEs select one of the 16 access preamble symbols of the access preamble signature set by using the received access information, and match the access preamble according to the start of the available uplink access slot. AP) to the network side (UTRAN). At this time, the UE uses a physical common packet channel (PCPCH).

Thereafter, the UE waits for a predetermined time for the information of the AP-AICH on the transmitted access preamble, if the information of the AP-AICH does not arrive at the UE. In the UE, the UE pre-transmits the access preamble repeatedly to a predetermined threshold number of times while increasing the transmission power to a predetermined level.

However, when the information of the acquisition indication channel (AP-AICH) for the access preamble is transferred, the user side (UE) again transmits a collision detection preamble (CD) to the physical common packet channel (PCPCH).

In this case, the AP-AICH information of 20 symbol lengths transmitted by the network side UTRAN has 16 symbols of access preamble signature information corresponding to the access preamble received from the user side (UE). The allocation information of the common packet channel (CPCH), which is included in the acquisition indicator (AI) portion of the UE and is assignable to the user side (UE), is included in a code form in an empty part of the remaining four symbol lengths. The side (UTRAN) transmits to the user side (UE) in accordance with the start time of the downlink access slot.

The UE (UE), which receives the acquisition indicator (AI) and the common packet channel (CPCH) allocation information through the acquisition indication channel (AP-AICH) for the access preamble (AP), collides with the physical common packet channel (PCPCH). The reason for delivering the protection preamble (CD) is when different users (UEs) receive the acquisition indicator (AI) and channel assignment information on the same acquisition indication channel (AP-AICH) when they use the same access preamble at the same time. Is to reduce the conflicts between these users. Therefore, the UE (UE) has already reselected one access preamble symbol from an access preamble signature set and another access preamble symbol set, and then matches the start point of the available uplink access slot. The collision protection preamble (CD) is transmitted to the network side (UTRAN).

The network side (UTRAN) then selects a relatively strong transmit power for the collision protection preambles (CDs) of different preamble symbols transmitted simultaneously from multiple user sides (UEs) and then captures the indicator for the collision protection preamble (CDs). Information for the (AI) and common packet channel (CPCH) allocation is transmitted to the corresponding UE on the acquisition indication channel (CD-AICH).

At this time, the 20-symbol acquisition indication channel (CD-AICH) information transmitted from the network side UTRAN is the corresponding access preamble signature information on the collision protection preamble (CD) received from the user side (UE). Is included in the 16-symbol length acquisition indicator (AI) portion, and the allocation information of the common packet channel (CPCH) that can be allocated to the user side (UE) is included in the remaining four symbol length empty-parts in the form of a code. The network side (UTRAN) then transmits to the user side (UE) in time for the start of the downlink access slot.

Accordingly, the UE transmits packet data through the uplink common packet channel (CPCH). However, prior to packet data transmission, a power control preamble is exchanged between the UE and the network UTRAN for a predetermined time.

In the scenario of allocating a common packet channel (CPCH) so far, the reliability must be ensured when the network side (UTRAN) provides allocation information for the common packet channel (CPCH) to the user side (UE).

Therefore, in the common packet channel (CPCH) allocation scenario according to the present invention, the following schemes for ensuring reliability when transmitting channel allocation information are proposed. In the present invention, the frame structure of the general acquisition indication channel (AICH) described above with reference to FIG. 2 is referred to for clarity.

First, channel information that can be transmitted through the blank portion of the AP-AICH and the CD-AICH is 8 symbols long.

4 is a diagram illustrating an acquisition indication channel (AICH) structure for transmitting common packet channel (CPCH) allocation information according to the first embodiment of the present invention.

Referring to FIG. 4, when the common packet channel (CPCH) allocation information available to the UE is transmitted, an empty part of each AP-AICH and CD-AICH is used as a first method for guaranteeing reliability. Through 4 symbol length channel information is repeatedly transmitted. In other words, the 4-symbol length channel allocation information is transmitted through the empty part of the AP-AICH, and the same 4-symbol length channel allocation is then transmitted through the empty part of the CD-AICH. The information is sent repeatedly.

At this time, 16 symbol patterns (0000-1111) are possible for the 4-symbol length code repeatedly transmitted to each acquisition indication channel (AP-AICH and CD-AICH).

5 is a diagram illustrating an acquisition indication channel (AICH) structure for transmitting common packet channel (CPCH) allocation information according to a second embodiment of the present invention.

Referring to FIG. 5, as a second scheme for ensuring reliability when the common packet channel (CPCH) allocation information is transmitted, 16 common packet channels (CPCHs) usable by the user side (UE) are first grouped into four groups of AP- After transmitting the 4 symbol length code indicating the channel group through the blank portion of the AICH, the 4 symbol length code indicating the common packet channel (CPCH) to be allocated among the corresponding channel groups through the empty part of the CD-AICH. send.

