WO2009086657A1

WO2009086657A1 - Access method for terminal in large bandwidth wireless communication system

Info

Publication number: WO2009086657A1
Application number: PCT/CN2007/003916
Authority: WO
Inventors: Xiaojiang Han; Wei Gou
Original assignee: Zte Corporation
Priority date: 2007-12-29
Filing date: 2007-12-29
Publication date: 2009-07-16

Abstract

An access method for a terminal in a large bandwidth wireless communication system is provided. First of all, the system bandwidth of the large bandwidth system is divided into several working frequency bands, and then the terminal searches a network, wherein the base station in the network side assigns a corresponding working frequency band to the terminal and the terminal is adjusted to the working frequency band according to the assignment. The procedure can be called an initial access. After the initial access, the terminal performs an adjustment on the working frequency band and the uplink resource request and assignment, and the working method is the same as the existing method for symmetric bandwidths.

Description

Terminal access method in large bandwidth wireless communication system

Technical field

The present invention relates to the field of wireless communication technologies, and in particular, to an access method for a medium terminal. Background technique

The fourth-generation mobile communication system has higher spectral efficiency than the third-generation mobile communication system. The goal of the fourth-generation mobile system is to make the mobile user data transmission rate reach 100 Mbit/s before 2010, and the static user data transmission rate reaches 1 Gbit. /s. Due to the smooth evolution of mobile communication systems, in order to protect the interests of operators, the fourth generation mobile communication systems will be compatible with third generation mobile communication systems (such as TD-SCDMA systems or 802.16E systems) within a certain period of time. Or coexist.

The bandwidth of the fourth generation wireless communication system can be as high as 100 MHz. In order to enable the fourth generation wireless communication system to flexibly set the system bandwidth of each cell according to the service requirements, the bandwidth of the fourth generation wireless communication system is variable.

In the prior art, the access method of the wireless terminal in the mobile communication system is that, according to the bandwidth of the communication system, the terminal bandwidth takes the maximum system bandwidth to achieve compatibility with different system bandwidths. This requires a terminal that is 4 艮 high and requires a relatively large capacity. This method has the following disadvantages:

1. The terminal battery has a large energy loss. Too much pursuit of the terminal's large bandwidth will lead to high computational complexity and high battery energy loss. For the terminal, it is necessary to pursue the transmission rate and also consider the energy saving of the terminal. Therefore, the IMT-Advanced (International Mobile Telecommunications Advanced) system, which is the basis of the fourth generation mobile communication technology, should support the use of small-capability terminals.

2. The terminal cost is too high. In order to handle the processing and reception of large bandwidth, a higher level chip is required. However, advanced chips are also costly, which can lead to excessive terminal costs.

3. User bandwidth requirements are not large. For the terminal itself, the small bandwidth has already met the needs of some users to a certain extent. Therefore, the bandwidth of these terminals does not need to increase with the bandwidth of the system, and does not need to be consistent with the system bandwidth. 4. The processing of the chip is limited. Due to current process conditions, some of the terminal's ability to process chips does not meet the needs of larger bandwidth data processing.

In summary, it is critical to provide access to small bandwidth terminals in large bandwidth systems. The prior art has not provided a small bandwidth terminal access method in a large bandwidth system. Summary of the invention

The technical problem to be solved by the present invention is to provide a method for accessing a terminal in a large-bandwidth wireless communication system, which can provide an access service for a small-bandwidth terminal in a large-bandwidth system, thereby reducing requirements on the terminal and improving The efficiency of the terminal.

The present invention provides a method for accessing a terminal in a large bandwidth wireless communication system, and includes the following steps:

(1) dividing the system bandwidth into a plurality of working frequency bands, each of which sets a synchronization channel, a broadcast channel, and a random access channel, and sets at least one group within a unit bandwidth centered on the system center frequency point. Synchronization channel, broadcast channel, and random access channel;

(2) The terminal searches the network, and interacts with the network side through the synchronization channel, the broadcast channel, and the random access channel to complete downlink synchronization, cell search, uplink random access, and registration on the network side;

(3) The network side allocates a working frequency band to the terminal, and notifies the terminal of the allocated working frequency band, and after receiving the terminal, works on the allocated working frequency band.

Further, in the step (1), the bandwidth of the minimum bandwidth terminal supported in the system is used as a unit bandwidth, and the system bandwidth is equally divided into multiple working frequency bands.

Further, in the step (1), the synchronization channel, the broadcast channel and the random access channel of each working frequency band are set at a central position of the corresponding working frequency band.

Further, in the step (3), the base station on the network side sends the working frequency band allocation information to the terminal by using a control channel, a data sharing channel, or a newly added channel.

Further, in the step (3), after receiving the working frequency band information allocated by the network side, if the terminal does not allocate the working frequency band, the terminal needs to adjust the frequency to the allocated working frequency band, and then Synchronous adjustment or synchronization is performed on the working frequency band, otherwise no adjustment is needed.

Further, in the step (3), the terminal completes synchronization on the allocated working frequency band. After adjustment or synchronization, other work information sent by the network side is received, and work is performed on the allocated working frequency band.

