WO2007128236A1

WO2007128236A1 - Method and system for distributing random access resource of wireless network

Info

Publication number: WO2007128236A1
Application number: PCT/CN2007/001466
Authority: WO
Inventors: Yusun Fu; Zhilin Zhao; Tao Cai
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-04-29
Filing date: 2007-04-29
Publication date: 2007-11-15
Also published as: CN1968511A; CN100450308C

Abstract

Method for distributing random access resource of wireless network includes: network side broadcasts broadcast signal on the broadcast channel(BCH) of cell, and the broadcast signal includes usable frequency band information and/or slot; mobile terminal receives the broadcast signal and obtains the usable frequency band information and/or slot; the mobile terminal selects one frequency band information and/or slot from the frequency band information and/or slot used for random access to start the random access to the cell. A system for distributing random access resource of wireless network is provided in the invention also. The invention realizes the random access of resource distribution and/or the distribution of time resource, random access interference could averagely be distributed in cell as far as possible.

Description

Method and system for allocating random access resources of wireless network

Technical field

The present invention relates to resource allocation of a wireless network, and in particular, to a method and system for allocating frequency resources for random access of a wireless network, and a method and system for allocating time resources for random access of a wireless network. Background of the invention

Since the 3rd Generation Partnership Project (3GPP) announced the first commercial version of the Universal Mobile Telecommunications System (UMTS) network, Realse99, 3GPP members have continued to improve the network in order to obtain More network features and better network performance. The R5 version released in 2003 introduced High Speed Downlink Packet Access (HSDPA) and the R6 version released in 2005 introduced High Speed Uplink Packet Access (HSUPA) to enable wideband code division. The wireless access performance of Wideband Code Division Multiple Access (WCDMA) has been greatly improved.

HSDPA integrates a series of new wireless access technologies, including: Hybrid Automatic Repeat Request (HARQ), Adaptive Modulation and Coding (AMC), and Base Station (NodeB) control. Fast-Scheduling method. The overall system's downlink throughput rate and peak rate have been greatly improved (from 2 Mbps to 14 Mbps for R99), which improves the system's frequency efficiency; in addition, HSDPA's shortest transmission time interval (TTI) is from Reduce the 10ms of R99 to 2ms, combined with system architecture and implementation The improvement can effectively reduce the connection and transmission delay of the wireless access network, and improve the user experience of the wireless service. HSUPA also improves the uplink throughput and peak rate of the system (from 2 Mbps of R99 to nearly 6 Mbps) by using HARQ and Fast-Scheduling technology on the uplink, and at the same time reduces the minimum ΤΉ from 10 ms of R99 to 2 ms, in order to reduce the wireless connection. The delay into the network provides the basis.

For the evolution of the Radio Access Network (UMTS RAN), most equipment manufacturers divide the evolution phase into two phases: Medium Term Evolution (MTE) and Long Term Evolution (LTE). Shown. The main purpose of the medium-term evolution is to optimize as much as possible without changing the existing network. Long-term evolution focuses on some essential innovations in existing networks to improve the system performance of the wireless access network.

With the introduction and improvement of features such as R5, R6 version HSDPA, HSUPA, and Multimedia Broadcast and Multicast Service (MBMS), the UMTS network has completed the medium-term evolution phase. The network performance enhancements brought by HSDPA and HSUPA can basically meet the business needs before 2010 and have sufficient competitiveness compared with other cellular networks. At the end of 2004, with the end of the agreement between HSUPA and MBMS, the long-term evolution of the UMTS network was also put on the agenda. In November 2004, the 3GPP RAN Working Group convened a number of operators and equipment vendors to hold a special meeting in Canada to discuss issues and technical routes related to the long-term evolution of UMTS, as well as the establishment of standardized projects.

At present, the standard work on the LTE system is under intense discussion. It is preliminarily determined that the downlink physical layer access technology of the LTE system is Orthogonal Frequency Division Multiple Access (OFDMA), and the upper 4 亍 physical layer is connected. The incoming technology is Single Carrier-Frequency Division Multiple Access (SC-FDMA). Compared with WCDMA, there is no Radio Network Controller (RC) node, but the function of RNC is decomposed into the access gateway. (E-UTRAN Access Gateway, aGW) and evolved base station (E-UTRAN NodeB, E-NodeB) nodes.