In other words, 16 common packet channels (CPCHs) usable by the user side (UE) are grouped into four groups and classified into a first channel group, a second channel group, a third channel group, and a fourth channel group. Thereafter, a 4-symbol length code indicating a channel group is transmitted through a blank portion of the AP-AICH to inform which channel group the channel to be allocated to the UE belongs to.

Accordingly, when the collision protection preamble (CD) is received from the UE (UE), the common packet channel (CPCH) to be allocated to the UE (UE) of the channel group informed again through the empty part of the CD-AICH Tells you if it's a channel.

At this time, the 4-symbol length code of the AP-AICH and the 4-symbol length code of the CD-AICH are orthogonal to each other.

For example, the four symbol length codes representing the first channel group, the second channel group, the third channel group, and the fourth channel group have '1111', '1001', '1010', and ' '1111', '1001' with a four-symbol length sign with a 180 ° shifted phase, set to 0011 'and representing the first, second, third, and fourth assigned channels of each channel group. , '1010' and '0011'.

5 illustrates a case where a third channel of the first channel group is allocated.

The following is the third scheme extended from the first scheme and the second scheme when the common packet channel (CPCH) allocation information is transmitted, and the 16 common packet channels (CPCH) available to the UE (UE) are available. It is represented by a four-symbol length code and repeatedly transmits four-symbol length channel information through an empty part of each AP-AICH and CD-AICH.

However, this scheme differs from the first scheme in which four symbol length codes are represented by sixteen code patterns (0000 to 1111), and four code patterns are set for 16 channels and the four code patterns have orthogonality to each other. Set the sign phase. In other words, four code patterns of '1111', '1001', '1010' and '0011' are set for 16 common packet channels (CPCH), and 0 °, 90 °, 180 ° and 270 for each code pattern. Sets the code phase shifted by ° respectively.

After all, since 16 common packet channels (CPCH) can be represented by 4 symbol length codes in this manner, the 4 symbol length codes indicating the common packet channel (CPCH) are transmitted through a blank portion of the AP-AICH. After that, the same code is repeatedly transmitted through an empty part of the CD-AICH.

Finally, we generate eight Orthogonal Gold Codes (OGCs) of eight lengths and 180 degrees out of phase with them, as shown below. Four symbols are placed on the AP-AICH and four symbols on the non-shaded portion of the back are loaded on the CD-AICH.

In the present invention described so far, a symbol indicating channel allocation information is transmitted through an empty part of the AP-AICH and the CD-AICH. However, the above-listed methods may be applied only to one channel of AP-AICH or CD-AICH.

In addition, the present invention may be applied not only to allocating a common packet channel (CPCH) but also to a reverse access channel (RACH) if symbols are not repeatedly transmitted.

According to the present invention described above, since the allocation information for the common packet channel (CPCH) is provided to the user side (UE) through the blank portion of the AP-AICH and the blank portion of the CD-AICH, the conventional common packet channel (CPCH) The acquisition indication channel (CA-AICH) used when providing allocation information for the UE to the UE is unnecessary. As a result, the acquisition indication channel (CA-AICH) code for transmitting channel allocation information is not additionally used.

In addition, since the UE receives the allocation information for the common packet channel (CPCH) through the blank portion of the AP-AICH and the blank portion of the CD-AICH, the UE actually uses the common packet channel (CPCH). It takes less time to allocate and send its own packet data.

Claims (3)

When the network side (UTRAN) allocates a common packet channel (CPCH) to a plurality of user sides (UE), channel allocation information for the common packet channel (CPCH) in the blank portion of the acquisition indication channel (AICH) which is a downlink physical channel. The common packet channel allocation method, characterized in that the repetitive transmission to each user side (UE) by inserting. 2. The method of claim 1, wherein in inserting channel allocation information into the blank portion, the codes are orthogonal to each other among codes transmitted through respective downlink access slots. (a) transmitting a corresponding access preamble (AP) to a network side (UTRAN) in order for a user side (UE) to be allocated a common packet channel (CPCH) necessary for transmitting its packet data; b) providing, by the network side UTRAN receiving the access preamble, the allocation information for the common packet channel CPCH to the user side via a blank portion of an acquisition indication channel AP-AICH; c, a user side (UE) receiving the channel allocation information transmits a collision protection preamble (CD) to a network side (UTRAN), d, the network side UTRAN receiving the collision protection preamble CD receives the remaining allocation information for the common packet channel CPCH through a blank portion of another acquisition indication channel CD-AICH. Providing a common packet channel assignment method.