Further, the terminal continuously synchronizes in the working frequency band when adjusting the working frequency band or after entering the working process. If the synchronization is not completed after reaching a certain delay, it is determined that the working frequency band is not in the network, and the frequency is jumped back to the central frequency point to search again. The internet.

Further, in step (1), the set of synchronization channels, the broadcast channel, and the random access channel are set at a system center frequency point, and if the system bandwidth is equally divided into an odd multiple, the group channel is also located at the same time. The channel of the working frequency band.

Further, in step (2), when the terminal performs downlink synchronization, for the terminal whose bandwidth is a multiple of the unit bandwidth, all the synchronization channels in the bandwidth of the terminal are filtered out by the filter to perform downlink synchronization.

Further, in the step (2), when the terminal is in the uplink random access, the terminal having the bandwidth of the multiple unit bandwidth is the random access in the plurality of random access channels.

The invention has the beneficial effects that the access service can be provided for the small bandwidth terminal in the large bandwidth system, the requirement for the terminal is reduced, the cost of the terminal is reduced, the working time of the terminal battery is prolonged, and the terminal is further improved. The efficiency of the work and the utilization of the system network can be adapted to the needs of different users. The invention solves the compatibility problem of various bandwidths in the system under the condition of small bandwidth of the large bandwidth terminal of the system, and also gives the processing flow of the terminal accessing and allocating to the working frequency band and working process. The terminal only performs this process when booting to the network, the process is simple, and the downlink process performance is good. Therefore, with this method, the terminal can effectively and quickly access the high-bandwidth system, and the high-level scheduling is single. BRIEF abstract

1 is a schematic diagram of an example of dividing a system bandwidth into a plurality of operating frequency bands, wherein the system bandwidth is equally divided by an odd number;

2 is a schematic diagram of another example of dividing a system bandwidth into a plurality of operating frequencies, wherein the system bandwidth is equally divided by an even number;

3 is a flow chart of a terminal initially accessing a large bandwidth wireless communication system according to an embodiment of the present invention. Preferred embodiment of the invention

The invention proposes an access method for a terminal in a large bandwidth system. In the method, the system bandwidth of the large bandwidth system is first divided into multiple working frequency bands, and then the terminal searches for the network, and the base station on the network side allocates the corresponding working frequency band to the terminal, and the terminal adjusts to the working frequency band according to the allocation. This process can be referred to as initial access. After the initial access, the terminal adjusts the working frequency band, and the uplink resource application and allocation work in the same way as the existing symmetric bandwidth. Therefore the initial access can be independent.

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

In the system frame structure, the system bandwidth is first divided. The division principle is to form a plurality of working frequency bands by dividing the system bandwidth by the bandwidth of the terminal supporting the minimum bandwidth. A synchronization channel (SCH) is set at a central position (or other specified position) of each working frequency band, and a broadcast channel (BCH) and a random access channel (RACH) are respectively set in each working frequency band to match the synchronization channel. When the system bandwidth is equally divided into even multiples, a set of SCH, BCH, and RACH channels are added at the center frequency. When the system bandwidth is equally divided into odd multiples, there is also a set of SCH, BCH and RACH channels at the center frequency. The SCH, BCH and RACH channels also serve as the corresponding channels in the working frequency band.

However, a set of SCH, BCH, and RACH channels used for initial access does not have to be set at the center frequency of the system, but can be set within a unit bandwidth centered at the center frequency of the system. Bandwidth is the bandwidth of the smallest bandwidth terminal supported by the system.

Below are two examples of dividing the system bandwidth. The first one is shown in Figure 1. The system bandwidth is 60M. The bandwidth of the terminal with the smallest capacity (that is, the smallest bandwidth) in the system is 20M. The system bandwidth is equally divided into three working frequency bands in units of 20M. Synchronization channel 1, broadcast channel 2, and random access channel 3 are set in each of the operating bands. The case where the synchronization channel SCH shown in FIG. 1 occupies one OFDM symbol, in other embodiments, the synchronization channel SCH may also occupy a plurality of OFDM symbols. The second one is shown in Figure 2. The system bandwidth is 40M. The minimum capacity of the terminal in the system is 20M. Then divide the system bandwidth into two working frequency bands in units of 20M. Set the synchronization channel in each working frequency band. , broadcast channel 2 and random access channel 3. Since the system bandwidth is equally divided by an even number, a set of synchronization channels, a broadcast channel, and a random access channel are added at the center frequency. As shown in FIG. 3, based on the above frame structure, the process for the terminal to initially access the network includes the following steps: Step 301: After the terminal is turned on or just after entering a cell, the terminal searches for the network, and completes downlink synchronization through the synchronization channel at the center frequency point. And obtaining broadcast channel information;

When the terminal searches for the network, the center frequency is used as a reference point, and the synchronization channel time domain data is filtered at a certain interval (determined in the frame structure) within the terminal bandwidth to complete synchronization. For a large bandwidth terminal with a bandwidth of multiple units of bandwidth, there are multiple synchronization channels in the bandwidth. Therefore, all synchronization channels can be filtered out through the filter for downlink synchronization, so that synchronization has better performance.