The random access procedure is used for the initial access of the user equipment (User Equipment, UE), and the purpose is to implement uplink synchronization and request uplink air interface resources to the E-NodeB. In a cell, the frequency band used for random access and the frequency band used for transmitting data are orthogonal, as shown in Fig. 2, but how to allocate random access band resources among different cells is currently not determined by LTE. The maximum bandwidth supported by the UE is determined by the capabilities of the UE, with a minimum of 10 MHz and a maximum of 20 MHz. The minimum bandwidth allocated to random access is 1, 25 MHz or 375 KHz, and there is no decision yet. Whether or not the base stations (inter-cell) are synchronized has not yet been determined.

In a WCDMA system, the frequency resources used for random access are the same, so there is no problem of allocation of frequency resources. Summary of the invention

Embodiments of the present invention provide a method and system for allocating a random access resource for a wireless network, which are used to implement allocation of random access band resources and/or time resources, and distribute random access interference as evenly as possible among cells.

The first method for allocating random access resources of a wireless network according to the embodiment of the present invention includes the following steps:

The network side broadcasts a broadcast signal through a broadcast channel of the cell, the broadcast signal includes available frequency band information, the available frequency band information is information indicating a frequency band usable for random access; and the mobile terminal receives the broadcast signal to obtain the available frequency band Information

The mobile terminal selects a frequency band from the frequency bands available for random access to initiate random access to the cell.

A distribution system for implementing the allocation method includes:

a broadcast device, configured to broadcast a broadcast signal, where the broadcast signal includes available frequency band information, The available frequency band information is information indicating a frequency band usable for random access; the mobile terminal is configured to receive the broadcast signal, obtain the available frequency band information, and select one frequency band from the frequency band that can be used for random access. Random access.

A method for allocating a second wireless network random access resource according to an embodiment of the present invention includes the following steps:

The network side broadcasts a broadcast signal through a broadcast channel of the cell, where the broadcast signal includes available time slot information, the available time slot information is information indicating a time slot available for random access; the mobile terminal receives the broadcast signal, obtains a Describe the available time slot information;

The mobile terminal selects a time slot from the time slots available for random access to initiate random access to the cell.

A distribution system for implementing the allocation method includes:

a broadcast device, configured to broadcast a broadcast signal, where the broadcast signal includes available time slot information, where the available time slot information is information indicating a time slot available for random access;

And a mobile terminal, configured to receive the broadcast signal, obtain the available time slot information, and select a time slot from the time slots available for random access to initiate random access.

Through the above technical solution, the present invention broadcasts, by using a broadcast channel, information of a frequency band usable for random access to a mobile terminal, the available frequency band is equally divided into a plurality of random accesses from the total bandwidth supported by the mobile terminal. One or more selected ones of the equal frequency bands, and the frequency bands allocated for random access allocated between adjacent cells are not interfered with each other as much as possible, and the present invention also broadcasts to the mobile terminal through the broadcast channel under certain conditions and can be used for randomization. The information of the accessed time slot, and the time slots allocated for random access allocated between the adjacent cells are not interfered with each other as much as possible, so that the random access interference in the radio access network is distributed as evenly as possible among the cells in the long-term evolution phase. , thereby increasing the access probability, capacity, and throughput of the system. 1 is an evolution plan diagram of a UMTS network;

2 is a diagram showing a relationship between a frequency band for random access and a frequency band for transmitting data in one cell;

3 is a flow chart of a method for allocating frequency resources for random access according to Embodiment 1 of the present invention;

4 is a block diagram of a system for allocating frequency resources for random access according to an embodiment of the present invention;

FIG. 5 is a flow chart of a method for allocating time resources for random access according to Embodiment 2 of the present invention; FIG.

6 is a block diagram of a system for allocating time resources for random access according to Embodiment 2 of the present invention;

7 is a subcarrier partitioning diagram for random access according to an embodiment of the present invention; and FIG. 8 is a frequency band allocation diagram that different cell UEs may use for random access according to an embodiment of the present invention. Mode for carrying out the invention

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The embodiment of the present invention provides a method for allocating frequency resources required for implementing random access in the initial access and resource request phase of the mobile terminal. The method includes the following steps:

S102: The network side broadcasts a broadcast signal by using a broadcast channel, where the broadcast signal includes available frequency band information, and the available frequency band information is information indicating a frequency band that can be used for random access;

S104. The mobile terminal receives a broadcast signal, and obtains available frequency band information. S106. The mobile terminal selects one frequency band from the frequency bands available for random access to initiate random access.

As shown in FIG. 4, the random access frequency resource allocation system 10 according to the first embodiment of the present invention includes: a broadcast device 20, configured to broadcast a broadcast signal, the broadcast signal includes available frequency band information, and the available frequency band information indicates that the available information is available. Information of a frequency band of random access; and a mobile terminal 30 for receiving a broadcast signal, obtaining available frequency band information, and selecting a frequency band from a frequency band available for random access to initiate random access.

FIG. 5 shows a method for allocating time resources required for implementing random access according to Embodiment 2 of the present invention, including the following steps:

S302. The network side broadcasts a broadcast signal through a broadcast channel, where the broadcast signal includes available time slot information, and the available time slot information is information indicating a time slot available for random access;

S304. The mobile terminal receives the broadcast signal, and obtains available time slot information.

S306. The mobile terminal selects one time slot from the time slots available for random access to initiate random access.

As shown in FIG. 6, the random access time resource allocation system 40 provided by the second embodiment of the present invention includes: a broadcast device 50, configured to broadcast a broadcast signal, the broadcast signal includes available time slot information, and the available time slot information is represented. Information for a time slot that can be used for random access; and a mobile terminal 60 for receiving a broadcast signal, obtaining available time slot information, and selecting a time slot from a time slot available for random access to initiate random access.

The third embodiment of the present invention combines the first embodiment with the solution of the second embodiment, that is, by playing a broadcast signal, transmitting frequency resource information and time slot information for random access to the terminal, and the terminal according to the obtained frequency resource information. And time slot information, select available time slots and frequency resources to achieve random access.

The embodiment of the invention provides a method for allocating frequency/time resources used for random access between different cells, so that random access interference is distributed as evenly as possible among cells to improve the system. Access probability, capacity, and throughput. The allocation method includes the following basic points:

(1) Notifying a frequency band and/or a time slot that the UE in the corresponding cell can use for random access through a broadcast channel (BCH).

The division of the random access frequency band is illustrated by taking FIG. 7 as an example. Figure 7 shows a cell with a bandwidth of 20 MHz. The bandwidth of each random access is 1.25 MHz, which is divided into 16 equal parts, numbered 0, ..., 15. The BCH tells the UE number, which may be one of 0 to 15, or may be a set (such as several), which may be determined according to an application scenario.

If the cells are synchronized (e.g., the base station is synchronized, or the base station is not synchronized but the cells are synchronized under the same base station), the BCH needs to broadcast access time slots on the frequency bands corresponding to the different cells. An access slot refers to a slot that is accessed on an access band, and other slots can be used for data transmission. For example, 1, 11, 21 transmit access signals, and other transmit data signals, then 1, 11, 21 are access slots. The access slots between different cells are as different or evenly distributed as possible. It is assumed that the same frequency band is set as the random access frequency band in the cell 1, the cell 2, and the cell 3. If the cell 1 is connected by the time slots 1, 11, 21... In the time slot, cell 2 can use time slots 2, 12, 22... as access time slots, and cell 3 can use time slots 3, 13, 23... as access time slots.

(2) The frequency bands and/or time slots allocated for random access allocated between adjacent cells should be as uninterrupted as possible.

As shown in FIG. 8, UE1 belongs to the user of cell 1, UE2 belongs to the user of cell 2, and the frequency bands occupied by UE1 and UE2 do not overlap each other, and so on.

(3) The UE detects the broadcast signal of the BCH, and selects one of its designated frequency bands and/or time slots to initiate random access.

With the above-mentioned embodiments of the present invention, in the initial access phase of the mobile terminal, allocation of random access resources is realized, and random access interference is evenly distributed among the cells as much as possible.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Where in the present invention Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A method for allocating a random access resource for a wireless network, characterized in that the method comprises the following steps:

The allocation method according to claim 1, wherein before the network side broadcasts the broadcast signal through the broadcast channel, the method further includes: the network side allocates the frequency band resource available for random access to the cell.