Step 302: The terminal parses the broadcast channel information to complete a cell search.

Step 303: After monitoring the network, the terminal performs uplink random access, and completes registration of the terminal on the network side.

For a large-bandwidth terminal with a bandwidth of multiple units of bandwidth, since there are multiple random accesses in the bandwidth range, the resources can be randomly accessed in multiple random access channels, so the performance of random access is also compared. it is good.

Step 304: The base station on the network side analyzes the load status of each working frequency band, allocates a working frequency band to the terminal after performing load measurement, and sends the allocation information to the terminal;

The base station can send the working frequency band allocation information to the terminal through the control channel, the data sharing channel or the newly added channel. The new channel may be an operating band allocation channel added at a central frequency point, and the synchronization channel, the broadcast channel and the random access channel at the center frequency point together form a channel used for initial access. The working frequency band allocated by the base station to the terminal may have one or more.

Step 305: After receiving the working frequency band allocation information sent by the base station, if the terminal does not allocate the working frequency band, the terminal performs the working frequency band adjustment.

When the working frequency band is adjusted, the terminal adjusts or fine-tunes its frequency to the assigned working frequency band. If you are assigning the current working frequency band, you do not need to adjust it.

Step 306: The terminal performs synchronous adjustment or synchronization on the working frequency band.

After the terminal adjusts the working frequency band, because the frequency band adjustment may cause delay, it needs to be synchronized according to the synchronization channel in the new working frequency band. If the frequency band adjustment causes the out-of-step, it needs to be re-synchronized in the new working frequency band.

Step 307: The terminal receives other work information delivered, and enters a working process. For a terminal with a bandwidth of unit bandwidth, it can work according to the method of the small bandwidth system in the prior art. Including synchronization and synchronization tracking, BCH information reception, service resource application, network side monitoring, control channel and other processing. For a large-bandwidth terminal, the uplink bandwidth can be divided into one or more unit bandwidths in the uplink process, and the data is transmitted and processed separately on each unit bandwidth.

After the terminal adjusts the working frequency band or enters the working process, the terminal continuously synchronizes in the working frequency band. If the set delay is not completed, it is determined that the working frequency band is not in the network, and then the frequency back to the center frequency is restarted according to the above procedure. Search the web.

The present invention can be applied to a minimum bandwidth terminal, and can also be applied to access of a terminal whose bandwidth is a multiple of a unit bandwidth. For a terminal with a bandwidth of 2 times the unit bandwidth, if it is less than the system bandwidth, the working frequency band adjustment may also occur during access. Terminals with the same bandwidth and system bandwidth can also be accessed in this way, but there is no need to adjust the working frequency band.

Industrial applicability

The invention solves the compatibility problem of various bandwidths in the system under the condition of small bandwidth of the large bandwidth terminal of the system, and also gives the processing flow of the terminal accessing and allocating to the working frequency band and the working process. The terminal only performs this process when booting to the network, and the process is valid. Therefore, with this method, the terminal can be efficiently and quickly accessed in a large bandwidth system, and the high-level scheduling is simple.

Claims

Claim

A method for accessing a terminal in a large-bandwidth wireless communication system, comprising the steps of:

The method according to claim 1, wherein in the step (1), the bandwidth of the minimum bandwidth terminal supported in the system is used as a unit bandwidth, and the system bandwidth is equally divided into a plurality of working frequency bands.

The method according to claim 2, wherein in the step (1), the synchronization channel, the broadcast channel and the random access channel of each working frequency band are set at a central position of the corresponding working frequency band.

The method according to claim 1 or 2, wherein in the step (3), the base station on the network side sends the working frequency band allocation information to the control channel, the data sharing channel or the newly added channel. The terminal.

The method according to claim 1 or 2, wherein, in the step (3), after the terminal receives the working frequency band information allocated by the network side, if the terminal does not allocate the current working frequency band , you need to adjust the frequency to the allocated working frequency band, and then make synchronous adjustment or synchronization on the working frequency band, otherwise no adjustment is needed.

The method according to claim 5, wherein, in the step (3), after the terminal performs synchronization adjustment or synchronization on the allocated working frequency band, the terminal receives other work information sent by the network side, Work on the assigned operating frequency band.

The method according to claim 5, wherein the terminal continuously synchronizes in the working frequency band when adjusting the working frequency band or after entering the working process, and if the synchronization is not completed after reaching a certain delay, determining the network Without this working frequency band, jump back to the center frequency to search the network again.

The method according to claim 1 or 2, wherein in step (1), the set of synchronization channels, broadcast channels, and random access channels are set at a system center frequency point, such as a system. The bandwidth is equally divided into odd multiples, and the set of channels also serves as the channel of the working frequency band.

9. The method of claim 1 or 2, wherein

Step (2) When the terminal performs downlink synchronization, for the terminal whose bandwidth is a multiple of the unit bandwidth, all the synchronization channels in the bandwidth of the terminal are filtered out by the filter to perform downlink synchronization.

10. The method of claim 1 or 2, wherein

Step (2) When the terminal is in the uplink random access, for the terminal having the bandwidth of the multiple unit bandwidth, the resources are randomly accessed in the multiple random access channels.