The allocation method according to claim 1, wherein the network side allocates a frequency band resource that can be used for random access to the cell, and further includes:

Divide the total bandwidth of the cell into several equal frequency band resources;

One or more of the divided frequency band resources are set as frequency bands for implementing random access by the mobile terminal.

The allocation method according to claim 3, wherein the dividing the total bandwidth of the cell into a plurality of equal frequency band resources comprises: dividing each divided frequency band resource number; and dividing the divided frequency band resource One or more of the frequency bands set to implement random access of the mobile terminal are: setting one or more numbers in the number corresponding to the set frequency band as available frequency band information;

The receiving, by the mobile terminal, the broadcast signal comprises: the mobile terminal knowing the frequency band available for random access from a number set to the available frequency band information.

The distribution method according to claim 3 or 4, wherein each of said The share is the minimum bandwidth for each random access.

The allocation method according to any one of claims 2 to 4, wherein the network side allocates a frequency band resource that can be used for random access to the cell, including: assigning different different cells to different cells. The frequency band of random access is such that the frequency bands allocated for random access allocated between adjacent cells do not overlap.

The allocation method according to claim 1, wherein the broadcast information further includes information of an access slot available in a frequency band that can be used for random access, and the mobile terminal follows

One frequency band and one access time slot from the selected time slots on the selected frequency band are used to initiate random access.

The method according to claim 6, wherein before the network side broadcasts the broadcast signal through the broadcast channel of the cell, the method further includes: allocating different access slots for different cells, so that the random access pair The interference of random access by neighboring cells is minimized.

A frequency resource allocation system for wireless network random access, characterized in that the distribution system comprises:

a broadcast device, configured to broadcast a broadcast signal, the broadcast signal includes available frequency band information, and the available frequency band information is information indicating a frequency band usable for random access;

And a mobile terminal, configured to receive the broadcast signal, obtain the available frequency band information, and select a frequency band from the frequency bands available for random access to initiate random access.

The distribution system according to claim 9, wherein the advertisement device is further configured to: divide a total bandwidth of the cell into equal parts, each aliquot is a minimum bandwidth of each random access, and the One or more of several aliquots are provided as frequency bands of the mobile terminal that are available for random access.

11. The distribution system according to claim 10, wherein the advertisement device is further configured to: number each aliquot, one of the numbers corresponding to the set frequency band or Setting a plurality of numbers to the available frequency band information, and transmitting the number corresponding to the available frequency band information to the mobile terminal;

The mobile terminal is configured to receive the number, and according to the number, the frequency band that can be used for random access is known.

The distribution system according to any one of claims 9 to 11, wherein the broadcast-and-play device is further configured to: allocate different frequency bands available for random access to different cells, so that neighboring cells The frequency bands that are allocated for random access are not overlapped.

The distribution system according to claim 9, wherein the advertisement device is further configured to broadcast, to the mobile terminal, a broadcast signal carrying information of an access slot available on a frequency band of random access;

The mobile terminal is configured to select a frequency band from the frequency band information available for random access and select one access time slot from the access time slots on the selected frequency band to initiate random access according to the received broadcast signal.

The distribution system according to claim 13, wherein the advertising device is further configured to allocate different access slots for different cells, so that random access minimizes interference to random access of neighboring cells. .

A method for allocating time resources for random access of a wireless network, characterized in that the method comprises the following steps:

The network side broadcasts a broadcast signal through a broadcast channel of the cell, where the broadcast signal includes available time slot information, the available time slot information is information indicating a time slot available for random access; the mobile terminal receives the broadcast signal, obtains a Said to use time slot information;

The allocation method according to claim 15, wherein before the network side broadcasts the broadcast signal through the broadcast channel of the cell, the method further includes: allocating for different cells Different access slots enable the random access to minimize the interference of random access of neighboring cells.

17. A time resource allocation system for wireless network random access, characterized in that:

The distribution system according to claim 17, wherein the advertisement device is further configured to allocate different access slots for different cells, so that interference of random access to random access of neighboring cells is minimized. .